cincinnati vmc needs new spindle bearings diy project ?

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 12, 2003

• #1

hello folks, bought a sabre 500 at an auction. couldn't see it run but took a chance. hooked it up, run thru some programs, works ok except
>tool carosel sorta comes in hard when landing toward spindle
>2 or 3 of the keboard keys don't work
>the 'best' for last, the spindle bearings sound terrible. a surprise as one employee who used to use it said it ran fine. I had to keep it outside under a tarp for a couple of months...reckon humidiy did it in ? anyway, just how much trouble and expense are replacing the spindle bearings ?

 

ARB

Titanium

Joined

Dec 7, 2002

Location

Granville,NY,USA

• Aug 12, 2003

• #2

Are you sure it is the bearings and not the belt causing the racket? We were "Sure" that the spindle bearings we going in our Arrow 2000 3 years ago. That was 3 years ago and they are still just fine. It turns out that the belts were making the noise.

Does the machine have a parlel arm mechanism that is air operated for the tool changer? If so there should be a gas shock that decellerates the mechanism at the end of the stroke. That may be shot or out of adjustment.

Take Care

ARB

 

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 12, 2003

• #3

that would be neat if it is the belts but it's a metallic metal on metal sound. how can belts make a noise..rubber gets hard ?

since posting i looked in service manual and bearing are totally sealed type so unlikely humidity got to 'em..must be just worn out or belts like you say. cincinnati sez $284 for set of bearings or about $1800 for reconditioned spindle. wonder if bearings are actually under 100 bucks for set if bought from bearing house ?

correct on the tool changer mech., gas shock idea makes sense, i'll check that out.
thanks

ps any thought on the not working keyboard keys ? is it likely the key itself or something in the control ? if it matters, the numbers '1' and '2' don't work. the letter 'd' works but only when you press hard. keyboard 'looks' like new, previous owner used a dnc terminal---heck, maybe that's why huh ?

 

doug925

Titanium

Joined

Nov 21, 2002

Location

Houston

• Aug 12, 2003

• #4

I would ASSume that the tool changer has a gas shock, also. On mine (not Cinci.) I have a small knob for adjustment of the changer inward, and outward speed.

On the spindle bearings, DO NOT go to Cincinnati. Do some research and buy the bearings direct. Find a reputable spindle rebuild shop in your area, and have them rebuild it.

Mine was only 1.7K total. That was a 5 pack of new bearings, Kluber(sp?) grease, and total rebuild. I was told I "should" rebuild the spindle pack once a year! B.S.!!
Mine ran great for 6 yrs. and thru 8-10 minor crashes!
Best of luck, Doug.

 

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 12, 2003

• #5

mine has only 3 bearings according to cincinnati. service book has instructions on removal and more. what's the hard part---getting preset torque just right, or ?

 

WILLEO6709

Diamond

Joined

Nov 6, 2001

Location

WAPELLO, IA USA

• Aug 12, 2003

• #6

I'd have to know the year on the machine to tell you for sure. If it is a sealed cartidge type spindle, loosening the belts and 6 bolts drops it out the bottom. Echange it and you are back running. Beware you have to retrim the tool change position, which requires a little control and drive knowledge. My 95 arrow 750 merely has flow controls on the cylinder moving the drum. always control the exit air, never pressurized air. a screwdriver and a brush to clean away the years of chips is all you need to adjust turret speed. I have had god luck with Cincinnati replacement spindles. Belt noise sounds kinda between a rubber squeeak and a " fingernails on chalkboard" noise. kinda consistent as the spindle turns, more prominent at low speed. is it a 6k or 8k spindle?

 

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 12, 2003

• #7

92 year, 8000 rpm spindle. my noise gets much worse with higher rpms--even 600 sounds bad---4000 sounds horrible ! can't believe the dimwit employee didn't warn me--still for $3300 what the hey--

 

WILLEO6709

Diamond

Joined

Nov 6, 2001

Location

WAPELLO, IA USA

• Aug 12, 2003

• #8

you may not have a cartridge type spindle. If not, you have to tear the housing down and do it on site. I have never done that, but it wounds like a big job from those I have spoken with who have. One way to check it out: put in a 1" end mill holder with a length of drill rod in it. a mag base on the table against the drill rod and check the lash at say 6" from the nose of the spindle. Pull and push on the toolholder, pry if it is convenient, and see what the indicator does. Anything over 0.002 @ 6" means your beariongs are definitely done for. I have run machines with 0.005 @ 4", they will cut ok on smaller cutters, comps go wierd, but for the most part they really chatter. Make sure your lube system is working properly if you replace the spindle. some of the dropsa units had a nasty habit of losing prime.

