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Daewoo DMV spindle regrind or rebuild?

mmcgrew10l

mmcgrew10l

Plastic
Joined
Apr 17, 2013
Location
Rollag MN
bc350ff50bd84b4f846449d20d4ebfeb.jpg

Anyone have any luck regrinding spindles? Also in Minnesota that can do that?

Went and checked out a used Daewoo DMV today that looked to be in wonderful shape up until a closer inspection of the spindle, see attached photos.

Supposedly the spindle came down on top of a part with out a tool in it. The boss didn’t even know until I pointed it out and asked when and how it happened.

I guess it happened over a year ago and they never noticed an issue? Seems hard to believe but it would make sense as the drive dog pockets aren’t half destroyed.

Any chance the spindle cartridge/bearings arnt totally fubar’d?

Thinking about rolling the dice on it but I will say I’m a little uneasy on it with hearing all of the complaints as far as service goes since Ellison took over the Doosan/Daewoo product line.

71d226e78d018b1504fb58c1e6dfa939.jpg



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I'd remove the drive dogs and check for signs of damage to their pockets. They must be replacements, as the originals could not have been undamaged given the rest of the pocket gouging.

As to whether a regrind will work - there's signs of heat discoloration of the taper nose, meaning an excess of heat and maybe softening. I can't tell how deep the gouging is, but between it and the color change I think I'd want to rebuild it with a new spindle (itself, housing looks OK) and bearings.

But if the spindle turns smoothly and doesn't make noise while running (is it under power?), and you're willing to take the gamble of it going down at some point at random, AND at a good price, you can take a flyer on it.

As to who does grinding in your area, call a couple spindle rebuilders and see who does on-site repairs. These guys are about 210 miles from you: Spindle Repair Services | Benning Inc. and I have no idea how good they are. You should be able to find other options with some searching.
 
Add to the above:

If the drive dogs are original (and I agree that what's visible doesn't show damage to the pocket sides), then what they're saying is they dropped the spindle down onto a part that fit just inside the spindle, which means they'd screwed the offset severely (no tool, and the work still goes inside?), and the work was hard enough to gouge the spindle. Or is it material buildup, as if part stock welded to the taper?

Whatever happened, I'd be cautious unless you can accept repair cost and downtime at some point.

Let us know what you find or decide.
 
It looks like some serious heat discoloring around the edge of the taper like poster above said. I’m not sure I believe a guy that said he knew nothing about that. The runout has got to be bad.

I bought a Kitamura vertical in an auction several years ago. Didn’t inspect it, it went cheap and I took a gamble on it. In that machine, it was clear that a pull stud must have broke, and toolholder spun inside the spindle. Tools had some crazy runout, like 0.03” or more. I had the spindle reground by a business that brings equipment and mounts it to your table. It cleaned up nice and worked good again. $700ish was the price. One thing he mentioned tho, that you loose some drawbar force with a regrind, that makes it hard to get back even with new Belleville springs. But I think someone is lying about that spindle. Either his employees or the owner.


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I would contact Doosan and check on a new spindle ,, its my understanding that Daewoo machinery went under and Doosan got the rights to Daewoo right before Doosan started to fold and they got bought up only to be put back on the market for sale ,,,

Bottom line is Daewoo is no longer going and Doosan is not looking good the last few years ,, up side is there ok machines and Fanuc ,, if you like Fanuc
 
D.D.Machine said:
I would contact Doosan and check on a new spindle ,, its my understanding that Daewoo machinery went under and Doosan got the rights to Daewoo right before Doosan started to fold and they got bought up only to be put back on the market for sale ,,,

Bottom line is Daewoo is no longer going and Doosan is not looking good the last few years ,, up side is there ok machines and Fanuc ,, if you like Fanuc
Click to expand...


Jesus Christ, how many times do we have to say this. D.D., get your facts straight. Daewoo is Doosan, Doosan is Daewoo. Doosan supports all Daewoo machines and always has. Daewoo did not "fold", they got sold to Doosan. Doosan never started to fold but, yes, we got sold. You make it sound like both were on their death beds when neither was the case. D.D., you sound like a jilted lover.

