Re: Some useful 3D printing data
#3D
That is useful. Thank you ?
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Re: Step #1 Encoder
#RELS
Well, generally, the telescope folk don't use encoders they count steps and do it all with dead reckoning and some compensation factors for periodic error and the like. Of course they have the stars themselves as precise points of reference.
As you've discovered reliable microstepping? is very much limited by rapid torque drop off for a given power input. Increasing the power as high as the motor can safely use and/or using a bigger more powerful overrated motor are the way forward to this.
After about x16 microsteps the additional steps are more about smoothing the motion and reducing noise/vibration than reliably precise positioning.
There's a "devestating" table somewhere showing torque drop with increased microsteps and the relationship between power input and achievable reliability.
I can find it if you like. It lets you calculate the size of motor and PSU you need to achieve the microstepping level you desire for a given torque requirement.
Some of the SSS drivers allow mode switching on the fly using the spi interface. ?
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Re: Step #1 Encoder
#RELS
I am a bit busy painting my office to analyse all of your comments,
however a couple of points
1 My lathe cannot run much above 1400 rpm but even so I can still turn a
1mm diameter x 6mm long and put a 1/64 drill down the centre
2 If my lathe ran at 5000rpm I would 1:1 belt drive the? encoder but
would not expect my RELS to work at that speed
Every system has limitations, thanks for the explanation.
Richard
toggle quoted message
Show quoted text
On 15/12/2019 19:03, John Dammeyer wrote: Long answer with some ELS theory.
Using this web page as a reference, if you are cutting clock parts or tiny robotic stuff with diameters below 0.25", for example, the SFM for brass and aluminium goes up as high as 300 SFM (for Al).
So pick the high end and turn a piece of 0.25" brass down to 0.1875" that will serve as a spacer and perhaps be threaded at one end. With 200 SFM we get 4200 RPM and that's with high speed steel tool bit. At the low SFM end it's 2133 RPM. The web page states carbide can run 2 to 3 x that speed.
So pick aluminium at 0.1875 with carbide at 2x the speed = 600 SFM. Yikes! That's 12,800 RPM.
Even this kit from Sherline wouldn't let you get there but normal max speed for Sherline is 2800 RPM for turning.
That's over the high end of 5000 RPM for a tooth belt coupled encoder with 3:1 ratio so we're back to wanting an encoder disk right on the spindle. Assuming once can get one with a bore as large as the outside of the lathe which for my South Bend I can't but then I also can't run it really fast either.
Say a Sherline at 2800 RPM. If the lead screw is 20 TPI it's got a pitch of 0.050". IF you wanted to cut a 20 TPI thread you turn at the same speed as the spindle so the lead screw moves 0.050" per spindle rev.
Smooth turning is usually done with a larger radius tool bit at about 0.003" per rev which is close to 1/17th the lead screw pitch so the lead screw moves at 1/17th the spindle speed and that's only about 170 RPM.
Therefore a 100 line encoder that produces 400 pulses per rev results in 18666.6666 pulses per second or one about every 50 uS. Theoretically the RELS unit should be easily able to handle a Sherline since for turning the software uses only one rising edge while for threading it uses two rising edges. It doesn't use quadrature. That means a 200 line encoder for the spindle would also work.
Not only that, it appears to be limited to handling only 4 micro-steps per step so the output frequency for the carriage isn't nearly as high as a system that needs to handle a Gecko Drive at 10 micro-steps per step.
As I understand the poorly documented RELS software, the end result is the number of encoder pulses from the spindle must always be larger than the step rate of either of the axis. Most stepper motors have trouble running more than about 750 RPM before their torque falls off so badly that they lock up and lose position.
Gecko gets around that in an interesting way that I'd really like to try one day. They use 10x micro-stepping until they pass the resonance point where the torque on the motor dips. After that point they switch over to full step mode which provides much more current for a longer time period and allows the motors to reach much higher speeds.
But again in the above example we require the stepper to only turn 170 RPM or 2.8 RPS which is only 5666.666667 steps/second with a 10x micro stepping driver. And that's lower than the 100 line quadrature spindle rate so the lead screw needs one step for every 3.294117645882353 spindle clock pulses. (186666.6666667/5666.666667).
So as long as you know what to change in the RELS software, it would be possible to put a toothed wheel with 100 teeth and an optical sensor on just about any lathe and probably run that high speed turning.
How about low speed. Turn the spindle at 60 RPM or 1 rev per second. That's in 2x mode then 200 interrupts per second or one every 5mS. To turn lead screw pitch of 20 TPI means the stepper motor also needs to turn 1 RPS; with a Gecko that's 2000 steps per second.
Oops! That's no longer less than the number of spindle clocks per second. So the software would have to issue a burst of step pulses at every encoder interrupt at a speed that results in 10 steps before the next encoder interrupt. Ideally the last step would be out before the next encoder edge interrupt.
And it gets even worse if you start turning the spindle by hand. But go back up to the pulley driven encoder at 1800 pulses per rev and a stepper motor running 4x micro-stepping (800 steps per rev) and the lead screw is always running with less steps per rev than the spindle and then the limitation on threading becomes 2x the encoder lines (3600 edges per rev and 800 micro-steps/step) or 4.5 times lead screw pitch. If the TPI on the lead screw is 8 TPI then the coarsest thread is 1.777778 TPI with one step per encoder edge.
What it all means is that software that relies on the high res encoder to create step pulses can't run high RPM or is stuck with 4x miro-stepping and therefore can't run a AC Servo with a 2500 line encoder on the lead screw.
Hopefully this all makes sense. And if I've made a mistake in the math please do speak up.
John Dammeyer
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 2:56 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
Thanks for clarifying that John.
Richard
On 15/12/2019 10:11, John Dammeyer wrote:
That number is what we decided on for the ELS about 10 years ago. For example my little Unimat DB-200 as well as the Sherlines easily turn 6000
RPM. So my ELS had that as a stipulation since it was to be used for both
turning and threading.
