Thread: Out of round solution

Tiger ! an alternative is to get a collet type mandrel ,this allows you to extend or shorten the mandrel as you wish it also allows you to replace the mandrel as a seperate item when and if needed ! cheers ~ John

Originally Posted by gawdelpus

Tiger ! an alternative is to get a collet type mandrel ,this allows you to extend or shorten the mandrel as you wish it also allows you to replace the mandrel as a seperate item when and if needed ! cheers ~ John

Like the idea John, have you used one that you can recommend?

Originally Posted by Tiger

Like the idea John, have you used one that you can recommend?

https://www.woodworkforums.com/showth...38#post1777638

Tiger Bigshed is right but he uses collets a lot and needs a range of sizes , the one I use for pens I got here when I first started some years ago now, I got the number 2 morse taper to suit my woodfast ,I have replaced the mandrel rod a couple of times, but I have done thousands of pens in that time I mainly turn between centres for real accuracy and concentricity . Less room to work, but made up for by getting it right every time , I am sure there are local suppliers as well I just never look anymore . Basically it allows you to position the mandrel to whatever length you need, from a single blank to some of the longer styles like long clicks, and not need a stack of spacers , hope that helps a bit , cheers ~ John

Originally Posted by gawdelpus

Tiger Bigshed is right but he uses collets a lot and needs a range of sizes , the one I use for pens I got here when I first started some years ago now, I got the number 2 morse taper to suit my woodfast ,I have replaced the mandrel rod a couple of times, but I have done thousands of pens in that time I mainly turn between centres for real accuracy and concentricity . Less room to work, but made up for by getting it right every time , I am sure there are local suppliers as well I just never look anymore . Basically it allows you to position the mandrel to whatever length you need, from a single blank to some of the longer styles like long clicks, and not need a stack of spacers , hope that helps a bit , cheers ~ John

I have one of these. MT2, collet at headstock end, brass nut at tailstock end.

I picked it up either from GPW or Timberbits (not sure which).

This is the one I use. It is a very neat fit in the mandrel saver.

Thanks all, like the adjustable mandrel but will give TBC a go, accuracy is so critical and I think I value that over anything else these days.

Originally Posted by Tiger

Thanks all, like the adjustable mandrel but will give TBC a go, accuracy is so critical and I think I value that over anything else these days.

Good move, once you try it you wont go back.

Okay so have tried a few things. Have tried tbc 2 ways, number 1 with no bushings so the brass tube sits between the centres, number 2 with some homemade bushings as per johnnycnc, they slip into the brass tubes. I still get slight out of round generally on the tailstock end of the brass tube. The out of round is virtually non-existent at the headstock end, always at the other end. Centres line up, blanks are squared, morse taper on headstock is clean, live centre appears to run true, still searching for that elusive perfect pen, by the way, a pen that appears perfect in the garage at night reveals flaws glaringly in the morning sun. Will keep trying.

Sounds like you may need to check that the tailstock is aligned properly with the headstock. A tool like this is handy. http://www.packardwoodworks.com/Merc...ct_Code=113121

Are you deburring the inside edges of the tubes once glued and trimmed ,that can make a difference as ,when the pressure is applied it can push off to one side slightly , also pays to not overtighten the tailstock ,just enough to drive while you are cutting ,I slacken the pressure off a bit for the finishing as it doesn't take much to drive and reduces any chance of distortion ,even so it sounds a frustrating process for you if its right at the headstock end ,maybe try finishing that end to the sanding stage ,then turn the blank around and finish the other end, that may tell you something , also are you using a proper engineered live centre with a 60 degree taper, even cheap ones of these are heaps better than any wood turning live centre . cheers ~ John

JT useful bit of gear there, John barrels are clean inside, the bushings won't go in to the barrels if there are any burrs however i noticed that the centre band on slimlines is not a tight fit. This means that the barrel will never look 100% because the centre band moves, so still getting some out of round but it's very slight. Should i be doing something about ensuring that the centre band stays fixed or is just faulty pen kits? Think i have to establish this first before trying to determine amount of out of round.