Denford Triac VMC with ATC Conversion / Fix

**Chaz** · 17-03-2017

Originally Posted by andy_con

bit of a thread hijack sorry.

so when I got the machine it turned on and worked, but every time I started the spindle it tripped the RCD. I notice straight away the main fuse on the sprint drive card had been bridged, so assuming it was a known problem.

after many hours of faffing I took the top cover off the sem motor and it was filled with burnt carbon from the brushes. after a really really good clean and hoover, it worked and didn't trip the rcd.

I also replaced the brushes in the side of the sem motor just for piece of mind.

a problem since I had the machine is you start the spindle at say 3000rpm and it starts to jump around going up and down, by like 300-400rpm. so sent it away for a £500 refurb and it hasn't fixed the problem just changed the problem. now days when I set the motor to 3200rpm, it will go to that speed then after about 10 seconds jumps to 3800 where it will just sit until turned off. its not a big deal I have live spindle feed back so I can account for it, but it shouldn't be doing it.

I had similar issues. Brushes need to be clean and carbon free (And clearly not worn out). I stripped the motor down as far as I could and found that previously someone had put some putty on the wingdings. I Can only assume the motor had basically started to fail and this was a 'plaster' to keep it going.

I would only get around 30% of full current before the motor would stall. It would then overheat and start smoking from the brush area.

I triple checked the setup and verified with the supplier of the drive (they were really good) - KEITH SANSBY <[email protected]> . So clearly the motor was the problem. Symptoms also included 'hunting' around high speed and any loading would make it worse.

**m_c** · 20-03-2017

Originally Posted by Chaz

put some putty on the wingdings.

I've just got to say, that typo made me smile :-)

Did you get any pics of how the servo fitted?

**Chaz** · 20-03-2017

Originally Posted by m_c

I've just got to say, that typo made me smile :-)

Did you get any pics of how the servo fitted?

LOL, I saw that after too but left it.

No, but will sort. I do have some older pics, lemme see if I can find them.

**Chaz** · 20-03-2017

Originally Posted by m_c

I've just got to say, that typo made me smile :-)

Did you get any pics of how the servo fitted?

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Difficult to show with existing pics. Ill take a vid on the weekend.

Tight squeeze, had to remove some material for it to fit and a pic of the bracket used.

**m_c** · 20-03-2017

That's certainly a tight fit.
Any idea what size flange is on the motor?

I think a 100mm flange motor would squeeze in, however I couldn't find any with the power I was aiming for, so opted for a 110mm motor, and spacing it up.

**Chaz** · 21-03-2017

Originally Posted by m_c

That's certainly a tight fit.
Any idea what size flange is on the motor?

I think a 100mm flange motor would squeeze in, however I couldn't find any with the power I was aiming for, so opted for a 110mm motor, and spacing it up.

Ill share the sizes tonight. Ive got the original flange drawn up as well as the info on the Panasonic 1.5 KW servo.

**Chaz** · 21-03-2017

Originally Posted by m_c

That's certainly a tight fit.
Any idea what size flange is on the motor?

I think a 100mm flange motor would squeeze in, however I couldn't find any with the power I was aiming for, so opted for a 110mm motor, and spacing it up.

The plate that goes across for the DC motor is 115mm x 110mm (Depth).

The motor mount bolts are 81mm across from C to C. The recess flange is 100mm.

This is the motor mount for my Thor machine Y Axis (same motor as used on my Denford for spindle here).

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**robertpearce4** · 05-08-2017

Hi Chaz,

I have just acquired 1/2 of a TRIAC VMC today so will follow your threads with interest. The Miller was going for scrap. Unfortunately I don't have the controller or a schematic but do have the monitor/PC, not that I think it of much use on its own. I have to decide if the miller is worth the time of effort to "upgrade". Even with the latest electronics/controllers its not as simple as plug and play. I agree its heavier than it looks. The C of G is not where you expect it either. The lifting eye on the top gives the game away.

**m_c** · 06-08-2017

Originally Posted by robertpearce4

Hi Chaz,

I have just acquired 1/2 of a TRIAC VMC today so will follow your threads with interest. The Miller was going for scrap. Unfortunately I don't have the controller or a schematic but do have the monitor/PC, not that I think it of much use on its own. I have to decide if the miller is worth the time of effort to "upgrade". Even with the latest electronics/controllers its not as simple as plug and play. I agree its heavier than it looks. The C of G is not where you expect it either. The lifting eye on the top gives the game away.

I noticed your post over on the Denford forum earlier.
Without the control box, there will be a lot more wiring needed done, but there's nothing insurmountable if you really want to get the machine running.
From the photos you posted over on the Denford forum, you've got a BT30 spindle (it's got an 8 position tool changer), and stepper motors.
Ultimately to get it running, you'd need 3 stepper drivers (plus suitable power supply), a spindle drive, some form of controller, and lots of relays.

If you do decide not to keep it, I'd be interested. I've got a BT35 spindle version, but would quite like a BT30 version as toolholders are far easier to get, so I could swap the required bits.

**robertpearce4** · 07-08-2017

Originally Posted by m_c

I noticed your post over on the Denford forum earlier.
Without the control box, there will be a lot more wiring needed done, but there's nothing insurmountable if you really want to get the machine running.
From the photos you posted over on the Denford forum, you've got a BT30 spindle (it's got an 8 position tool changer), and stepper motors.
Ultimately to get it running, you'd need 3 stepper drivers (plus suitable power supply), a spindle drive, some form of controller, and lots of relays.

If you do decide not to keep it, I'd be interested. I've got a BT35 spindle version, but would quite like a BT30 version as toolholders are far easier to get, so I could swap the required bits.

Hi Chaz,

Thanks for your quick reply. I obtained a battery powered folk lift truck (FLT) from the same source...with 50% of the battery's shot. I used the FLT to move the miller with the aid of some deep cycle battery's. I need to do a little more reasearch on the cost, time, effort, choice of controllers + do I need a miller....etc before I write it off. My current urgent need is to buy a small metal lathe (Viceroy) off a friend in Magor now that I have 3 Phase on site.. Dare I ask what its worth to you? Can you swap the toolholder easily between machines? Yours for mine? I don't need this functionality and it probably complicates the control electronics. BTW I am near Welshpool. You would need to collect. There is a slim possibility the controller is about in the factory it came from. I need to have a search now I know what I'm looking for.