If I'd been limited to only about 1200 RPM I'd have probably looked more closely at encoders but both cost and capability ruled them out for a small 8
bit PIC without a quadrature encoder interface.
John
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 1:59 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
I am not really sure where this number of 6000 rpm for the lathe spindle
came from?
The RELS certainly has limits of operation and I am not sure what they are.
As far as threading is concerned the limits are suggested as a maximum
rpm against each pitch value.
For interest some of the max threading speeds are quoted below
?? Pitch ? ? ?? Max Speed
"0.25mm" " 999rpm"
"0.70mm" " 810rpm"
"1.75mm" " 320rpm"
"4.00mm" " 140rpm"
"80tpi " ? ? " 999rpm"
"48tpi " ? ? " 999rpm"
"20tpi " ? ? " 440rpm"
" 6tpi "????? " 140rpm"
I cannot guarantee these speeds as they would be based upon the original
lead-screw pitch but they should give an idea of what is possible.
For feeds I am not sure what the maximum speeds are and I am not
competent enough to determine the values from the software or timing
the
interrupt.
I can say however that if you want to run your spindle and feed at
6000rpm then the RELS is not for you. What maximum speed you can feed
at
say .1mm per rev I am not sure.
With lower cost come limitations.
Richard (who has an RELS and is very happy with it.)
On 14/12/2019 22:04, John Dammeyer wrote:
Behalf Of grumpy via Groups.Io
is this usable
|
Re: Step #1 Encoder
#RELS
Without a doubt the newer technology is nothing short of amazing.? I based my ELS on the paper: Electronic Lead Screw Drive Fritz.Linck@... (Germany) ? Implemented in 1999 and 2000 Documentation completed March 1, 2001, Revised Dec. 5, 2005 ? His was all done in hardware with digital counters and multiply/divide logic.? Fascinating approach.? I started doing it that way with an FPGA so all the logic would be in one chip.? But eventually I went with the PIC18F family after an initial false start with a TI Digital Signal processor that required too high a development tool cost. ? The approach used by Mr. Linck was to read a pair of rotary switches that created a multiplier/divisor combination.? So he could multiply the number of encoder lines from the spindle by X and divide that by the other switch value Y.? The Leadscew motor was a DC motor with an encoder and he used the difference between the leadscrew motor encoder counter and the X/Y spindle counter as an error term.? The larger the error the faster he turned the leadscrew.? As the leadscrew caught up to the spindle speed ratio the error dropped to zero and the motor speed stayed stable. ? He could now treat the leadscrew as coupled through a gear chain and engage the half nut using the threading dial indicator to choose when to engage.? ?I'm not sure how well it worked for stopping the spindle, reversing it and running carriage backwards before restarting in forward. ?For imperial threads on a metric lathe.? I don't think it could do it.? ? And certainly not bore to depth repeatedly. ? But with a faster processor or a dual processor core, one could create that ratio closed loop motion that also tracked position. ?I suspect that is what LinuxCNC does since it needs multi-line quadrature encoder on the spindle and can run Servo motors on the lead screw. ??It doesn't suffer from the RELS limitations. ? John Dammeyer ? ? ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Ant No
Sent: December-15-19 10:16 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? Sure, the niche is for custom boards with application specific functions.
Having said that, plugging standard boards, like SSSmotor drivers into headers on your custom board reduces the labour burden to help make builds more accessible.
When using the Arduino Mega it may be relevant to note that the oscillator comes in two forms; a ceramic resonator, which is common and less repeatably precise and a crystal oscillator which is rarer and significantly more dependably precise. I don't understand this application enough to know if that will matter.
Other cheap Arduino chips like the ESP32 are faster and more powerful. It's dual CPU, more memory with Bluetooth and wif built in. The last two are useful to connect hand held controllers or laptop/tablet/PC with.
But I know nothing. Just what I see others do.
Less than nothing about this particular use.
Just throwing the spaghetti at the wall. You judge if it's cooked.
Ant?
|
Re: Step #1 Encoder
#RELS
Long answer with some ELS theory.
Using this web page as a reference, if you are cutting clock parts or tiny robotic stuff with diameters below 0.25", for example, the SFM for brass and aluminium goes up as high as 300 SFM (for Al).
So pick the high end and turn a piece of 0.25" brass down to 0.1875" that will serve as a spacer and perhaps be threaded at one end. With 200 SFM we get 4200 RPM and that's with high speed steel tool bit. At the low SFM end it's 2133 RPM. The web page states carbide can run 2 to 3 x that speed.
So pick aluminium at 0.1875 with carbide at 2x the speed = 600 SFM. Yikes! That's 12,800 RPM.
Even this kit from Sherline wouldn't let you get there but normal max speed for Sherline is 2800 RPM for turning.
That's over the high end of 5000 RPM for a tooth belt coupled encoder with 3:1 ratio so we're back to wanting an encoder disk right on the spindle. Assuming once can get one with a bore as large as the outside of the lathe which for my South Bend I can't but then I also can't run it really fast either.
Say a Sherline at 2800 RPM. If the lead screw is 20 TPI it's got a pitch of 0.050". IF you wanted to cut a 20 TPI thread you turn at the same speed as the spindle so the lead screw moves 0.050" per spindle rev.
Smooth turning is usually done with a larger radius tool bit at about 0.003" per rev which is close to 1/17th the lead screw pitch so the lead screw moves at 1/17th the spindle speed and that's only about 170 RPM.
Therefore a 100 line encoder that produces 400 pulses per rev results in 18666.6666 pulses per second or one about every 50 uS. Theoretically the RELS unit should be easily able to handle a Sherline since for turning the software uses only one rising edge while for threading it uses two rising edges. It doesn't use quadrature. That means a 200 line encoder for the spindle would also work.
Not only that, it appears to be limited to handling only 4 micro-steps per step so the output frequency for the carriage isn't nearly as high as a system that needs to handle a Gecko Drive at 10 micro-steps per step.
As I understand the poorly documented RELS software, the end result is the number of encoder pulses from the spindle must always be larger than the step rate of either of the axis. Most stepper motors have trouble running more than about 750 RPM before their torque falls off so badly that they lock up and lose position.
