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Gallery, Projects and General => Project Logs => Topic started by: John Hill on March 25, 2010, 01:58:00 AM

Title: Centre drill arbor.
Post by: John Hill on March 25, 2010, 01:58:00 AM
Do you ever get tired of swapping the centre drill in and out with other drills in your tailstock chuck? Me too, so this I what I did this morning.

(http://farm3.static.flickr.com/2798/4461130585_4592a6c94d_m.jpg)
First I found a centre with a drilled centre at the small end.


(http://farm3.static.flickr.com/2736/4461130589_c09c0500b8_m.jpg)
I mounted that in the lathe. One could say "A centre between centres"!


(http://farm5.static.flickr.com/4027/4461130595_4ed6d26853_m.jpg)
I used my DRO to accurately align the axis of the compound with the side of the centre.

(http://farm3.static.flickr.com/2786/4461130605_04162cd794_m.jpg)
I turned a taper using just the compound being careful to lock the cross slide and carriage.

(http://farm5.static.flickr.com/4015/4461130607_f75586207b_m.jpg)
I also drilled and tapped the end of the taper.


(http://farm5.static.flickr.com/4003/4461130611_27142ac523_m.jpg)
After removing the chuck I could test my taper in the spindle,  good fit!


(http://farm3.static.flickr.com/2707/4461138333_6def2fbfc2_m.jpg)
I turned the end of the work so that there was a parallel piece and another taper.  The small bit was parted off after I had cut a thread on the parallel section.

(http://farm3.static.flickr.com/2757/4461917320_546c3b81a0_m.jpg)
Using a specially ground tool I was able to run the spindle backwards and with the compound still set for the taper angle I cut another taper inside the end of the workpiece.

(http://farm5.static.flickr.com/4007/4461917630_1b878ba5f5_m.jpg)
The end of the workpiece was then tapped deeper.


(http://farm3.static.flickr.com/2733/4461139981_e0bb419034_m.jpg)
Then I tried the small piece screwed into the end of the workpiece. It looked good.


(http://farm5.static.flickr.com/4058/4461918334_3c1f159830_m.jpg)
This is the completed small piece, you can see the thread, the taper, the hole through the middle that matches the diameter of the centre drill and of course the slots that I cut with the HACK saw.


(http://farm3.static.flickr.com/2701/4461918680_c0f8f057ed_m.jpg)
Not much more to do except to put the assembly in Sally shaper to cut spanner flats on it.


(http://farm5.static.flickr.com/4049/4461141117_11dfeb00f0_m.jpg)
Here it is mounted in the tail stock. I also put a plug in the small end so that the tail stock ejector thingy would have something to bear on.

Although not the most elegant device to be posted on Mad Modders I must confess to being quite pleased with the outcome.



















Title: Re: Centre drill arbor.
Post by: sbwhart on March 25, 2010, 02:44:54 AM
Nice work John  :thumbup: :thumbup: :thumbup: :thumbup: :thumbup:

I guess you could make a range of those collets for different drills, a real handy bit of kit.

Stew

Title: Re: Centre drill arbor.
Post by: dsquire on March 25, 2010, 02:48:46 AM
John

Nicely done. That could turn out to be real handy. It's little things that can make a big difference sometimes.  :D :D

Cheers  :beer:

Don