Home made Pin Chuck

vendredi 2 mai 2014

Well I been at it again, playing around. My chuck jaws are absolutely off centre. Not happy Jan!!!



The need to mark the jaws is very apparent. I have decided on custom chucking for multiple use. I have put a screw in the jam chuck next to the No. 1 jaw in line with the key hole. May be a little hard to see below, had to go out side to take the pic because of the lighting. Still not much better lol. Oh and because of this screw I have decided to make my tenons a little larger than optimal. I have ground the head off the screw and just left a smooth shank sticking out. I thought of a nail but did not like the idea of it comeing out at 3000 rpm







Now I needed to take it down to size to suit the forstner bit. Lets try one of my plugs ... the the short side of the tenon has a centre point to work off







Jamb that up agains the chuck using the tail stock and I have an instant guide .... no measuring or making mistakes .... can do a visual without stopping the lathe (I'll just add that the end of the jamb chuck needs to be trued up before trying to use the plug and care taken to put it on central and keep the required pressure)







Moments later









What I decided to do was make another 'pin chuck' of sorts. I did not want the hastle of having to make sure the pin stays in place or worry about it coming out so this is my prototype. Not sure that I would spin it without something on it as the timber may give may. Also was chasing a way to clamp the chuck while I drill it.







Next was to turn some custom pins ... could have used steel but did not feel like cutting heads off of bolts. The idea with the holes is for them to be exact leaving a slot where the dowel can protrude under force but when stopped the pins need to be flush with the tenon. The dowels are about 1.5mm smaller than the holes drilled.







Little oversight on my part. When I drilled the holes above I lined up the first one, clamped the two fences in place and drilled the hole. Great line nice and square .... I was happy. Being that the chuck is round all I had to do was rotate it round to each position and drill again.



Oh Yeah .... the jaws are not closing to centre. The holes were out. One was perfect two were out. I ended up re-drilling the two holes that were not breaking through enough with another drill one size up. This worked but still .... should not have to compensate like that.



Next was to try it out. I have a blank with a hole cut in it so lets slide it on and give it a whirl .... and polish it while we are at it







Worked like charm. Steel pins being heavier would likely grip better, a nurled pin likely even better.



My only concern with a steal pin would be if it broke through the chuck and worse yet through the job being turned. Even with timber dowel I am not game to run the chuck without something on it.



Hope some may get inspired





Dave the turning cowboy



turning wood into art




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