Thread: The all-wood tail vise - rugged & reliable

Ian

I assume your garter is two halves , but in the photos it looks like one part. That had me stumped as how the garter was installed, and spent a little time trying to decipher. Just in the off case there was magic involved could you please clarify it is too halves.

Thanks

Yes, Martin, it is two pieces.

This pic of the parts might be more self-explanatory: tail vise parts1.jpg

The garter fits in a rebate in the vise arm & is held in place by a backing plate (placed on the screw in the pic.).

Assembling the garter doesn't need any magic, but it can take a bit of patience! I have to keep the garter in place in its groove in the screw while I close up the screw & backing plate & get it to enter the rebate. There's no room for fingers, so I start with the screw backed off 20mm or so, fit the garter in its groove on the screw, then push hard against the backing plate as I carefully rotate the screw. Sometimes it pops into place perfectly first go, sometimes the garter turns with the screw & I have to use a thin stick to push it into position, & sometimes one side falls out while its opposite side goes in & I have to start over. Once both halves of the garter have started in the rebate, the game is won.

There are other ways to fit garters. For my bar clamps, the garters sit in mortises cut from each side of the head block & are retained by two side-pieces screwed to the head block which also act as guides to keep it aligned with the bar:

1 Moving jaw assembly.jpg 1a Moving jaw assembled.jpg

A few old benches I've seen use a one-piece garter (i.e. one half of the one above)which fits in a slot chopped down from the top of the screw hole. This system is far easier to fit - you just tighten the screw and drop the garter in. It's not easy to cut such a thin mortise (a good place to try out one of those sash-mortise chisels that were discussed not so long ago ) & it needs to be pretty accurate so it matches the groove in the screw cleanly or you could end up with a sloppy action. It is also a bit more difficult to extract if you need to dismantle the vice, and it's only bearing on half the groove in the screw. The latter is probably of no consequence whatever, the 'half-garter' clearly works & one of the benches I saw was getting on for 120 plus years old & though 'retired' by the time I saw it, it had clearly done a LOT of work in its day.

Fitting a "full" garter is probably more to satisfy my obsessive nature than to add anything significant to its function....

Cheers,
Ian

Hi Ian

Thanks for this , I have end up gluing on ring to the shaft. My little home drill press was annoying me s the too cuts for the rings off by 1mm. Hopeless accuracy. Dont feel too much pity. I have mill elsewhere and it would hit .002mm if I was using the NT40 compression cones in the . But 1mm thats .

I had to fit an urge to pull out the key and try and modify. But it is a hopeless cause. The reason mills have dovetail slides and adjustable shims.

I did it the way as the thread I using is 3/4 and cutting channel into seem a poor idea. I make a two part cover. It for a moxon vise but I am planning to rebuild two vises into low rack designs - one incorporating mitre jack features but this time built into the vise. Put an add on my vise , mentioned in the hand tools sect ion- I find it useful an annoying enough that it will have major rebuild.


PS

I reading your making threads book that taps are easy. Without bothering to reread your the pdf , just winging it that they are easy I made tap. What I did was cut a groove down the centre and glued a saw plate. File that tho the shape of the threads. It worked... squeals going in

The thread was a tad tight, so I made a tiny slit in the thread further up and shove another bit of saw blade and filed the to a shape to cut a slightly deeper thread

That was where easy took me..

Martin, necessity stirs the imagination, and there is certainly more than one way to make a tap, so kudos for your effort!

Funnily enough, the first tap for wood that I saw was the 'mediaeval' style one I described in AWR. I had had no experience of wooden threads at that stage & I just could not properly comprehend the thing. It seemed cumbersome as well, so when I first wanted to make a large wooden screw I went about it in a vaguely similar way to you. I hand-chased a thread on a maple blank turned to the 2" diameter I wanted, tapered the threads at the end down to the minor diameter & drove 14G screws in at even spacings around the tapered section. These were filed to make 'cutters' of gradually increasing height and some wood scooped away in front of each cutter for chip collection. This is the tap & the crude thread-chasing tool I made to form the thread:
Wooden tap.jpg

.... imaginative maybe, but it was not something to rave about. It was tough to turn once all the 'cutters' were engaged and needs constant backing out to clear the swarf. However, it worked, and I used it to tap the thread for the tail vise on my main bench, which is still working well 40 years later.

The tap held up better than expected (in Canadian woods), but after I came back to Oz I was never game to try it on hard woods like spotted gum or ironbark. Many years later, a mate made me a 2" steel tap so I could tap the river red gum for the bench we made for him: 2 inch tap.jpg

This cuts a beautiful thread, but it's a bear of a thing to start, and hard to turn! By backing it out & applying some linseed oil to the hole every few turns, it eases things, but I cannot turn it on my own any more (I could 30 years ago, just).

