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
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-----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.
