Offset finish to blank

[ni9eofse7en]

I have not turned too many pens, but I have noticed that on more than one occassion I seem to have an offset turning, in that when the kit is put together one end of the finished tube will have an area where it stands pround of the end cap or similar.

I do have a vibrtion when using the mandrel which has been there since day one. The bar appears to be straight when put against a flat metal surface. ie the lathe bed, but there is a wobble when you put the lathe on, but dont bring up the tailstock. The kiss test is spot on.

I do not get it with chucks etc.

It appears to be at the morse taper end as well which would or should be less likely, I would have thought.

Any tips on what to look for?

 

[Barry]

Try turning one blank at a time and have a light touch

 

[ni9eofse7en]

Try turning one blank at a time and have a light touch

Yes I think I am going to try this, also thought about turning down one end and reversing the tube before turning down the other. Funny thing was it was fine on the Zeta and the Pheonix, both one tube but not on the Omega or a couple of slimlines both two tubes. MMM!!

I'm not sure I can do a light touch, not with hands like shovels.

I can see its going to be about experimentation till I find my ideal.:pray:

 

[Buckeye]

I only ever turn 1 tube at a time. If you can't find the reason for the out of round turning then tbc.

Peter

 

[Jim]

Knurl to tight, rod bent is a couple John, but as said if you have this issue try between centers ..

 

[Chilprufe]

How much pressure are you putting on the tailstock ... I used to get the same thing and it turned out to be putting to much pressure on the mandrel and it flexing

 

[ni9eofse7en]

How much pressure are you putting on the tailstock ... I used to get the same thing and it turned out to be putting to much pressure on the mandrel and it flexing

I bring it up to touch, then tighten just to the point where the tailstock starts to spin in time with the mandrel

 

[Grump]

How much pressure are you putting on the tailstock ... I used to get the same thing and it turned out to be putting to much pressure on the mandrel and it flexing

Sounds like your most likely cause but could be any of above plus bearing wear in the headstock.
With sharp tools you should need to apply any pressure to the tool just a firm grip to guide the tool.

 

[Grump]

Ill fitting or out of round bushes could also be a cause.

 

[Neil Lawton]

You're not too far from me, bring your kit and try it on my lathes.
I'm sure we can sort it out.

 

[wm460]

Does you tails stock lock up firm?

 

[ni9eofse7en]

I am resurrecting this, has the machine an Axminster AW1416VS bought Feb 2013 now has a vibration in all speeds, which is worse in reverse, without any attachments. I have contacted Axminster and they will collect and inspect for £30 plus parts and I suppose re delivery. Does any one have knowledge of changing the bearings on these machines, or perhaps pointing me in the right direction. If it has to go back then so be it, it will still be cheaper than constantly ruining turnings, but if it is a relatively easy job, I will tackle it myself.

Thanks in advance.

 

[paulm]

I had a similar thing to you when I had the bearings go in my lathe John and was getting vibration and it wasn't turning true. I'm not that savvie engineering wise and found someone locally to change them for me and hey presto it solved the problem. Gradually over a period of time it went again and he changed them again but I've been told they can't be changed again so I'll be looking for a replacement lathe for turning pens as I have another vs lathe but don't like it for penturning as it takes too long to stop.

 

[Grump]

The bearings are simply a press fit.
I use a socket of the right size and push them out with G clamps.
Fit the new ones with a block of wood and G clamps.
Simples init?

I get my bearings from here but any bearing services will have them without paying through the nose at Axminster.

 

[ni9eofse7en]

Cheers Guys,

Axminster have just said about £50-£70 to replace, add pick up £30 then cost of sending back, another £30, thats a hefty bill for a bearing thats costs £??

Will check it out further.

thanks a lot for your time and assistance.

 

[PhillH]

Find a decent engineer local to you, should be loads where you are (used to be at least a few years ago)

They should be able to do the bearings for a LOT less than that. Even a decent mechanich should be able to do it, similar principle to wheelbearings after all.

HTH

 

[Grump]

Like Phil says a local garage / engineering workshop will have a press and do it minutes.

 

[Penpal]

There are numerous other reasons for out of round. Do you use a 60 degree live centre to the mandrel, is it worn there are too many clues missing. Personally I like Neils suggestion a best solution two heads and all that one with great experience and kindness.

Peter.

 

[ni9eofse7en]

Thanks for the feedback and offers of assitance guys.

Brian, thanks alledgedly their is a branch of your suggested site about 5 miles from me. So will contact them in due course.

I have today followed Axminsters suggestions and I have loosened and slid forward (it moved about a mm or two) the spindle pulley and retightened it, and it has improved to an almost imperceptible wobble on the end of the mandrel and this without tail stock pulled up. Before you could see a definite oscillation. I think long term it may have had a negative effect on the bearings but will turn something in the next few days to see if my results have improved.

The motor on its own was smooth and quiet, so I know now its the spindle end that was an issue.

There is no obvious movement in the spindle, so it may have been an out of balance or misaligned pulley to pulley. fingers crossed.

 

[ni9eofse7en]

Brian, quick question.

Sealed bearings I assume, metal or rubber sealed?