I was a beginner to start with and then took a break from turning for the better part of a year.. now that I'm trying to turn again it seems like nothing I turn is round. (This wasn't a problem a year ago.)
There was a recent thread discussing things like changing moisture content while turning which could cause a piece to get out of round, but some of the pieces I've tried are well seasoned.
I yet to turn a bit of MDF to make sure it's not the wood, but I'm hoping ya'll can answer a couple questions I have and/or suggest other things to look at.
If it matters, I'm turning on a Nova DVR-XP, though I think this is more about operator error.
First, to check concentricity (after roughing), I very slowly bring a pencil up to the spinning piece until it just barely touches, then turn the lathe off. If the pencil mark doesn't go all the way around the piece, I know it's not round in that spot. (I usually get the feeling it's out of round and then do this to check.)
Does this seem like a valid way to check concentricity, or have I missed something?
Second, I've noticed that when I'm roughing the gouge moves in and out like a sewing machine needle as I make the cut. As the piece gets closer to "round" this travel is reduced and eventually eliminated. Is this normal, or does it mean I'm trying to make too deep a cut?
Lastly, on the pieces that start out very out-of-balance, I generally start the lathe very slow and then increase the speed until I feel a little bit of, but not excessive, "sway" in the headstock. Is this an acceptable method, or should I slow it down to where there's no sway and slowly increase the speed as it becomes more balanced? Could this cause the concentricity problems I'm having?
I'm rapidly becoming frustrated, so any help ya'll can offer would be greatly appreciated!
-Mike
There was a recent thread discussing things like changing moisture content while turning which could cause a piece to get out of round, but some of the pieces I've tried are well seasoned.
I yet to turn a bit of MDF to make sure it's not the wood, but I'm hoping ya'll can answer a couple questions I have and/or suggest other things to look at.
If it matters, I'm turning on a Nova DVR-XP, though I think this is more about operator error.
First, to check concentricity (after roughing), I very slowly bring a pencil up to the spinning piece until it just barely touches, then turn the lathe off. If the pencil mark doesn't go all the way around the piece, I know it's not round in that spot. (I usually get the feeling it's out of round and then do this to check.)
Does this seem like a valid way to check concentricity, or have I missed something?
Second, I've noticed that when I'm roughing the gouge moves in and out like a sewing machine needle as I make the cut. As the piece gets closer to "round" this travel is reduced and eventually eliminated. Is this normal, or does it mean I'm trying to make too deep a cut?
Lastly, on the pieces that start out very out-of-balance, I generally start the lathe very slow and then increase the speed until I feel a little bit of, but not excessive, "sway" in the headstock. Is this an acceptable method, or should I slow it down to where there's no sway and slowly increase the speed as it becomes more balanced? Could this cause the concentricity problems I'm having?
I'm rapidly becoming frustrated, so any help ya'll can offer would be greatly appreciated!
-Mike