Gecko gets around that in an interesting way that I'd really like to try one day. They use 10x micro-stepping until they pass the resonance point where the torque on the motor dips. After that point they switch over to full step mode which provides much more current for a longer time period and allows the motors to reach much higher speeds.
But again in the above example we require the stepper to only turn 170 RPM or 2.8 RPS which is only 5666.666667 steps/second with a 10x micro stepping driver. And that's lower than the 100 line quadrature spindle rate so the lead screw needs one step for every 3.294117645882353 spindle clock pulses. (186666.6666667/5666.666667).
So as long as you know what to change in the RELS software, it would be possible to put a toothed wheel with 100 teeth and an optical sensor on just about any lathe and probably run that high speed turning.
How about low speed. Turn the spindle at 60 RPM or 1 rev per second. That's in 2x mode then 200 interrupts per second or one every 5mS. To turn lead screw pitch of 20 TPI means the stepper motor also needs to turn 1 RPS; with a Gecko that's 2000 steps per second.
Oops! That's no longer less than the number of spindle clocks per second. So the software would have to issue a burst of step pulses at every encoder interrupt at a speed that results in 10 steps before the next encoder interrupt. Ideally the last step would be out before the next encoder edge interrupt.
And it gets even worse if you start turning the spindle by hand. But go back up to the pulley driven encoder at 1800 pulses per rev and a stepper motor running 4x micro-stepping (800 steps per rev) and the lead screw is always running with less steps per rev than the spindle and then the limitation on threading becomes 2x the encoder lines (3600 edges per rev and 800 micro-steps/step) or 4.5 times lead screw pitch. If the TPI on the lead screw is 8 TPI then the coarsest thread is 1.777778 TPI with one step per encoder edge.
What it all means is that software that relies on the high res encoder to create step pulses can't run high RPM or is stuck with 4x miro-stepping and therefore can't run a AC Servo with a 2500 line encoder on the lead screw.
Hopefully this all makes sense. And if I've made a mistake in the math please do speak up.
John Dammeyer
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 2:56 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
Thanks for clarifying that John.
Richard
On 15/12/2019 10:11, John Dammeyer wrote:
That number is what we decided on for the ELS about 10 years ago. For example my little Unimat DB-200 as well as the Sherlines easily turn 6000
RPM. So my ELS had that as a stipulation since it was to be used for both
turning and threading.
If I'd been limited to only about 1200 RPM I'd have probably looked more
closely at encoders but both cost and capability ruled them out for a small 8
bit PIC without a quadrature encoder interface.
John
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 1:59 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
I am not really sure where this number of 6000 rpm for the lathe spindle
came from?
The RELS certainly has limits of operation and I am not sure what they are.
As far as threading is concerned the limits are suggested as a maximum
rpm against each pitch value.
For interest some of the max threading speeds are quoted below
?? Pitch ? ? ?? Max Speed
"0.25mm" " 999rpm"
"0.70mm" " 810rpm"
"1.75mm" " 320rpm"
"4.00mm" " 140rpm"
"80tpi " ? ? " 999rpm"
"48tpi " ? ? " 999rpm"
"20tpi " ? ? " 440rpm"
" 6tpi "????? " 140rpm"
I cannot guarantee these speeds as they would be based upon the
original
lead-screw pitch but they should give an idea of what is possible.
For feeds I am not sure what the maximum speeds are and I am not
competent enough to determine the values from the software or timing
the
interrupt.
I can say however that if you want to run your spindle and feed at
6000rpm then the RELS is not for you. What maximum speed you can feed
at
say .1mm per rev I am not sure.
With lower cost come limitations.
Richard (who has an RELS and is very happy with it.)
On 14/12/2019 22:04, John Dammeyer wrote:
Behalf Of grumpy via Groups.Io
is this usable
|
Re: Step #1 Encoder
#RELS
Sure, the niche is for custom boards with application specific functions.
Having said that, plugging standard boards, like SSSmotor drivers into headers on your custom board reduces the labour burden to help make builds more accessible.
When using the Arduino Mega it may be relevant to note that the oscillator comes in two forms; a ceramic resonator, which is common and less repeatably precise and a crystal oscillator which is rarer and significantly more dependably precise. I don't understand this application enough to know if that will matter.
Other cheap Arduino chips like the ESP32 are faster and more powerful. It's dual CPU, more memory with Bluetooth and wif built in. The last two are useful to connect hand held controllers or laptop/tablet/PC with.
But I know nothing. Just what I see others do.
Less than nothing about this particular use.
Just throwing the spaghetti at the wall. You judge if it's cooked.
Ant?
|
Re: Step #1 Encoder
#RELS
Thanks for clarifying that John.
Richard
toggle quoted message
Show quoted text
On 15/12/2019 10:11, John Dammeyer wrote: That number is what we decided on for the ELS about 10 years ago. For example my little Unimat DB-200 as well as the Sherlines easily turn 6000 RPM. So my ELS had that as a stipulation since it was to be used for both turning and threading.
If I'd been limited to only about 1200 RPM I'd have probably looked more closely at encoders but both cost and capability ruled them out for a small 8 bit PIC without a quadrature encoder interface.
John
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 1:59 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
I am not really sure where this number of 6000 rpm for the lathe spindle
came from?
The RELS certainly has limits of operation and I am not sure what they are.
As far as threading is concerned the limits are suggested as a maximum
rpm against each pitch value.
For interest some of the max threading speeds are quoted below
?? Pitch ? ? ?? Max Speed
"0.25mm" " 999rpm"
"0.70mm" " 810rpm"
"1.75mm" " 320rpm"
"4.00mm" " 140rpm"
"80tpi " ? ? " 999rpm"
"48tpi " ? ? " 999rpm"
"20tpi " ? ? " 440rpm"
" 6tpi "????? " 140rpm"
I cannot guarantee these speeds as they would be based upon the original
lead-screw pitch but they should give an idea of what is possible.
For feeds I am not sure what the maximum speeds are and I am not
competent enough to determine the values from the software or timing the
interrupt.
