'Moxon' add-on vices

[No skills]

So any newer versions of this vice will have bosses and little turn handles on both ends of the threads? :wink:

Nice vice btw.

 

[condeesteso]

v4 now done, ready for a new home. Just made the screws a bit shorter as I saw no point having lots of capacity. This one will open to almost 4" which I think is more than enough and it becomes a little easier to store. I think I'll stop now.

 

[condeesteso]

Getting common, these things. v5... has to be the last surely?
I tend to raid the 'offcuts' pile for these, and fell upon a short board of lime. It dawned on me lime is much favoured by carvers partly because it behaves so well across the grain, and the screws are all cross-grain. I must say the threads into the lime are blinding. Usual pre-soak with boiled linseed 50/50 with white spirit (turps if you feel posh). Given the thread bearing surface is quite considerable, I am very confident the lime will work really well for many years.
The pegs for the bosses are African blackwood this time... inspired by the bridge pins of violins, cellos and the like ('twas a tuneful day).
See those curls of lime from the thread cutter... a good sign

 

[Richard T]

Wow Douglas - the V4 looks fantastic.
The shorter screws make sense, considering its obvious primary use will be for the sawing of dovetails and dovetailing railway sleepers is not my bag - plenty long enough.

I can't work out from the picture though, how the connection to the legs differs from Andy's V3; there seems to be only one sliding dovetail each side of Andy's and two each side on the V4 ...? or is it just too early in the morning?

 

[xy mosian]

I haven't seen the review but it may be worth noting the thread depth. The smallest 1/2" has a nut bored before tapping of 3/8ths. the biggest 1 1/2" is bored 1 3/8ths, so relative thread depth reduces as you go up in size. I find this odd, but on the v1 the 'nut' depth is effectively about 60mm. Whatever breaks I cannot see it being the threads.
The main reason I bought this one was for the taps really. I feel 'not fit for purpose' would have been extremely harsh, at £40. But as I say not seen the review.

Hi Douglas, sorry to go back to an earlier post of yours, but I am interested in the thread form. The Axminster images seem to show a thread angle of about 60 degrees. Your dimensions for the 'tapping hole' would appear to give a thread depth of 1/16". I can't quite get my head around the maths. Is the thread in the female really that shallow?

Well done on the whole development by the way. A fascinating job on your part and a good collaboration with Jim.
xy

 

[condeesteso]

Yes Richard, no two are quite the same. v4 has dovetail at front (an engineering aberration but still easily strong enough). v5 has a fatter dovetail at back again.
Re thread depth xy, the hole for internal is bored 1 3/8, the round for thread external is turned 1 1/2, so thread depth can only be a mere 1/16th". It's odd as it looks much deeper than that but the start dimensions are right. I'll take a closer look at actual thread and angles anyway. Generally the axial depth of thread is about 60mm anyway, and I could not imagine ever stripping a thread.

 

[xy mosian]

Thanks Douglas. As you say it works. Brings into perspective the need for accurate turning of the un-threaded male screw.
xy

 

[keithkarl2007]

Sorry for dragging this post up again, but I just came across it for the first time. These look awesome.

 

[jimi43]

Sorry for dragging this post up again, but I just came across it for the first time. Theses look awesome.

Don't apologise mate! This thread deserves a new lease of life...Douglas made a brilliant bit of kit there...use mine a lot!

Jimi

 

[keithkarl2007]

I'd love to make one but my woodworking skills wouldn't include great threading and tapping like that.

 

[condeesteso]

sorry slow back on this. It's a big cheat KK, just a thread cutting set from Axi, about £40 I recall. I got the biggest they do 1 1/2 inch. If you were closer I'd happily lend it out. Cover post and borrow it if you fancy. The only other stuff you need is some offcut hardwoods, and a bit of plumbing 1 1/2 pipe (pvc), blocked one end, drop the screw blanks in and soak in thinned linseed for a day prior to cutting the threads. The set includes the tap for female also, so it's easy really.

 

[Eric The Viking]

There's a "Woodwright's Shop" episode on these vices (Chris Schwartz + Roy), I think in the most recent series.

It's a really interesting discussion IIRC.

