Re: Step #1 Encoder
#RELS
Oh yes, the motors used are from the 3d printing world too. Neema17 is a popular size although there are larger and smaller.
Ant?
|
Re: Step #1 Encoder
#RELS
I follow a forum called On-Step where similar technology is used to point telescopes at specific parts of the sky and follow the apparent motion of the stars for astrophotography.
The same issues arise. Gears have backlash, except for harmonic drives. Belts and pulleys have zero backlash and are the favoured method of gearing up a small stepper motor to provide sufficient torque. Or just to link the drive to the driven 1:1.? Harmonic drives are ace but kinda spendy for most of us. There are a couple of builds in the gallery that use them.
Technology from 3D printers is heavily leaned on in the form of various supported motor drivers. Mostly of the silent stepper stick variety. They have a fair bit of intelligence built in and can change the way they drive the motor to optimise it's use for a given task. Microstep control features quite a lot in this. The TMC2130 is well used and the TMC5160 or the S109 can handle more current. The TMC2209 shows promise but the clone makers haven't settled out a standard format yet.? 3D printers are also often used to print parts and cases.
Cheap microcontrollers are used to run the On-Step software. There is a range of options with varying cost and capabilities. The ESP32 is well favoured at the moment. Good bang for little bucks.
The software to run it all is written by the group founder with help from others and feedback and testing from all users. It uses GitHub as a repository for development of the open source code.
The purpose of this snapshot of another group is not to advertise that group but to suggest that as a development model it has worked very well to achieve a similar goal with similar tech. I'm sure some of what they use would be helpful here. You have a lot in common.
They have the same intelligent, rational approach and discussion that happens here. Like minds. I think that develops in these groups because you can't blag a machine.
Ant?
|
Re: Step #1 Encoder
#RELS
When I converted my South Bend Heavy 10L I wanted to maintain the historical (1942) operation of the lathe.?? I wanted to keep the gear cover.? I can post some pictures of failed attempts.? Ultimately I went this route with one hall sensor detecting a magnet embedded into the spindle clamp bolt hole.? A small bracket held the plastic tube. ? 
? The sensor fits into the tube with the backside at right angles. 
? The sensor is epoxied in place. 
? That's the extent of the electrical work for spindle sensing. ? The mechanical side of the lead screw drive is at the other end.? I bought a surplus lead screw mount and machined away a bit to make room for the shaft extension.? The 2:1 reduction provides enough torque/speed with the 280 oz-in motor driven with 8 micro-steps/step from my ELS. ? At the gear box end the appropriate leavers are placed into neutral or not engaged.? The lathe now runs very quietly and the loudest noise comes from the stepper motor.? I plan on mounting the Bergerda AC servo with probably 3:1 for a dramatic increase in spead and better torque. ? 
? And if I want full CNC I can add a motor to the cross slide and then run MACH3 which can also do CNC with a single pulse per rev. John Dammeyer ? ?
toggle quoted message
Show quoted text
> -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Richard > Sent: December-10-19 1:30 AM > To: [email protected] > Subject: Re: [digitalhobbyist] Step #1 Encoder > > Just for info here are some (poor) photos of the encoder and stepper > mount on my lathe. Just remove that 32 tooth gear and replace with a pulley. > Note that I mounted the stepper on the banjo and drive through the > original gear box which allows drive to the sliding feed or lead-screw. > Ralph, on your lathe I would initially remove all of the bits associated > with the change wheels then assess how you will handle the X mechanics, > maybe by refitting some items. > Richard > > On 09/12/2019 21:26, Ralph Hulslander wrote: > > Actually I will be using 1:1 I have a 32t gear to match the 32t gear > > on the end of my spindle: > > IMG_20191209_153625804.jpg > > > > I will have to come up with a shaft but gee isn't that why we have a > > lathe? > > Also a mounting bracket I have some 3x4 aluminium angle and some plate > > steel > > also a vertical?mill and a welder and drill press so I should be able > > to come up with something. I can even use the indexed pivot to engage > > the encoder. > > > > Ralph > > > > On Mon, Dec 9, 2019 at 2:13 PM Bruce J <bruce.desertrat@... > > <mailto:bruce.desertrat@...>> wrote: > > > > > > > >>???? On Dec 9, 2019, at 11:46 AM, Richard <edelec@... > >>???? <mailto:edelec@...>> wrote: > >> > >>???? That option is still available to you if you can get hold of a disk, > >>???? read head, mount and drive it in some way and add some electronics. > > > >???? Note these are readily available for free, by picking up dead > >???? inkjet printers. The encoder needed is on the left-hand end of the > >???? platen and the sensor circuit is usually a simple U-shaped board > >???? attached to another circuit on there. I have several of these at > >???? home; if I can remember, I?ll post a pic later. There are a number > >???? of online projects recycling these parts > > > >???? printers are also useful sources for nylon gears, a variety of > >???? springs, small DC motors and steel rods of different diameters > >???? (mostly like 5-8 mm or so) Old laser jet printers also have a > >???? wealth of motors and mechanical parts, but they?re harder to find. > >???? I've scavenged a half-dozen inkjets simply by picking them up out > >???? of the tip. > > > >???? The scanners on the multi-function ones also provide a very nice > >???? 8x12 or so piece of optically flat glass; quite useful for things > >???? like a base for a tool sharpening setup. > > > >???? -- > >???? Bruce Johnson > > > >???? "Wherever you go, there you are." B. Banzai, PhD > > > > > > -- > > 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: Hobbyist CNC - is it worth it?