I can say however that if you want to run your spindle and feed at
6000rpm then the RELS is not for you. What maximum speed you can feed at
say .1mm per rev I am not sure.
With lower cost come limitations.
Richard (who has an RELS and is very happy with it.)
On 14/12/2019 22:04, John Dammeyer wrote:
Behalf Of grumpy via Groups.Io
is this usable
|
Re: Step #1 Encoder
#RELS
That number is what we decided on for the ELS about 10 years ago. For example my little Unimat DB-200 as well as the Sherlines easily turn 6000 RPM. So my ELS had that as a stipulation since it was to be used for both turning and threading.
If I'd been limited to only about 1200 RPM I'd have probably looked more closely at encoders but both cost and capability ruled them out for a small 8 bit PIC without a quadrature encoder interface.
John
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Richard
Sent: December-15-19 1:59 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder
I am not really sure where this number of 6000 rpm for the lathe spindle
came from?
The RELS certainly has limits of operation and I am not sure what they are.
As far as threading is concerned the limits are suggested as a maximum
rpm against each pitch value.
For interest some of the max threading speeds are quoted below
?? Pitch ? ? ?? Max Speed
"0.25mm" " 999rpm"
"0.70mm" " 810rpm"
"1.75mm" " 320rpm"
"4.00mm" " 140rpm"
"80tpi " ? ? " 999rpm"
"48tpi " ? ? " 999rpm"
"20tpi " ? ? " 440rpm"
" 6tpi "????? " 140rpm"
I cannot guarantee these speeds as they would be based upon the original
lead-screw pitch but they should give an idea of what is possible.
For feeds I am not sure what the maximum speeds are and I am not
competent enough to determine the values from the software or timing the
interrupt.
I can say however that if you want to run your spindle and feed at
6000rpm then the RELS is not for you. What maximum speed you can feed at
say .1mm per rev I am not sure.
With lower cost come limitations.
Richard (who has an RELS and is very happy with it.)
On 14/12/2019 22:04, John Dammeyer wrote:
Behalf Of grumpy via Groups.Io
is this usable
|
Re: Step #1 Encoder
#RELS
The 600 pulse encoders are being run a 3 times spindle speed.
This gives limitations on spindle speed. If the max encoder speed is
5000 rpm then spindle speed should be limited to 1600rpm.
Not a problem on my machine.
Richard
toggle quoted message
Show quoted text
On 14/12/2019 22:24, Ralph Hulslander wrote: John, I believe people running RELS are using 600 pulse encoders not
1800.
Ralph
On Sat, Dec 14, 2019 at 5:04 PM John Dammeyer <johnd@...
<mailto:johnd@...>> wrote:
> Behalf Of grumpy via Groups.Io
>
> is this usable
>
>
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill
press, 40 watt laser, Consew brushless DC motors and a non working 3D
printer
|
Re: Step #1 Encoder
#RELS
I am not really sure where this number of 6000 rpm for the lathe spindle
came from?
The RELS certainly has limits of operation and I am not sure what they are.
As far as threading is concerned the limits are suggested as a maximum
rpm against each pitch value.
For interest some of the max threading speeds are quoted below
?? Pitch ? ? ?? Max Speed
"0.25mm" " 999rpm"
"0.70mm" " 810rpm"
"1.75mm" " 320rpm"
"4.00mm" " 140rpm"
"80tpi " ? ? " 999rpm"
"48tpi " ? ? " 999rpm"
"20tpi " ? ? " 440rpm"
" 6tpi "????? " 140rpm"
I cannot guarantee these speeds as they would be based upon the original
lead-screw pitch but they should give an idea of what is possible.
For feeds I am not sure what the maximum speeds are and I am not
competent enough to determine the values from the software or timing the
interrupt.
I can say however that if you want to run your spindle and feed at
6000rpm then the RELS is not for you. What maximum speed you can feed at
say .1mm per rev I am not sure.
With lower cost come limitations.
Richard (who has an RELS and is very happy with it.)
toggle quoted message
Show quoted text
On 14/12/2019 22:04, John Dammeyer wrote: Behalf Of grumpy via Groups.Io
is this usable
|
Re: Step #1 Encoder
#RELS
The files I have that I downloaded 19OCT2019 list 1800 lines.? Not to say that someone hasn't modified the code to use a different encoder but the spreadsheet and the document file with photos show 1800 lines. ? Even so, at 100 RPS a 600 line encoder with quadrature encoding is still 240,000 edges per second. Of course on a lathe with backlash on a half nut one could probably get away with only using rising edges.? In one direction A will always be high when B goes high while in the other direction it will be reversed.? The 1/2 period of one pulse with a 600 line encoder probably won't matter.? ? It's not clear from the source code but I'm guessing the RELS tops out at about 1200 spindle RPM which is 20 RPS and then if you look at a 600 line encoder with the 2x quadrature (again according to the source code) equals 24,000 interrupts per second or one about every 42uS. ? If all you do is translates those interrupts into stepping pulses with scale ratio and acceleration you can probably keep up. ? ? John ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Ralph Hulslander
Sent: December-14-19 2:25 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? John, I believe people running RELS are using 600 pulse encoders not 1800. ? On Sat, Dec 14, 2019 at 5:04 PM John Dammeyer <johnd@...> wrote: > Behalf Of grumpy via Groups.Io
>
> is this usable
>
>
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
|
Re: Step #1 Encoder
#RELS
John, I believe people running RELS are using 600 pulse encoders not 1800.
