[RDTymko]

I want to add spindle control from the board to a VFD which will allow me to control spindle speed from Mach3?

I can not find a manual for this board but I found a manual for rev 1.8 but no instructions to add spindle control from Mach3.

The board has 6 pins allocated to spindle but can not figure out how it all connects up.

Any help is appreciated.

Richard

[planebuilder]

Wow, no response. I have run the same BOB for years, no problems, but now I want to do the same thing, control a VFD & spindle. From pics I found online, a plug goes on the "6 pins" and connects to another smaller board to control the VFD. Sound Logic seems to be gone, so I'm not sure what to do. Any suggestions?

[awerby]

Sound Logic made boards with and without spindle control modules. If yours is the latter, it doesn't seem feasible to make it control a VFD. You're better off replacing it with a more modern breakout board that has the features you need.

[planebuilder]

I hear you, but this machine has been bullet proof and runs regularly, for over 16 years. I just don't want to spend the time to redo it all, and maybe screw it up. I can turn the spindle on/off with a relay and control speed with a POT.

[joeavaerage]

Hi,
to control the spindle you'll need two spare outputs on your breakout board, one to control an On/Off relay and the other for PWM. If you wish to forgo
speed control then you can also do away with the second output.

Do you have two spare outputs?

Assuming you do, just assign one output to SpinOn/SpinOff and use a relay to control the VFD. Note this does not mean turn the power on and off but rather the control contacts.
You'll have to program the VFD to accept external On/Off control.

The second output you will assign to Machs PWM output. Program the PWM base frequency to say 100Hz. Now when you program a speed in Mach to PWM should reflect that.
You'll need a small external circuit. I cheated and used a MCP1416 MOSFET driver as a quasi rail-to-rail amplifier. If you want a circuit diagram let me know.

Craig

[planebuilder]

Craig, If it's easy for you I would like to see the circuit diagram.

[joeavaerage]

Hi,
I have excerpted a bit of my own design breakout board. It shows the PWM output circuit, and while I haven't highlighted or annotated it the SpinOn/SpinOff relay also.

The PWM signal comes in at the bottom left. In my circuit it goes through a buffer amp, not that you'll probably need that. Then, and this is where it gets a little tricky, it
goes into a teen-tiny little IC, a MCP1416T. It is a MOSFET driver but in this case I'm using it as an amplifier. It switches from the positive supply to the negative common ground.
Note also that the supply in this case comes from the VFD. So the VFD produces a low current 10VDC supply, it gets modulated by the MCP1416T and sent back to the VFD
on the PWM output line. Note that I have one resistor and a capacitor as a low pass filter, it turns the PWM into an analog voltage.

People may ask why I use the MCP1416T in this way...and the reason is that if you use say an op-amp as would be common: they ARE NOT genuine rail-rail output...and therefore
your PWM output would never quite get to 10VDC nor would it get right down to 0VDC. The MCP1416T does exactly this. It is, what's more, very linear; I measured a duty cycle to analog output
linearity of better than 95%.

There is another capacitor as a supply bypass, which is almost mandatory and an input resistor again almost mandatory. They provide a measure of dV/dt stability for the MCP1416T, which
being very high gain are inclined to oscillate unless you pay attention to supply bypassing and have some definite impedance at the input.

The circuit requires two resistors, two capacitors and one MCP1416T, five components in all. I use surface mount components in all my designs and these parts amount to $3.00USD in total.
How are you with a soldering iron?

Craig

[planebuilder]

Craig, Thank you for the info. I can solder, but my understanding of electronics is no where near yours, I would have to study your drawing and learn, lots!
I want to get this running and I installed a POT to control speed, it's working and I can live with manual speed adjustment for now.
The problem I have now ( and this will show my electronic ignorance) is to turn it on and off with mach. I have an SSR, controlled by mach, that turns the old router on and off.
So I thought I could use the same type of SSR, instead of passing voltage through it to run the router, I can use it as a switch to connect/disconnect DCM+For to turn the spindle on/off.
Connecting DCM+For manually works. When I connect the wires to the SSR, weird things happen. When I energize the ssr the spindle doesn't start, if I disconnect a wire from the ssr ( still energized) then reconnect, the spindle starts. If I shut off the ssr the spindle continues to run until I manually remove the wire. If I put the wire back on the ssr, the spindle stays off.
Your probably shaking your head if you read this far.
I assume the ssr is the wrong one for this application. Pic below. Is there one I can buy that would work, energized by 12V from my BOB to connect DCM+For?

[joeavaerage]

Hi,
an SSR might be okay for a router but VFD's don't like it.

Almost ALL VFDs have an a pair of inputs (signal levels, ie lightweight) that when shorted together start the VFD running. If you have a relay then a pair of contacts can start and stop the VFD.
You will have to review the manual for the VFD and program it to accept Start/Stop commands from that pair of contacts. POT speed control is fine.

The vast majority of times I find that the speed is set to max and left there. Seldom do I ever run my spindle at part speeds.

Craig

[planebuilder]

I have the vfd programed and was using the ssr to "short" the 2 contacts. Are you saying I should use the ssr to energize an electromagnetic contactor and use that to short the 2 contacts on the vfd?

[joeavaerage]

Hi,
do not use the SSR to turn the power on and off to a VFD....they hate it and you'll eventually pop something.

The pair of control contacts are probably 24VDC and when shorted together carry a current of something like 20mA. That is not a suitable use for an SSR, for that you need
a signal relay.

Craig

[planebuilder]

I wasn't using the ssr to turn the vfd on/off, I tried to use it to short the pair of control contacts to turn the spindle on/off.
I'm not familiar with signal relays, when I searched all I came up with were relays for car turn signals.
Could you show me one I should order or a part #, ebay or amazon?

[joeavaerage]

Hi,
what voltage is your breakout board?. Ideally you'd choose a relay with a coil voltage so you can drive it direct from your breakout board.

Craig

[planebuilder]

My BOB outputs 12 volts.

[joeavaerage]

Hi,
then a simple automotive relay would be OK.

If you want to buy one something like this would be fine:

https://nz.element14.com/omron/g6a-2...-2a/dp/1608296

Craig

[planebuilder]

Thank you, I was reading the spec sheet, and it said not for continuous on? I don't know what time duration they consider continuous. I asked the seller here in Canada and he recommended this one,
Panasonic TX-12, but I still have the same question about continuous on, he said he would get back to me. Maybe I'm over thinking this.

Signal Relay, 12 VDC, DPDT, 2 A, TX Series, Through Hole, Non Latching

[joeavaerage]

Hi,
signal relays of this type often are energised for hours or even days at a time without demur.

I used this exact one in my breakout board for SpindleOn/SpindleOff. Note that its 24V, but a 12V version would be nearly identical.
Quite frankly I would not get to hung up on it.

https://nz.element14.com/multicomp/h...vdc/dp/9480226

One thing that is highly recommended is a catch diode. When a relay coil is de-energised it can produce a large voltage spike which could potentially damage you breakout board.
A 10cent diode across the relay coli will suppress it. Some relays have it already built-in. It is called either a Catch diode or sometimes a Freewheeling diode.

Craig

[planebuilder]

Thanks again, parts ordered.

[planebuilder]

Thank you for your patience Craig. I found the relay to order. When I look for Diodes I get a huge range of specs, and the salesman just asks me what diode I want.. Any suggestions what I should order?

[joeavaerage]

Hi,
just about any common diode will do.

1N4148 is a signal diode, cheap as chips and its 'like an arsehole'...everyones got one.
1N4004 or 1N4007 would also work perfectly well, cheap and readily available.

Craig