Yet more bench questions...

Fir legs

Ted Owen, Pittsburgh

>I'm considering using Douglas Fir (sold as "Oregon" in Australia) as the base and legs...

The leg mortise and tenons will take a lot of racking stress over the years. I'd recommend a hard wood.

Best, Ted

Re: Fir legs

Patrick Gibbons, Houston, TX

>I used doug fir 4x4's on my bench with the Veritas bolts and nuts to keep them tight. No problems so far. I put rubber feet on the end grain and did not use a bottom stretcher. My bench is also on concrete. The floor is not level and I have had to take measures to counter that. Be prepared for the same problem.

Re: Fir legs

Robin Frierson

>I made by bench with Doug Fir 4x4's held together with threaded rod run through the stretchers and unglued M/T's. When the bench loosens up I just tighten the rod every few yrs. But I have noticed the washer/nut does compress the fir and after about 10yrs my washers are dug into the wood a good 1/4in or more. So using hardwood may not be a bad idea, since it is the Ultimate bench.

Re: Fir legs

Patrick Gibbons, Houston, TX

>I've had the same experience with my washers. I think if I had used oversized washers it would have been advantageous.

Re: Yet more bench questions...

William R. Duffield, on the Cohansey

>There is no maximum benchtop thickness which would preclude use of the Veritas twin screw vise, as long as you can find a piece of wood wide enough for the back face.

Yup

Roger Nixon

>My bench top is dressing out at 3 1/4" and I'll be using the Veritas twin screw vise on it. The vise jaws need to be 3 3/4" deeper than the bench top thickness if you follow the Veritas directions.

Twin screw

Clay Craig in Miami

>My twin is due from Veritas any day, but I thought the distance between the rods and the bottom edge of the jaw was fixed ... ?

If so, and in your example the jaws are 7" tall, do you risk vertical racking if you clamp a piece with only the top inch or so 'grabbing'? Seems these aren't designed to resist vertical racking (or, put another way, spread its pressure much above the rods) in the same way that a face vise like the Record 52 1/2 does.

I'm considering putting a second Veritas twin on a new bench as a face vise, so I've been pondering (in my fumbling way) these depth/apron/jaw/rod questions. Does anyone know of a link to the schematic or installation instructions for the Veritas twin?

Clay

Re: Twin screw instructions *LINK*

Ed Mulligan, Cape Cod

>See link for instructions - Ed


LV Vise

Re: Yet more bench questions...

Russell Seaton

>The reason is that this will be sitting on concrete so I do not want to have end grain on the concrete. I'm considering using Douglas Fir (sold as "Oregon" in Australia) as the base and legs for economy reasons. If well selected, it can look good as well.

Whether Doug fir looks good as a base will depend on what would you use for the top. If you use a hardwood, the softwood Doug fir will look out of place. It will be a noticeable mismatch. Look at the Ian Kirby bench in the Workbench book. What's wrong with end grain on concrete? Is your concrete under an inch of water? Why not just seal the end grain of the legs? I have about 3 or 4 or more coats of oil on the end grain of my bench legs and I can guarantee no moisture will ever get into the legs. Unless its literally sitting in water, and then I have more important things to worry about.

The legs will also be flush with the front edge of the bench. I plan to bore holes in the front legs to use a board as a board jack with the holdfasts.

Flush legs are good. Good for clamping stuff to the legs. I hate the idea of holdfast holes in the leg to support a board for a board jack. A far easier and superior method is to drill 1/4" holes in the legs at about 2" on center along the entire front vertical side of the legs. Try to keep the holes in both legs in the same places. Then get a 2x4 or something and glue a 1/4" dowel in one end. For the other end try gluing a 1/4" dowel in it too. The dowels should then slide into the holes you drilled in the legs and you have an adjustable full length board jack. And no huge holes in your legs for the holdfast with fewer adjustments possible. On one end of the 2x4 the dowel may have to be loose in an oversized hole to accomodate the discrepancy in the holes drilled in the legs.

I will also leave myself the option of putting a metal face vise on later by allowing sufficient bench overhang but for the moment, I will put a planing hook where a face vise might go.

If I could get my money back for the Record vise I have, I would. The Veritas twin screw vise does everything the Record does and much, much more. Don't waste your money on a Record vise.

I did consider the Veritas twin screw vise instead of the traditional tail vise, but I'm assuming that this would not work with such thick top. Or at least, that's what I'm thinking anyway. Is that belief mistaken?