Ralph
On Sat, Dec 14, 2019 at 5:04 PM John Dammeyer < johnd@...> wrote: > Behalf Of grumpy via Groups.Io
>
> is this usable
>
>
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
|
Re: Step #1 Encoder
#RELS
Behalf Of grumpy via Groups.Io
is this usable
-=-=-=-=-=-=-=-=-=-=-=- Yes but not without a bit of work. If you look at the Schematic of my ELS motor driver section you can see that not only is the ELS a lathe controller but also built in is a micro-stepper controller. On each X axis step event it uses the SPI bus to send out the next micro-step phase information. There's also the step/dir signals that would go out to the DB-25 connector. So one could use the Motor_LATCH, /RESET, SPI_CLK and SPI_MOSI pins along with the Z_STEP/Z_DIR pins to use the Pololu module. Although I haven't looked it's possible that there's an extra pin available for selecting either X or Z in which case the SPI bus on my ELS could be used for both axis. It doesn't change the fact that at 6000 RPM (100RPS) an 1800 line encoder as required for the RELS, my ELS would be receiving 180,000 falling edges from one line of the encoder. If you wanted to deal with back and forth motion it has to be quadrature so now it's 720,000 edges per second. That's an interrupt every 1.3888 uS. The processor on the ELS can't handle that speed. However it can handle 100 interrupts per second (index pulse) easily. The BEI encoder I have has 100 lines or 400 edges per rev. That's 40kHz or an interrupt every 25uS. When looking at the way I do step pulses etc. I was limited to 20kHz step rates (way more than a micro-stepping motor could handle) Anything more often and I found I'd spend too much time inside the interrupt routine and scanning keys and other processing became very slow or was blocked. Now if the processor had a quadrature encoder module then once can capture the count every 50uS (for example) and scale both it and the desired speed to calcuate a step rate for the Z that is slaved to the spindle. But the PIC 18F doesn't so a processor upgrade would also be required. John
|
Re: Step #1 Encoder
#RELS
On Sat, 14 Dec 2019, John Dammeyer wrote: It's not just the PC board of course. I was going through some folders looking for something when I stumbled on a copy of an email that had some links.
<> &cur_warehouse=CN
Currently on sale for $21.40Cdn regular $53.52Cdn (60% off) with 24V to 50V supply and 5.6A and up to 256 micro-steps.
Now compare that with the Digikey supplied LMD18245
with price of $30.46 each and two are required ($60.92 Cdn) rated for a 55VDC supply, 3A and 8 micro-steps plus a few more parts and connectors are required on the ELS PC board.
If I bought 100, enough for 50 ELS kits the price drops to $45 for the pair. Still more than an external stepper.
John
is this usable
|
Re: Step #1 Encoder
#RELS
It's not just the PC board of course.? I was going through some folders looking for something when I stumbled on a copy of an email that had some links. ?
? Currently on sale for $21.40Cdn regular $53.52Cdn (60% off) with 24V to 50V supply and 5.6A and up to 256 micro-steps.? ? Now compare that with the Digikey supplied LMD18245
with price of $30.46 each and two are required ($60.92 Cdn) rated for a 55VDC supply, 3A and 8 micro-steps plus a few more parts and connectors are required on the ELS PC board. ? If I bought 100, enough for 50 ELS kits the price drops to $45 for the pair.? Still more than an external stepper.? ? John ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Ant No
Sent: December-12-19 6:17 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? Not sure if I understood correctly but custom circuit boards can be sourced from Chinese suppliers in batches of 5 nowadays. Inexpensive and decent quality. You can specify the thickness of copper in the tracks as one quality in the overall design. There are at least two tried and tested sources that are known to do good work for little money?
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Re: Step #1 Encoder
#RELS
I've made use of that now already.? I had 5 of these boards made, 3 are assembled.? They serve as an interface between inputs step/dir/enable and output Fault to either the STMBL which runs my A axis or a Bergerda AC Servo which requires RS422 for the high speed step signal.? The STMBL also needs RS422 for DIR and ENABLE and provides RS422 for Fault.? The board adapts that to open collector so multiple drives can all pull the same fault signal low.??? It can also provide the 5V for the MESA 7i92H and has two Open Collector outputs to pull the HP_UHU DC Servo drive reset signals to ground since the HP_UHU doesn't have an ENABLE to clear the FAULT output. 
? I also had 5 of these made.? It converts the DB-25 RS422 Encoder signals from the Harmonic Drive into RJ45 connections for the STMBL driver.? The header strip and pcb shorting traces underneath the board let me move signals around so I can use any DB-25 based encoder and connect it to the STMBL ? 
? So yes.? I have been taking advantage of incredibly cheap PC boards.? Once I finish the mill conversion I may well build that interface board that plugs into the ELS CPU socket and the header block and turn the entire ELS into a cape for the BBB.? Essentially mimic the cape for MachineKit that I already have but add the ELS as part of the package. ? But there's no market for this sort of product anymore. ?Not until Chinese prices fall back into line with what it costs to make here.? But that's a different subject. ? John ? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Ant No
Sent: December-12-19 6:17 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? Not sure if I understood correctly but custom circuit boards can be sourced from Chinese suppliers in batches of 5 nowadays. Inexpensive and decent quality. You can specify the thickness of copper in the tracks as one quality in the overall design. There are at least two tried and tested sources that are known to do good work for little money?
|
Re: Step #1 Encoder
#RELS
Not sure if I understood correctly but custom circuit boards can be sourced from Chinese suppliers in batches of 5 nowadays. Inexpensive and decent quality. You can specify the thickness of copper in the tracks as one quality in the overall design. There are at least two tried and tested sources that are known to do good work for little money?
|
Some useful 3D printing data
#3D
Found via Hackaday: a serious study of using brass threaded inserts in your 3D prints , a comparison of cheap vs expensive and the kinds of stress they¡¯ll take.
--
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: Step #1 Encoder
#RELS
One of the reasons I made the 3D printed encoder for the Gingery is so I could try the BeagleBone Black with the MachineKit LinuxCNC.? I had in mind that it would be reasonably easy to interface to the existing ELS to turn it into keypad display and do the heavy processing on the BeagleBone.? That would have the added advantage that if you plugged in your keyboard, mouse and monitor you could flip a switch, so to speak, and have full CNC. ? The ELS can use the same signals, instead X axis Step/Dir, for CAN bus.? Just solder on the driver.? There's already a place for it.? The Serial Port RS232 driver is already there.? For one customer I built an add on board that plugged into the place where all the jumpers go.? It had 4 relays, 4 optical isolated inputs, current and voltage measurement and also a CAN driver.? It could even have its own processor and be a standalone board. ? But I can't afford to sell an ELS for $19.95 like Arduino's and since it uses the PIC processor the IDE to develop software for it, though free requires C programming knowledge. ? So a cape for the beagle bone that gives it CAN bus, firmware for the ELS that makes it a CANopen compatible device and the two can talk to each other.? The Beagle can run the stepping motors using the LinuxCNC core doing all the threading etc. and the display/keypad ?on the ELS maintain their current personality. ? ? 
