[DLIDGEY80]

i have a 4020a cat 40 spindle and just recently the tool holders have started coming loose in the spindle i have changed the belleville washers, drawbar, the gripper all the ball bearings, i had a tech come out and change all that stuff but the tool holders are still loose in the spindle and wont lock up, he told me the only thing he can think of is the spindle is worn out and needs to be replaced, any other ideas out there of what would keep my tool holders from locking up completly?

[txcncman]

Air pressure. Bad solenoid. Trash in the air lines. Water in the air lines. Excessive vibration.

[DLIDGEY80]

i know about 7 years ago the airvalve on the top of the drawbar bride went bad and the machine was dropping tools out right could that airvalve be the culprit again of would it be more logical that there is a leak or a bad air line somewhere else. i didnt think the whole spindle was bad because sometimes toolholders will lock up tight and sometimes they wont

[sudip]

I think you should check the draw bar cylinder and the tool holder collet.you may try this

tool is not inserted into spindle,problem in drawbar, disc spring or collet.

[DLIDGEY80]

everything is new inside the spindle as far as the drawbar, gripper, all the ball bearings that hold onto the retention knob, the cup that fits in the spindle which compresses the bearings is new, and the disk springs are brand new

[ad64075]

3 things I would check right away is your air pressure at the manifold, voltage at the draw bar solinoid, and the solinoid/valve unit for operation. It sounds to me like the valve is most likely the problem, especially if it only occurs intermittently.

[SpindleRepair1]

Usually we look at the Belleville springs which do all of the work holding the tool holder in. When you replaced them did you check the stack height? A few thousands can make a big difference in the retention force.

You may have a worn profile inside the shaft that is not allowing the gripper fingers to clamp down properly on the retention knob.

[DLIDGEY80]

spindlerepair- i had a tech service come and do all the work on the machine so i am not sure if they checked the actual stack height or not, and im not positive but i dont think my drawbar has actual fingers it has ball bearings that ride in a gripper cup and that slides into another cup that has a taper on the i.d. and that was all replaced with the draw bar and belleville washers

ad64075- where do i find the solenoid to check and what should the voltage be

[DLIDGEY80]

is it possiblt that the retention knobs are worn out, it doesnt seem like that would be the problem because all the tool holders lock up tight in my other fadal

[SpindleRepair1]

Whether your machine has gripper fingers or balls for grabbing the retention knob the shaft has an internal profile. As the draw bar is pulled back the profile causes them to close down on the retention knob and then pull it back into the taper.

If that profile is worn the balls or the fingers may be closing down later in the stroke and gripping on the back of the retention knob or not closing down enough. If that is the case you may find that it pulls the tool holder back. However, it will have insuficient force to hold the tool during a cutting operation.

Try putting some blue on the balls and see where it grips the retention knob. or better yet see if you can get your hands on a dynamometer and see what your pull force actually is.

Is the gripper assembly adjustable?
Does it pull the tool holder in?

We wish you the best man.

[carbidecraters]

Things it most definately is not

1. Air pressure
2. Bad spindle

Things it may be

1. Bad draw bar
2. Not enough washers
3. Wrong retention knobs

Did the tech perform a pull test on the draw bar. You should be between 750-1400lbs. If your lower then the bellville washer count or quality is not there.

[DLIDGEY80]

i do not believe that he did a pull test, but the draw bar is brand new so are the belleville springs, and the retention knobs are the same i have always used.

i dont think it is adjustable, and it does pull the tools into the spindle just not enough to actually lock into the taper, and i know on my spindle the drawbar doesnt actually use the spindle profile to compress the gripper balls it has a tapered sleeve that is in the bottom of the spindle near the retention knob gripper that compresses the gripper balls as the drawbar pulls up and that was replaced at the same time as the draw bar, belleville springs and the gripper assm.

[SpindleRepair1]

DLIDGEY80, I went over this problem with our repair techs and we pretty much agree with Carbidecraters. Your drawbar assembly is most likely not adjustable and you have a new sleeve that has the cam profile on it. Your retention force is a factor of your Belleville spring arrangement. So our techs feel that an error in your drawbar assembly is the most likely culprit. As was noted you should have around 1000 lbs of pull force.

Your spring stack will have between 50 and 70 discs. (The last Fadel we repaired had 50). It is important that the correct size springs are installed. If the spring height or thickness is off by even a small amount that error is multiplied by the number of springs. Additionally, the assembly configuration must be correct. To get additional pull force the springs are cupped together, to get more height they are arranged opposed. Most drawbar spring stacks are a specific combination of both arrangements. Any error in assembly or spring dimensions can result in insufficient drawbar pull force.

You really need someone to check the pull force with a dynamometer.

[DLIDGEY80]

thank you all very much for your help looks loke i will be calling a different tech service to come out and take a closer look at it and i will make sure they have the right equipment to check what u have all recommended, but i belive that carbide and spindle are probably right, it all atarted awhile ago with broken bellevilles, and was never right even after they were replaced

[Delw]

Check the manifold good, if I remember correctly its hydrualic/air.
When the guys from idaho were at my shop, he told me how and the why and said its a very overlook item.

what it esentually is a a big rectangular box with a plate and oring. if anything is worn it tends to cock a little and get stuck. I know we clean mine out and then added oil to some spots. it has fill ports. Made a huge difference. it could be stuck from coming up and not releasing all the way

Brian is the owners name and I forget who was in town here( and name of company), real nice guys.

[RalphWilson]

We got a new plate installed for the square cylinder and it worked a while.
Then did not work again.

We took it apart and found the corners of the plate where the o-ring groove was machined , was too deep. letting air by the corners.

We made new plates with proper o-ring groves in corners and has worked fine since.

[hydes]

Are you sorted yet ?

Through tool cooling fitted or not ?

Look up the spindle to check all the balls are there if so stick your finger up there and check there solid (they definitely should be with just finger pressure)

Remove head cover

Remove draw bar actuator block 6 hex bolts(this should sit freely on the front pulley guard, if it lifts then it will be pushing the draw bar open

While all that's off look at the draw bar locking half rings, undo the 4 allen bolts and remove the cap, there is an o ring grove above the groove for the locking half rings, if they didn't compress the springs enough they may have used the o ring groove

If the locking half rings are in the right position, and the draw bar is not being pushed from above then it is the spring count/layering that is the issue (first last springs not facing outward)

Hope this helps

I can write a walk through if required but be aware due to the compression forces there is a degree of danger (i know a guy that was lucky just to loose the tips of a few fingers when a weld broke on the pusher plate he was using)