PM-728VT Spindle Control #3 with Centroid Acorn

[@pauldarnbrough4179]

Stop putting yourself down, along with Marty your videos are of real help in an area where most people haven't a clue what they are doing (me).

[@3dmakerzone75]

Electronics are so sensitive. Sorry you had a set back. I was able to control the spindle on my PM30-MV based on your previous video on the KBSI-240D and the schematic you posted. Thanks for all you do to support the home / hobby machining community.

[@FKreider]

Perfect timing on this video Franco! I am just getting ready to wire up my KBSI-240D with my Acorn cnc conversion!

[@martyscncgarage5275]

Sorry to hear about toasting the motor control board....i don't know everything! Smoking boards is a right of passage I suppose, do it a couple times and you get much better about being careful. You were spot on in your description by the way.

[@makosharkcnc7730]

Good info, Glad to see you didn't get hurt!

[@ADBBuild]

You might look at the board before ordering a new one. It might have just fried a capacitor or transistor that is easily replaced. Burnt electronics are usually pretty easy to spot. If there is a computer chip that fried, then you are hosed.

[@CryoftheProphet]

I purchased some kind of daughter board directly from pm when I bought my 728vt, its basically a board that allows you to send a 1-10v signal to the spindles controller and use your controller to engage the spindle. It was like 20 bucks I think.

[@joecnc3341]

Great Video, Vince. Would it be possible for you to post those schematics on a google drive?

[@seanmathews7908]

Please send photos of the PCB both sides so we can build a schematic for repairs.

[@kenjames6172]

HOW DID YOU CONTROLE THE SPENDLE SPEED ON THE SHERLINE LATH. IT IS THE SAME AS MY SHERLINE MILLL

[@mrmodfi]

Hi Franco, I'm right in the middle of wiring my PM-30 spindle motor control with the KBSI-240D. The motor controler board I have is not configured the same as your wiring diagram. It's actually coated in black epoxy so I can't even see pin outs. Can you help please?

[@donaldhollingsworth3875]

Where did you wire the ground wire for this board? I assume that were you have your leads connected are for the wires going to the spindle with no ground wire.

[@FrancoCNC]

Look on the instructions for the board - no ground. I guess this is what they call "floating the ground".

[@EZ_shop]

Great progress. Sorry to hear about the fried board. Stuff happens. Cheers.

[@Chris-hy6jy]

Are you going to use a 3rd relay to provide mains power to the motor control board? My PM25 removes power to the board when the FWD/REV switch is in the center position. I use a 3rd relay commanded by the Spindle Brake Release signal on the Acorn to power the motor controller. Just something to consider.

[@michaelbrocato7535]

Is this the same as the 0 -10 board precision matthews offers for the pm728vt?? On their website for 49 bucks?

[@kh8553]

Nice Presentation, you mentioned a nonlinear relationship between the KBSI-240D and your lathe. My southbend 8k lathe with a bldc motor has the same problem using the kbci-240D. How did you compensate to achieve proper rpm ? Again thanks all the good info. My PM728 is following yours to cnc. I will comment on acorn forums. kilo7

[@livium2002]

Hey, one who works, will make mistakes. One who doesn't work will not make mistakes. It happens to all of us. Instead of using the KBSI board to reduce the voltage, can you use only the 0 to 5 v spectrum from the centroid board ? Basically limiting the centroid board from the software. Or are you using the KBSI more for protection ?

[@frijoli9579]

Oh man.... Sorry to hear about the board. I hate crap like that. I did something very similar to my Acorn relay board. Buy a KB DC motor control on ebay.

[@cornpop7805]

Here's the link to the manual for the KBSI-240D acim.nidec.com/drives/kbelectronics/-/media/kbelectronics/documents/dc-drives/manuals/kbsi_manual.ashx?la=en