#CNC
#CAD
Hi Richard, I have recently assisted a friend in uprating his Boxford CNC mill. We
used HSS 2Nm Servo Steppers and the results look great at the moment.
Feed rates now up to 2500mm/min and acceleration at 250mm/s/s. I may
discuss these units further at a later date.
Richard
Interesting about the servo steppers. I'm using DC Brushed Servos (or the Bergerda AC Servo) with a 3000 RPM constant torque rating of 1.6Nm and 3:1 reduction on the X axis. The Y has 4:1 because it's got to carry that extra weight from rotating X axis assembly. Peak Torque on the KL34-180-90 is 8Nm. Anyway, with LinuxCNC and the MESA 7i92H allow me to move the X axis at 150 IPM (3810mm/min) and the Y at 120 IPM (3048mm/min) and they are incredibly quiet. What sort of reduction did you use (if any)? What's the max RPM of the motors you used? John Dammeyer
|
Re: Step #1 Encoder
#RELS
Just for info here are some (poor) photos of the encoder and stepper
mount on my lathe. Just remove that 32 tooth gear and replace with a pulley.
Note that I mounted the stepper on the banjo and drive through the
original gear box which allows drive to the sliding feed or lead-screw.
Ralph, on your lathe I would initially remove all of the bits associated
with the change wheels then assess how you will handle the X mechanics,
maybe by refitting some items.
Richard
toggle quoted message
Show quoted text
On 09/12/2019 21:26, Ralph Hulslander wrote: Actually I will be using 1:1 I have a 32t gear to match the 32t gear
on the end of my spindle:
IMG_20191209_153625804.jpg
I will have to come up with a shaft but gee isn't that why we have a
lathe?
Also a mounting bracket I have some 3x4 aluminium angle and some plate
steel
also a vertical?mill and a welder and drill press so I should be able
to come up with something. I can even use the indexed pivot to engage
the encoder.
Ralph
On Mon, Dec 9, 2019 at 2:13 PM Bruce J <bruce.desertrat@...
<mailto:bruce.desertrat@...>> wrote:
On Dec 9, 2019, at 11:46 AM, Richard <edelec@...
<mailto:edelec@...>> wrote:
That option is still available to you if you can get hold of a disk,
read head, mount and drive it in some way and add some electronics. Note these are readily available for free, by picking up dead
inkjet printers. The encoder needed is on the left-hand end of the
platen and the sensor circuit is usually a simple U-shaped board
attached to another circuit on there. I have several of these at
home; if I can remember, I¡¯ll post a pic later. There are a number
of online projects recycling these parts
printers are also useful sources for nylon gears, a variety of
springs, small DC motors and steel rods of different diameters
(mostly like 5-8 mm or so) Old laser jet printers also have a
wealth of motors and mechanical parts, but they¡¯re harder to find.
I've scavenged a half-dozen inkjets simply by picking them up out
of the tip.
The scanners on the multi-function ones also provide a very nice
8x12 or so piece of optically flat glass; quite useful for things
like a base for a tool sharpening setup.
--
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
--
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: Hobbyist CNC - is it worth it?
