I'm trying to make a between centers boring bar to use for boring the Sparey Dividing Head I've cast.
I'm not having much luck. I have drilled the centers in the ends twice, and when the bar is mounted between centers, I get .003" to .005" runout on the bar.The first time I cut the centers I used a flange type ER32 collet chuck that I made. I know it has .003" runout. I tried again with my 4 jaw independent chuck and got the same runout when mounted between centers.
The bar I'm using is from a platform roller on a treadmill. Lathe is an 10 year old Micromark 7x14.
Any ideas where I'm going wrong?
Chuck
I'm not having much luck. I have drilled the centers in the ends twice, and when the bar is mounted between centers, I get .003" to .005" runout on the bar.The first time I cut the centers I used a flange type ER32 collet chuck that I made. I know it has .003" runout. I tried again with my 4 jaw independent chuck and got the same runout when mounted between centers.
The bar I'm using is from a platform roller on a treadmill. Lathe is an 10 year old Micromark 7x14.
Any ideas where I'm going wrong?
Chuck
Micromark 7x14 Lathe, X2 Mill , old Green 4x6 bandsaw
The difficult takes me a while, the impossible takes a little longer.
The difficult takes me a while, the impossible takes a little longer.