As for the OP, we have a full spindle rebuild facility here in New Jersey. Contact our service group to inquire about your machine.

Paul
 
Paul, more seriously - have you ever seen a spun holder produce damage like that without wiping out the drive dogs? I can only think it dropped an inch or so while spinning, so the toolholder didn't catch the lugs but still dragged around the taper.

Also, those six tapped holes - they look sort of large for balancing, but at the same time I'd not used to seeing smaller spindles with the ability to bolt cutters directly to the face - do you have the 411 on the holes?

I do see at least one set screw, so maybe it is for balance.
 
Milland said:
Paul, more seriously - have you ever seen a spun holder produce damage like that without wiping out the drive dogs? I can only think it dropped an inch or so while spinning, so the toolholder didn't catch the lugs but still dragged around the taper.

Also, those six tapped holes - they look sort of large for balancing, but at the same time I'd not used to seeing smaller spindles with the ability to bolt cutters directly tom the face - do you have the 411 on the holes?

I do see at least one set screw, so maybe it is for balance.
Click to expand...


Someone is lying I think. What ever happened to this machine, the original keys could have been wiped out. The ones in there now show normal wear, see pic 1. That or the tool holder split into 2 or more pieces. But at any rate, those might be newer keys. And if that machine was run for any length of time with that spindle the way it was, who knows what other underlying issues are there. Who does that to a spindle then runs it like that? For a year? Like that? We would not even recommend grinding a spindle that was that bad and no guarantees because we don't know what else that spindle has gone through. If the machine is in good condition otherwise, I would do a spindle rebuild, and get a warranty with it. And I asked, those holes are for balancing. Honestly, I would pass for a couple of reasons. Condition of the spindle. Lack of knowledge or honesty about the spindle. There are definitely better options out there.

Paul
 
I have gone into a poor spindle bore with a round file and a round hone, then in with a rouged-up old taper and made run much better..Agree that one looks prety bad.. if mine I would invest about 2 or 3 hours to see if I could make it OK.
Regrinding is very tricky with not having the right gear
re grind srevice can be had. Some come to your shop and do it in the machine.
http://spindlegrinding.com/
 
LockNut said:
Honestly, I would pass for a couple of reasons. Condition of the spindle. Lack of knowledge or honesty about the spindle. There are definitely better options out there.

Paul
Click to expand...

I get what you're saying. FWIW, I had a very similar (maybe identical) type of damage occur to my Haas spindle when during a tool change there was a f-up, the tool was captured by the taper but not far enough in to secure the pull stud, and when the spindle came down it bounced against the workpiece enough to cause taper scoring.

I was lucky to be near the machine and shut it down quickly, and after some DIY checks of the damage and the spindle bearings, decided a regrind was worth it. Pulled the spindle and brought it to a local spindle service co (NH has a bunch of them), and it's been working fine for a couple years now.

So if the rest of the machine looks OK and the price is right, I might give it a go.
 
michiganbuck said:
I have gone into a poor spindle bore with a round file and a round hone, then in with a rouged-up old taper and made run much better..Agree that one looks prety bad.. if mine I would invest about 2 or 3 hours to see if I could make it OK.
Regrinding is very tricky with not having the right gear
re grind srevice can be had. Some come to your shop and do it in the machine.
http://spindlegrinding.com/
Click to expand...


You shouldn't grind if you can't get 100% cleanup. And if you have to remove too much material to cleanup, then you ruin the integrity of the spindle/clamping interface. Just not worth it.

Paul
 
LockNut said:
You shouldn't grind if you can't get 100% cleanup. And if you have to remove too much material to cleanup, then you ruin the integrity of the spindle/clamping interface. Just not worth it.

Paul
Click to expand...

I agree with Paul, the hand job is just back to the original surface. I would blue the taper up with red dykem and not take away anything from the original manufacturer surface.

A grind service has a fixture slide to travel the grinder on.. they can come to original taper and just skim grind to just take off the blue. Dents and dings patt original, that they dont grind out.
Trying to do it yourself is so tricky..you need talk to someone who has done it.

High limit of the taper is as far as you can grind ..yes you can take a little from the taper big end face.

most/many good grinder hands could do that job.
 
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