Its mistaken. My bench top is 2.5" thick and the screws are about an inch lower than the benchtop, so in affect my twin screw vise is on a 3.5" thick top. With the twin screw vise you have to make the jaw face about 3" taller than the bench top to accomodate the hardware. So on your bench it would necessitate about an 8" tall jaw face. My jaw face is 7" tall. It just means more room above the screws. No big deal.

Re: Twin screw

Roger Nixon

>The distance between the centerline of the screws (is that what you are calling rods?) and the bottom of the jaw is 2 1/2" minimum for the thrust plates. That is the only limitation I saw.

Re: Twin screw--Vertical racking

Wiley Horne--Glendora CA

>Hi Clay,

I have two twin-screws installed. Like you, I was concerned about vertical racking. As you will see from the instructions in Ed's link, Lee Valley makes two main provisions against vertical racking. One is to provide a 'slope' of 3/32" top to bottom on the inner face of the front jaw, so that the top engages first, then the whole jaw engages as the 3/32 takes up the play in the jaw drive. You need that slope and it does work.

The second provision against vertical racking is the spacer block between the top of the screws and the underside of the bench. LV recommends leaving 1/16" clearance between the spacer block and the screw threads. I didn't do that. I closed the jaws all the way and put in a soft wood spacer (redwood in my case) that had no clearance against the screws. In other words, it was scraping against the threads when I slid it in, and I might have had to tap it lightly to get it into place. Now as the jaw operates, the threads cut into the soft wood (or hard wood for that matter) until the main body of the screws are bedded against the spacer. This is just about a zero clearance spacer, and it removes about all the vertical play, other than the play in the front jaw attachment. The lubrication on the screw threads works into the spacer, so that the added friction is OK. It'll still turn with one finger.

For what it's worth, the distances from centerline of screw to top of jaw on mine are 4-1/2 and 4-1/2". Vertical racking is offset very well by the measures listed above.

Wiley

Correction

Wiley Horne--Glendora CA

>That's 4-1/4" and 4-1/2" in the third paragraph.

Wiley

Re: Twin screw--Vertical racking

Frank Mutchler

>Wiley, did you mount the two vises as a tail & face vise? Do you have a double row of dogs the lenght of the bench? Thanks.

Thanks - Consider me reassured!

Clay Craig in Miami

>

Re: Twin screw--Vertical racking

Wiley Horne--Glendora CA

>Hi Frank,

Yes, one covers the right end, and the other is at the left front.

When I built the bench about 18 months ago, I decided to put in rows of holes when I needed them, as I (irrationally) couldn't bear to make swiss cheese out of my new bench. So far, I've only needed a single row of holes along the front, even to do diagonal planing on panels. There's probably some killer app that I'm missing out on, and perhaps someone can let me know what it is.

Those long vises have been great for edge-jointing boards 3 to 3-1/2 feet and under, of which there seem to be a zillion on the projects I do--the vise just grabs most of the board. Also for sawing. And for transferring dovetail marks from the first board to the second.

Wiley

Re: Twin screw--Vertical racking

William R. Duffield, on the Cohansey

>Wiley,

Why did you choose a wood as soft as redwood for the spacer blocks? I was considering making a spacer block out of something at the other end of the spectrum, specifically lignum vitae. Would that be a good idea, or do you think something softer would work better?

Re: Twin screw--Vertical racking

Wiley Horne--Glendora CA

>Sir Wm,

Here's my reasoning, which is offered with only modest conviction. I was going for a tight fit. With the vise in closed position, the spacer is actually tapped into place above the screws, scraping across the threads as it seats. The reason for making it so tight was to hold the screw level as it passes through the nut which is let into the rear jaw.

The problem I was worried about at the time was that I didn't want to misalign the screw, and create metal on metal grinding between screw and nut. So I figured if the tight spacer were to create any stress on the nut--due to imperfect flatness or thickness of (a) the rear jaw, (b) the underside of the benchtop or (c) the spacer, or (d) seasonal wood movement--that such stress would be quickly relieved by the softwood spacer yielding.

Of course a question is whether the screws would over time chew up the con-heart redwood. I didn't know. My guess was that the threads would follow the same path in every time, and that the body of the screw would just lay on the spacer--and therefore would not chew up or crush the spacer.

