Machining PEU slots: How to glue in trits?

Gary123

Enlightened
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Jan 5, 2007
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Trits in my PEU bezel are too dim. Replacement trits I got are same diameter but about 1mm longer. Anyone I can contact to break out old trits and enlarge slots for my new trits? I have a contact who can install the new trits, but if the machinist can do that too, that would be great.

Thanks.
 
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Re: Machine work needed to enlarge PEU slots

While Pablo is technically correct, his advice (this one time) may lead to trouble.

"armed with a dremel, good grip, pulse and a lot of patience"

RIIIIIIIGHT

Dremels tend to slip around and grab and jump a lot when you first try to use them. A skilled person can get great results, but I'd recommend a drill press or mill with an appropriate cutter.


If you try the dremel technique, you will want to practice, a lot, before you start. The cutter you use will make a big difference, but I do not know which one would be best. You will need to hold the light steady, preferably in a vice.

If all the trit vials are not visible at the same time, then the relative sizes do not matter much and you can be fairly sloppy.

BTW, when you break the tritium vials, do so outside with the wind blowing the gas away from you. There is not much radioactivity in the vial, but inhaling it is the danger, so do not take chances.

Daniel
 
Re: Machine work needed to enlarge PEU slots

Bingo! Daniel is 101% right, I should put more emphasis on:

good grip by using a vice
patience by practicing
pulse by more practice :)

Small tools on the dremel tend to climb and get out of slots in no time.

Regarding the tritium radioactivity, I think (I may be wrong) if you pass near a nuclear plant or some nuclear medical device you will get more radiation than a small tritium slot venting.


Pablo
 
Re: Machine work needed to enlarge PEU slots

The dremel can be a very useful tool. Like any hand held tool, it can slip, jump, or other wise move around. To enlarge a slot without a milling machine - you might be able to get by with a series of small holes drilled on a drill press.
 
Re: Machine work needed to enlarge PEU slots

Since he's adding only 1 mm to an existing slot, he might even be able to get good results uisng a drill press and a drill bit that is the same diameter as the slot is wide. Drilling into it at an oblique angle may do the trick.


re: the radiation: Yes, driving past a nuke plant will give you more exposure, but there was a thread that said inhaling the gas will cause it to lodge in the lungs, creating long term exposure. I'm not a doctor, but since you can be protected by the simple act of doing it when a breeze is blowing or a fan is pushing the gas away from you.... Why not?

Dan
 
Re: Machine work needed to enlarge PEU slots

Trits in my PEU bezel are too dim. Replacement trits I got are same diameter but about 1mm longer. Anyone I can contact to break out old trits and enlarge slots for my new trits? I have a contact who can install the new trits, but if the machinist can do that too, that would be great.

Thanks.

Do you know what was used to install the Trit vials that are in the light now? One can use chemicals to break the bond and remove the Trit vial without resorting to breaking it.

I would suggest getting the slot milled that extra 1mm longer to fit the new vial.

No way would I try milling anything on a flashlight unless it were properly held in place and the cutting tool similarly held by the appropriate holding device.
 
Re: Machine work needed to enlarge PEU slots

I would suggest getting the slot milled that extra 1mm longer to fit the new vial.

No way would I try milling anything on a flashlight unless it were properly held in place and the cutting tool similarly held by the appropriate holding device.

Yes Fred, but we've seen the marvelous tools you have at your disposal. :) Your definition of "appropriate holding device may be somewhat .... jaded? :)

But Photon Fanatic is right. I'd use a mill too.

Daniel
 
Re: Machine work needed to enlarge PEU slots

BST Trade bezel with a member who has one with no trits, win win.
Norm
 
Re: Machine work needed to enlarge PEU slots

I'm not familiar with this bezel, but if the slots pass all the way through, your best bet is to get a cheap set of needle files and file away that 1mm. You can take your time and get the slots perfect without any risk of damage. If the slots are blind, well that's a different story...