#CNC
#CAD
I CNC'd my Seig X2 because I could! Just about all of my projects seem
to be about making or enhancing tools, actually very little in the way
of making anything else!
The Seig is simple to CNC in my mind. For X I just mounted a stepper on
the end of the screw? on the left end. Y took a little more thought. I
did not like the idea of the stepper on the end of the screw so I
installed a timing belt drive with the stepper mounted back and under
the machine. For Z I created a "spinning nut" with a fixed ball screw
mounted to the head. It all works well.
Control is via Linux CNC. Since the original build I have added a
pendant control (thanks John) and changed the X axis to a ball screw.
I am using Cambam to generate my G code (2.5D not full 3D). Drawings via
Solidedge (2D), Mastercam 8.1 (3D) or Solid????? (3D).
Having CNC capability has enabled me to do things I cannot do on my
other mill. However it was primarily an exercise in making things!
I have recently assisted a friend in uprating his Boxford CNC mill. We
used HSS 2Nm Servo Steppers and the results look great at the moment.
Feed rates now up to 2500mm/min and acceleration at 250mm/s/s. I may
discuss these units further at a later date.
Richard
toggle quoted message
Show quoted text
On 09/12/2019 12:47, CLevinski wrote: Hello, All,
I have been considering a conversion of my mini-mill to CNC.? I don't
do any commercial machining, only my own projects, many of which are
tools and accessories for other machine tools. *Do you think a
mini-mill CNC conversion is worthwhile, and what would you do with it?*
I also realized that I am not fully aware of what the finished CNC
mill consists of, or HOW you use it.? For example, when wishing to do
a simple machining operation, I know there is an electronic control
box that is used; no more cranking the handles.? But how do you get
your CNC-machined part to, well, machine?? Let's say I draw up a 3D
model.? I know how to do that because it's necessary for my 3D
printer.? But if I now want to machine this part, what do I do?? I
*think*?that there is some kind of CAM (Computer Aided Manufacturing)
program in which I define which end mills and such to use, and then
define "tool paths" of where the tools will actually move, but I am
not sure.? Is the CAM program completely independent from the CAD
system?? Or must they be related?? Can I draw a 3D part with Fusion
360, for example, and then use a separate CAM program to specify the
end mills and define the tool paths?
Any enlightenment would be appreciated.
--
Regards,
Charlie
New Jersey, USA
/*MURPHY'S CONSTANT: Matter will be damaged in direct proportion to
its value.*/
|
Re: Hobbyist CNC - is it worth it?
#CNC
#CAD
Hi Charlie. Thanks for the post as I am sure many forum members are thinking the same as "is CNC mill conversion worth it." ? So iIf I may throw in my 10 cents worth.then here i go. My Weiss mill was first modified for a power feed on the X axis only, then due to physical restraints I fitted a power feed to the Z axis.I must mention here that both of these conversions were very doable and the Weiss mill with the solid Z column IE a positive feed screw was almost a given. I understand alot of hobbyist own a Sieg type mill with a rack and pinion? type Z axis movement. but not to worry, Richard UK has done an excellent job on a full CNC mill with this type of head and fitted a ball lead screw powered by a stepper. So it?s all doable, and i am sure he will assist if you ask as he says ?"just yell out". Richard was the instigator for me to go the "full Monty" to convert my mill to CNC incl a 4th axis. As i already had a stepper indexing head ( again using a Nema motor) the A 4th axis was a no brainier. So this left only the Y axis, again not difficult, a stepper motor slung under the X axis table mounted on the side of the mill bed and drives the Y axis via a belt.and pulleys. After much shopping around i decided on the purchase of a CNC control box, i opted for the DDCS v 2.1? and basically built a control unit to power everything up from there. I will gladly send photos as and when. The choice of controller I admit had a few teething problems but the support from the suppliers engineering staff has been? amazing and having there own web site and Facebook, I receive regularly new updates that can be easily installed. by a USB stick.They have now introduced a v 3.1, but all the upgrades are suitable for V 2.1 and v 3.1. So back to charlies is it worth it question. IMHO YES. Of course there are those that still prefer the manual use of a mill, nothing wrong in that, but i have a different outlook on my hobby, why work hard when you can work smart. The first job I did on my mill after CNC conversion was to cut scrolls on some new soft jaws, , not impossible manually but very tricky to do. Very rarely do i use the mill manually, only for a quickie fix it type job. I have attached a video of milling in some finger grooves on a knob, again easy to do manually with a dividing head but the grooves actually "roll around" the circumference, that?s difficult if approached manually. If members need any help then i am also available.  John Lindo -- John
|
Re: Hobbyist CNC - is it worth it?
