Flying head!

Today I finished the laser head. It was my first time doing threads internally and I'm delighted with the results!(don't forget you can do a slide show by clicking on the images)

The beginnings of this piece can be seen in an earlier post, so this is the continuation.
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I'm going to test the ZNSE focal point with a red laser. I wonder if it is different from the focal point of the IR from the Co2 laser? Yes, I would say.
I think the images do a good job of explaining what i'm up to here so I'll keep this short.
The air assist fitting is 8mm tube diameter on a 1/8 bsp thread. Drilled and tapped.

Its difficult to see in this picture but the end of the middle tube is threaded externally at the end.

The thread I used is 24mm X 1mm. I learned how to thread off a video on youtube.(search "tublicain")
I decided to do air assist while I was at it.
I got a lovely 50.8mm focal lenght ZNSE lens off ebay. It is 20mm dia', so I cut a little sholder for it to sit on inside the nozzle.I'll put a thin washer/seal under it so as to protect the lens and seal the pressurised air from comming out the wrong place

The outlet for the air/laser is 2mm dia. I have no idea if this is too big or not. If anybody reading this has more information about what size it should be please leave a comment.

Adjustable mirror mount, The first.

 

This is the first one I'm making and it is for the gantry, which seems to dictate a few different heights on other parts of the machine.

I mostly copied this design from mirror mounts I saw for sale on Ebay. The plate with the mirror attached is pulled tight against the thumbscrews by a pair of springs. It all pivots on a ball bearing.

 

I decides to go with 25mm diameter mirrors because it allowed for the best chance of alignment to happen at all!

I started by using a 1" hole saw to cut the recess for the mirror to sit in. I just cut 2mm or so in to the 6mm thick aluminium.
Then I drilled out the rest of the material to a 22mm hole. It wandered all over the place as can be seen from the back view. Not too big a deal in this case, just looks poor.
For the ball bearing hole and thumb screw holes I used the cone of a centreing drill. it gives a chatter free conical hole, unlike a counter sink in my drill press.
Perhaps not the best cone angle.
I'm using a 6.5?mm dia ball bearing here. It was just one I had lying/rolling around. It seems okay.

The adjusting screws are M4 by .5, the fine version of the standard M4 thread. I did so because I read someone giving out about a similar set-up which was using a standard thread here and it was very difficult to get an accurate adjustment with it.(this was on a commercial, cheapo Chinese laser cutter.)

I cut the springs from a long spring I had and bent the loops up. They work well. 4mm dia with wire of .9mm I think.They are held in place with TIG filler rod pins.
I made the thumb screws on the lathe. Turned from 6mm brass rod, down to M4 by .5!(with a die). I should have faced off, then centre drilled the ends of the bar before I started, as I need to put a small ball bearing into the end of the thumb screw to stop it biting into the aluminium.

The mirror will be held in place with a ring held in with three M3 socket heads. To be cut on my router from 2mm aluminium sheet.