? 
? 
? I've also run the ELS with a 4 line display. ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Ralph Hulslander
Sent: December-11-19 2:06 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? As for myself I can cover upto $1,000.00. Using the ELS on the mill would?be interesting and a savings as I could use it on both of my lathes and the mill. ? On Wed, Dec 11, 2019 at 4:34 PM Richard <edelec@...> wrote: Hi John, I only asked as you raised costs in an earlier mail. Whether we
like it or not it is one of the factors considered when choosing a system.
Richard
On 11/12/2019 20:51, John Dammeyer wrote:
> Hi Richard,
> My ELS is way more expensive than that.? But there's a historical reason for it.? Not made in China is the biggest one.? Get PC boards made locally (if even possible anymore)? for each of the RELS parts, manufacture 200 including all the pick and place setup charges and you will find the RELS will be way more expensive.? ?Get the three or four boards made in China in that quantity and maybe you will meet that price.? Maybe.? At the time (2006) none of that was available.
>
> The ELS was also designed to have an on board micro-stepping driver good to 55V and 3A for the Z axis.? It's always been primarily designed to replace or augment the gears on old lathes with missing gears or where metric is needed for an imperial screw.? ?As such the behaviour is still very manually oriented rather than CNC.? But the cost of the devices has also been undercut by cheap Stepper Motor drivers made by people who get paid the equivalent of one Starbucks Coffee per day.? So Although the infrastructure is still there for the ELS it's just not cost effective.
>
> The custom metal back plates were bought to serve as mounting and heatsink.? I had 100 made.? Too bad it wasn't 200.? The company that made them is out of business.? Retooling costs to get another 100 made compared again to costs of other items from China just doesn't make it worth it.? So yet another reason not to use the on board stepper driver feature.
>
> A read through the E-Leadscrew archives will show that one member from Australia did make an ELS with a much smaller footprint, a couple of switches and a rotary encoder.? Cost of parts was under $50 I believe.? When I see the commercial CNC systems operated with a single MPG knob and a single button I'll believe that it's cost effective for time and energy to use a rotary knob to enter numbers etc.
>
> We went through that discussion extensively.? As a result my ELS has a keypad, soft keys under the LCD display and dedicated motion keys with shortcut keys to set things like BEGIN/END.? It's those things that make it easy to use.? It tracks slightly varying spindle speeds.
>
> And yes, I don't have a PC connected to the lathes.? Only to the CNC router and the Mill.? ?Although now surplus LCD displays and small footprint PCs (or BBBs with MachineKit) come in at under $100 so a true cost argument would have MachineKit on a lathe run with a BeagleBone and Cape.? All other costs for hardware and spindle being equal.? And then so much more is possible with the lathe than just an electronic gear.
>
> The example of 3D printed encoder is an example of how to save money.
>
> So I think a comparison of costs isn't really the issue since full CNC is now available for so little.? And as I said, I have a friend over 70 who isn't interested in an ELS because the CNC lathe is just so easy to use for him.
>
> If costs really were the issue then there would only be one model car available at a very low low cost.? No Mercedes, Audi, Lexus etc.? After all, cost is the only criteria for choosing a car.
>
> Cheers,
> John
>
>
>
>
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]] On
>> Behalf Of Richard
>> Sent: December-11-19 11:54 AM
>> To: [email protected]
>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>
>> I see that my cost shows as ?90 which may not display correctly as GB
>> Pounds 90. Just to complete the discussion what price is your ELS these
>> days?
>> You also have discussed using Mach3 with one pulse per rev, we must not
>> forget that there are hardware and software costs involved with Mach3,
>> plus a PC sitting in the shop.
>> Reloading into a system in the shop for me only involves plugging in a
>> USB lead and uploading, it is the work of a few minutes.
>> I really do not think that the average guy will ever need to upload new
>> parameters.
>> ATB
>> Richard
>>
>> On 11/12/2019 18:21, John Dammeyer wrote:
>>> Hi Richard,
>>> All good points.? I'd rather put my money into a higher quality spindle drive
>> that doesn't slow down with deep cuts.? Surface finish by maintaining a
>> constant SFM is more important to me.? Having said that the ELS does track
>> slightly varying spindle speeds that show up with the smaller lathes.
>>> Having to compile and reload code into a system sitting in the shop for me
>> is a complete non-starter.
>>> John
>>>
>>>
>>>> -----Original Message-----
>>>> From: [email protected] [mailto:[email protected]] On
>>>> Behalf Of Richard
>>>> Sent: December-11-19 7:32 AM
>>>> To: [email protected]
>>>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>>>
>>>> Tracking the spindle backwards and forwards is not a feature that
>>>> interests me, however tracking the spindle at varying speeds does. The
>>>> problem that I have had with one pulse per rev monitoring is that if the
>>>> spindle slows whilst cutting a deep thread the tool ends up cutting too
>>>> much metal, the result is further slowing and probably a stall or broken
>>>> tool. This has not happened with the encoder system.
>>>> As you say pitches, feeds and tapers are pre-calculated in a
>>>> spreadsheet. The current feed values are adequate for most people I
>>>> would think. The tapers cover all of the MT plus a number of angle and
>>>> ratio tapers. If a user feels that he would need a special then load it
>>>> before the first compile. The same with threads the majority of metric
>>>> and imperial threads are loaded. If a real special is subsequently
>>>> required then yes it needs to be added and a recompile executed. Not a
>>>> major problem IMHO and I have not needed to do it.
