ST-V3 Breakout board - Want to control spindle - Need Help

[allanhbmartin]

I have UCCNC Software, UC400ETH, ST-V3, Huanyang 220v 4kw VFD and I want to control my spindle through the software. I'm still learning how the boards communicate with the VFD. My ST-V3 only has a relay, but no PWM or 10v output. It's currently my understanding that the computer gives the PWM signal to the board which then gives the 0-10v to the VFD which interprets the info to spindle speed via frequency. BUUUUUT, what I'm hug up on is how the signal flow goes from one board to the other and the connections for each one. Also, my breakout board (ST-V3) only has a relay. So, I was considering getting a C41S (Variable Speed Control Board) from CNC4PC and using the relay on the BOB to trigger the C41S or should I just get a new BOB with integrated DAC? (I believe I used that acronym correctly) Any help on this would be appreciated. I like the setup I have, just want to control the spindle. So cheapest is preferred. Easiest will also be considered!

[ger21]

Depending on which Huanyang VFD you have (HY or GT series?), the cheapest method is to use RS-485 and Dan's HY plugin, or modbus with a GT series. Costs about $10 for an RS-485 adapter.

[allanhbmartin]

The machine I have was purchased from a builder a couple of towns over. I don't have any paperwork on the vfd but judging by the configuration I believe it's an HY model. If I didn't want to go the cheap route what would be a better design route? I've done things cheap before and they don't usually work, so I should learn my lesson. I have my sights set on the C41S. Would this be doable?

[Soler]

While the RS-485 is a cheep route is not a bad one, you can accurately command the VFD to a set frequency instead of it reading an analogue value. The C41S will also work. I just googled the ST-V3 and it should have 0-10V out.

[ger21]

I just googled the ST-V3 and it should have 0-10V out.

Is says it does NOT here:
https://www.sainsmart.com/products/cnc- ... tor-driver

While the RS-485 is the cheapest, I've found it to work the best with the HY VFD's. I (and many others) have had issues with RPM oscillation when controlling a HY VFD with an analog signal. Mine would vary by 2000-3000 rpm, and constantly oscillate up and down. With RS-485, it's rock solid.

[Soler]

Is says it does NOT here:
https://www.sainsmart.com/products/cnc- ... tor-driver

yes your correct, the one I looked at was not the same model.

[allanhbmartin]

OK. So I purchased a C41S R1.1 Spindle Control board from CNC4PC and I was told to bypass the relay on the ST-V3 BOB. He was saying I can go directly from the UC400ETH to the C41S to the VFD. Now curiosity, can i set a dedicated pin in UCCNC to send the PWM via the Ethernet to the C41S?

[ger21]

No, the C41S does not connect via ethernet. You need to use two pins from your existing breakout board to the terminals on the C41S.

[allanhbmartin]

No, the C41S does not connect via ethernet. You need to use two pins from your existing breakout board to the terminals on the C41S.

OK. The technician from CNC4PC said that I would have to use a pin from the UC400ETH to send the to the C41S. Thus, bypassing the breakout board. He said I could use the breakout board relay for something else.

Here's my question, on the UC400ETH it has two 25 pin connections. How to you set a specific pin to receive the PWM?

[ger21]

port 1 or port 2.