doosan hmc spindle problem

[Brando]

anybody else have the 4000 and/or 5100 model with the 30hp 40taper 14,000rpm motor spindle cartridge? we have 4 of these and have had new/rebuilt spindles in every one of them some have had more than one replaced

 

anybody else have the same machine and having the same issue?

 

we have a 2001 doosan dhp400 , which is not an integral motor spindle and its the original spindle and still 14000 rpm, and its been crashed a few times now and still keep on gettin it 24/6..

[Guest SAIPEM]

Are you running balanced tool holders?

[Brando]

well we dont have a balancer, all of out holders are g2.5@25,000 we dont run tools that aren't symmetrical at high rpm, and if we do feel vibration on the spindle head we lower the rpm until it stops or switch tool holders, gauge lengths etc, were not letting things run at 14000 if its vibrating, you really cant even run a tool @14000 if its vibrating because the tool chatters and the surface finish and tolerance sucks so im really sure its not vibration

[GoetzInd]

We went through a few spindles on one of our doosans. Is it grease or air/oil? Ours was perm. greased and the bearings were getting contaminated with fines from small machining. After doosan stop replacing them even though they were under warrenty, we had a spindle house rebuild it with a different bearing setup. Was never a problem after that.

 

Mike

[Brando]

it is grease,

was it northland that rebuilt it? they have rebuilt one thats in our dhp5000, its running good so far been in there for about 8months

i took em a few trys to get it right but they found something that seems to work better then the factory

every time one burns up its usually the rear bearing that supports the motor shaft, you would think they would try something different instead of just fixing it over and over

 

im pretty much set on just dialing every thing back a notch or two on roughing aluminum that seems to be where they lack in reliability but it does suck not being able to use 30hp

the job we had running was 100cuin removal in some areas

[Newbeeee™]

Is it integral motor? Hitachi used to do this (VS50) and we went through 8 spindles on one machine and 6 on the other, in a 2 year period.

Hitachi was crap design because all the heat from the motor was transmitting to the bearings.

If you have an integral motor, check your chiller has no air bubbles and is working/set correctly.

HTH

[GoetzInd]

I don't remember who did it but it cost about 4K. Not too bad IMO. I don't understand why builders use grease. I've no success with that vs. the air/oil.

 

Mike

[Guest SAIPEM]

Are you using Big-Plus CAT40 tool holders?

 

Is this actually a Doosan labeled machine or a Daewoo labeled machine?

Is this the machine in question?

http://www.doosan.co...85542843750.pdf

If it is, check your spindle chiller.

 

I went through this on a 2000 era Johnford VMC.

I agree on the grease packed spindles.

Grease packing is fine if you stay within the specked duty cycle.

No one eve does and its unreasonable to expect that they would.

 

Even on grease packed live tools, the life cycle before rebuild is only 1000 hours.

[Brando]

Is it integral motor? Hitachi used to do this (VS50) and we went through 8 spindles on one machine and 6 on the other, in a 2 year period.

Hitachi was crap design because all the heat from the motor was transmitting to the bearings.

If you have an integral motor, check your chiller has no air bubbles and is working/set correctly.

HTH

 

yep integral motor

[Brando]

Are you using Big-Plus CAT40 tool holders?

 

Is this actually a Doosan labeled machine or a Daewoo labeled machine?

Is this the machine in question?

http://www.doosan.co...85542843750.pdf

If it is, check your spindle chiller.

 

I went through this on a 2000 era Johnford VMC.

I agree on the grease packed spindles.

Grease packing is fine if you stay within the specked duty cycle.

No one eve does and its unreasonable to expect that they would.

 

Even on grease packed live tools, the life cycle before rebuild is only 1000 hours.

 

yes those are the the machines we have, they are labeled doosan

 

the one hmc thats labeled daewoo is like a 2000 and its dosent have the integral motor spindle its has the inline type and its still has the original spindle cartridge and is used just as hard as the others

 

yeah and we are using some bp holders when the support is needed, high rpm roughing and large dia boring long end milling etc.

[Newbeeee™]

_{yep integral motor}

_{To use the wise words of Bender - your'e boned!}

_{With the Hitachi's, and I cannot see that your machines are any different, to have (effectively) 30 electric fires adjacent to the spindle bearings, is fundamentally p1ss poor design in my book. The heat from the motor (when you're loading the cut) has to go somewhere, and the bearings get their share of it. Inline is the way to go - ask Matsuura.}

_{All you can do is check the chiller has new oil, no air locks, and is set correctly. Do not run it too cold. We made the mistake of this on a Leadwell once, and it caused condensation of the bearings which screwed them.}

_{Have/use the warm up cycle and ask Mike (GoetzInd) nicely to go back through his invoices and find out who rebuilt his spindle if all is ok!}

[Brando]

lol well i guess i gotta make the best use of what i got, and i guess thats why makino patented the under race lubrication on their integrated design then huh?

today we put a rebuilt spindle spindle in the newer dhp4000 from northland http://www.northlandtool.com/, and were getting a brand new one as a replacement spare from the factory with a one year warranty from the date its installed so the owner is happy , we didnt get one for free we had previously purchased a spare to have, that was used in another machine then had one rebuilt at northland

im gonna heed your advice about the chiller because i was gonna turn it down some but i guess ill just go about 5deg less then ambient

 

i looked at the motor when it was out today and the full load amps is 173!!! 10min and 152 continuous duty on the high winding side ,

thats gotta be a crap load of heat,, and the heat on the rotor has to go thru the spindle shaft then thru the bearings to get to the chiller oil (i never though of it before but makes perfect sense now)

 

we were running a job the does about 20min worth of 14000rpm roughing @ 80-100% im sure thats the bearing cooker right there

 

im just gonna dial the roughing back to about 11500 max, and if that dosent do it well hopefully then i can convince the owner to buy something with some engineering behind it because this knock off stuff sucks

although everything else seems to be built reasonably well, would you keep your car if the engine blows every 5mos

[Brando]

and we do use the warm up cycle its written into the plc from the factory as an alarm , you cant run the machine if you dont run the program

[Newbeeee™]

Perhaps someone like James or Sapiem can jump in, but there must be a reason for companies going integral motor?

I think it's fundamentally wrong but a few did/do it, for *some* reason?

Just interested to know why.

Our robodrills are in line and I think they are the same as the Matsuura in that the coupling is a low thermal transfer mtl.

[Guest SAIPEM]

Damned if I know.

 

This kind of thing is where Okuma is on the cutting edge.

They really spend the time to design the machines so thermal transfer is minimal.

They also have the best temp control system out there.

They spend the time on little things like pump placement that reall makes a difference,

Now, it doesn't come free and the price reflects it but you can't argue with their results.

 

Doosan is coming along on this kind of thing but they have separate engineering groups responsible for different machine lines.

One of the smart things they finally did was uniform standardization of M-Code assingments for Mills & Lathe (including Mill/Turn).

Previously each engineering group developed their own and it was difficult to keep up with.