Thread: Problem...

Originally Posted by funkychicken

At the bit of a pen where the wood meets the middle band (on a slimline) If the wood is bigger than the band at one point and smaller at another point... Is vibration the culprit?

If you are turning both parts of the blank at the same time on a mandrel, and the bit that is out of round is in the middle, then I would suspect you are putting too much pressure on the mandrel while turning, thereby creating an out of round centre.

If you are not doing that, you could have a problem with your live centre, but then the bit at that end should also be out of round, and probably worse.

Could also be too much pressure applied by the tailstock as well. Bring the tailstock up just shy of touching, then start the lathe up and wind the tailstock up then, it will sound like its vibrating and about to take off but once that sound goes away that is about where you need it. What is happening is the end of the mandrel is flapping against the live centre, but once it makes full contact it stops flapping and it has full support supplied to the mandrel.

Feathered one, just what sort of live centre are you using? If it's the one you had in last Saturday then I think that that is your problem. Try a Live centre that doesn't look like a volcano but has a simple conical tip.

Originally Posted by artme

Feathered one, just what sort of live centre are you using? If it's the one you had in las Saturday then I think that that is your problem. Try a Live centre that doesn't look like a volcano but has a simple conical tip.

And that makes a better mating surface between tailstock centre and mandrel?

More money spent

Originally Posted by funkychicken

And that makes a better mating surface between tailstock centre and mandrel?

More money spent

You need a 60 deg live center. The pen mandrel is drilled out at a 60 angle. A 60 deg live center fits in there snug as a bug in a rug and holds it steady. Your normal woodturning live center has a much sharper angle/point to it so it doesn't fit in there and when you put pressure on it or you have a heavy unbalanced blank on there it can/will move around in the end of the mandrel.

I saw improvement after I bought mine.

I went to a local tool supply store and bought it, just a cheapie for less than $20, it works well.

I got a cheap one from Woodworking warehouse a while back - blunt as, and perfect for pen mandrels (and $A15)

Originally Posted by artme

Feathered one, just what sort of live centre are you using? If it's the one you had in las Saturday then I think that that is your problem. Try a Live centre that doesn't look like a volcano but has a simple conical tip.

I like the way you put that...

Just my 2 cents worth but it fixed the same problem I had like that. The mandrel is only drilled a very short way in in the end & a pointed live center causes a wobble. Get a drill bit the same size as the hole & drill it 1/8 inch deeper, that way it will find the same size on the center on the point to fit the hole exact. Make sence? After buying 3 different mandrels that did the same crap & drilled & haven't had that wobble problem again.

I think you have your information. Let us know what you've decided and how you get on.

So where's the greenie Skew?

you think your getting a greeny

Originally Posted by artme

So where's the greenie Skew?

On the tip of my finger...

I'll buy a 60 degree centre...


Mr Toowoomba Woodworks must love seeing me walk in the door, I always walk out broke

**Feathered One- That's called "the real world". I note you have accees to free timber!

**Carl- Yes!

**Skew- Are you the president of the Nose Pickers' Union or just a paid up member?