#CNC
#CAD
Hi Charlie, ? One thing I might mention.? Almost from day 1 I've had a Shumatech DRO-350 and scales on the quill and X/Y axis. ?With a touch probe it's easy to find the center of a hole.?? Same with ensuring that an edge is parallel.? The Shumatech can even do hole patterns etc.? Guiding me to each new XY position before I bring the quill down to drill or mill.?? ? So series of holes that start with the initial center drill, then tap drill, then clearance hole and finally counter bore where the tool is only changed once per set of holes is dirt simple with the Shumatech DRO. Not nearly as easy with scales and counting turns.? And even easier with CNC where you just program in the X,Y positions and still manually move the quill.?? Otherwise you have to have the tool # and length of each tool calibrated so the automatic drilling works properly.? ? If you haven't had a DRO then the CNC will be a wonderful addition.? If you have the DRO, then not as much depending on what you do. ? ? 
John ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of CLevinski
Sent: December-09-19 7:17 PM
To: [email protected]
Subject: Re: [digitalhobbyist] Hobbyist CNC - is it worth it? #CNC #CAD? John,
Many thanks for the examples, explanations and links!? It seems to me that "following the curve" and such otherwise extremely difficult tasks are the biggest benefit.
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
Re: Step #1 Encoder
#RELS
Gears have way more "slop" than the steps on your encoder. If the gear rattles a bit, your encoder could go crazy trying to discern speed and direction.
Just saying I could disengage, who knows why. I could put a flat belt on the two gears, if you really want a timing belt.
I am really looking for feedback and help since I do not know what I am doing (I have never done this) but I need the whys.
Ralph
On Mon, Dec 9, 2019 at 6:42 PM Richard < edelec@...> wrote: There is no way I would run an encoder for the ELS via a gear. I would
suggest that with an encoder with a shaft you only consider a timing
belt drive.
Also why would you want to disengage the encoder?
Richard
On 09/12/2019 21:26, Ralph Hulslander wrote:
> Actually I will be using 1:1 I have a 32t gear to match the 32t gear
> on the end of my spindle:
> IMG_20191209_153625804.jpg
>
> I will have to come up with a shaft but gee isn't that why we have a
> lathe?
> Also a mounting bracket I have some 3x4 aluminium angle and some plate
> steel
> also a vertical?mill and a welder and drill press so I should be able
> to come up with something. I can even use the indexed pivot to engage
> the encoder.
>
> Ralph
>
> On Mon, Dec 9, 2019 at 2:13 PM Bruce J <bruce.desertrat@...
> <mailto:bruce.desertrat@...>> wrote:
>
>
>
>>? ? ?On Dec 9, 2019, at 11:46 AM, Richard <edelec@...
>>? ? ?<mailto:edelec@...>> wrote:
>>
>>? ? ?That option is still available to you if you can get hold of a disk,
>>? ? ?read head, mount and drive it in some way and add some electronics.
>
>? ? ?Note these are readily available for free, by picking up dead
>? ? ?inkjet printers. The encoder needed is on the left-hand end of the
>? ? ?platen and the sensor circuit is usually a simple U-shaped board
>? ? ?attached to another circuit on there. I have several of these at
>? ? ?home; if I can remember, I¡¯ll post a pic later. There are a number
>? ? ?of online projects recycling these parts
>
>? ? ?printers are also useful sources for nylon gears, a variety of
>? ? ?springs, small DC motors and steel rods of different diameters
>? ? ?(mostly like 5-8 mm or so) Old laser jet printers also have a
>? ? ?wealth of motors and mechanical parts, but they¡¯re harder to find.
>? ? ?I've scavenged a half-dozen inkjets simply by picking them up out
>? ? ?of the tip.
>
>? ? ?The scanners on the multi-function ones also provide a very nice
>? ? ?8x12 or so piece of optically flat glass; quite useful for things
>? ? ?like a base for a tool sharpening setup.
