Rough threads on a Al PD?

[gjg]

Hello All:
Finally got my first McG - an Al PD with a TYOJ Lux III - Great Light!! Figured I would want to swap out the emitter with a Seoul right away, but MAN this baby is bright and white!! Anyway, the previous owner somehow nicked up the threads on the body a little bit, just enough to cause some roughness and slight binding when turning the head. Not nasty, but not normal, either. So, do I buy the equipment and clean the threads myself, or do I send it in and let a pro do it? My concern in doing it myself is the possibility of taking off a little TOO much metal, or even the coating, and ending up with too loose a fit, and a bigger problem. And right now I have NO idea of the thread size. So, any suggestions? I KNOW I gotta make it right somehow, or I'll never really use it like I should...
TIA,
Greg :shrug:

 

[Oddjob]

Greg,

My PD had some areas on the threads where the anodizing did not quite take-almost as if there were some small chips in the anodizing. This is somewhat of a normal occurrence from what I understand. More importantly though, the outside of the light has no imperfections. My threads are a little rough but I cannot feel it when twisting it especially after the application of some lube. I'm sure Don will chime in and if he does not you can always e-mail him and ask for some guidance.

 

[PhotonFanatic]

Hello All:
Finally got my first McG - an Al PD with a TYOJ Lux III - Great Light!! Figured I would want to swap out the emitter with a Seoul right away, but MAN this baby is bright and white!! Anyway, the previous owner somehow nicked up the threads on the body a little bit, just enough to cause some roughness and slight binding when turning the head. Not nasty, but not normal, either. So, do I buy the equipment and clean the threads myself, or do I send it in and let a pro do it? My concern in doing it myself is the possibility of taking off a little TOO much metal, or even the coating, and ending up with too loose a fit, and a bigger problem. And right now I have NO idea of the thread size. So, any suggestions? I KNOW I gotta make it right somehow, or I'll never really use it like I should...
TIA,
Greg :shrug:

Buy a tube of diamond polishing compound, anything from 15 micron to 3 micron should be fine. Just do a Google search on diamond paste to find some.

Apply to threads and just work the pieces back and forth until things smooth out. You may have to thoroughly clean off the junk a couple of times enroute to the very smooth threads that you want.

 

[Groundhog66]

I have used toothpaste on my Ti PD-S before, and it worked quite well. Give it a shot.


Tim

 

[datiLED]

I have used toothpaste on my Ti PD-S before, and it worked quite well. Give it a shot.


Tim

Great tip. This is a good way to get your light into mint condition. :tinfoil:

 

[Kiessling]

Yeah, right. But he is talking about an aluminium PD

Is there actualy damage or deformation to the threads? Al PDs are usually butterly smooth ...

bernie

 

[gjg]

Bernie - Yup, thre is some slight damage to the threads in the body near the top, like a previous owner used a tool of some type and slipped :shakehead. I'll try the polish idea first (not sure if the damage is enough to cause the problem), if that doesn't work the threads will have to be chased or professionaly (Don?) fixed.
gg

ps - would Flitz work as a polish, or is that too coarse??

Yeah, right. But he is talking about an aluminium PD

Is there actualy damage or deformation to the threads? Al PDs are usually butterly smooth ...

bernie

 

[Kiessling]

I have no idea, sorry. I am just a dumb user :green:
You'll have to wait for the experts.
bernie

 

[easilyled]

I would also recommend the toothpaste.
I've heard this tip from some of the best machinists on CPF.

 

[Anglepoise]

I personally would be very careful about using diamond paste as recommended above.
Because diamond is many times harder than aluminum, you have the distinct possibility of the diamond embedding itself permanently into the aluminum.
You have now made yourself a 'lap' and every time you twist the threads, you will get accelerated wear.

I would suggest toothpaste or Brasso liquid and gently turn the threads to try and 'knock off ' the high spots.

If there is a little play, one layer of Teflon tape will do wonders for smoothness.

 

[jumpstat]

I polised my PD-s threads on both sides (PD & Head) with normal polishing compound and soft cloth. I did it to the point that threads do not have any more crap on it. Then apply the nyogel. I tried the Krytox but nyogel buttery smooth..

 

[PhotonFanatic]

I personally would be very careful about using diamond paste as recommended above.
Because diamond is many times harder than aluminum, you have the distinct possibility of the diamond embedding itself permanently into the aluminum.
You have now made yourself a 'lap' and every time you twist the threads, you will get accelerated wear.

I would suggest toothpaste or Brasso liquid and gently turn the threads to try and 'knock off ' the high spots.

If there is a little play, one layer of Teflon tape will do wonders for smoothness.

David,

Diamond polishing compounds are routinely used to optically polish aluminum and moldmakers also use diamond paste to polish their work.

Most laps use a groove of some sort to hold the diamond paste and to provide space for the metal being removed. And aluminum laps are definitely used extensively, so I think your fear of diamond embedding itself in the aluminum is unfounded, but I am willing to be shown otherwise.

I usually just wash out the diamond paste and aluminum grit with some hot water, detergent and a brush, or occasionally I will use mineral spirits to clean things up.

 

[McGizmo]

Would it be possible to get a pic of the damaged area? if there is deformation of the threads in a single spot or two, lapping compound would take a fair amount of time to work this out and the "high spot(s)" would be working away the anodize on the mating thread which is fine, as is.

If the damage is in the female thread, chasing the thread with a 13/16"x20 tap would likely remove the offending portion. You could also use a dremmel tool to remove the interfering section of thread assuming it is not extensive.