>>>> Re cost, Steppers, drives and power supply are common to both so can be
>>>> ignored. The RELS cost therefore comes down to:-
>>>> Arduino Mega, Encoder, belt and two pulleys, 2 line display, 5 button
>>>> pcb, 4 buttons with integral LED's, 1 joystick, 5v psu, 74LS86
>>>> chip+resistors+terminals+cable+connectors
>>>> For me that comes at a say ?90. I make my own enclosures from 6mm
>>>> laminate flooring so near zero cost there.
>>>> Obviously your system includes the Z drive so that should be allowed for.
>>>> The capability of cutting external and internal tapers was a big plus
>>>> and something I have had no problems with, however that was not the
>> case
>>>> with another system!
>>>> Having run both a one pulse per rev system and the RELS on my lathe I
>>>> prefer the latter.
>>>>
>>>> Richard Edwards
>>>>
>>>> On 11/12/2019 09:03, John Dammeyer wrote:
>>>>> Thanks for the endorsement Richard.? But I know that there are features
>>>> from the RELS that don't exist on mine.? I'd really like to learn more about
>>>> what is different.
>>>>> I know that I can't stand pressing buttons to enter a value.? My ELS has a
>>>> keypad for numeric input.? My 3D printer menu does not.? Arrow keys to
>>>> select and increment/decrement a value.? As a result I never use it.
>> Instead? I
>>>> use Octoprint for dealing with my 3D printer.? My PC has a keyboard with
>>>> numeric keys.
>>>>> But as I understand it the Russian ELS tracks spindle motion backwards
>> and
>>>> forward and the lead screw tracks.? Useless on my South bend which has
>>>> over 0.025" backlash on the half nut.? ?I'd toast a thread if I move the
>> spindle
>>>> back and forth with the tool in the thread.? ?So the feature to be able to
>>>> rotate the headstock for a large part is a useless endeavour on my South
>>>> Bend.
>>>>> The lead screw threading pitches are calculated in a spread sheet.? You
>> then
>>>> change the software.? Then compile and update the firmware in the
>> Arduino.
>>>> My ELS lets you enter any ratios that you want.
>>>>> I'm not sure when all is said and done that the RELS is that much less
>>>> expensive so I'd love to hear exactly what makes it better.
>>>>> One thing I've heard is a German ELS has less problems win internal
>> taper
>>>> boring.? It's something on my list to look at.
>>>>> John Dammeyer
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: [email protected] [mailto:[email protected]] On
>>>>>> Behalf Of Richard
>>>>>> Sent: December-11-19 12:17 AM
>>>>>> To: [email protected]
>>>>>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>>>>>
>>>>>> Ralph,
>>>>>> I suggest you forget the RELS but go with John D's system. the single
>>>>>> pulse is easy to handle.
>>>>>> Richard
>>>>>>
>>>>>> On 10/12/2019 19:09, Ralph Hulslander wrote:
>>>>>>> Thanks for the replies!!
>>>>>>>
>>>>>>> Rex, yes I wondered about slop in the gear.
>>>>>>>
>>>>>
>>>>
>>>
>>>
>>
>>
>
>
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
|
Re: Step #1 Encoder
#RELS
Oh and here's a 4 ine display mounted on an ELS with less keys for the generator charger controller project.? The display was a sample.? Way more expensive than all the ELS parts combined but good to -40C where an LCD display wouldn't even light ip. John ? ? 
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Ralph Hulslander
Sent: December-11-19 2:06 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Step #1 Encoder? As for myself I can cover upto $1,000.00. Using the ELS on the mill would?be interesting and a savings as I could use it on both of my lathes and the mill. ? On Wed, Dec 11, 2019 at 4:34 PM Richard <edelec@...> wrote: Hi John, I only asked as you raised costs in an earlier mail. Whether we
like it or not it is one of the factors considered when choosing a system.
Richard
On 11/12/2019 20:51, John Dammeyer wrote:
> Hi Richard,
> My ELS is way more expensive than that.? But there's a historical reason for it.? Not made in China is the biggest one.? Get PC boards made locally (if even possible anymore)? for each of the RELS parts, manufacture 200 including all the pick and place setup charges and you will find the RELS will be way more expensive.? ?Get the three or four boards made in China in that quantity and maybe you will meet that price.? Maybe.? At the time (2006) none of that was available.
>
> The ELS was also designed to have an on board micro-stepping driver good to 55V and 3A for the Z axis.? It's always been primarily designed to replace or augment the gears on old lathes with missing gears or where metric is needed for an imperial screw.? ?As such the behaviour is still very manually oriented rather than CNC.? But the cost of the devices has also been undercut by cheap Stepper Motor drivers made by people who get paid the equivalent of one Starbucks Coffee per day.? So Although the infrastructure is still there for the ELS it's just not cost effective.
>
> The custom metal back plates were bought to serve as mounting and heatsink.? I had 100 made.? Too bad it wasn't 200.? The company that made them is out of business.? Retooling costs to get another 100 made compared again to costs of other items from China just doesn't make it worth it.? So yet another reason not to use the on board stepper driver feature.
>
> A read through the E-Leadscrew archives will show that one member from Australia did make an ELS with a much smaller footprint, a couple of switches and a rotary encoder.? Cost of parts was under $50 I believe.? When I see the commercial CNC systems operated with a single MPG knob and a single button I'll believe that it's cost effective for time and energy to use a rotary knob to enter numbers etc.
>
> We went through that discussion extensively.? As a result my ELS has a keypad, soft keys under the LCD display and dedicated motion keys with shortcut keys to set things like BEGIN/END.? It's those things that make it easy to use.? It tracks slightly varying spindle speeds.
>
> And yes, I don't have a PC connected to the lathes.? Only to the CNC router and the Mill.? ?Although now surplus LCD displays and small footprint PCs (or BBBs with MachineKit) come in at under $100 so a true cost argument would have MachineKit on a lathe run with a BeagleBone and Cape.? All other costs for hardware and spindle being equal.? And then so much more is possible with the lathe than just an electronic gear.
>
> The example of 3D printed encoder is an example of how to save money.