Jeff
 
Re: Machine work needed to enlarge PEU slots

Trits in my PEU bezel are too dim. Replacement trits I got are same diameter but about 1mm longer. Anyone I can contact to break out old trits and enlarge slots for my new trits? I have a contact who can install the new trits, but if the machinist can do that too, that would be great.

Thanks.

If you remove the trits, I will enlarge the slots length by one MM for you. Heat and a dental pick are known to work well on removing epoxies.

Daniel
 
Re: Machine work needed to enlarge PEU slots

Thanks for all the help folks. PEU - no way I would attempt a dremel on such a beautiful bezel - totally forget that option.

Norm: This doesn't address the problem that the slots are still be too small, I'm not concerned with removing the old trits.

JHanko: I have needle files, interesting idea. goes slow and much more control.

Daniel: I think I will take you up on your offer. I will work on getting the old trits out. I will take a quick look at the needle files as I have several of them. I will PM you when I am ready.

Thanks all.
 
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Re: Machine work needed to enlarge PEU slots

Hi Gary,

I was a little concerned about doing mine but I did it with my Dremel and a diamond coated bit hand-held with great effect. Once the tritiums were installed there was no evidence that it had been altered.

Good luck if you try to mod it, Peu has done a fantastic job in making the rings, there are really nice.


Andrew
 
Re: Machine work needed to enlarge PEU slots

Daniel: Very good! Heat and the dental pick worked fine! Old trits are out.

On closer inspection, both ends of all slots have like a little "cup" for trits to "seat" into (gorgeous machining btw), a little wall at each end. And my new trits are more like 1/2 mm too long. Just a hair too long.

I imagine the easiest way to machine the slots bigger would reduce or remove that little bit cup. Maybe I should leave it alone.

Andrew: did you remove the little cup at either end of each slot?

I do have green trits that will fit; but everything I have has green trits! I wanted to put in different trits on my HDS so I easily distinguish it (I have both white and blue).

Daniel, what say you?
 
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Re: Machine work needed to enlarge PEU slots

Hi Gary,

Just to clarify;

The ring from the outer circumference has a slot for the tritium and the inner circumference has a smaller aperture machined through.

I left the inner aperture and merely increased the length and depth of the outer tritium slot, so I was left with a slot in which to drop the tritium phial but the inner thickness stopped the phial from passing through the bezel ring.

Does that make sense?

Andrew
 
Re: Machine work needed to enlarge PEU slots

Norm: but the slots would still be too small.
But you wouldn't have the problem of removing the trits and someone else would have the benifit of trits on there light.
Norm
 
Re: Machine work needed to enlarge PEU slots

I imagine the easiest way to machine the slots bigger would require removal of that little bit of wall at either end of each slot. Maybe I should leave it alone, maybe this is too much.


Daniel, what say you?

Since I would be using a mill, there is no problem with leaving the little bit of wall alone. I'm planning on putting the part in the vice, with the edge of the slot at the top. Move the table 1mm to the right and a quick cut with an appropriately sized end mill should do the trick.

The problem, as always, is seeing if I have an endmill of approximately the same size as the existing cut.

PM sent with mailing info.

Daniel
 
Re: Machine work needed to enlarge PEU slots

Daniel:

I may take you up on that.

But I just compared my trits in a dark room, and the green trits I have are the original ones for the PEU bezel (I got the last three from gregw) which are significantly brighter than the white and blue I got from Bart. But green should be brighter.

If I decide to use the green ones that fit, how do you glue them in? What type of cement do you use and are there any things to be aware of?
 
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Re: Machine work needed to enlarge PEU slots

Gary decided that he would like my help.

He mailed me the bezel and a tritium vial.

Here's the bits I used next to the bezel. They are 1/8 inch shanks. I mounted one in an morse taper collet. These are sitting on the table of my micro mill.

tritslot2.jpg



And here's the bezel nounted in a 2 inch, 3 jaw chuck on a rotary table. The rotary table just... rotates, but in a very controlled maner.

tritslot1.jpg




And last, a quick and dirty up close picture using the wrong camera. It shows the cutting in action.

tritslot3.jpg





The part is on it's way back to Gary now.


Daniel
 
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