New Project! (Chevalier bed mill, Allin1DC retrofit)

[Ldguinn1]

Well I finally broke down and bought a new project, got it home and lo and behold, its about 3 inches too tall to get through the door with everything that can be removed from the top. 7 ft Door, 7 ft machine. well actually the door is 80" my mistake, math is hard.

Before this purchase was already working on my G0704 with an Acorn, so that may end up going toward the new machine. I have servos and drives I purchased several years ago for a different machine, but never used them, so they are MIGE drives and servos, .75 KW.

The plan is to get it where it belongs, get it running with the current Dynapath control that is supposed to be completely functional, and then build up the control box going with either an Oak, or Acorn. Maybe find someone to buy the current control to offset the costs. I'll be documenting once it is in its new home. Pics are below.. thanks for looking.

[Chaz]

Following - looks like a nice retrofit.

[slodat]

That is a great machine! I did a retrofit on a similar ish Tree J-425 that originally had Dynapath Delta 20 control. I sold the control on ebay for more than I paid for the mill. I wish mine was a bed mill like yours!

My build thread has a lot of info you may find useful, including how I powered the large spindle motor with single phase power. I'm happy to help where I can, if you need it.

Excited to see where you go with it!

[Muzzer]

Neat looking machine and tidy install. Can't see any date codes but I'd guess late 80s, possibly early 90s? Also can't see a spindle motor, assume you took it off to get it in the workshop. No VFD but it appears to have the varispeed head. Looks like three DC brushed servo amps. Industrial PC, probably quite feeble given the date.

Looks as if you could remove the PC and drives, to replace them with Acorn and modern DC drives (little mechanical work required) or go the whole hog and replace the drives AND motors for all modern AC servos. Either way, looks like an interesting project, worthy of an Acorn!

[Ldguinn1]

Thanks, everyone. Spindle motor is off the machine, needs to be rewound or replaced, Still have some work to do to actually get it in place, slowly but surely. Actually the head looks identical to a bridgeport.. Except its BT- 40. Too good of a deal to pass up.

[martyscncgarage]

Likely DC brush Servo. Consider new encoders and an All in One DC retrofit when the time comes.
Marty

[Ldguinn1]

hi Marty, watch a ton of your YouTube videos. They are brushed DC servos, If I'm going through the trouble to upgrade was just considering AC servos because I already have them, and Acorn because I was already building a control for another machine.

The All-in-one is more than budget allows, was thinking start with Acorn, then possibly switch to Oak down the road.

Not truly knowing how good the current servos are, and knowing they have been in operation for almost 30 yrs, kind makes me want to avoid all the things that could go wrong, plus there's the whole 208v 3 Ph power reqirement, thats another $1500.. So if I can switch to 220 1 ph use current technology servos, and Acorn, might make the transition easier. Or am I looking at it wrong?

[martyscncgarage]

hi Marty, watch a ton of your YouTube videos. They are brushed DC servos, If I'm going through the trouble to upgrade was just considering AC servos because I already have them, and Acorn because I was already building a control for another machine.

The All-in-one is more than budget allows, was thinking start with Acorn, then possibly switch to Oak down the road.

Not truly knowing how good the current servos are, and knowing they have been in operation for almost 30 yrs, kind makes me want to avoid all the things that could go wrong, plus there's the whole 208v 3 Ph power reqirement, thats another $1500.. So if I can switch to 220 1 ph use current technology servos, and Acorn, might make the transition easier. Or am I looking at it wrong?

I understand. You can test the current servos:
https://www.centroidcnc.com/dealersuppo ... ds/155.pdf
You use single phase for the control and the servo power
You use a VFD to convert single phase 220VAC to 3 phase 220VAC and gives you analog spindle control
You are maintaining TRUE closed loop control system
You WOULD have to change to differential encoders, but you could check your current servos to see if they have them. At least 1000 line

Yes you could use Acorn
Yes, you could change to AC Servos
Decent AC servos with cables, and Acorn, will approach the cost of All in One DC
Acorn currently has a Free, Pro and Digitizing. We are working on a similar approach for Servo.

At the end of the day its your decision to make! Nice machine.
Marty

[Ldguinn1]

Update!
Finally got it moved into position. Received my Allin1DC, looking at the hook up schematics, not sure which one is best to use for my application. I will be using a VFD, has a coolant pump, automatic oiler, power crowbar. Any hints? Thanks in advance.

[slodat]

I used a Hitachi SJ-P1 vfd on my Yaskawa spindle motor. They are rated for single phase input, are a modern full featured drive and priced well for what they are.