However, I always remembered that tap I'd first seen & so a few years ago, I was musing about the different ways one might make a tap & decided to take another look at it. 1.jpg

Whether it was the many years of wood-threading I'd amassed by then, or my brain just decided to work for a change, the penny dropped almost immediately, and it all made sense. My first attempt worked like a charm & I've since made numerous others, the smallest being 7/8", just to see if I could. The limitation on size is the hole through the shaft for the cutter - there is very little wood left around the hole at that diameter so it gets a bit fragile, but if you take it easy, it will work. I made several sets of handscrews using it: d.jpg

It has a couple of advantages over any of my other taps, the main one being it cuts the thread in 6-8 passes and is far, far easier to turn (a big consideration for me these days!). Another advantage is that I can adjust the thread at will, so if I happen to make a screw that is off-spec, I can easily make the nut tighter or looser to match. And once I cottoned on to the principle of the thing, I realised how easy it is to make a tap for any pitch & diameter I choose.

Now I wish I'd tried a bit harder to understand the thing 40 years ago!

Cheers,

Originally Posted by IanW

Now I wish I'd tried a bit harder to understand the thing 40 years ago!

Cheers,

But if you don't travel ALL the blind alleys how do you know this is the best way?

Think I have handle on your method. metal work taps could use less cutting action too. There are machines that are designed with one application - remove broken taps.

I do speculate that if the guide plate was shaped like this is might do away cutting the slot with a saw and possible misalignment with slot angle.scraper.png

Cheers and thanks.

Originally Posted by MartinCH

.....I do speculate that if the guide plate was shaped like this is might do away cutting the slot with a saw and possible misalignment with slot angle.scraper.png ....

Martin, I'm missing something there, I can't see how that would eliminate cutting the saw kerf in the tap stem. That's the very heart of the tap, the kerf drives the tap & determines the pitch of the screw. Remember, we're starting with the tap, it's the first thing you make. About the biggest mistake you can make is to lay out the threads the wrong way - I managed to set out a left-hand thread on my my first try, & got as far as starting to saw the kerf before my dull brain noticed it looked a bit weird.

Don't be too anxious about sawing the kerf with sufficient accuracy. I was really worried about that too, but it turned out to be easier than I anticipated. I had the tap chucked in the lathe & turned it with my left hand as I sawed. Keep the saw aligned to the helix angle of the thread and make a shallow cut, which you can then deepen a bit by going over it once or twice more, which will also even up the depth a bit. The kerf only needs to be 3-4mm deep to work perfectly well & don't worry about the depth so much, concentrate on following the line, that's the more critical part.

Even if your saw cut doesn't look machine-made, it will work fine as long as it's not totally wonky. This is the first one I made (after I realised I'd set it out wrong to start with!) & you can see the kerf isn't perfect: Tap kerfed1.jpg

But it makes clean nuts (these are 3tpi): Celtis threads2.jpg

And a threading jig for the router, made using that tap cut pretty acceptable screw threads : Good thread.jpg

You don't have to be super-precise with wooden threads, in fact you can't work to the same tolerances as for metal threads. Wood moves with the seasons so you need more generous clearances or you are likely to have them seize in the first spell of wet weather. And that's not theoretical, it has happened to me & with commercially-made screws (there was a thread on it some years ago).

Taking a theme from another thread we've been posting in, it's all a matter of working with appropriate accuracy....

Cheers,

Ian


Will take on board sawing will work.Was speculating that plough style edge with a extended body could carve a spiralled groove.

untitled.png

Regards

Originally Posted by MartinCH

.....Was speculating that plough style edge with a extended body could carve a spiralled groove. ...

Well, it probably would, but how do you get it to follow a specified course to create groove at the desired pitch?? Like I said above, at this stage, you have nothing it's the kerf that is going to create everything that follows.....

And a point worth adding: I think there is no need to put much of an indent in the guide-plate, certainly no more than you show with your drawings. I started out trying to make it a full half-circle, thinking it would need as much surface area bearing on the kerf as possible. But a) that adds to the difficulty, and b) creates more drag unless you have a perfect fit of everything.

Because you cut the threads a little at a time, the pressure on the guide plate is not huge (which is why you can use quite thin material for it), so the groove in the wood doesn't need to be deep and just a small scoop out of the plate is enough to get good engagement with the kerf....

Cheers,
Ian

Hi Ian

The drawings concept and a 30 second sketch with features exaggerated.

Thoughts on use.
Knock up small plate with a circle in it. Curve does not need to exact it assist in grabbing a bit more timber.
Initiate by bashing - sorry gentle accurate tapping to shear in a start groove.
Also add to your clever slotted box an angled hole and wedge with a dowel cut on appropriate angle.

Adding a self cutting guide plate is not a big deal.
But it is untested

The downfall is
Usually when I try something new I am obligated to make a really obvious boo-boo.