Configuring a custom VFD and spindle

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Sid,

a VFD and its spindle cable usually is a source of heavy EMI. That’s why a shielded spindle cable like shown here is strongly recommended, otherwise you have to expect disturbances. The same applies to the VFD itself, which is usually enclosed in a earthed control cabinet like shown here.

Usually for the ModBus communication cable, a twisted-pair cable is enough, however you can still have hum if you have not grounded everything properly.

Also I would look for poor connections, e.g. this issue already mentioned above, however there are even issues known like this:

@Hansvk

@Hansvk

I had a good signal on the 485+ pin, none on the 485- pin (checked with oscilloscope).Turns out the DB25 connector had some poor solder joints on the board, I applied some new flux and solder after which the signal was fine. (I think this is why some people are saying you need to screw the connector down tightly… this may push loose pins back against the pcb).

@Aiph5u

I assume you mean the board of the breakout board adapter (not the Onefinity Controller Mainboard).

I actually was talking about the main Onefinity (Buildbotics) control PCB, not the breakout board adapter! I should have been more clear on that. Also, I can imagine not everyone wants to try this repair for that reason […]