Might need a part machined

[BrokenBiker]

not entirely sure yet as I haven't got all the parts together, but may need a lens adapter machined out of Ali...

Rough dimensions would be about 50mm long, m42 female thread one end, 30x1.0mm male thread on other end and taper down from large end to small end...

Bore would need to be tapered to match outside dimensions, ideally about a 2-2.5mm wall thickness.

Would anyone be interested in such a job? Obviously willing to pay

 

[Richard.]

Produce a drawing. I may have a go.

 

[BrokenBiker]

Produce a drawing. I may have a go.

Will have to be hand drawn, will be mid next week when I know if I need one but in no mad rush to have it done.

Basically to put a better lens on a night vision rifle scope to give more mag and clearer image...won't knownthe malenthread dimensions until scope arrives and I have pulled it apart

 

[Hood]

Is it definitely M42 thread (4.5mm pitch) ?

 

[Richard.]

Hand drawn is great. I'm a beginner on a lathe so it may prove too challenging but I'll give it a good bash

 

[Kayos]

M42 lens threads are mostly 1.0, except the ones that are 0.75

 

[BrokenBiker]

Is it definitely M42 thread (4.5mm pitch) ?

Sorry, thought I said it was m42 lens thread, so 1.0mm pitch

 

[BrokenBiker]

Hand drawn is great. I'm a beginner on a lathe so it may prove too challenging but I'll give it a good bash

No worries, will let you know

 

[Hood]

Ah OK, the M in front of a metric thread denotes it being a standard metric course thread, metric fine threads always have the Dia followed by the pitch as in your male thread.
Just thought it weird that something like that would be metric course.

 

[BrokenBiker]

@Richard. have a butchers at this and see what you think. The instructions at the top for lather hearing are irrelevant obviously. Both threads are 1.0mm pitch. shape can be whatever is easiest as long as threads are right

This is a photo of a drawing I stole from another forum

 

[Hood]

If the internal shape could be starting at 38mm dia (inside dia of 42 x 1.0 internal thread) and taper down from there it would make things much easier to machine, having the start of the internal taper being the 42mm dia (or possibly more) would mean you have to plunge in after the thread. Not really a problem but just added complexity unless for some reason it needs to be that way?

 

[BrokenBiker]

If the internal shape could be starting at 38mm dia (inside dia of 42 x 1.0 internal thread) and taper down from there it would make things much easier to machine, having the start of the internal taper being the 42mm dia (or possibly more) would mean you have to plunge in after the thread. Not really a problem but just added complexity unless for some reason it needs to be that way?

Photo is just what someone else made...as long as threads are right, length is right (quite important that shoulder of smallest thread to end is close) and largest Dia is right them I'm happy.

Still not 100% the thread size is right, that drawing is for an older model so will need to measure mi e when it arrives

 

[Richard.]

I'll have a look see if it's within my skill level.
Couldn't of asked for a bloody welding job could ya lol!

 

[BrokenBiker]

I'll have a look see if it's within my skill level.
Couldn't of asked for a bloody welding job could ya lol!

Make it in sections and weld them together...overall result is still the same haha

 

[BrokenBiker]

As I say, I won't know until atleast mid next week whether I need it made yet. Would do it myself in work but took room is kept locked now

 

[Hood]

I could do it but my problem would be the thread fit as I don't have gauges for that. If corresponding threads could be supplied for fitting then not an issue.
Below is a cross section of what I was meaning regarding the internal taper starting at the inner thread dia.

 

[Pete.]

Your post says 30mm thread but the drawing shows 34mm, well, 33.75mm. You couldn't have a 30x1.0 and a ID of 28 anyway.

 

[BrokenBiker]

Your post says 30mm thread but the drawing shows 34mm, well, 33.75mm. You couldn't have a 30x1.0 and a ID of 28 anyway.

You are correct, and as mentioned in another post, that drawing is for an adapter for an older model so I need to check when mi e arrives as I have been told by people that have done this that it's a 30x1 thread

 

[Richard.]

I could do it but my problem would be the thread fit as I don't have gauges for that. If corresponding threads could be supplied for fitting then not an issue.
Below is a cross section of what I was meaning regarding the internal taper starting at the inner thread dia.

You have more of an idea than I do.
You should make it.

 

[Hood]

You have more of an idea than I do.
You should make it.

I have that much of an idea I said 38mm ID for the 42 x 1.0 thread, should have been 40 Must have had it in my head it was a 40 x 1.0.
This is fairly easy on a CNC, not so easy on a manual, I have both. I use my manual lathe more than I do the CNC because of the type of work I do but if there are more than one needed or the part involves any kind of taper or any kind of thread then I will use the CNC as it makes things like that simple.

As said my only problem would be thread fit unless I had gauges or corresponding parts to test with, I have neither. The external thread wouldn't be too bad as it could be measured fairly easily but the internal would be awkward.