New Rebuild on Sherline Chucker Lathe & New build on 5400 mill

[BillB]

It is possible you maybe missing steps between your Acorn and the drives.
Can be EMI noise, poor wiring practices.

Set up an indicator zero it out and create a program to go a distance and return to zero. Loop it See if it's repeatable.

To clarify The machine is not missing steps when programmed correctly.
As per my video posting, the ONLY reason it was missing steps is that my programming was wrong "lathe newbie". Way too fast on the feed rates so the drive and motor could not keep up. After I adjusted it to a useable feed rate it has not missed steps at all.

My wiring is crap but it was not the cause.

My concern is in the future if there is an issue the drive will just keep running, be assuring to know the drive will fault when and if it does have an issue.

Understand.
The loop is closed between the drive and the motor.
If the motor is not where the drive commanded it, it "hits or lets off on the gas" to get it there. If it can't it faults
The drive receives the step and direction pulses from the controller (Acorn) via the wiring you provided.
The step pulse frequency is on the order of 100k per second on the minimum and HIGHER if you set the step rate higher.
You can imagine if there is any electrical noise, it can disturb that pulse stream.
As a general rule, I use shielded cable between Acorn and the drives to carry the step and direction signals.

I only suggested you test your machine for repeatability.
Likely not your issue is mechanical connection between the motor and the ballscrew or the ballnut mounts.
Have you tested your machine for backlash? I like (and use) Marc Leonard's (cncsnw) method for testing backlash. http://www.cncsnw.com/Lashhowto.htm

Don't take it personal. I am just sharing further thoughts and ideas. After all, its why we are here. We are making suggestions, might be right, might be wrong, but better than nothing at all.

You have come a long way with your projects. Be proud of that, continue to learn, keep an open mind.

Marty

I did test and adjust backlash and used your videos to do so. Not sure if it in was Marcs method but if that's what you use maybe it was I will take a look. I did set up an indicator and was it was repeatable. The overall backlash was adjusted to between .001-002 on both axes. "i think" as far as I can remember, its been a while.

I think the couplings are good but will check them.

I wired the drives with shielded cable.

Nothing personal taken, I'm so grateful you guys are here. : )

[BillB]

My 1st successful part, Not perfect but will get there. Comments and suggestions are welcome.

I would like to extend a personal thank you to all of you who helped me get this build done, I could not have done it without you guys!
: )

A very special thanks to
Marty @ martyscncgarage
&
Karl & John @ Sherline

suntravel
cnckeith
tblough
cncsnw
centroid467
Upnorth
Muzzer
Sword
ShawnM
Richards
Gary Campbell
Nigelo
VW_Chuck
Franko
John @ Automation Technologies
Dillan @ work

And for anyone else I may have missed, Thank You.

[cnckeith]

Nice!!
and thanks for the post and linking the video, and you are welcome. Please keep spreading the word about Acorn and its great CNC support community!

[suntravel]

Cool to see you making first parts.

After this point things will become more easy every day

Uwe

[BillB]

Nice!!
and thanks for the post and linking the video, and you are welcome. Please keep spreading the word about Acorn and its great CNC support community!

Yes you guys all rock!

[BillB]

Cool to see you making first parts.

After this point things will become more easy every day

Uwe

Yes now that the hard part is done for me, the fun starts and can now finish developing my product/s. On to Fusion CAM and work out the kinks in that workflow. But Ive got the basics down. I cant wait to make a threaded part, LOL! The first time I did tapping on my Tormach I almost pissed myself! LOL.

[BillB]

Hey all, IIIIIIIIIM Back to the mill now. Need help figuring out what the heck is going on with the spindle control on it. So long story short a few weeks back when trying to figure out how to dial in speed control on the both machines somehow the DC speed control (KBIC-240DS) got fried. I ordered a new one, installed it and the spindle will not spin up. SO now question is, IS this board the issue???? Or something else.

So this setup is the same as my Lathe same exact boards, a KBSI-240D signal isolator, and a ( BRAND NEW KBIC-240D) direct drop-in replacement for the bad one.

I tested voltage from inputs 5&6 from acorn to the KBSI-240 and 9&10 coming out of the KBSI-240D and in both cases I get a predictable voltage In and out for the MDI OR manual Spindel input Im entering into the control. IF I start with an M5 I get 0-.1V, AND I get 0-.1 voltage when the spindle is off as expected, IF I enter any speed RPM from 500-3000 I get the expected voltage.
S500= 1.7V
s1000= 3.3
s2000= 6.6V
s2800=9.2V (Max RPM my motor is capable of and set up for) Same as the lathe.

My AC supply voltage is 115 going into the KBSI-240DS

The trim pots are set at default on the KBIC-240 so they should be good, however, did adjust the min and max on the speed control but they have no effect on the voltage. cranked them both ways. The trim pots on the KBSI-240 max works as expected when adjusting it, I see voltage increase or decrease based on the turn direction of the screw.

How can I determine IF the spindle motor itself is ok? Just to double-check it. FYI, back when my friend from work and i were trying to figure out what was going on with the mill spindle we swapped out the controls and hooked up the lathe control to the spindle motor and it was working fine. SO unlikely the motor is bad, but I figure I should check it again anyways.

How can I check the voltage on the motor? It has NO accessible leads I can put probes on.

[martyscncgarage]

While your Acorn spindle voltages out to KBSI240D and your output voltages FROM KBSI240D are similar,
My next step would be the original DC Spindle drive.

The spindle motor is a regular DC Brush motor. If you have strong battery, or a good 10A power supply, you could apply DC voltage to the motor leads (disconnected from the original DC drive of course) and see if your motor spins

You can run a resistance test from the spindle motor frame to each of the motor leads to see if you have any leakage, you shouldn't

[BillB]

To test motor I’ve disconnected leads p2 & f- from the KBIC240, connected a 9volt 500ma AC adapter to the wires going into the KBSI-240, plug in the ac adapter and get nothing, no spindle.

To make sure PSU is working test a small toy motor to see if it spins up and it dose, and test with volt meter and I get voltage 13.8 not sure why so much but I know its workimg.

I also attached leads directly to the black and white wires going into the motor and nothing. This was done with the control off.

I also have my volt meter on leads 9&10 on the KBSI-240 while Inputting a spindle command from control. I do see expected voltage range.

To test resistance “IF I did this right” I put meter on setting probes on the black and white wires going into the motor, I get nothing. I also tested on 20K same result nothing. From the videos I watch on testing resistance I see we’re looking for a low number but in my case I get no response from the meter at all?? I preformed same test on my lathe with same results. Am I doing the correctly?

[tblough]

1/2 amp probably is not enough to move the motor. Was the meter turned on when you tried to measure the resistance? Have you checked the battery in the meter?