+- MetalworkingFun Forum (http://www.metalworkingfun.com)
+-- Forum: Machining (http://www.metalworkingfun.com/forum-5.html)
+--- Forum: General Metalworking Discussion (http://www.metalworkingfun.com/forum-6.html)
+--- Thread: Centering a punch mark in the 4-jaw (/thread-2667.html)
Pages:
1
2
RE: Centering a punch mark in the 4-jaw - krv3000 - 05-11-2015
hi well in my post on me air engine one way is to use a needle in a tale stock chuck the other one that I have is a wobbler I will have to get a pic of it and post but the way it works is it goes in the tool post it consists of a gamble and a long rod with a point at both ends one point goes in the pop Mack turn the lathe chuck by hand and the other end will run of centre keep adjusting the parte until the rod says still
RE: Centering a punch mark in the 4-jaw - doubleboost - 05-11-2015
https://www.youtube.com/watch?v=PR3pTlDrjBU
RE: Centering a punch mark in the 4-jaw - Pete O - 05-11-2015
Good to see I'm not too far from the mark. I can see a spring loaded arrow in my future- although I've found it easy enough to set it up either in the tailstock chuck or with the hollow end of the arrow shaft positioned over the tailstock centre, so whatever is in the tailstock at the time can stay there.
A friend loaned me LH Sparey's 'The Amateur's Lathe' a couple of years ago and he shows the gimballed wobbler that krv3000 describes, the free end is much longer than the end that engages the punch mark, so the eccentricity is magnified at the free end. A nice tool, but I like using the clock like John does in his video, knowing exactly how far to adjust in each direction. I must make a second chuck key to make this easier.
The last bit of your video was gold John.
RE: Centering a punch mark in the 4-jaw - Hawkeye - 05-11-2015
I made a wiggler out of about 10" of 3/16" music wire. Ground to about 60*, with a wheel collar made for holding the wheels on the landing gear of an RC plane added near the point. The collar was to make the surface bigger to work with a dial indicator, about the same diameter as an arrow. I never felt the need for a spring on the end.
Sorry. No pictures until I get my equipment back, possibly withing the next few weeks.
RE: Centering a punch mark in the 4-jaw - mcostello - 05-12-2015
Easier way- just lightly clamp the center punch in a tail stock drill chuck and put it in the center punched hole. Put indicator on center punch mark and have at it.