82-70 Jerking table

[AMFHighWycombeUK]

Hi guys, been floating around on here for a while but this is my first post

This has been an ongoing problem with one of our machines. Whenever the table goes down on either first or second ball (it doesnt matter which one) it jerks up and down quite violently. This can sometimes cause the table to knock pins over, but mostly they just wobble, but on the 2nd ball it will usually drop a pin or two or places them well off spot. We have tried many things. I have lubed and oiled nearly every part of the machine imaginable. we have replaced the motor and gear box, we have also replaced the eccentric drive all to no avail. if anything, its gotten worse.

Sometime the pin cups get stuck on the Respot cell rails too, im not sure if the two problems are connected or not but a possible solution to the both problems would be greatly appreciated

Thanks

Marc

[rivmike]

Hi guys, been floating around on here for a while but this is my first post

This has been an ongoing problem with one of our machines. Whenever the table goes down on either first or second ball (it doesnt matter which one) it jerks up and down quite violently. This can sometimes cause the table to knock pins over, but mostly they just wobble, but on the 2nd ball it will usually drop a pin or two or places them well off spot. We have tried many things. I have lubed and oiled nearly every part of the machine imaginable. we have replaced the motor and gear box, we have also replaced the eccentric drive all to no avail. if anything, its gotten worse.

Sometime the pin cups get stuck on the Respot cell rails too, im not sure if the two problems are connected or not but a possible solution to the both problems would be greatly appreciated

Thanks

Marc

I would say the table shaft key slot for the table drive is wore. Try a new key and super tighten the table drive. Watch it when the table goes over the top and see if you can see any slop in the key. (bouncing)

[8270king]

Tighten the 3/4 head bolt that secures the table drive to the table drive shaft

Use a breaker bar and long wrench for leverage

[felix]

A broken black yoke spring will cause this to some degree.

[smurtland]

I had a pillow block bearing on the end of the torque tube go bad and cause jerky table.

[chicken954]

I would have to say the table drive is starting to fail. I have had that happen in my center

[Tablejam]

Since the motor and gearbox and table drive have been replaced, that leaves possibly bad clevis bearings, the table drive is not clamped tight enough on the shaft, or the table shaft splines are shot. Put the table all the way down in spotting on a piece of wood then crank it so the weight is off the table drive. Now grab the table drive and try to rotate the table shaft, you really should not be able to. If the table drive moves keep doing it looking at the drive then shaft to see if anything else on the shaft moves. If it does then the splines are probably shot. At this point look at where the shaft goes into the gearbox to see if the output shaft or the table shaft or both move. Could also be a bad locking collar bearing.

If its just a loose table drive clamp I like to put the table at BDC, put a wrench on the nut/bolt on the bottom and turn it until it is tight against the machine frame. Then holding a wrench on the top I hit it with a hammer until it is as tight as I can get it, then knock off the wrench on the bottom.

[slb785]

I had the same problem on a lane. Followed pretty much the same path you did. Ended up replacing the table drive shaft. The slot as well as the key were worn

[Grit]

Sounds like you've got a good start on your bouncy table. I'm not sure how much good it did, but the spring hangar brackets and spot rod were way worn out on the machine I had this problem with and it ended up being the eccentric anyway.

As for your second problem it sounds to me like your table needs repositioning. Perhaps the previous mechs have moved the cups when they should have moved the table which is now casing the cups to grab your rails as they are trying to be set on spot.

[mechanic8230]

You might also check the table shaft bearings. Pop one of those puppies and weird things can happen. Most of the time though I would do like a couple of the others said..........look for a worn key or keyway for the table drive.

[AMFHighWycombeUK]

Thanks for all the replies guys. guna jump on the lane tonight and go through what people have suggested. Will let you know how i get on
Cheers

[keeth]

You could also put the table to spotting height and lift it up and down some by hand to see if there is a mechanical bind other than a drive issue.

[Pin_Head]

I know you said you have changed table drive already BUT double check as I have seen it so many times before, that the rod end on the table drive clevis has 2 bearings inside it, MAKE SURE there is a spacer inside BETWEEN the 2 bearings otherwise it will squeeze the 2 bearings together and can result in a very jerky action....

[AMFHighWycombeUK]

okay, so i decided to rip half the lane out last night and i replaced every bearing and possible part i could and it has sorted the problem, but now i am having the problem of the table will spot pins but not re-spot. i think this is due to the pin cups hitting the top of the pins, so i've raised the table slightly and now it wont go to its home position, when i push home on the chassis the table just sits half way?

[MarkyB]

Knowing your company's area technicians, i'd be giving one of them a call and get this wrapped up. Sounds like whatever you have done has caused a fault elsewhere, either by overlooking something when you have put it back together, or it was set up with bad parts in place, or something you have put on is duff.

By the sounds if it your keyway was worn, this will cause all sorts of jolts and bouncing. Do you know 100% that the replacement eccentric drive was good? You said it continued to do it when you replaced it, which would have steared me away from this unit and onto the mounting of the drive or the clevis assembly. Had it been me, if it didn't fix the fault i would have put the old one back on. Maybe this is the cause of bad respotting?

I have no idea what chassis/cam set up you have there, so as for the table home position it could need readjusting via the cam switches/cams, or again it coulld be a duff drive installed knocking it out of whack.

I'd be starting all the table adjustments from scratch, level it, check the height on spotting, flag and set toe in, check the yoke for damage and see if it continues to hit the tops of the pins on respots.

Personally i'd be on the phone to your area techs, they can come there and see the problem in action, quickly, instead of the descriptions put on here, you maybe overlooking something vital that would lead us to solve it quicker on here- hope that makes sence