Boring Reflectors

[Alan B]

I've tried a couple different techniques when boring aluminum reflectors (on the lathe) for a larger bulb, but usually end up with some scratches in the reflector.

What's the best way to do this?

 

[Anglepoise]

I asked the same question back in 2006 and got good explanations
from Don, 'tvodrd' and others.

Here is the link to the thread on CPF

http://www.candlepowerforums.com/vb/showthread.php?t=130850

 

[Alan B]

Thanks for the link. Interesting.

That thread was mostly about outside turning rather than boring the bulb hole, and the most useful suggestion there seemed to be use a vacuum.

I have tried the step drills and the boring bar from the backside, but both seem to manage to get some chips to the inside of the reflector. I can try the vacuum through the spindle, not sure if that will help.

Any other success stories?

 

[Anglepoise]

I used my shopvac pointed right at the boring bar on a number of 'enlargements' for bigger bulbs. Very fine depth of cut and it all gets sucked away. Just a fine dust that can be washed away.

All my work has been done on reflectors gripped in the chuck with the reflector pointed at the tail stock.

 

[QtrHorse]

PM sent

 

[Alan B]

I used my shopvac pointed right at the boring bar on a number of 'enlargements' for bigger bulbs. Very fine depth of cut and it all gets sucked away. Just a fine dust that can be washed away.

All my work has been done on reflectors gripped in the chuck with the reflector pointed at the tail stock.

Thanks for your experience. I'll have to try that next time.

 

[darkzero]

I've had different results over the years. I've always bored out the opening of reflectors by hand using a tapered reamer & shortened reflectors using a cut off wheel in a Dremel drill press stand for plastic reflectors or using a diamond hone for metal reflectors. I always get dust onto the reflective coating but I've never really had the reflective coating damaged because of it, both metal & plastic reflectors. I cut down to the size I needed them blew out the dust with compressed air.

Now that I have a lathe I've bored & turned now numerous of McR & Mag reflectors & again still haven't had the reflective coating damaged yet. I get paranoid with metal reflectors when I see chips fly into the reflector since they're actually mostly "chips" & not "dust" as I'm used to but still no scratched reflectors yet. I do the same, blow it out with compressed air when finished. Maybe I've just been lucky?

Only time I have damaged reflectors is when trying to mill the back side of a McR reflector using a 1/8" end mill in my Dremel drill press & the reflector caught the bit & flew. I've done this succesfully but after that time I'll never try again!

Other time was when trying to turn down the outside diameter of a LEDIL Boom reflector & the reflector flew as my cutter touched the reflector. Probably cause the 3 jaw chuck couldn't hold the plastic reflector very well. The Boom's shape didn't get damaged but the reflective coating flaked off from the impact. I was dumb enough to try it a second time with the same result. The coating on the Boom seems really fragile IMO.

These two incidents is mainly cause of my stupidity though & I have learned my lesson (well not with the Boom yet, going to try again with a 6 jaw).

 

[wquiles]

I have just been taking light cuts and used compressed air to remove the dust/chips - I never touch the reflector with anything. Works better on the stippled reflectors since they are more forgiving (already have an irregular surface that hides well any potential tiny scratches).

 

[The Dane]

I use a sharp 2-4 face endmill and go slow. It makes nice cuts that curl backwards and stay out of the reflector.

 

[will]

Any dust or debris can be cleaned away by swishing the reflector in soap and water, followed by a complete rinse with plain cold water. Never touch the surface, blow it dry with compressed air, or even the filtered output of a vacuum cleaner. I have not had any problems using this technique.