>
>? ? ?--
>? ? ?Bruce Johnson
>
>? ? ?"Wherever you go, there you are." B. Banzai, PhD
>
>
> --
> 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
>
--
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
On Mon, Dec 9, 2019 at 06:42 PM, Richard wrote:
There is no way I would run an encoder for the ELS via a gear. I would
suggest that with an encoder with a shaft you only consider a timing
belt drive.
Ralph, I agree with Richard.? The bearing on a small, inexpensive encoder of the type we can source easily from China would simply not support the radial load of a gear that size.? (Personally, I would not drive it with any sized gear, but that's me.)? Timing belt drive would really be the preferred approach, IMO. The company I worked for made very heavy-duty encoders that would handle a gear like that (price: around US $600.00 each and up), but we would STILL recommend that a separate shafted bearing assembly was used with the gear, and the encoder coupled to the end of that shaft, thereby minimizing loading.? Another alternative, of course, would be a hollow-shaft encoder, but again, not very price friendly when big enough for our spindles.? You might be able to find a not terribly expensive one from China; I have never searched. -- Regards, Charlie New Jersey, USA MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
Re: Hobbyist CNC - is it worth it?
#CNC
#CAD
John,
Many thanks for the examples, explanations and links!? It seems to me that "following the curve" and such otherwise extremely difficult tasks are the biggest benefit.
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
Re: Hobbyist CNC - is it worth it?
#CNC
#CAD
Many thanks, Bruce...?
Sounds like the CAM component must be compatible with the CAD element...
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
Re: Step #1 Encoder
#RELS
Just saying I could disengage, who knows why. I could put a flat belt on the two gears, if you really want a timing belt.
I am really looking for feedback and help since I do not know what I am doing (I have never done this) but I need the whys.
Ralph
On Mon, Dec 9, 2019 at 6:42 PM Richard < edelec@...> wrote: There is no way I would run an encoder for the ELS via a gear. I would
suggest that with an encoder with a shaft you only consider a timing
belt drive.
Also why would you want to disengage the encoder?
Richard
On 09/12/2019 21:26, Ralph Hulslander wrote:
> Actually I will be using 1:1 I have a 32t gear to match the 32t gear
> on the end of my spindle:
> IMG_20191209_153625804.jpg
>
> I will have to come up with a shaft but gee isn't that why we have a
> lathe?
> Also a mounting bracket I have some 3x4 aluminium angle and some plate
> steel
> also a vertical?mill and a welder and drill press so I should be able
> to come up with something. I can even use the indexed pivot to engage
> the encoder.
>
> Ralph
>
> On Mon, Dec 9, 2019 at 2:13 PM Bruce J <bruce.desertrat@...
> <mailto:bruce.desertrat@...>> wrote:
>
>
>
>>? ? ?On Dec 9, 2019, at 11:46 AM, Richard <edelec@...
>>? ? ?<mailto:edelec@...>> wrote:
>>
>>? ? ?That option is still available to you if you can get hold of a disk,
>>? ? ?read head, mount and drive it in some way and add some electronics.
>
>? ? ?Note these are readily available for free, by picking up dead
>? ? ?inkjet printers. The encoder needed is on the left-hand end of the
>? ? ?platen and the sensor circuit is usually a simple U-shaped board
>? ? ?attached to another circuit on there. I have several of these at
>? ? ?home; if I can remember, I¡¯ll post a pic later. There are a number
>? ? ?of online projects recycling these parts
>
>? ? ?printers are also useful sources for nylon gears, a variety of
>? ? ?springs, small DC motors and steel rods of different diameters
>? ? ?(mostly like 5-8 mm or so) Old laser jet printers also have a
>? ? ?wealth of motors and mechanical parts, but they¡¯re harder to find.
>? ? ?I've scavenged a half-dozen inkjets simply by picking them up out
>? ? ?of the tip.
>
>? ? ?The scanners on the multi-function ones also provide a very nice
>? ? ?8x12 or so piece of optically flat glass; quite useful for things
>? ? ?like a base for a tool sharpening setup.
>
>? ? ?--
>? ? ?Bruce Johnson
>
>? ? ?"Wherever you go, there you are." B. Banzai, PhD
>
>
> --
> 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
>
--
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
There is no way I would run an encoder for the ELS via a gear. I would
suggest that with an encoder with a shaft you only consider a timing
belt drive.
Also why would you want to disengage the encoder?
