forum.cncdrive.com

Some advice from the collective please

I have at present a uc100 but about to start building a new system as the axis are being a bit glitchy which may be due to a failing bob which to replace would be about £200

new system plan

I have a UC300 ETH am i right in thinking this will drive my inverter with the analog 0-10 out put or have i got that wrong
I dont need to got through a bob if my axis drives have built in optos
and i can just interface I/O though opto couplers normal speed but if i want spindle or servo feed back I would need to use high speed optos (spindle only capable of 3500 converted turret mill Kondia FV1)
if i need high speed what chip would be recommended I would like to try ridged tapping in future

chinese opto 4 inputs/outputs are about £1 each opto isolated relays about £2.5 the idea is to use easy swappable boards at low cost

although my current board does coolant spindle control direction etc when it goes wrong its a pain. it has a custom pic which comes from the states and sometimes its not easy to trace the glitches

Thanks Andrew

Yes, the UC300ETH has 0-10V analog output in the analog port of it's -5LPT motherboard.
You can use that analog voltage to control your spindle motor with a VFD.

Interfacing an encoder for rigid tapping as you pointed out you need to consider the cut frequency of the optocoupler and any low pass filters on the BOB.
You need an optocoupler or BOB input which can throughput the frequency your encoder will produce when you do the rigid tapping.
So, how fast frequency throughput will you need depends on your encoder resolution and the spindle RPM.

And if the encoder outputs TTL signals and if the encoder wires are not going through in a noisy environment, I mean together with high voltage cables then you may even connect the encoder directly to the UC300ETH-5LPT pins.

andrewbishop66 wrote:...failing bob which to replace would be about £200

Is it made of gold? Mine costs $5...

Or buy an MB2. Rock solid, full featured board. Far better than the CNC4PC stuff, which is what you probably have?

The board is a campbell design combo board $245 +shipping + import duty it been a good board so not really any complaints but like to keep it a bit more modular this time
I have found a 100 p/r encoder

after i posted i found a post from spumco explaining a proximity pick up on the spindle and a encoder on the motor which balazs help him do which for my set up is possible as i already have rpm pick up on the spindle so I need to contact balazs for his solution

in the mean time i may use a cheep chinese board for testing
would love a mb2 but at nearly $400 that will be a no

Thanks for the pointers

would love a mb2 but at nearly $400 that will be a no

I think you looked at the price with a Smoothstepper.
For just the MB2, I paid $158 US delivered. http://www.cncroom.com/break-out-board/smooth-stepper

Then made a plate to mount my UC300ETH/5LPT on to it.

Thanks Gerry

thats not quite so bad that may be the route i take in the end looks quite impressive



Andrew

If I were starting over with my build, Gerry's plan would be exactly what I'd do: 300ETH with MB2 BOB. Looks fantastic.

Any whatever inductive sensor you want that has a voltage compatible with your BOB will work as a spindle index. I'm just using a set-screw to trigger mine.

And the new pulley fix Balazs cooked up means you don't have to trick the software to use pulleys. I'm running a 100ppr encoder - gives me a 400-count resolution. Plenty for tapping and doesn't overload the BOB with too high a frequency pulse at my spindle max RPM.