ELS Kit For Old Craftsman 101 - Calibration Testing

[Dan-O]

Hello all. Curious about something from those far smarter than I am. I'll link the short video I did to show this test.

I've been tinkering around with a cheap ELS kit on my 101. It was designed to work on a lathe with a M16 2mm leadscrew. My 101 has a 1/2" 16tpi leadscrew, as they do. For fun this evening, and expecting the numbers to be all wrong, I ran some tests on leadscrew run. And to my amazement, when I set the ELS to travel 2mm and checked that on my dial indicator it was really close at around 78 thou. I have got to be missing something here, right?

 

[GrifterGuru]

The fact it is so close suggests that the encoder is doing its job. The encoder gear size combined with the spindle gear for it create a specific ratio. In use, the encoder sends a signal to the controller that then outputs a control signal to the stepper motor. The fact that the stepper motor is also a tied to a fixed gearing ratio will also form part of the overall reduction between spindle and leadscrew rotation equating to overall travel.

2mm is 0.0787", so if you have a digital indicator that reads thousandths, it might be worth checking using that. I have one purely for this type of testing.

Final callibration settings are, I hope, easy to set in the controller. I have an ELS kit for my 7x which I will be fitting soon, so I hope they are easy to set.

If I may make a suggestion? Run the ELS over a 10mm length (0.3937"). Measure the overall movement. You will have to base it off 100mm travel to get percentage, so 10mm being 10% of 100mm, you will need to do the math. However shy it is will be the error percentage you have. It will also give an idea of how accurate the ELS kit actually is.

Also, does your ELS have provision for using limit switches on the control board? Would be marked as "GND | LM2 | GND | LM1" at the left hand end of the board above the screen. The switches should be Normally Open (N/O) if it is based on the same controller that I have here and when closed would activate the "Stop" signal.

 

[Dan-O]

Many thanks for the reply and the detailed information. I'll do the 10mm testing. The ELS I have has the same layout as yours - most likely the same basic board. It was a very inexpensive, relatively speaking kit (~$219 plus shipping), that included everything. I was going to source the materials separately but when I added it all up it was close to the kit price.

I'm still in the proof of concept stage and don't have the encoder really mounted well - it's kind of temporarily screwed to the table, but it does seem to be working as designed. I even 3D printed one of the gt2 encoder drive pulleys to fit over the belt pulley that is on the old lathe. I have documentation that explains how to customize settings, it's a bit involved, but can certainly be done.

 

[GrifterGuru]

Many thanks for the reply and the detailed information. I'll do the 10mm testing. The ELS I have has the same layout as yours - most likely the same basic board. It was a very inexpensive, relatively speaking kit (~$219 plus shipping), that included everything. I was going to source the materials separately but when I added it all up it was close to the kit price.

I'm still in the proof of concept stage and don't have the encoder really mounted well - it's kind of temporarily screwed to the table, but it does seem to be working as designed. I even 3D printed one of the gt2 encoder drive pulleys to fit over the belt pulley that is on the old lathe. I have documentation that explains how to customize settings, it's a bit involved, but can certainly be done.

@Dan-O

Huh! The only "documentation" I got for how to set the controller was a PDF in chinese. Hardly helpful either. If yours is in English, could I nab a copy?

The "how to install" document was also in nothing but chinese, though I did manage to get that translated.

 

[markba633csi]

Not sure how that is working since 16 tpi is .062 per turn- 2mm is .078
Hmmm
Your code must be set up for an inch leadscrew

 

[Dan-O]

Not sure how that is working since 16 tpi is .062 per turn- 2mm is .078
Hmmm
Your code must be set up for an inch leadscrew

That's what I'm thinking. Puzzling. I need to also check if I had lateralled to the inch programming mode or if some setting had defaulted to it - more testing to do.

 

[Dan-O]

@Dan-O

Huh! The only "documentation" I got for how to set the controller was a PDF in chinese. Hardly helpful either. If yours is in English, could I nab a copy?

The "how to install" document was also in nothing but chinese, though I did manage to get that translated.

I'll attach the documentation I have. I haven't dug too deep into it other than a quick read.

 

[Dan-O]

I'll attach the documentation I have. I haven't dug too deep into it other than a quick read.

And this doc for my button settings/allocations.

 

[markba633csi]

It must have an entry for the leadscrew pitch I would think somewhere- and somehow it's defaulting to 16

 

[GrifterGuru]

@Dan-O

Check section 1, bullet letter "D", of the "quick installation and debugging guide" which I will quote below.

D) Set screw pitch:

Short press the 【SET/SAVE】 key to switch to the 【Lead Screw】 item. That is, for each revolution of the stepper motor, the distance that the screw drives the large drag plate to travel. For example, if the pitch of the screw is 2mm and the ratio of stepper motor to screw is 1:2, the value is: 2mm x 1/2 = 1mm.

Also, the "button settings/allocations" doc is not showing.

Thanks for the quick installation and debugging guide Doc, much better than what I had


Heres that PDF I mentioned... Should provide a good laugh!