Richard
toggle quoted message
Show quoted text
On 09/12/2019 21:26, Ralph Hulslander wrote: Actually I will be using 1:1 I have a 32t gear to match the 32t gear
on the end of my spindle:
IMG_20191209_153625804.jpg
I will have to come up with a shaft but gee isn't that why we have a
lathe?
Also a mounting bracket I have some 3x4 aluminium angle and some plate
steel
also a vertical?mill and a welder and drill press so I should be able
to come up with something. I can even use the indexed pivot to engage
the encoder.
Ralph
On Mon, Dec 9, 2019 at 2:13 PM Bruce J <bruce.desertrat@...
<mailto:bruce.desertrat@...>> wrote:
On Dec 9, 2019, at 11:46 AM, Richard <edelec@...
<mailto:edelec@...>> wrote:
That option is still available to you if you can get hold of a disk,
read head, mount and drive it in some way and add some electronics. Note these are readily available for free, by picking up dead
inkjet printers. The encoder needed is on the left-hand end of the
platen and the sensor circuit is usually a simple U-shaped board
attached to another circuit on there. I have several of these at
home; if I can remember, I¡¯ll post a pic later. There are a number
of online projects recycling these parts
printers are also useful sources for nylon gears, a variety of
springs, small DC motors and steel rods of different diameters
(mostly like 5-8 mm or so) Old laser jet printers also have a
wealth of motors and mechanical parts, but they¡¯re harder to find.
I've scavenged a half-dozen inkjets simply by picking them up out
of the tip.
The scanners on the multi-function ones also provide a very nice
8x12 or so piece of optically flat glass; quite useful for things
like a base for a tool sharpening setup.
--
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
--
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
Actually I will be using 1:1 I have a 32t gear to match the 32t gear on the end of my spindle:
I will have to come up with a shaft but gee isn't that why we have a lathe? Also a mounting bracket I have some 3x4 aluminium angle and some plate steel also a vertical?mill and a welder and drill press so I should be able to come up with something. I can even use the indexed pivot to engage the encoder.
Ralph
On Dec 9, 2019, at 11:46 AM, Richard < edelec@...> wrote:
That option is still available to you if you can get hold of a disk,
read head, mount and drive it in some way and add some electronics.
Note these are readily available for free, by picking up dead inkjet printers. The encoder needed is on the left-hand end of the platen and the sensor circuit is usually a simple U-shaped board attached to another circuit on there. I have several of these at home; if I can remember, I¡¯ll post a pic later. There are a number of online projects recycling these parts
printers are also useful sources for nylon gears, a variety of springs, small DC motors and steel rods of different diameters (mostly like 5-8 mm or so) Old laser jet printers also have a wealth of motors and mechanical parts, but they¡¯re harder to find. I've scavenged a half-dozen inkjets simply by picking them up out of the tip.
The scanners on the multi-function ones also provide a very nice 8x12 or so piece of optically flat glass; quite useful for things like a base for a tool sharpening setup.
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
--
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
On Dec 9, 2019, at 11:46 AM, Richard < edelec@...> wrote:
That option is still available to you if you can get hold of a disk,
read head, mount and drive it in some way and add some electronics.
Note these are readily available for free, by picking up dead inkjet printers. The encoder needed is on the left-hand end of the platen and the sensor circuit is usually a simple U-shaped board attached to another circuit on there. I have several of these at home; if I can remember, I¡¯ll post a pic later. There are a number of online projects recycling these parts
printers are also useful sources for nylon gears, a variety of springs, small DC motors and steel rods of different diameters (mostly like 5-8 mm or so) Old laser jet printers also have a wealth of motors and mechanical parts, but they¡¯re harder to find. I've scavenged a half-dozen inkjets simply by picking them up out of the tip.
The scanners on the multi-function ones also provide a very nice 8x12 or so piece of optically flat glass; quite useful for things like a base for a tool sharpening setup.
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: Step #1 Encoder
#RELS
The original RELS software was based upon using an 1800 line encoder
disk taken from an HP printer, therefore No Cost!
That option is still available to you if you can get hold of a disk,
read head, mount and drive it in some way and add some electronics.
If you do not want to go that way then as you say purchase an encoder.
You do not need an "Index" output just an A and B signal. The original
software was written around 1800 line per spindle revolution however it
is possible to use a different number of lines but pick something
somewhere close to this sort of value.
I would assume that you will be belt driving the encoder so there is
really no need to stay at 1:1.
