Beginner Problem with New Tripod

[skir67]

I recently bought a new tripod, really happy with it all, but for one problem: the thumb screw (not sure if this is what they're called) that controls the rotational plane does not have a long enough thread to lock the tripod in that plane. I've measured the thread and it looks to me like it is 1/4 inch diameter or 6.16mm. The threaded bar is only about 1cm long, if it were 2cm long it would do its job. Do tripods tend to have their dimensions in imperial as standard?

I've looked everywhere for a replacement longer threaded part, but can't find anything. The retailer just wants me to ship it back to them, but I actually want to keep it and don't mind if I have a non-matching thumb screw just as long as it works! The tripod is a phot-r if that helps and I couldn't find a manufacturers website for them as I guess it's probably made in China. Quality seems absolutely fine bar the one issue.

Does anyone know of a good place to buy this kind of thing? Being I think I need an imperial part everything that pops up is state side.

 

[kendo1]

http://www.ebay.co.uk/itm/2-x-M4-X-...725?pt=LH_DefaultDomain_3&hash=item1a001fdc5d

They do other sizes on request.
Alternatively
http://www.ebay.co.uk/itm/Wing-knob-Wingnut-male-M4-M5-M6-thread-thumbscrew-trend-router-jig-dewalt-saw/271886592016?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=20140122125356&meid=4f5a79165a40417880eff11a8767e7a3&pid=100005&rk=1&rkt=6&sd=271872012847&rt=nc

If they are too long pack them out with washers- it's what I had to do with my 35 year old Slick tripod.
I could always cut it to size but never got around to it.

Tip: don't put 'knobs for sale' into Google.

 

[droj]

These days it's probably M6 (6mm). Consider that it may not be gripping because there should be an insert that's missing. This could be a short unthreaded plug that transmits the clamping force between the screw and whatever needs to be clamped. Such could be easily improvised ...

(The purpose of such a plug would be to prevent the end of the screw raising a burr on whatever's being clamped that would impede its further motion ...)

 

[skir67]

Thanks. I hadn't considered that it could be that something is missing. If it is M6 then that will make things a lot easier to get a replacement if needed. But I may try packing it out first and use the existing screw to tighten that. Perhaps a short length of dowelling rod will do the trick

 

[droj]

Perhaps a short length of dowelling rod will do the trick

I wouldn't use wood - it might splinter / disintegrate and jam things up. I'd cast about for a suitable diameter of brass, maybe - or nylon ...

 

[skir67]

Well I found some heavy gauge solder and have use short lengths of that and compressed them with the thumb screw and it has done the job. As its soft it compresses nicely under pressure and has meant that the internal collar can put enough pressure on the centre column to hold it in place firmly. Thanks for the suggestions.