Denford Software & Machines

Hi I have just bought a Triac VMC and a Mirac PC from a local school. Although they have come with almost no tooling, no software and no instruction manuals.

I have found some instructions but I cant find what software I am supposed to use for each machine. I have found alot of files on the denford support site but I have no idea what goes with the machines.

The Triac VMC has a floppy drive and is asking for a system disc.

Both machines are September 1995.

Any help would be great

Phil

You must format a Dos boot disk and copy the fanumd.zip contents onto said disk for the VMC to run. For the Mirac PC you will need Mirac.zip extracting onto your standalone PC. This Zip will be in our downloads section shortly.

The Mirac is working great however I have a problem on the Triac machine

The X axis moves fine, the Z axis moves fine but the Y axis just stutters around making a buzzing noise. I have swapped the stepper drive cards around and all of them work I have also swapped the leads to check that the Y axis stepper works ok. I have buzzed each pin on the backplane back to the power supplies and the controller PCB each seems fine.
Lastly I have poked about on the controller board to look for dry joints etc to no avail.
Do you have a circuit diagram for this PCB?
OPTIMISED CONTROL LTD D281 issue 4 ( MINT 3.28 v1.6c/S-JD3 )

Could there be a software setting causing the stepper rate to be so fast that the motor wont run?

Any help would be great

Phil

This sounds like:
The axis could be tight (check the strips and/or remove the motor and test again)
or
The Stepper Motor has burnt out
or
The wiring to the stepper motor is damaged/broken

Steppers tend to buzz (and don't spin):
1. If the load is too great
2. If the step pulse frequency is too high, or is accelerated too quickly
3. If a coil inside the motor is damaged
4. The wires to the motor are damaged and shorting/earthing out
5. If the output driver chip has broken down
6. If there is no inertia on the motor shaft

Hope this helps

The motor spins fine when I connect it to one of the other axis outputs also the stepper driver works properly when plugged into another axis.

How would I adjust the frequency from the drive PCB

I cant see it being anything else other than this unless its faulty

I think the forum will need some more details:

Is this a rack based system with seperate 5Amp stepper drive cards ?
My own knowledge of these is sketchy but I think we do have some of these in stock for service exchange.
I don't know how you configure the step rate in software or hardware - sorry

yes there are 3 identical stepper cards in a rack. There are also 2 other cards one is the controller and another I am not sure what it does.

The step and direction outputs come from the controller card which I think maybe at fault as I have narrowed down all the other cards.

How much would a OPTIMISED CONTROL LTD D281 issue 4 card cost me if I cant sort this one?

We will have one for somewhere in the region of £200


I'd check your back plane and connectors first though, for corrosion and damage (eg bent pins) !

Any chance of a circuit diagram for the control board?

I have checked continuity from the control board to the drive boards and it all seems fine.

Phil

Its not something we have - you would need to try Baldor
https://www.baldor.co.uk/default_eu.asp

Are you able to scope the step pulses to the problem axis ?
I'm pretty sure you'll be able to spot the step driver chip (ULN2003 or something like that)
How does it compare to the others that are working ?

Just to clarify what you have tried:

One axis will not work.

1 Have you tried switching the rack mounted drive card? If so what happens to the fault? Does the same axis not run or does the fault transfer?

2 You have tried switching the stepper motor wiring to another drive. Does the stepper motor work Ok with another drive?

I do not think the problem will be with the clock frequency. It will be
a A faulty stepper drive card.
b A faulty motor (unlikely)
c The slide is overtight and needs mechanical adjustment
d A wiring fault on the cable harness to the rack board.


Will the faulty slide drive if you switch drive cards?

Can you manually turn the ballscrew and move the slide?

I have managed to find a fault which now allows the Y axis to move, one of the pins in the main umbilical was arcing causing intermittent connection.

BUT

the axis moves in the wrong direction and then hits the emergency stop switch. If i turn the connector upside down the motor drives to the front of the machine and hits the emergency stop switch. It wont find a home position like the X and Z axis.

Any ideas?

Phil

You will need to trace and check the wiring to the datum switch.
It could be a proximity switch on a Triac.