Strand Minim Tilt Lock Knob Thread

[Don Allen]

What is the imperial size of the threaded tilt lock knob used on Strand Minim please Minim Spare Parts . I am working on putting a led source into some Minims to use in a theatre foyer for poster lighting.

[pmiller056]

Going by the silence, no-one knows. I'm guessing a Whitworth thread would be common for that era. Good luck finding British Imperial nuts and bolts in today's world. With a vernier caliper, a ruler and machinist's thread tables (internet search) it is straigtforward to work out what an external (male) thread is. Use the caliper to measure the outside diameter (inches) of the thread - what you measure will be slightly undersize compared to the 'official' size. With the ruler count the number of threads per inch. From the thread tables you should be able to pick out the relevant size. Internal (female) threads are harder to measure and it is usually quicker to find a bolt that fits correctly and then take measurements from the bolt. Don't forget that imperial 'things' tend to use 1/8ths and 1/16th etc of an inch which needs a bit of calculator-work after looking at a 1/1000 inch marked scale.

[J Pearce]

Most standard imperial threads are pretty easy to come by. Finding a knob/handwheel with imperial threads might be more complex, but maybe not impossible.

Alternatively take a metric handwheel and either drill out and retap or remove the inserted nut and epoxy the correct one in.

[pmiller056]

The person who started this thread (no pun intended) is from Australia, hence the 'good luck'. Most imperial threads I've seen recently on things are American sizes, because they are still in everyday use. I did consider suggesting altering by re-tapping, however this can significantly reduce part strength, so without knowing more about the application details, I said nothing. The simplest and quickest solution may be to change all the parts involved to a similar metric size (or whatever is locallly available).

[Don Allen]

Thanks for the explanation of finding thread sizes. I will metricate the tilt lock, go to m8. It would be nice to get a four point threaded knob.

[Junior8]

Over here nuts and bolts are available in virtually every thread size but I think the chances of finding an imperial handwheel off the shelf are remote.

 

Thanks for the explanation of finding thread sizes. I will metricate the tilt lock, go to m8. It would be nice to get a four point threaded knob.

 

Search Handwheels like https://www.essentracomponents.com.au/index.php?option=com_virtuemart&view=category&virtuemart_category_id=79

[Gerry]

Just checked one of my Minim Fs and it is an M6 bolt and lock knob for the tilt mechanism.

Cheers

Gerry