Fenner Drive wiring for mach3

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LucDav
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Joined: Wed 27 Sep , 2017 20:46 pm

Fenner Drive wiring for mach3

Post by LucDav » Fri 15 Jan , 2021 19:27 pm

I am converting the starmill to mach3 with the intention of selling it as i have acquired a triac. I am having a little trouble getting the fenner drive to work without the denford boards. I bought the mill with a lot of electronics missing but have the fenner. I have a 0-10V input this goes through an opto isolator i seem to be able to get the drive to spin the motor over but without any control or with barely any speed. I have the manual for the drive off here but it seems very light on troubleshooting.

Any help would be appreciated.

DavidB
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Re: Fenner Drive wiring for mach3

Post by DavidB » Fri 15 Jan , 2021 20:48 pm

From what you describe you're using a 0-10V signal to drive an optoisolator which isn't going to work. IIRC Mach3 and typical BOBs use pin 14 to provide a PWM signal through an optoisolator to circuitry that converts the PWM to a 0-10V signal which is what you need so it's isolated from ground as IIRC the tacho is referenced to the motor supply voltage. Maybe something like this https://www.ebay.co.uk/itm/PWM-To-Volta ... 3414797990 if your BOB or circuitry doesn't do it.

LucDav
Posts: 25
Joined: Wed 27 Sep , 2017 20:46 pm

Re: Fenner Drive wiring for mach3

Post by LucDav » Fri 15 Jan , 2021 23:56 pm

I belive the BOB was generating an isolated 0-10V however when hooked up it seemed to create a floating live which gave me a belt. What I meant to say is I used an optocoupler isolator to get around this. That worked. I'm very much at the stage of researching and muddling my way through this build so I very much appreciate the help. It seems regardless of the signal I give to the drive I can't vary the speed. I wonder if it can be done with a voltage deviser just to ensure the drive itself works as it should. I have ordered one of the boards you suggested as that seems to make a lot of sense and I know I have the 5v PWM pin I can use for a signal.

Any more ideas or tests I can do would be much appreciated.

DavidB
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Re: Fenner Drive wiring for mach3

Post by DavidB » Sat 16 Jan , 2021 1:07 am

The question about whether a pot could be used to test the 0-10V input and speed control functionality came up recently but IIRC for a Sprint board, the technical data indicated it could be done that way and the board provided the 0V and 10V references to do so. Do you have the technical data for the Fenner motor controller or what model it is.

The link to the PWM to 0-10V module was just one of many on ebay and although it didn't say it was optoisolated that I could see in the technical details there is an optocoupler on the board, the PC817, just inboard of the GND and PWM connections indicated on the underside of the board. Like many of these sort of ebay listings the technical data is often lacking or badly translated and I've had to go elsewhere to find the same item with better details but a quick look seemed to indicate enough info was there about the jumpering for the various settings. With Mach3 I think you can set-up and test the 0-10V functionality before actually connecting it to the hardware.

LucDav
Posts: 25
Joined: Wed 27 Sep , 2017 20:46 pm

Re: Fenner Drive wiring for mach3

Post by LucDav » Mon 18 Jan , 2021 10:22 am

I received the new board yesterday but the machine had progressed to the naughty corner for the weekend. I will be back looking at it tonight so hopefully will make some headway. The drive I have is a Fenner 522A3700. Any understanding of the connections would be of use. Im very much out of my depth with this particular controller.

I have one other problem with the Z-axis disabling its stepper drive after a few minutes to sort out. Other than that everything seems pretty dandy. I also want to make some changes as the machine currently doesn't fail safe.

DavidB
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Posts: 174
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Re: Fenner Drive wiring for mach3

Post by DavidB » Mon 18 Jan , 2021 13:20 pm

There's some details of a Fenner card here http://www.denfordata.com/bb/viewtopic. ... 645&p=5510 showing where to connect a 5k pot, do the details match your card. Searching for 522A3700 turned up questions but no answers.

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