Handscrew with wooden threads

[AndyT]

I've a bit of a fascination for wooden threads and already have a few cramps/clamps/handscrews which use them. However, I recently managed to make a tap to match an old thread box - I wrote it up in the Metalwork section here making-a-tap-for-wood-t116626.html

This is the box and tap.

Having got the pair working ok together, it was time to make something with them. Something like one of these:

The lower jaw has both holes threaded. The upper jaw has a clearance hole on the right and a blind hole on the left.

I have a nice chunk or two of some unknown hardwood, which looks a bit like rosewood and used to be a table until some neighbours threw it out and I caught it. This bit is from the underframe on the circular top.

I marked out between the holes aiming to get two threaded handles out of it. To keep it simple, I cut away most of the waste on the bandsaw.

It may be only a little three wheel Burgess from the 70s but with a Tuffsaws blade it does the job.

I marked the centres and octagons on the ends

and planed down

I turned the round parts as close as I could to finished size

then finished them off in a dowel plate

At last it was time to cut a thread, which was quick and easy. I've read suggestions of slathering the wood in linseed oil when cutting but this didn't need any of that. Maybe it would have been different if I'd been cutting 2" boxwood but this was nothing like that.

Next time - making the jaws!

 

[Trevanion]

Looks like Cuban Mahogany to me, very nice stuff to work if you can get your hands on it anymore. It's been illegal to harvest for a very long time. I was given a large (about 7" square) pool table leg of the stuff a long time ago, I've still got a carved section that I planned to turn into a vase.

 

[DannyEssex]

Great stuff Andy, I enjoyed that! I have been think about making myself some cramps, but with a threaded rod.

 

[AndyT]

The suspense is over - here's part two! Not quite so many pictures for this, as I think everyone will know how to find a spare bit of wood, rip it to width, plane it square and cut it in half... One practical point is that for greatest versatility with these handscrews, you want the jaws to be wider than the handles of the rods. That way, the whole thing will lie flat, which is handy if you need to cramp the handscrew down to the bench. For example, if you are cramping a thin piece while mortising it (to avoid bursting the sides) for example.
In this case I'm not entirely sure what the wood was that I used. It was some sort of fairly soft, mild, straight grained wood - possibly parana pine. Anyway, I selected some suitable drill bits for the holes to be threaded and the larger clearance holes. In the end these were a mixture of metric and imperial sizes. One had a round shaft so went in a hand drill,

and the other was an auger bit held in a brace

There's no need to mess about with a drill press for something on this scale.

Next off was a quick bit of tapping

which worked without any wax or oil in this case, though I can imagine it would help for larger sizes.

I did run some superglue over the internal threads afterwards. They looked well-formed and strong enough but I thought I might as well.

I trimmed the ends off at a bit of an angle

then cleaned them up all round and eased the arrises with a block plane and some sandpaper.

Then the bits all got a wipe over with some boiled linseed oil. As it happened, I had some previously diluted oil in a jar, so I used that. It seemed to dry off a bit quicker and still give enough colour for the job. As usual, I propped the bits up on scraps of wood with panel pins in. These get used on all sorts of jobs and then live in a box at the back of the bench, next to the packing scraps and other useful oddments.

And so, here's a posed shot from the next day showing the finished article.

What might not show from the photo is that the proportions are a little bit off. I had concentrated on making the handles as thick as I could from the wood that I had, when they could easily be a quarter of an inch smaller on these slender threaded rods. But maybe this one will prove to be the exact right size for something.

They wouldn't look too clumsy if I had used the 3/4" commercially made Chinese tap and die set which I also have.
Looking around, they seem to cost a lot more than I remember paying - £44.95 and upwards at Axi - but a lot quicker than making your own. Overall though, I think it's a good way to use up useful-looking offcuts to make something functional and useful.

I wonder how many you need? :wink:

 

[AndyT]

Great stuff Andy, I enjoyed that! I have been think about making myself some cramps, but with a threaded rod.

Hi Danny. Yes, well worth doing, and cheaper than setting yourself up for the pretty wooden ones. The downside is that the threads are much shallower, so they take longer to adjust, but that's negligible really. It's easy to get M10 or 12 studding and threaded inserts or tee nuts from Screwfix/Toolstation etc for very little cash. You can epoxy the studding into a hole in any offcut for a handle and shape it to taste.

Also, once you have put handles onto bits of studding, you can make up any sort of special clamp for a specific job using whatever wood you have handy. I once made a shelving unit (like the top bit of a Welsh dresser) and clamped it all together with 6mm studding and various bits of skip wood - it worked a treat.

 

[Noel]

Andy, would Acme threaded rod work better rather than the common or garden studding? Much like you'd find on a pipe clamp fitting etc.

 

[AndyT]

Andy, would Acme threaded rod work better rather than the common or garden studding? Much like you'd find on a pipe clamp fitting etc.

I think it would be excellent. Looking on eBay, I see that cheap Chinese leadscrews come with a matching nut which avoids the need to find/make a matching tap, or construct a "garter". (Actually, the garter option would be pretty easy.)

As with so many projects I guess it comes down to how much time and how much cash you want to invest. I wouldn't want home made cramps to cost more than equivalent bought ones but there could be scope for making a special cramp that nobody sells.

 

[Noel]

Andy, would Acme threaded rod work better rather than the common or garden studding? Much like you'd find on a pipe clamp fitting etc.

I think it would be excellent. Looking on eBay, I see that cheap Chinese leadscrews come with a matching nut which avoids the need to find/make a matching tap, or construct a "garter". (Actually, the garter option would be pretty easy.)

As with so many projects I guess it comes down to how much time and how much cash you want to invest. I wouldn't want home made cramps to cost more than equivalent bought ones but there could be scope for making a special cramp that nobody sells.

Thanks Andy. I use a few old Jorgensen examples and would consider making some with longer reach/throat. With, as you mention, lead screws costing relatively easy money it would make sense. Even without a nut a self made garter/washer/retainer type of adaption would certainly work.

 

[Phil Pascoe]

https://www.ebay.co.uk/itm/New-T8-Acme- ... ctupt=true
I had some larger stuff marked, but it's no longer there.

 

[scooby]

Nice work Andy.

I keep meaning to make some of these (as mentioned from threaded rod). They look incredibly useful and wish they were more redily available in the UK as I'd actually prefer buying than making.
Might have a look round for trapezoidal/ acme threaded rods as, like you mentioned, normal thread rod is a tad slow.

 

[Rorschach]

One day I will make some of these. They seem to sell for silly money.

I saw one at a car boot, tatty edges, covered in paint and really just rough and nasty. Thought I could clean it up though, asked the bloke the price, £40 :shock: