Centroid Community CNC Support Forum

If you use 5V from DB25 Dir+ Pin24 and Puls+ Pin25 on the Servo

This works perfectly with Lichuan and JMC Servos, but from those super cheap ones, I have even found some with defective bearings new or running as smoothly as a bag of seashells. My minimum requirement for getting Chinese CNC stuff is a complete ok manual in English and contact to factory support.

Uwe

ShawnM wrote: ↑Fri Nov 15, 2024 10:39 am

Chaz wrote: ↑Fri Nov 15, 2024 6:00 am I'm struggling to get some t3D servos running. Full manual here - https://www.hlt-cnc.com/uploads/38006/f ... ersion.pdf

Page 21 shows the connection options. Since Acorn doesnt do Differerential drive (which is a pity), am I in the same boat and need to use the DB25 instead of the board connectors? I can use 5V or 24V. I've tried 5V and I can get them to spin but they arent smooth and dont react as needed. Same issue?

Where are you getting your 5v from? Did you see the notes on page 15 and 16 in reference to the 5V and 24V supply?

If they aren't running smoothly then it sounds like a programming issue. I dont know what the default control method is but maybe it's not PUL/DIR so some additional programming of the drives might be needed. It's difficult to determine a few things because the manuals is half English and half Chinese.

Ive picked up 5V from the Acorn PSU. I did take note and I'm using their recommended input for 5V but need to get a resistor in the right size which will sort weekend.

Is using the DB25 different from the direct board connections?

suntravel wrote: ↑Fri Nov 15, 2024 11:06 am If you use 5V from DB25 Dir+ Pin24 and Puls+ Pin25 on the Servo

This works perfectly with Lichuan and JMC Servos, but from those super cheap ones, I have even found some with defective bearings new or running as smoothly as a bag of seashells. My minimum requirement for getting Chinese CNC stuff is a complete ok manual in English and contact to factory support.

Uwe

Agreed. This stuff was as cheap as chips. The full manual (which I only just found) is decent and I already have these working really well on my 5 Axis using UCCNC and a UB1/Eth board. In that case, they allow full differential, so all 4 wires in, no messing with voltages / resistors and they work well.

For differential signals you need Acorn 6 with the ad on board, but it is cheaper to get decent servos...

Low cost JMC an Lichuan is ok with 400khz TTL or open collector.

Uwe

suntravel wrote: ↑Fri Nov 15, 2024 2:01 pm For differential signals you need Acorn 6 with the ad on board, but it is cheaper to get decent servos...

Low cost JMC an Lichuan is ok with 400khz TTL or open collector.

Uwe

Yep. It's a pity its not included in the standard Acorn board when others are doing it at similar price points.

Chaz wrote: ↑Fri Nov 15, 2024 2:11 pm

suntravel wrote: ↑Fri Nov 15, 2024 2:01 pm For differential signals you need Acorn 6 with the ad on board, but it is cheaper to get decent servos...

Low cost JMC an Lichuan is ok with 400khz TTL or open collector.

Uwe

Yep. It's a pity its not included in the standard Acorn board when others are doing it at similar price points.

inexpensive way to add diff to Acorn.



https://centroidcncforum.com/viewtopic. ... 408#p19408


https://cnc4pc.com/c72-differential-lin ... 4bXHGGLWXk

That's interesting and sorry for hijacking the thread. Ive got a Denford Mill running on Centroid with Panasonics using the standard 3 wire method. Ironically the only issue I have is on the 0-10V input on the Panasonic servo we are using as a spindle which is some noise we cant seem to kill.

Got mine to work, 5V via the PSU and not DB25. Ironically it was accidental, fitted two correct resistors, motor still moved with no signal. I moved the motor out the way of something and it stopped. When the motor is touching the machine, it runs on its own so some earthing issue somewhere. At least it runs now on a 3D printed bracket as a temp measure. Ill work out later why it has this noise.

cnckeith wrote: ↑Fri Nov 15, 2024 3:31 pm

Chaz wrote: ↑Fri Nov 15, 2024 2:11 pm

suntravel wrote: ↑Fri Nov 15, 2024 2:01 pm For differential signals you need Acorn 6 with the ad on board, but it is cheaper to get decent servos...

Low cost JMC an Lichuan is ok with 400khz TTL or open collector.

Uwe

Yep. It's a pity its not included in the standard Acorn board when others are doing it at similar price points.

inexpensive way to add diff to Acorn.

cool, I have these kinds of converters too, but never thought about using them for servos.

Very good hint since most servos accept high steprates only diff.

Uwe

suntravel wrote: ↑Sun Nov 03, 2024 12:11 pm

Ken Rychlik wrote: ↑Sun Nov 03, 2024 11:46 am Looks like you didn't use the db25 port and 5v. Good luck with that, but lots of people have tried, failed, and then followed the db25 suggestion.

My mill is running perfectly with CL57T V4 24V on the Headers, but CL86T V3 is better on 5V DB 25.

Uwe

Just a quick note to Suntravel. I also got my 24V wiring to the "headers" and it DOES work. I'm getting Overall Turn Ratios dialed in as soon as I get my hands on a dial indicator. Just using a tape measure, I'm within 1-2 mm of a commanded moves now. Lots of cleaning up of wires, enclosure, mechanicals, switches, and so on, and so on, and so on...and other stuff but overall its just a project for the garage and not a production machine. Don't let perfect get in the way of good enough!!

Its also funny how people jump into the thread just to say what you did incorrectly and what you are doing won't work, etc and then jump out into the abyss. I still love the forum and use it al the time BUT you have to weed out the knuckleheads that just post and ghost.