securing thumbscrews for eyepieces

[The Mekon (John Briggs)]

Not sure if the title conveys what I want, but I would like to know what thread the small securing screws are on items like eyepiece holders, diagonals etc. In particular the GSO/Bintel types that are made in China. They are around 3.7mm diameter and I dare not run a thread die down one (they are too short to start with).

Reason for this request is that I have lost one from my 35mm Bintel 2" extension and would like to obtain replacement.

[ZeroID (Brent)]

Don't know what the thread is but I have a heap of knobbed knurled screws from stuff at work that seems to fit the commonly used astro equipment. They are all knurled thumbscrew type pieces, chromed, plated or anodised whatever.
I'll do a check tonight and see what fits what and send a few over if you are stuck. Can post a few pix of the selection later if you want.

[The Mekon (John Briggs)]

Thanks Brent, but I would not trouble you to send me any screws. I have now measured the screw as best I can and the pitch is definitely 0.7mm but seems awful loose in the 4 x .07 die nut.
In the meantime I have cannibalised another diagonal to get a securing screw.

And of course none of my spare Televue or AP screws fit as they are all imperial, and most stuff out of the east is metric.

[Ausrock (Chris)]

Interesting question.........I had hoped they may have been standardised across the various brands but I guess that would be too sensible.

I purchased some WO binos from someone here a couple of years ago that were missing the eyepiece thumbscrews.........a subsequent enquiry to the seller resulted in a dumbass reply that left me with binos that are unusable ........calls to Andrews, et al., didn't help and WO themselves quoted a silly price so I let it drop.

[ZeroID (Brent)]

A few screws in the mail is just a couple of dollars across the ditch. I have a plastic tub of about 150+ of them of about 20 different types, lengths etc and can get more all the time.

Offer is to you too Chris if it solves your bino problem. I am using several versions in various EP holders as a lot of them seem to be in the right thread\diameter range.

No charge, just helping out. I have a good source of 'bits' and will never use all the stuff I have in the garage. Think of it as helping me clean up the workshop ....

I'll post a pic anyway and you can peruse.

[ZeroID (Brent)]

Screw Pix just in case you're interested.. And where I've used a few. I have heaps of the shorter knob and a lot of the longer which has a smaller thread.

[Ausrock (Chris)]

Brent,

Thanks for that.

I found the only thing I have which has screws that fit my bino, is an unbranded diagonal, anything else has smaller diameter screws.

I'm going to take the diagonal's screw to a specialist bolt company and see if........: 1) they can tell me the pitch, etc., and 2) if they're able to supply something similar.

I'll post back here once I have more info.

[The Mekon (John Briggs)]

Originally Posted by ZeroID

Screw Pix just in case you're interested.. And where I've used a few. I have heaps of the shorter knob and a lot of the longer which has a smaller thread.

Brent, I reckon only the longer ones have the common metric thread, but the question remains - just what are the thread specs? Perhaps Chris (Ausrock) will come up with an answer.

[FI93 (Norm)]

The Chinese have adopted the yankee POZI screws as their standard in all things furniture.... think assembling Chinese Ikea.
Thats if this helps.

[Ausrock (Chris)]

Originally Posted by The Mekon

Brent, I reckon only the longer ones have the common metric thread, but the question remains - just what are the thread specs? Perhaps Chris (Ausrock) will come up with an answer.

Hopefully, early Wed or Thurs morning I will get to the bolt company to get some info.

[ZeroID (Brent)]

These are Japanese from PC's, Copier\Printers, they are all metric. I work at Fuji Xerox, most of these are leftovers from upgrades and accessory changes. Remove one device, chuck it, add another device instead. I have some very unusual configurations from various hardware that have been incorporated into my peltier experiments.
If you want I can just send over 4 of each for you to try, if they fit great, if not, into the DIY bin they go till something else comes along.

PM with an address if interested. Couple of dollars and a bubble bag is cheap fun.

[Ausrock (Chris)]

The screws I required turned out to be M4 and are readily available as an "Allen head" with light knurling....... cost me $1.90 for six this morning.