Well, data is better than theory, so just this minute I went out and pulled the top drawer of the bench and shone a light up under there so I could look at the spacers after 18 months of action. They are not chewed at all. The threads follow the same track, and have bitten in of course, but there is no crushing of the wood. I ran my fingers where the body of the screw beds into the spacer. There is just the slightest indentation perceptible to the touch. I would guess the total give of the wood is no more than 1/64th, probably less.

If I were going to do it over again, I would probably use hard maple. Mainly because my gut feel now is that misalignment is a non-issue if the components are all machine-thicknessed. It looks to me like there's a lot of latitude in the wood that is chosen, and that anything between soft maple and lignum would be just fine. Or even conheart redwood.

Sorry bout the length of this, Wiley

Re: Twin screw--Vertical racking

William R. Duffield, on the Cohansey

>Thanks, Wiley. That's the sort of thoughtful analysis I was looking for. It's a lot mre useful that an "Ijustdoit*NM*" post. It means I won't need to use up my limited stock of lignum vitae, because I now know that some scraps of tulip poplar (or even 2x4) will work just fine.

Re: Yet more bench questions...

Patrick Gibbons, Houston, TX

>Russell, I have a hard maple top with doug fir legs and it doesn't look like a mismatch to me at all. It's more a matter of what you get used to and in the end it's just a workbench. I'd like to use some Alaskan yellow cedar next time for the base and in even thicker dimensions, 6x6? That probably won't happen because I'm cheap, my present bench isn't perfect but it's still going strong and the cedar is not readily available here in the Bayou City. At its best doug fir is a beautiful wood and I snagged some nice looking 4x4's with very tight annular rings and hardly any knots. The hard maple top is quite dark (cheaper heart wood) and the two woods blend nicely. It's just personal preference.

Thanks...

Mark Harrison -- in Sydney, Australia

>Thanks everyone for the feedback.

This is a fairly big project because of the cost of the materials and hardware and I appreciate your review of my ideas.

It seems that the twin screw vise is not off the agenda as I thought. If anyone has any thoughts on my other questions on the traditional type of leg and tail vise, I would still be interested to hear them.

The Doug Fir idea is an economy measure. I would prefer to spend the money elsewhere, but I take the points mentioned. My local wood yard has been very helpful with my (for them) unusual requests in the past and have even helped me flip through the stack to find the right pieces.

The members of the frame will be at least 4 by 4, actual dimensions. If I need to glue up to get these dimensions, I will. I want something I can really pound on :-)

Re: Twin screw--Vertical racking

Russell Seaton

>It means I won't need to use up my limited stock of lignum vitae, because I now know that some scraps of tulip poplar (or even 2x4) will work just fine.

Why would you use a solid piece of lignum vitae as the spacer block? If you wanted to use lignum vitae as the rubbing surface, why wouldn't you slice off a thin 1/2" to 1/4" thick piece and glue it to a piece of other wood as the filler? Just like veneering is used by some to extend the coverage of a small but highly figured piece of wood.

I tried the spacer between the screws and underside of the bench on my twin screw vise and it caused the effort to turn the screws to increase too much. But my spacer was a 1"+ hole drilled through a 9" long piece of red oak. I might have to try the flat softwood spacer.

When fully extended, the vise jaw drops about 3/8" due to the slop in the screws. But if you are using the twin screw vise as an end vise, and have your dog holes spaced about 4" apart, then you will rarely ever open the vise beyond 4". So the drop in the vise jaw will be minimal.

Vertical racking - What I did...

David Barnett

>I made two half nuts from Jett-Sett, a wonderful reusable thermoplastic-ceramic stuff that conforms to any shape when softened in hot water for a few minutes. I then fastened these to wood blocks, planed to just fit, then glued these in place. Perfect. One could also use blocks of nylon or some similar low-friction thermoplastic that softens and deforms at reasonably low temperatures, gently heat the screw (well beneath drawing temper), press until moulded, and Bob's your uncle.

Leg Vise

Davy

>I just built a bench with a leg vise. One thing you should be very sure of if you use a leg vise is that you mortise at least that leg into the bench top. Doing this will prevent the leg vise from pushing the bench top away as you tighten the screw. I didn't do this and am now paying the price trying to figure out how to fix this problem without re-doing the whole leg.

Jett Sett

Roger Nixon

>David, can you tell us more about Jett Sett? I couldn't find anything about it on the Rio Grande site.