The final specification for the encoder therefore resolves to :-
5v supply, A and B signals, index not required, around 1800 lines per
rev after belt ratio, capable of the maximum spindle speed after belt ratio.
Do not get sidetracked by Quadrature counts if quoted, you are only
interested in the number of lines.
On my system I have a 600 line encoder running at 3:1 and it cost me
maybe ?15 from China.
If you need any further information just yell
Richard Edwards
toggle quoted message
Show quoted text
On 09/12/2019 15:55, Ralph Hulslander wrote: I am just about done with my Must Do's and will be headed to my shop
for the next two or three months.
I want to do ELS (#RELS) on my Craftsman?101.07403 12x36 Lathe. I also
have a Mini Lathe 4x12 which
I will do later.
I would like to document the full story possible for publication or at
least a detailed web post.
Thought I'd start with the encoder.
Where do I start? What encoder do I want? I googled rotary encoders
and my head is spinning.
Especially the price I can pay $16.00 - $30.00 or $300-$600.00, even
with the same brand name
there can be $200.00+ difference from different suppliers.
I will be mounting the encoder on the spindle at a 1:1 drive so a 2 -
3000 rpm encoder should work.
I appreciate the help and would really like to document this selection.
Ralph
--
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: Hobbyist CNC - is it worth it?
#CNC
#CAD
Hi Bruce, I've been doing a similar project for the last 10 years or so.? It started with adding Power Feed to the knee since the cast hand crank didn't fit very well and it was a pain to move the knee up and down.? So I mounted a stepper motor on it with a 3:1 belt drive and used a spare Electronic Lead Screw to serve as the motion control. ? The next bit of automation was using my Lathe ELS to drive my rotary stepper motor to simplify making a much of parts with holes in the same spot for the mill CNC conversion.? Each jog distance was the mount to turn the motor.
? Finally a few years ago I made it far enough to move the Y axis and the Z axis.? In this case I used a BeagleBone Black with MachineKit (LinuxCNC for the BBB) to test the motion.
? And then I was distracted by this really good deal on a harmonic drive and the STMBL AC Servo drive kits for an A axis for the CNC project.? Still haven't created the casting to hold the motor nor made a face plate for it.? But it does turn.? For testing purposes it's once again being driven by my ELS.
? Finally last spring the X axis was motorized and this video shows it running the roadrunner g-code with Mach3 on a WIN-XP system.
? In the process of hunting down a spindle motor I ran across the Bergerda company in China.? With really good support I managed to swap the X axis with an AC servo and test the smaller of the two I bought on the X axis.
? Since then I've built a cart to hold all the power supplies and motor drives.? Spindle changeover not yet complete.? For now back to the two DC Brushed drives and a PC that dual boots into either LinuxCNC or WIN-XP for Mach3.? The cheaper route to go is with a Mesa 7i92H Ethernet to Parallel port.? Only a lit bit more money buys an Ethernet Smooth Stepper for MACH3/4.? My conversion isn't finished yet.? I'll post some pictures and perhaps a video later this week. ? For software I use AlibreCAD/CAM.? What I'm finding is that the wizards that come with MACH3 are very handy.? I've yet to import the equivalent tools into LinuxCNC.? I've also not yet moved over my touch plate code from my MACH3/USB Smooth Stepper installation. ?Again, there is some sort of graphical add on for LinuxCNC that can do this but also not done yet. ? At the G-Code level the programming is the same.? It takes only a little bit of practice to type a few commands to set up power feed on any axis to mill something.? Many of the LinuxCNC people have become adept at writing their own small G-Code programs to say face a surface for that matter mill a step or groove in multiple passes. ? Where the CNC really shines though is doing what you can't do with two separately powered axis.? That's to follow a curve.? To mill out a slot.? So that's the biggest reason for adding CNC to your mill.? So although these could have been milled by hand, and probably even faster it was an exercise in using CAD/CAM and the CNC conversion. ? 
? ? 
? And even then there's a place for 3D printing since I didn't have any material in aluminum of the right size to machine the second part of the Z axis home/limit switch. ? 
? John Dammeyer ? "ELS! Nothing else works as well for your Lathe" Automation Artisans Inc. www dot autoartisans dot com ? ? ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Bruce J
Sent: December-09-19 7:42 AM
To: [email protected]
Subject: Re: [digitalhobbyist] Hobbyist CNC - is it worth it? #CNC #CAD? ?