E. (rapidly turning into a devotee of St. Roy!)

 

[condeesteso]

Eric, I would like to see that (those two never fail to impress) - how might I find it? Particularly I want to see what they do to cut the threads. The Axi set is rather fine pitch for a vice - the big specialist wood screws for vices (often 2"+ stock dia) are far coarser pitch and therefore way faster to use. In theory maybe I can cut really coarse threads on my Myford, but will I ever get around to investigating that??

 

[bugbear]

Eric, I would like to see that (those two never fail to impress) - how might I find it? Particularly I want to see what they do to cut the threads. The Axi set is rather fine pitch for a vice - the big specialist wood screws for vices (often 2"+ stock dia) are far coarser pitch and therefore way faster to use. In theory maybe I can cut really coarse threads on my Myford, but will I ever get around to investigating that??

Here's some inspiration:

http://www.woodworkforums.com/f152/wood ... se-131710/

Here's a big, coarse screw:

http://www.sawmillcreek.org/showthread. ... oden-screw

http://www.sawmillcreek.org/showthread. ... iant-screw

BugBear

 

[Eric The Viking]

Found it: http://video.unctv.org/video/2265291141.
It's also on the main PBS site. They use slightly different players, so you might find t'other works better.

Ee'll get trapped. Oi's warnin' ee!



E.

 

[condeesteso]

Thanks all - I had a look BB - the coarse thread will be excellent indeed, I just cannot face the time and effort of making the tap, and would need to investigate if the Myford can cut such coarse pitches. If I was serious about these things ('Moxon' vices) I'd maybe get a toolroom to make the tap for me... but it's too far down the 'to do' list.
I would say if anyone with the lathe and mill fancied making these, they would be worth quite a lot as custom-made wood screws for vices are pricey - Richard Maguire's are really excellent but £160 each (£295 a pair) - 2 1/2", 2 tpi. But even when you have the right tap, you still need a big lathe I guess to cut the male thread.
I'd been wondering if a good add-on vice could use steel screws (York-style).
I will definitely watch the video of Chris S and RH... 2 of my favourites.

 

[bugbear]

Thanks all - I had a look BB - the coarse thread will be excellent indeed, I just cannot face the time and effort of making the tap, and would need to investigate if the Myford can cut such coarse pitches.

AFAIK any screwcutting lathe can do what you need - you just need the changewheels.

Roy Underhill shows a method of using the large male screw itself to cut the nut, no tap required.

Wow.

This guy "did it all". I can't find a way to get a simple narrative on his blog, but it's all there

http://dblaney.wordpress.com/category/wooden-screws/

Finally found a "full on" trad write up:

http://lumberjocks.com/mochoa/blog/28554

(summary: make lead screw with "slot" thread, make false nut with bent metal thread segment, use cutter on lead screw to cut nut, couple lead screw to bolt blank to cut bolt)

BugBear

 

[AndyT]

All excellent links BB - straight into the Bookmarks! (some of them were there already but it's really useful to have them consolidated like this).

 

[condeesteso]

Agreed, excellent research BB. In shall look further into Mr Underhill's work on this too, although I am wary of the hours doing this could take. If only someone made a smaller wood screw and nut (say 1 1/2") with a steep pitch (3 tpi??) they would have a nice business I suspect.

 

[Eric The Viking]

The commercial screw boxes are all very well, but they make the assumption that you can cut the thread in one pass.

They have to work that way, because the cut thread then has to enter the wooden thread, to pull the work through.

It has to be said, though, that Roy Underhill screw box has a better design of blade than other people, using something that looks a bit like a carving "V" gouge. The picture quality wasn't very good on the episode about screw boxes (heavily over-compressed IMHO), but I think he ended-up with a much cleaner thread than most of the ones I've seen - less breaking of the tip of the thread.

On that subject, in metal the Acme thread form is supposed to be one of the strongest and suitable for leadscrews and vice screws. The wooden ones I've seen all tend to be basically triangular. Has anyone found any research as to the best thread for the purpose, or is the general idea just to make them as big, in diameter and pitch, as possible and hope for the best?

It's just tweaked my curiosity at the moment*

E.

*too easily done - must focus more!