[This message has been edited by WILLEO6709 (edited 08-12-2003).]

 

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 12, 2003

• #9

i fixed the tool carosel 'hard landing' at spindle problem-- wasn't a gas spring but a regular spring--plunger was stuck--little pb blaster and she's workin good now.

took the cover off the head and the spindle noise is not so bad--was vibrating the sheet metal of the guard--still probably not 'right' though--will test with tool bar tomorrow.

new problem--now the tool carosel has trouble 'aligning' during setup. get 'is pocket one aligned with spindle ?' message alot--i'm yellin at machine 'yes damnit, pocket 1 is aligined'--works after about 4 yells and moving carosel back and forth. what is it, proxmitiy switch or manual limit switch stickin maybe ?

 

WILLEO6709

Diamond

Joined

Nov 6, 2001

Location

WAPELLO, IA USA

• Aug 12, 2003

• #10

I assume you have an 850sx control, which is past my experience, never run one of them. BUT, on a 2100, when aligning the toolchanger, press mechanism align once, the screen asks " is drum one at pocket one?". If it is press mechanism align again, and you are homed. If it is not, you can jog the drum to the correct pocket number so you don't pick up tool 3 ( 4" facemill) instead of tool 1( 1/4" spot drill) and basically have a very BAD day. on my machines this is basically asking what pocket in the drum would be put in the spindle if a tool change occurred right now. It may be nature of the beast. There is a prox switch for drum parked and for drum at spindle ready for change, but I think this is just alignment procedure.

 

R

RickD

Plastic

Joined

Dec 30, 2000

Location

georgia, usa

• Aug 13, 2003

• #11

willie, since you mention the spindle bearing test, got any ideas on testin ball screws for wear ? the x axis is louder than the y so now i'm wonderin about that too...or would noise indicate worn thrust bearings rather than the screw ? x sounds kinda like one of those imperial fighters on star wars.

 

WILLEO6709

Diamond

Joined

Nov 6, 2001

Location

WAPELLO, IA USA

• Aug 13, 2003

• #12

The local cincinnati service manager used such highly precision tools as an 8 foot 2 x 4 for a pry against the door opening against a kurt vise to check the x thrust bearings in my 1250. The y is a little trickier, since it is harder to get a good hold of, but if you run the table all the way to the back and get a good wedge between the z column and the table it should do the trick. The Z axis just get a good lever under the spindle with the mag base on a ground surface on the spindle nose and heave it a little and see how much it moves. Thrust bearings will make them sound kinda like a fire engine at times. I'd start there anyway as thrust bearings run about 130.00 per pair and are the cheapest thing to try. The screws vary in price but there is a place called robert's ball screw in michigan somewhere that the cinci dealer uses for rebuilds. If the nut keeps spinning freely after you let go, the preload is gone in the screw, so is the accuracy. If the nut stops quickly when you let go of it, the ballscrew is still good.

 

L

locher

Plastic

Joined

Sep 12, 2002

Location

Carroll, Ohio, USA

• Aug 14, 2003

• #13

Rick, where about are you located? I could have one of our tech's stop in when we are in your area to take a look at that spindle... on the house of course. Thx, Dwayne @ Lochers

 

D

D. Thomas

Guest

• Sep 2, 2003

• #14

Rick, wish I had seen this earlier...your non working keyboard keys can be fixed easy as fallin off a log. They aren't working cuz of dirt...on a Cincinnati you can individually pry those little rubber keys up from the bottom and get a Q tip dipped in alcohol in there and clean the contacts. I did this on mine and the offending keys went from not working at all no matter how hard I pushed, to working like brand new with just a light touch.

 

D

donie

Diamond

Joined

May 17, 2003

Location

Walla Walla Wine and Wild Turkey

• Sep 2, 2003

• #15

Spindle repair? Barden has a video and info Free for the asking, then you decide if you are up to a spindle repair.
Don at Wally World

[This message has been edited by donie (edited 09-02-2003).]

 

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Rich Carlstedt

Stainless

Joined

Jan 20, 2002

Location

Green Bay Wisconsin USA

• Sep 4, 2003

• #16

Quick easy check for ball screww backlash is to mount a "last word" on the table and indicate the left hand side of the saddle.
You only need to move the table (or saddle for Y) about .010 in one direction. Then Zero out your position on the control and set the last word to zero. Now move BACK (away) .010 by program or MDI. any difference between the last word and the screen is the error(backlash) in your ball screw and thrust bearing.
To find error in the ballnut alone, mount a lastword on the table end and indicate the end of the ballscrew (remove cover).
Now push the table and pull the table to read any error..takes a good heave to do it however