? Hello, All,
I have been considering a conversion of my mini-mill to CNC.? I don't do any commercial machining, only my own projects, many of which are tools and accessories for other machine tools.? Do you think a mini-mill CNC conversion is worthwhile, and what would you do with it???
I also realized that I am not fully aware of what the finished CNC mill consists of, or HOW you use it.? For example, when wishing to do a simple machining operation, I know there is an electronic control box that is used; no more cranking the handles.? But how do you get your CNC-machined part to, well, machine?? Let's say I draw up a 3D model.? I know how to do that because it's necessary for my 3D printer.? But if I now want to machine this part, what do I do?? I think?that there is some kind of CAM (Computer Aided Manufacturing) program in which I define which end mills and such to use, and then define "tool paths" of where the tools will actually move, but I am not sure.? Is the CAM program completely independent from the CAD system?? Or must they be related?? Can I draw a 3D part with Fusion 360, for example, and then use a separate CAM program to specify the end mills and define the tool paths? You pretty much have it nailed. CAD for design, CAM to actually tell the mill what to do. Fusion 360 has a CAM component built in. Here is a listing of free and OSS software for CAM/CNC I found? I do know LinuxCNC is well supported.
Any enlightenment would be appreciated.
--
Regards,
Charlie
New Jersey, USA
MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
? "Wherever you go, there you are." B. Banzai, PhD ?
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Re: Step #1 Encoder
#RELS
Hi, Ralph, The existing RELS Arduino sketch is set up for 1800 pulses per spindle rotation, though that can be changed.? Have you thought about how you will affix the encoder to the spindle?? It might be more convenient, and easier to find a low-cost encoder, if you can increase the encoder speed and use a lower pulse per rev encoder.? John and I both (because I basically duplicated his implementation) used 600 PPR, belt driven with a timing belt at a 3:1 ratio, resulting in 3 encoder revolutions per spindle rev and 1800 pulses per spindle rev. There are several factors you have to consider.? (BTW, I spent 33 years working for a company that manufactures encoders. Besides working on applications, I also sometimes wrote specs for how they were supposed to perform.)? The most critical ones here are: RPM - All encoders have a maximum mechanical rotation rate. If the maximum spindle speed is 2500 RPM, and you are driving 1:1, then your encoder must have an RPM rating higher than that.? If driving 2:1 in the same example, the encoder will be running 5000 RPM at a 2500 RPM spindle speed. Output Frequency - The pulses are sent out of the encoder via a digital system, and this system has a maximum frequency.? Say that your encoder is 600 PPR and is turning at 2500 RPM. 600 P/R X 2500 R/M X 1/60 M/sec = 25,000 pulses/sec Or, 25 kHz.? So you need to decide on PPR, and gear or belt ratio between spindle and encoder, before you can calculate the maximum frequency rating you need. Radial Bearing Load - The bearings in an encoder are only rated for a certain number of rotations.? This number decreases rapidly with radial bearing load. There is also a maximum radial load the bearing can take at all. In large, industrial systems, this is carefully calculated, but in our application, just use the lowest load you can. In my photos below, I used the weakest springs that I could while still keeping the belt fully engaged.? BTW, don't be fooled into thinking that a flexible coupling eliminates this problem.? They only work correctly within a very small specified range.? Outside that range, they apply substantial loads to the encoder shaft. Below is a photo of my encoder installation, "borrowed", as I have said, from John Lindo's design.? I hope this helps...  -- Regards, Charlie New Jersey, USA MURPHY'S CONSTANT:?Matter will be damaged in direct proportion to its value.
|
I am just about done with my Must Do's and will be headed to my shop for the next two or three months.
I want to do ELS (#RELS) on my Craftsman?101.07403 12x36 Lathe. I also have a Mini Lathe 4x12 which
I will do later.
I would like to document the full story possible for publication or at least a detailed web post.
Thought I'd start with the encoder.
Where do I start? What encoder do I want? I googled rotary encoders and my head is spinning.?
Especially the price I can pay $16.00 - $30.00 or $300-$600.00, even with the same brand name
there can be $200.00+ difference from different suppliers.
I will be mounting the encoder on the spindle at a 1:1 drive so a 2 - 3000 rpm encoder should work.
I appreciate the help and would really like to document this selection.
Ralph
--
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
|
John Lindo
