Putting the ELS3 (Electronic Lead Screw ) on a LMS-3536 Lathe

alan856

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This project has a number of steps - I'll divide it into sections so you don't get overloaded!!

Ever since I had my first machine shop in the 80's (Sheldon 10x36) I've had the bug to build or get an Electronic Lead Screw. Back then the tech was so "low" that I couldn't begin to afford or think of it. In 2012 I became aware of the Arduino and mcu's in general, and began tinkering... and the dream of my "Digital Gear Box" of the '80's came to life again!

Back then all I could think about was using a digital control to allow setting of threading pitches to make single-pointing screws much easier. The Sheldon DID have a QC Gear box for threading - but I thought "electronic" would be so much better (and way cooler!).
As time went by - other simpler projects that took up the time. Not to mention working out the math for the spindle-to-leadscrew math took a bit - and then I struggled on how to actually get the steppers to run in relation to the spindle and follow it's speed - a some ratio.

Searching round the net I came across a very interesting design from (!) 2000! A link to is here: ELS Circa 2000
This is a VERY interesting design and uses discrete logic. Def a file worth putting in your FYI archive. Will def give you some

So anyway - the beat went on. Then last year I discovered the ELS3 from Rocketronics in Germany. After surfing the site I became more and more excited - that HERE was my "dream ELS" - done and ready to make chips (almost)!

I did not want to do the usual motor install where it sticks out front on the X axis and on the left side of Z. Right around this time I found Wade'O Design's web site and saw how he hung his X-axis motor off the back! Very elegant - but took some DOING in the LMS-3536

Here are some pix of the lathe with the ELS installed. Nothing seen on the X-Axis, and you can just see the X-Axis motor under the gear cover & control panel.


ELS (1 of 2).jpg

Apron view - no stepper showing!

ELS (1 of 1).jpg
 
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Cover.jpg

In order to have the leadscrew motor (Z-Axis on ELS3) not show, I had to "hide" it under the control panel and inside the gearbox cover. This took a lot of "Empirical Research" to get done (read: MUCH trial and error!) I had gone thru several iterations of how to exactly mount the motor, so its final position moved around just a bit...

Also the timing pulley had to line up with the leadscrew pulley above. Calculating center-distance is not that hard - Especially if you use SDP/SI's Distance Calculator. Even using that i screwed it up 3 times! (I have a couple spare belts now). I couldn't move the lathe, so at one point I had to take the whole cover off... ARGGH!

As it worked out,I was able to just remove all the change gears, and use the existing banjo-arm to mount the motor-encoder. Note: The motor now ONLY drives the spindle - not the leadscrew - something you might not think about.

Here is an overview of the left side gear cover & enoder hookup:

ELS (1 of 5).jpg

Next - closer view of the cuts needed to get everything to fit:

ELS (3 of 5).jpg

Final front view: Did a bit more chopping than needed - good ventilation I guess??? :)

ELS (5 of 5).jpg
 
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Z axis.jpg

View of encode hookup and Z-Axis motor mount

One of the feet of the lathe turned out to be in a convenient location to install a motor-mount plate. This was machined to match the NEMA-23 motor mount holes and an enlarged shaft mount hole for the drive-pulley shaft. This had to be made to get the motor pulley to be in-line with the leadscrew pulley. More "empirical research" on this aspect of the job. Mostly getting the distance-between-centers to be right... yet another ARRGJ!! :cool:

ELS (1 of 3).jpg

A little closer to the encoder mount. Had to machine a little shaft that would fit the encoder and tie to the spindle shaft. Still some old change-gear calcs on the cover...

ELS (2 of 3).jpg

Encoder and Rocketronics Line Driver. The ELS3 uses CAT5 Ethernet cables to tie the encoder & ELS outputs to the stepper Driver

ELS (3 of 3).jpg
 
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X Axis.jpg

X-Axis Motor - the toughest of project!

Here are some views of the X-Axis motor install. This was inspired by the work done by Wado'o on his "CNC Lathe" project. His work and drawing are SUPER - def take a look!

In order to get a pulley onto the X-Axis leadscrew I had to put and adapter on its end, and the create a mount plate that would allow the cross-slide to go over it, as well as maintain an (slightly) adjustable center-distance to the motor. There is a Delrin spacer in which the leadscrew drive pulley rides... all a very "one-off" custom fit!

Here is the view from behind the lathe to show the X-axis mount

ELS (5 of 5).jpg

Angle view of Delrin block, & leadscrew adapter; from above:

ELS (4 of 5).jpg

Top view - straight down - of motor mount system:

ELS (3 of 5).jpg

Overview of X-Axis. Cross slide has to be unscrewed from brass nut and removed to get access. Once up and running
one should not have to go here often.

Note this allows hand-operation of the X-Axis if the stepper is disabled (via an ELS3 control).

ELS (1 of 5).jpg
 
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Power.jpg

The ELS3, Drivers & Power (plus short parts list)

Here are some pix of the ELS3 and my modest "Power Center". ( The new ELS4 is even sexier looking!) The control is powered by 5VDC wall-wart, and the various control signals (X,Y,encoder) are routed by CAT5 cables.

ELS (3 of 4).jpg

End view - these are Leadshine DM556T drivers and a 350W 48VDC 7.3A power supply.
Purchased from SteppersOnLine. I tried a number of ways to connect the CAT5 wires to the
drivers, and ended up a piece of protoboard with male header pins going down to the green Phoenix
connectors and soldered to a male JST socket a few holes away on the board.
Then I hand crimped each CAT5 wire into a mating female connector.


ELS (4 of 4).jpg

The ELS3 control on a little ball-joint tied to the shelf. This is not the best setup as often you have
"cross-reach" for the buttons, a with something better.

ELS (1 of 4).jpg


Parts.jpg
Here is the major parts list:

From SteppersOnLine:
Digital Stepper Driver 1.8~5.6A 20-50VDC for Nema 23,24, 34 Stepper Motors (DM556-T)
Z-Axis Motor: Nema 23 Bipolar 3Nm (425oz.in) 4.2A
X-Axis Motor: Dual Shaft Nema 23 Bipolar 1.9Nm (269oz.in) 2.8A (didn't really need the dual shaft)
350W 48V 7.3A 115/230V Switching Power Supply

From Rocketronics:
ELS3 and his Line driver for the Encoder
From Mouser:

490-AMT103-V Encoder (per Rocketronics suggestion)
 
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I'd like to load this project in a series of several parts so I don't have so many images in each one.

May want to consider posting your updates all in the same thread. It avoids clutter & makes it easier for those interested to find all the content rather than having to search for seperate threads (seperate threads will not stay in order in the index as you post them).
 
Ah yes - now I see this. Guess I though they would sort by title... Still - it seems like too many images for a single thread. Perhaps if I can get a gallery going where I’d have folder for the ELS3 project, and sub folders for each section... have to see if there is much interest in this before I rework it
 
Alan, I merged the posts into one thread. If things are out of order let me know and I'll see if I can help with that.
 
Wow - didn't know you could do that! I'll go over and edit them to put some dividers in. THANKS!
 
Awesome photos and descriptions. Very helpful to me who has the same lathe except a bit longer.
I am converting my lathe also to ELS — rocketronics ELS4pro. I bench tested the electronics after mounting in a NEMA 1 enclosure and everything works. Now started the mechanical work.
 
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