# Would've been a CR2 light (lots of pics)



## yclo (Dec 3, 2006)

I remember I read on one of the threads that one shouldn't really work on a part that has a thin wall section, unfortunately this was after this happened:







It was going to be the head section of my very first light.

So anyway, after some  I went on and machined out the following parts:






1. Bezel ring
2. 
3. 
4. Threaded can to hold emitter/electronics (6 & 7)
5. CR2 battery tube
6. Cree XR-E emitter
7. Probably a BB400 for more runtime
8. 17mm UCL, 2mm thick

2 & 3 was my second attempt at my head section, problem is they should be one piece! The arrow is pointing to another thin wall section that I had forgotten about... 

I was after a flood so there was only a slight concave area surrounding the front of the emitter, and I also made the concave surface similar to an orange peel finish for a very clean flood. The front end would have looked like this if I hadn't screwed up.



 


(click on photos to view larger size)

To make myself feel better I modded an old KL1 I had lying around with a Cree XR-E emitter and a McFlood, the resulting beam is very ringy.



 

 




 

 


(click on photos to view larger size)

Hopefully soon I will complete my first light.

-YC


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## scott.cr (Dec 3, 2006)

Thanks for the pics... I've gleaned your way of mounting the LED concentrically (mounting it in the lathe tailstock). Don't know why, but I've never thought of this before.

You're not the only one to have an "oops" on a nearly-finished part, or while modifying a finished light! I have a drawer full of trashed parts (including some $40 Surefire bits) that I tried to take too heavy a cut on, slipped out of my lame three-jaw chuck, etc.


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## Anglepoise (Dec 3, 2006)

Looks fantastic to me. You might want to purchase a small quantity of 7075 T6 aluminum bar. Aluminum is so cheap that I think it is worth selecting the grade for each job.
I have just completed my first light with a very thin wall CLICK and the 7075 worked out really well. 

Also it helped me to work it all out on paper first so I had an exact drawing to refer to. Don't bore the piece out in one go. Drill in 1/2" and then bore and thread and groove that area. When completely finished and when you have tested the female thread for a perfect fit, continue on with the boring /finishing in small increments. This gives you less chatter, flex, vibration and opportunity for collapse.
Then when you are done, you could make up a stub mandrel threaded male end. Screw the part to it and continue machining the other end.

My threaded male ended stub mandrel does double duty as my go/nogo thread checker.
Good luck.


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## yclo (Dec 4, 2006)

I am using 6061 since the place I go to can only supply it in such, I'm playing safe this time and leaving the walls thicker. 

Didn't have a drawing, but there aren't that many dimensions to deal with in this case. And threading is done with a tap so I only had to make sure that the hole was bored to the correct size, battery pack was threaded with a die so there are no issues with the threads not fitting. The surface that rubs against the o-ring was a cut-test-repeat.

I made stub mandrels in both male/female threads for the bezel/battery pack, very useful for not getting jaw marks on the part.

I've just learnt that you shouldn't test fit a thick lens (2mm UCL) in a bezel until after you've made a through hole. If the fit is tight, there isn't enough space for the lens to rotate, it gets stuck very easily and the edges chip if you poke too hard.

I gave up trying to get it out and poked my boring tool into it with the lathe turned on:




(click on photos to view larger size)

This wouldn't have happened if I hadn't changed the bezel to not use a bezel ring! Then again it is a few operations less than before not including knurling, not to mention a bit shorter.

The new bezel!




(click on photos to view larger size)




(click on photos to view larger size)

I think for the part where the knurling tool didn't track properly was when I unscrewed the knurling tool too much to the point where the wheel wasn't in full contact with the metal. At least it tracked properly for a little bit, the knurling tool wheel is only 1/3 the width of the knurled area.

All is left now is assembly.

-YC


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## will (Dec 4, 2006)

Just a quick thought on using a tailstock. Make sure it is perfectly centered to the chuck. Of course this depends on how dead-on you want it to be. One easy way to check, get a piece of dowel rod ( wood - cheap and easy to cut. ) make it a reasonable length 6 inches or so, Put it in the chuck, the end flush with the jaws, drill a center point. Use a live center in the tailstock, extend the dowel out 4 or 5 inches, Have the live center extended out of the tailstock just 1/4 inch or so. 

Take a cut on the dowel making sure you cut the entire length. Use a micrometer to measure each end of the piece. If the tailstock is centered the measurements will be the same. If not, you will have a tapered work piece, 
second step - using the same piece, extend the live center as far as it can go from the tailstock. Take another cut - measure each end. 

The first measurement will verify the center is centered in the lathe bed. There is usually an adjustment on the tailstock to do this. the second measurement checks to see that the center goes parallel to the bed, 

If you have a dial guage, and a piece of stock that is the same diameter end to end. Put a center point in the end of the stock, put the dial gauge on the hold down. Move the stock out 4 - 5 inches and the far end centered in the live center. sweep the dial guage across the piece - it should stay on the same reading.

One other gotcha . I have used a threaded plug to hold something that was very thin. as the lathe is turning and if you are cutting on the outside, it is like taking a pair of pliers and tightening the work on the plug. sometimes it gets so tight you can't get it off, unless you use a pair of pliers. A little safer method - clean all the oil off the part. wrap some masking tape around each piece and try to unscrew it - that some times works..

I too have some parts that didn't make it all the way..


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## modamag (Dec 4, 2006)

*yclo: *From the look of the dame it looks like you're using a 3-jaw chuck.
Have you thought of going with a 6-jaw or 5C collets? Once you go collet you will rarely go back 

Beautiful part and execution!

*will: *I normally use Scotch Brite to grip and remove my threaded parts. Or if you want to be extremely careful make a delrin tube with slightly undersize, cut a thin slot so it become a "C" then use your plier on top of the delrin. This method will take care of those EXTREMELY hard stuff (eg. Ti Draco).


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## yclo (Dec 4, 2006)

will, 

I use the quick and easy (but less accurate) method of just gripping the drill chuck with the 3 jaw chuck. 

modamag,

Some how I don't think they make 6 jaws / 5C collets for the taig...




(click on photos to view larger size)

-YC


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## tvodrd (Dec 4, 2006)

Sympathies, friend! Having been there done that several times! Don calls it "pieces of pieces." When going "free style," (no sketch/print) even with a full set of 5C's and a Royal 5C quick-closer that prolly cost more than the Taig, making pieces of pieces is just faster! 

Larry


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## kromeke (Dec 5, 2006)

Yep, 5c is out of the question on a Tiag, but can you put soft (aluminum) jaws on the chuck? If you are doing several, you bore the soft jaws to the OD of the part, and you can clamp with much more surface area. 

Good work, it is always satisfying to see one's ideas come to reality.


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## yclo (Dec 5, 2006)

Further changes, seems that when I was turning the parts "free style" (as Larry put it) the length was a little off. After assembly the battery pack only engages about 1 turn before it switches on (using 1mm thread pitch), so I had to make up another battery body that fits a CR2 deeper.



 


(click on photos to view larger size)

As you can see I've decided to add an attachment point on the base, it still tail stands.... just don't bump the table...

Completed light has been posted here.

-YC


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