MadModder
The Shop => Tools => Topic started by: websterz on June 05, 2011, 12:43:24 AM
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Today I cut my very first metric single point thread! :D
I have been working a 3 3/4" diameter lump of mystery steel down into the shape of an ER32 collet chuck for my 7x12 for the past several days. Today I finished turning the collet boss to diameter (40 mm or 1.575 for us Colonial types) and single pointed a lovely 1.5mm thread for the closer nut. Considering my lathe is Imperial I was a bit nervous about cutting metric threads on it. I was worried about nothing as it turns out! By a stroke of good fortune my new control board does not require that the speed be set to zero before reversing the motor. So it was a simple matter of one hand on the F/R switch and one on the compound. Back and forth, pretty as you please, until I had about 2 full threads engaging on the nut. Then I switched over to a double cut 3 corner file and dressed the thread until I had a very snug fit. A quick polish with 200 grit emery to clean up the ragged crown and the nut spins on and off like silk. Here's a video of the final result. (Sorry about the loud radio in the background)
http://vid797.photobucket.com/albums/yy258/websterzdesign/er32chuck.mp4 (http://vid797.photobucket.com/albums/yy258/websterzdesign/er32chuck.mp4)
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Websterz,
Congratulations, another string to your bow.
Isn't it nice when you discover how to do something that has previously eluded you?
Sorry I couldn't watch the vid, but I won't allow Quicktime anywhere near my computer, but I am sure you are well proud of your achievement. As you should be.
Bogs
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Thanks John, I feel like one of the guys now! :)
I just came in from the shop for a bite to eat. This morning I set up for cutting the 8* taper and finished the lathe portion of the collet chuck project. I had about .003" of non-repeatable TIR according to my Starrett Last Word DTI. I am chalking that up to a bit of a rough job boring the taper. I will spend some time with my cratex sticks and hone the bore down and I imagine the runout will drop dramatically. Now I have to pull the chuck and set it up on the mill to drill tommy bar holes and d/t set screw holes for dialing out the runout (if there is any left). I recessed the back of the chuck and left a 3/8" thick lip that extends over the spindle face. It will act like a Set-Tru chuck and allow me to dial the chuck in dead nuts. I know there wiill be no error in the collets as they are top o' the line Parlec brand. I was going to buy the cheap Chinese stuff but I got these on the 'bay for a couple bucks more than the cheap stuff. I love it when a good bargain comes along!!
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Websterz,
Well done - give yourself a pat on the back :thumbup:
DaveH
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Websterz,
Well done - give yourself a pat on the back :thumbup:
DaveH
Hey!! A guy can break an arm that way! :bugeye: Let the rest of us do the patting. Congrats. Websterz :clap: :clap: :clap:
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Websterz,
Congratulations, another string to your bow.
Isn't it nice when you discover how to do something that has previously eluded you?
Sorry I couldn't watch the vid, but I won't allow Quicktime anywhere near my computer, but I am sure you are well proud of your achievement. As you should be.
Bogs
Here are a couple of pics of the final product. I added the 4 set screw holes and numbered them for easy reference. I also added 2 tommy bar holes. Ignore the mess behind the lathe...I'll get to it later. Oh, a little trick for indexing the part on the mill for drilling holes. I mounted a 3/8" stud in the collet chuck with a square nut on the end of it, held solidly with a smaller jam nut to keep it tight. It was a simple matter of rotating the chuck in the vise in 90* increments and clamping down on the square nut for equally spaced holes. Why set up the rotab for six quick holes?
(http://www.okiegauges.com/images/er32/closeup.jpg)
The bar is the one that came with my mill for locking the spindle during tool changes. I built a spring loaded one a long time back but kept the little Chinese persuasion bar...knew I'd find a use for it eventually! As luck would have it the spanner that came with the lathe for adjusting preload on the spindle bearings is also a perfect fit on the closer nut. My lucky day!
And yes, the power was OFF when I left the tools in the chuck for the pic. :)
(http://www.okiegauges.com/images/er32/tools.jpg)
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Websterz,
Congratulations, another string to your bow.
Isn't it nice when you discover how to do something that has previously eluded you?
Sorry I couldn't watch the vid, but I won't allow Quicktime anywhere near my computer, but I am sure you are well proud of your achievement. As you should be.
Bogs
Vid is just an MP4 John - I right-clicked, save as and watched it with GOMplayer.
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Well done
There is nothing like screw cutting to clear the mind
Total concentration is a relaxing thing
John
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...Total concentration is a relaxing thing
John
Indeed it is. It is also a great way to speed up the clock. I put in 8 hours in my little playground today and it feels like half that.