Losmandy counterweight bar screw thread?

[milosz]

Hi,

Does anyone know what is the size of the screw that prevents counterweight to fall from losmandy counterweight bar? I measured it and it doesn't look like a metric thread. It has around 9.2 mm outside diameter. The closest popular imperial size is 3/8''. Does anyone know where to buy replacement for this knob? I'm enclosing the picture so it's clear which part I'm talking about.

 

milosz

[Davey-T]

Probably 10mm, if you're measuring into the thread it will be about 9.2mm, 9.8mm outside diameter.

If you've got a local B&Q you can get a 10mm bolt for a few pence to check the fit.

These people do all sorts of knobs

Dave

http://www.goodhanduk.co.uk/default.aspx

 

[milosz]

The outside diameter is 9.2mm, so it's surely not a metric thread. M series screws have outside diameter in full mm (i.e. 9, 10...)

 

milosz

[Davey-T]

If you can count the pitch in imperial you can work out what thread it is, could be UNC

Dave

[Davey-T]

 UNC is .373 inch, 9.4mm diameter, 16tpi I think.

Dave

 

[milosz]

https://en.wikipedia.org/wiki/Unified_Thread_Standard

I measured again. The outside diameter is 9.48 - 9.5mm. I counted 9 threads per 0.5 inch, but as I'm measuring in mm, this might be slightly off. So 16tpi looks about right. Basing on wiki, the closest is 3/8 UNC thread. Any idea where can I get such screw?

 

milosz

[Davey-T]

Lot's of stainless steel bolt suppliers on Ebay.

Dave

[milosz]

Silly me. It seems that it's the same thread as for photo tripod/head. So there are quite a few options out there

 

milosz

[glowjet]

Losmandy replacement parts are available through Orion Optics UK, however, they are, as one would expect, on the expensive side. I have used 3/8" stainless whitworth, at this size it is almost a match with the 3/8" UNC used by Losmandy. Ebay will provide you with suppliers for small quantities of stainless bolts and studding, often sold in short lengths. Use a short bolt, Araldite a wing nut or plastic knob on at the head end, to use as a grip, job done

[milosz]

Thank you all for your help. I'll figure out some replacement. Quick search on amazon revealed this: https://www.amazon.co.uk/5x-Knurled-Screw-alloy-steel/dp/B00CBILCQA. This is a bit too long, but should do the job. I just need one. Anyone interested?

 

milosz

[glowjet]

Expensive, as you only need one, if you source Ebay you can get a 4" length of 3/8" stainless UNC ( HPC gears ) for just over £1.50  and a scallop 10mm female threaded star knob for just over £4-0. Cut your thread to length, Araldite / epoxy, centrally and upright into the threaded part of the knob and allow to set, this will give a strong bond. Job done at just under £6. Just a suggested alternative solution  

[cesco]

It seems that a large washer that also sits there is missing....

[milosz]

Indeed, it's missing. But that is pretty easily available.

 

milosz