>
> So I think a comparison of costs isn't really the issue since full CNC is now available for so little.? And as I said, I have a friend over 70 who isn't interested in an ELS because the CNC lathe is just so easy to use for him.
>
> If costs really were the issue then there would only be one model car available at a very low low cost.? No Mercedes, Audi, Lexus etc.? After all, cost is the only criteria for choosing a car.
>
> Cheers,
> John
>
>
>
>
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]] On
>> Behalf Of Richard
>> Sent: December-11-19 11:54 AM
>> To: [email protected]
>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>
>> I see that my cost shows as ?90 which may not display correctly as GB
>> Pounds 90. Just to complete the discussion what price is your ELS these
>> days?
>> You also have discussed using Mach3 with one pulse per rev, we must not
>> forget that there are hardware and software costs involved with Mach3,
>> plus a PC sitting in the shop.
>> Reloading into a system in the shop for me only involves plugging in a
>> USB lead and uploading, it is the work of a few minutes.
>> I really do not think that the average guy will ever need to upload new
>> parameters.
>> ATB
>> Richard
>>
>> On 11/12/2019 18:21, John Dammeyer wrote:
>>> Hi Richard,
>>> All good points.? I'd rather put my money into a higher quality spindle drive
>> that doesn't slow down with deep cuts.? Surface finish by maintaining a
>> constant SFM is more important to me.? Having said that the ELS does track
>> slightly varying spindle speeds that show up with the smaller lathes.
>>> Having to compile and reload code into a system sitting in the shop for me
>> is a complete non-starter.
>>> John
>>>
>>>
>>>> -----Original Message-----
>>>> From: [email protected] [mailto:[email protected]] On
>>>> Behalf Of Richard
>>>> Sent: December-11-19 7:32 AM
>>>> To: [email protected]
>>>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>>>
>>>> Tracking the spindle backwards and forwards is not a feature that
>>>> interests me, however tracking the spindle at varying speeds does. The
>>>> problem that I have had with one pulse per rev monitoring is that if the
>>>> spindle slows whilst cutting a deep thread the tool ends up cutting too
>>>> much metal, the result is further slowing and probably a stall or broken
>>>> tool. This has not happened with the encoder system.
>>>> As you say pitches, feeds and tapers are pre-calculated in a
>>>> spreadsheet. The current feed values are adequate for most people I
>>>> would think. The tapers cover all of the MT plus a number of angle and
>>>> ratio tapers. If a user feels that he would need a special then load it
>>>> before the first compile. The same with threads the majority of metric
>>>> and imperial threads are loaded. If a real special is subsequently
>>>> required then yes it needs to be added and a recompile executed. Not a
>>>> major problem IMHO and I have not needed to do it.
>>>> Re cost, Steppers, drives and power supply are common to both so can be
>>>> ignored. The RELS cost therefore comes down to:-
>>>> Arduino Mega, Encoder, belt and two pulleys, 2 line display, 5 button
>>>> pcb, 4 buttons with integral LED's, 1 joystick, 5v psu, 74LS86
>>>> chip+resistors+terminals+cable+connectors
>>>> For me that comes at a say ?90. I make my own enclosures from 6mm
>>>> laminate flooring so near zero cost there.
>>>> Obviously your system includes the Z drive so that should be allowed for.
>>>> The capability of cutting external and internal tapers was a big plus
>>>> and something I have had no problems with, however that was not the
>> case
>>>> with another system!
>>>> Having run both a one pulse per rev system and the RELS on my lathe I
>>>> prefer the latter.
>>>>
>>>> Richard Edwards
>>>>
>>>> On 11/12/2019 09:03, John Dammeyer wrote:
>>>>> Thanks for the endorsement Richard.? But I know that there are features
>>>> from the RELS that don't exist on mine.? I'd really like to learn more about
>>>> what is different.
>>>>> I know that I can't stand pressing buttons to enter a value.? My ELS has a
>>>> keypad for numeric input.? My 3D printer menu does not.? Arrow keys to
>>>> select and increment/decrement a value.? As a result I never use it.
>> Instead? I
>>>> use Octoprint for dealing with my 3D printer.? My PC has a keyboard with
>>>> numeric keys.
>>>>> But as I understand it the Russian ELS tracks spindle motion backwards
>> and
>>>> forward and the lead screw tracks.? Useless on my South bend which has
>>>> over 0.025" backlash on the half nut.? ?I'd toast a thread if I move the
>> spindle
>>>> back and forth with the tool in the thread.? ?So the feature to be able to
>>>> rotate the headstock for a large part is a useless endeavour on my South
>>>> Bend.
>>>>> The lead screw threading pitches are calculated in a spread sheet.? You
>> then
>>>> change the software.? Then compile and update the firmware in the
>> Arduino.
>>>> My ELS lets you enter any ratios that you want.
>>>>> I'm not sure when all is said and done that the RELS is that much less
>>>> expensive so I'd love to hear exactly what makes it better.
>>>>> One thing I've heard is a German ELS has less problems win internal
>> taper
>>>> boring.? It's something on my list to look at.
>>>>> John Dammeyer
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: [email protected] [mailto:[email protected]] On
>>>>>> Behalf Of Richard
>>>>>> Sent: December-11-19 12:17 AM
>>>>>> To: [email protected]
>>>>>> Subject: Re: [digitalhobbyist] Step #1 Encoder
>>>>>>
>>>>>> Ralph,
>>>>>> I suggest you forget the RELS but go with John D's system. the single
>>>>>> pulse is easy to handle.
>>>>>> Richard
>>>>>>
>>>>>> On 10/12/2019 19:09, Ralph Hulslander wrote:
>>>>>>> Thanks for the replies!!
>>>>>>>
>>>>>>> Rex, yes I wondered about slop in the gear.
>>>>>>>
>>>>>
>>>>
>>>
>>>
>>
>>
>
>
>
--
Clausing 8520, Craftsman 12x36 Lathe, 4x12 mini lathe, 14" Delta drill press, 40 watt laser, Consew brushless DC motors and a non working 3D printer
|
