Tool rest

[bwlossie]

Hi,
Would appreciate some ideas/suggestions please.

I have just bought a Perform CCL [4 weeks ago] and am not sure if I am doing anything wrong......

When roughing out from square to cylinder my tool rest cam lock keeps coming lose from the vibration of the square edges hitting the gauge.

I have tried lowering the speed and also increasing. Still works lose and Mr Sod decrees that the rest slides in the direction of the spinning blank and not away from it.

I am constantly having to reach my fingers inside the bed bars and try to tighten or should I say retighten the nut on the cam assembly in order to give me some grip. It still works lose again. Any ideas???

Barry.

 

[TEP]

Hi Barry.

Sorry to hear about the problem with the the tool rest. By the sound of it you mean the 'banjo' the part the tool rest fits into. If this is the case the nut should at least be a lock nut that does not come undone. Or occasionally you may find two nuts locked together.

I have found that when you get a new lathe with cam operated slides you may have to play about a bit with the adjustment of the cam. If you have the handle adjusted too tight, (little movement) often the vibration can loosen the slide.

Make sure the nut locks in place, and adjust so that you have plenty of movement in the lever yet can't push over the highest cam position. (I hope I explained that OK, I'm confusing myself) Good luck.

 

[bwlossie]

Hi Tam,

Thanks for the reply.

I have certainly not got a lock nut on it because I can turn the nut by hand [fingers through the bed bars]

Can't get to the lathe today to check exactly what is under there. It came already assembled so never thought to look.

From your reply it sounds as though I may be trying to have too little movement on the lever. My thinking being "let it grip as soon as possible, then there will be plenty of adjustment to hold it" Perhaps I am wrong!

Certainly a bit disconcerting to have it slowly creeping in to the work.

Barry.

 

[TEP]

By the sounds of it you have the cam mechanism set too tight, and if there is no lock nut please fit one straight away, or if there is room add another nut to lock the first.

You DON'T want the tool rest moving while you work.

 

[CHJ]

Barry, on the perform I had I turned up a disk of hardwood, about 75mm diam X 20mm thick with a hole in the middle just big enough to allow the force fit of the nut in it, (using a vice) this allowed me to more easily turn the nut to a better tension.

The outer diameter of the disk needs to be small enough to clear any casting webs, I had to remove about 5mm of casting flashing on mine to give clearance.

 

[bwlossie]

Thanks for replies chaps.

If you, Chas, had to modify yours, then it seems this is a common problem. Is the idea of a wooden insert so that it will grip the casting better than steel?

Will have a better look at it over the weekend. Some sort of locking needs to be in place. I assume I will be able to take it out by removing the stop bar at the end of the bed then sliding off the tailstock?

Barry.

 

[Russell]

Replace the nut on the underside of the banjo with a nylock nut that will solve the problem. I have had customers with similar problems with that type of lathe.

 

[bwlossie]

Thanks Russell,

Will do.

Good service department we have here!!!!!!!!!!

Barry.

 

[CHJ]

If you, Chas, had to modify yours, then it seems this is a common problem. Is the idea of a wooden insert so that it will grip the casting better than steel?
Barry.

No, just to make the nut larger diameter so that it is easier to turn.

You do not need to slide the tailstock off. If you just undo the nut and let it fall the lower clamp plate will fall off and you can lift the toolrest assembly off.

One restriction with using a Nylock nut with the perform variants of the lathe is that the bed casting thickness varies a few mm along its length, you may find it difficult to get a set nut position that allows proper clamping along the whole length of the bed.

I got into the habit of just poking my index finger between the bed ways and moving the nut disk a few degrees as required.

 

[bwlossie]

Chas,

You say you moved the disc a few degrees. I am having to turn the nut at least half a turn to catch up the amount it has loosened.

Barry.

 

[CHJ]

Chas,

You say you moved the disc a few degrees. I am having to turn the nut at least half a turn to catch up the amount it has loosened.

Barry.

Then I would try either the nylock route or tighten the thread fit of the existing nut with a couple of judicious centre punch dimples in the lower face of the nut.

If you have some stiff sheet rubber try bonding a washer made from a piece to the back of the nut (poor mans Nylock fix) or try winding a Rubber Band round the exposed lower thread to stop nut unwinding.

I suspect it is moving whenever you move the rest rather than when you are turning, but of course does not manifest itself until the clamp is not firm enough.

 

[Bodrighy]

I have had the same problem with myCCLl. The nut underneath works loose. As I don't have Chas's engineering background I just keep tightening it up. It is most prevalent, as Barry said, when there is a fair bit of vibration, ie when roughing out or if the wood is off centre.

Pete

 

[Paul.J]

Hello Barry.
I have the ccbl and it as loosened but not when i was working,and have now tightened the nut up just so that when i tighten the rest there is very little play in the handle.
Something that i am now aware of and just check it each time i use the lathe.If there is too much play in the handle on tightening the rest i tighten the nut.
Paul.J.

 

[CHJ]

Pete, Paul, if you try my wood disk on the nut you will find it easier to tighten the nut.

I tried a locknut on my machine but there was too much difference in the bed casting thickness to allow a setting that covered the whole bed.

 

[Paul.J]

Your right Chas.There is too much discrepancy on my lathe bed which is why i left the nut as it is,but i will give your method a go.
Paul.J.

 

[Bodrighy]

Thamks Chas, I'll have go at that.

Pete

 

[bwlossie]

As I said earlier, it appears to be a common problem with this lathe. I think the wooden disc seems to be the answer. Variation in casting thickness would be a problem if a nylock nut were used and it would be "fiddly" getting a spanner under there to release/tighten over a high point.

Barry.

 

[TEP]

Been following this thread and I have never owned a CCL, but surely the bed is machined underneath as well as on the top to allow the locking plates/stubs to slide.

I stand to be corrected on this.

 

[bwlossie]

Hi Tam,
Yes they are machined underneath but only for about 1/2 inch width of the bed assembly. There is, as Chas mentioned, casting flash in places where the supports go across and up.

Barry.

 

[TEP]

Thanks for that Barry. Hope you get it sorted.