feedrate override using rotary momentary switch?

I'm in the process of building a new control box with higher voltage drivers, new BOB etc.

The front panel will have various new controls such as power on/off, e-stop, ancillaries (lights, pump,etc.), VFD on/off and speed, all of which will be hardware controlled through simple circuits.

I'll also add buttons to control cycle start/feedhold/stop, and feedrate override up/down buttons. I'm hoping to do this bit through something like pokeys. Now to my question.

To control the feedrate override up/down I will have 2 seperate momentary push button switches to increment the feedrate in small steps, emulating a keyboard input. Is it possible instead to employ some sort of rotary momentary switch? The idea being that as I turn an infinite dial it clicks past detents which send a pulse to the pokeys system to emulate a key push. I think there would be two sets of detents so it would know whether the dial is being turned clockwise or anti-clockwise.

I've been looking at this:
http://www.ebay.co.uk/itm/5-Pin-Digi...ht_1230wt_1190

Would this do it? If so, how would you expect the 5 pins to be wired up?

Thanks

Doesn't need to be that hard.? The Pokey's has 7 Analog inputs so just use 0-10V and a POT. Can do the same for Spindle override as well.!

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Originally Posted by JAZZCNC

Doesn't need to be that hard.? The Pokey's has 7 Analog inputs so just use 0-10V and a POT. Can do the same for Spindle override as well.!

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I'd not studied the pokeys system in detail so thank you for that. I assumed it was just a simple keyboard emulator, but obviously not.

As it happens I over-ordered on pots and have a 10k spare one which would be ideal. I have 12v in the control box so I guess I could put a resistor in series with the pot to get 10v across it?

I'd thought about spindle override software control but in the end I decided to run direct manual control using a pot to the VFD. I tend to cut the same things so don't change speed much.

Thanks again

I am also interested how a pot will do the feed override. The CSMIO IP has this function in their plugin but as I understand from their manual, you have to decide whether to use the mach3 feedrate or the manual pot. I cannot imagine a way to do the override (+/- of the mach3 feed value) with a pot.

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Originally Posted by paulus.v

I am also interested how a pot will do the feed override. The CSMIO IP has this function in their plugin but as I understand from their manual, you have to decide whether to use the mach3 feedrate or the manual pot. I cannot imagine a way to do the override (+/- of the mach3 feed value) with a pot.

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Yes that's correct and it's easy. The analog connector provides 10V for the pot and you feed it back into the analog input. The control then overrides feedrate or Spindle speed based on the returning voltage.

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Originally Posted by JAZZCNC

Yes that's correct and it's easy. The analog connector provides 10V for the pot and you feed it back into the analog input. The control then overrides feedrate or Spindle speed based on the returning voltage.

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I missed the important part, that the pot controls the override not the actual feedrate value, hence the confusion.

routercnc, sorry for hijacking your thread. I'm curious to see what controls you think are important to be put in the front panel.

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Originally Posted by paulus.v

routercnc, sorry for hijacking your thread. I'm curious to see what controls you think are important to be put in the front panel.

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No problem Paulus - it was all the same theme.

Here is an artists impression of my latest version. Switches are all on order but due to Chinese new year will be mid to end March before they arrive.

Attachment 14724

Still a bit of tidying up to do but you get the idea. The up/down triangles for the feedrate override would now be a simple pot, same as the spindle speed pot.

Thanks

Can anyone help with the following question. You'll notice on my new panel design the digital readout below the spindle on/off switch and the idea of this is to show the spindle rpm.

This is a voltmeter and I intend to connect it to the V0 and ACM pins on the VFD. See bottom right hand corner.
Attachment 14737

I haven't connected it yet but suspect that at maximum 24,000rpm it will read 10V and 0rpm will be 0V. I've looked into this but not found anything yet to confirm. Probably because the rpm is shown on the VFD and most people look at that but mine will be covered in the new enclosure.

I'd like to make it show 24V = 24,000rpm if possible. Can this be done? I looked at DC/DC convertors but I think they give a fixed output rather than a tracking one. Any other way?

If not then I think I can go the other way and make it read 2.4V = 24,000 rpm by using a pair of resistors in series, sized to drop the 10V to 2.4V across the top resistor, and reading across the lower one to ground. Should this work?

I'm not looked for complete accuracy but nearest 1000rpm would be fine. Any ideas?

If its one of the Chinese VFD's the front panel just clips out and you can fit it on the outside of the box.