Denford VMC1300 - Rescued

[m_c]

Have you downloaded the wiring diagrams from the Denford forum?

My guess would be one pair is a tacho feedback, and the other a thermal cutout (probably the ones that have been looped). If there's a model number on the spindle motor, you should be able to find a datasheet.
Also, check to see what wire numbers end up at the spindle driver, as that would give you a good idea, as only the power (probably via a relay or two), and tacho feedback will go to the driver. The thermal cutout would form part of the e-stop loop.

[Chas Ixion]

I have downloaded the wiring diagrams, and based on what I've seen so far I think this http://www.denfordata.com/bb/download/file.php?id=2528 is the right one for my machine.

I'm waiting for a m10 eye bolt I ordered from ebay (I ordered two but they only had one) which I am hoping will make lifting the thing a bit easier, then I can get into the guts of the electronics.

At the moment my plan is to replace the motion controller with either Linux CNC or something arduino based, but before I do I would like to establish if the steppers and drivers are functional. Is there an easy way to test the drivers and steppers without a motion controller?

[m_c]

It would depend what controller is fitted. I'd hazard a guess that it will be the later USB NextMove controller, but I've got no idea if it'll use the all in one daughter board like the smaller mills used, or if they'll of used separate drivers.
Either way, it would be a case of working out what the step/dir pins are, and patching into them, while also making sure power and enables have been connected correctly.

[Chas Ixion]

Making a bit more progress.

Eyebolt didn't work out, it fouls the casting and cant be screwed in. Resorted to using a crowbar on the legs of the stand and got it moved enough to get the backplate off.
Managed to get some photos of the main components. I'm guessing this is the main motion controller board.



Power distribution (????)



Stepper drivers



The stepper drivers appear to be labelled XLT50-S which should help me identify the wiring diagram to use.

My plan is to replace the motion controller with this http://www.ebay.co.uk/itm/EU-Stock-4...MAAOSwjDZYde-j

According to some documentation I have found online (http://www.parker.com/parkerimages/e...ive_manual.pdf ) the driver design is at least 14 years old, on the basis of this i'm going to investigate the options for replacing the drivers with something more up to date, any recommendations?

[Chas Ixion]

After spending hours on google I decided to go for Leadshine EM806 drivers from Zapp.... just placed the order.

[m_c]

EM806s are good drives. Did you order a programming lead, as it makes setting them up easier?


You'll need to study the wiring diagrams to work out what the power board does. I think some of the later Triacs used something similar, and some of the relays are used as interlocks, to ensure critical things weren't solely controlled by the controlled.
The top board is the later controller. Smaller machines used the in built stepper drivers in the lower board. If everything was still connected, you could possibly try powering it up and see what shows up on the 7 segment display. It would give an indication of if there was anything major wrong with the original controller.

[Chas Ixion]

Well only two years later and my mill has become my primary project and I have made some progress.

I have the RMHV controller hooked up to the EM806 drives connected to the original steppers. I have also connected the home switches. I have used the original power supply and relay board for this.



This gives me the following good things.

1) Movement on all three axis
2) Control of all three axis using either the buttons on the controller or a MPG pendant
3) Homing set up.

What isn't so good is
1) the z axis brake is errrr .... broken (I managed to loose the spring that applies the brake)
2) More of an issue is I let the smoke out of the spindle dc driver. The good news is they are still available off the shelf the bad news is they cost about 200 quid....

I have a replacement (https://www.transdrive.co.uk/shop/pr...q-non-isolated) and I'm in the process of wiring it up.

To start with I have copied the settings (potentiometers and dip switches) from the old board but I'm now beginning to doubt the wisdom of this as the old board died on me and at some point previous to me finding it on a scrap heap someone has written the word BAD on the heatsink.

I'll need to find some info on the motor as the old board is set for max voltage of 50V which seems a bit low (ISTR Triacs go up to 180V). I'm also trying to figure out how to use the 0-10v output from the RMHV controller to set the speed as I'm not sure if I need some form of isolation between the two.

Hopefully I'm not too far from being able to cut some chips although I'm starting to think that I might be better off using MACH3/4 or Linux CNC rather than the rather limited RMHV controller.