PM-833TV Spindle Speed Control

[martyscncgarage]

Yes, you would replace your manual forward/reverse switch with an output relay programmed SpinFwd and SpinRev
Look for schematic S15008
https://www.centroidcnc.com/centroid_di ... browse.php?

[Frankenstein]

Below is quick schematic I think might work. If I set the pot of the 240d board to max voltage of 12v for max RPM and calculate the min volts as the machine does not go to zero but 50 RPM min. Or, simply attach a meter to read the volatge at 50 RPM.
Looking for the least expensive way to have this function. When the budget allows I will upgrade the steppers to servos and upgarde the VSD
Any help please!!!! I am a nuts and bolts guy not an electrical wizard. Or just plain nuts as some believe!

[martyscncgarage]

Below is quick schematic I think might work. If I set the pot of the 240d board to max voltage of 12v for max RPM and calculate the min volts as the machine does not go to zero but 50 RPM min. Or, simply attach a meter to read the volatge at 50 RPM.
Looking for the least expensive way to have this function. When the budget allows I will upgrade the steppers to servos and upgarde the VSD
Any help please!!!! I am a nuts and bolts guy not an electrical wizard. Or just plain nuts as some believe!

I had forgotten about the KB Electronics KBSI240D. My apologies! Did you mention it previously?
I say yes give it a go. Um, your picture was sideways but I think you have the right idea.

[Frankenstein]

Below is quick schematic I think might work. If I set the pot of the 240d board to max voltage of 12v for max RPM and calculate the min volts as the machine does not go to zero but 50 RPM min. Or, simply attach a meter to read the volatge at 50 RPM.
Looking for the least expensive way to have this function. When the budget allows I will upgrade the steppers to servos and upgarde the VSD
Any help please!!!! I am a nuts and bolts guy not an electrical wizard. Or just plain nuts as some believe!

I had forgotten about the KB Electronics KBSI240D. My apologies! Did you mention it previously?
I say yes give it a go. Um, your picture was sideways but I think you have the right idea.

Thanks Marty,
So the 12 volt wire or supply from the old pot is no longer needed? I assume this as the isolation board will now supply power. Does anyting look blatantly wrong in my wiring? I don't want to fry the OEM board or motor.

[martyscncgarage]

I'm out retrofitting a router.
I'll look at the KBSI240 manual upon my return

You can always call KB Electronics support

[Frankenstein]

I'm out retrofitting a router.
I'll look at the KBSI240 manual upon my return

You can always call KB Electronics support

Thanks Marty!
No rush. I am still waiting for the ball screws to arrive.
Your help is most greatly appreciated.

[martyscncgarage]

For 115VAC(be sure to use the 1A fuse shown in the KBSI240 Instruction Manual):
Jumper Terminals 1&2 = Line
Jumper Terminals 3&4 = Neutral

Terminal 5 = Acorn Analog COM
Terminal 6 = Acorn Analog 0-10VDC
Terminal 9 = Inverter COM
Terminal 10 = Inverter Analog Input
Suggest you use separate relays for SPINFwd and SPINRev This ensures there is NO movement until one or the other relay is closed.

(IGNORE VFD RESET)

If you are using an ESTOP Relay (and you should) run the Inverter Common through one set of NO contacts of the relay. That way if you hit the Estop, you open up the Inverter Common from the Inverter and TO the SpinFwd and SpinRev Acorn relay outputs, then there is no way the inverter can spin the spindle or will shut it down in an Estop condition.

Make sure you connect NOTHING to Terminal 3 (12VDC) on the inverter.
You can test the inverter input by using a 1.5VDC battery across terminals 1&2 to supply a signal to the inverter with the manual switch in FWD or REV. Spindle motor should turn slowly. You can use a 9VDC battery similarly, motor should spin much faster. IF you have a bench power supply and know how to use it, you can connect it to 1&2 and test UP to 12VDC

My concern with this setup is that it looks like the Inverter wants to see 12VDC for full spindle speed.

Hope this helps, as always double check. This is only my suggestion, up to you to validate.

Marty

[Frankenstein]

For 115VAC(be sure to use the 1A fuse shown in the KBSI240 Instruction Manual):
Jumper Terminals 1&2 = Line
Jumper Terminals 3&4 = Neutral

Terminal 5 = Acorn Analog COM
Terminal 6 = Acorn Analog 0-10VDC
Terminal 9 = Inverter COM
Terminal 10 = Inverter Analog Input
Suggest you use separate relays for SPINFwd and SPINRev This ensures there is NO movement until one or the other relay is closed.
SpinFwd-SpinRev.JPG
(IGNORE VFD RESET)

If you are using an ESTOP Relay (and you should) run the Inverter Common through one set of NO contacts of the relay. That way if you hit the Estop, you open up the Inverter Common from the Inverter and TO the SpinFwd and SpinRev Acorn relay outputs, then there is no way the inverter can spin the spindle or will shut it down in an Estop condition.

Make sure you connect NOTHING to Terminal 3 (12VDC) on the inverter.
You can test the inverter input by using a 1.5VDC battery across terminals 1&2 to supply a signal to the inverter with the manual switch in FWD or REV. Spindle motor should turn slowly. You can use a 9VDC battery similarly, motor should spin much faster. IF you have a bench power supply and know how to use it, you can connect it to 1&2 and test UP to 12VDC

My concern with this setup is that it looks like the Inverter wants to see 12VDC for full spindle speed.

Hope this helps, as always double check. This is only my suggestion, up to you to validate.

Marty

Marty your the best!
Your help is greatly appreciated. I will order the board and install it. After the install I will provide and update. Others may want this as well. The PM-833TV seems to be popular.

[martyscncgarage]

Take a look at Ebay for KBSI240. Of course, you don't know what you are getting.

[Frankenstein]

Update.
I was able to check voltages at the pot/board. The machine has a min RPM of 50. At that speed the voltage is .3. With every 100 RPM increase the voltage changes on average between .324-.329. At max RPM 3200 the voltage is 10.8. I think if I set the max v to 10.0 (no load) and the min v to .3 on the output of the KBSI 240D board the machine will run fine. I will confirm this once I receive and install it. The loss of 100 RPM at the high range should not effect what I plan on machining.

The pot is a linear pot not a logarithmic. However, the voltage to RPM is not perfectly linear (certainly not logarithmic). I some that up to componet quality, display accuracy, meter, etc.