A Twin-Screw Vise Revolution

[george wilson]

Mark,do you ever look for steel? are you familiar with existing shapes you can get across the counter? Do you know what a cold rolled surface looks like?

As a machinist,I do these things,and I can promise you that oval is not available,and that the surface of those shafts look like typical cold rolled steel.

This is not meant to put you down,just to point out the facts that I know after also being a machinist as well as wood worker for many years.

[George Neill]

I have to agree with George about the steel shafts. The only way the shafts could be reasonably and affordably manufactured in a section other than round is if they were ground on a centreless grinder. However, as George says, the surface of these steel bars exhibit the surface marks typical of cold rolled steel.

I don't agree with George's assessment of the adjusters being used to prevent the clutch stack from fouling the pinions. If that were the case, a simple boss in the casting would suffice and be infinitely cheaper to produce. As I mentioned previously, I believe the adjuster is exactly that, a device to fine tune the clutch stack so it's as close as possible to grabbing the shaft. That way it minimises the amount of rotation of the bars required to engage the mechanism.

I'm pretty sure there will be a paragraph in the instructions about setting this adjustment for optimal performance.

I should own up to being in the engineering business myself.

[george wilson]

I don't quite see your point,George,but I think you may be right.

The part of my solution that I VALUE the most,in this little mechanical detective work,is my idea that the racks are tapered,and pinch the washer(s) thus. Other details could be different.

P.S. I do see your point now,and do think you are correct.

[Mark Koury]

So, what’s left to move the small gear?
A mythical hidden (not seen in any pictures) key way?
I guess the thing moves by telekinesis.

But, I still think it’s a neat machine. Durability - - Who knows?

[George Neill]

Well the pinions might contain twin opposing sprag clutches rather than two in series. I have never tried that, but if there's sufficient lag in the take up between the sprags (they could be custom manufactured to opperate so), that could provide positive rotation in both directions.

[george wilson]

Mark,you have mentioned that an oval shaft would be more "elegant". I made most of my living making elegant things that cost a lot of money.

The only elegant thing about this vise is the idea behind it. The casting is not elegant,the shafts would still not be elegant even if oval.The plain wooden knobs and handles are not elegant.

They can't afford to be for $350.00. The casting won't be real cheap these days,and neither will the rack be cheap to just cast,or the gear. You must buy thousands of a part to start getting them reasonable. Patterns have to be made,and aluminum match plates at least must be made,even if the sand flasks are hand stuffed. The parts that must be machined won't be cheap either,when the total has to be profitable to sell,materials and all,for $350.00.

A few years ago,I made a complete set of patterns for 18th.C. cast iron cookware for Williamsburg. They were cast for the kitchens in an Amish foundry. Even with the limited number of kettles,Dutch ovens,lids,etc,that we wanted,they took my patterns and made match plates of cast aluminum so they could stuff the flasks more quickly.

That's why we don't see fancy castings or pinstripes.

I often do machining jobs for others.Just did one last week. I know the time that is involved in this type of work.

There is no need for your sarcasm about the "mythical" keyway or telekinesis. If it was better for the inventor to not let us see the details more than he wanted to,it is perfectly reasonable for him to protect his invention,which may not yet be patented for all we know.

If you had more knowledge about making oval shafting and oval holes,it would help you to grasp the savings in manufacturing costs that the inventor must take advantage of in order to sell this vise for $350.00. It isn't a Holtey plane.

If you are man enough to put your money where your mouth is,I'll bet you $20.00 that when someone here buys one,it doesn't have oval shafts,keyway or not. Otherwise,keep your sarcasm out of it,because,frankly,I know a lot more about this work than you seem to. I know this because your ideas about oval shafting are very expensive,and roller bearing assemblies are totally off the wall. I can't see for the World how you think that has any way of working in this situation. Are you another teenager? With your avatar,it looks likely. And,even with the different ideas on how the vice works,we have had a civil discourse thus far,as it should be.

DO YOU AGREE TO THIS BET?

[George Neill]

... your ideas about oval shafting is very expensive, and roller bearing assemblies are totally off the wall.

I don't see where the roller bearings are.

[George Neill]

An even cheaper drive solution to my twin sprag clutches suggestion could be a similar, freewheel type set-up involving just two (per unit) steel balls in a single, tangentially drilled hole in the pinion, each ball sitting either side of the shaft and possibly even lightly spring loaded. This would only add a few dollars to the cost of each pinion which itself, wouldn't cost more than $25-30 for this size (I buy standard off the shelf pinions regularly from several local gear stockists).

Older members might remember freewheel hubs on bicycles which braked (locked) the rear wheel when the pedals' direction was reversed.

[george wilson]

Too expensive,George,though you have persuaded me in other posts. What's wrong with just a keyway and key? It isn't expensive to mess with too much. I'm out for the night.

[George Neill]

The freewheel set-up would cost a fraction of milling a keyway in the shaft and pinion and would avoid the problems we all know would arise from the clutch plates acting on the keyway area of the shafts.

Freewheel couplings are used in electric drills (at least the few that I have torn down) for the Foreward-Reverse function, and you can bet your $20 that they would cost less than the first inch of milled keyway!

[Will Blick]

Hey, this was civil, for once, lets keep it that way.... George W, I think the sarcasm was more from frustration and confusion vs. directed at you being wrong about something...... thats how I read it... not trying to be argumentative with you (we have done that b4) just giving you a 3rd parties assesment reading through the thread.... although its best to avoid that type of verbiage as you never know how it can be perceived.

I agree with George W about the shaft, this is ww produt we are dealing wth...., cost is an issue, shaft stock is readily available off the shelf at tolerances which are more than sufficient for a product like this.... also, an oval bearing becomes a custom made product, more cost. My guess is, this product might have an initial inventory of a few hundred, so you must keep that in mind with the parts being manufactured....

Based on this last round of input, and considering the need to control costs...I am convinced the system is narly identical to the rear of this bar clamp.... If you have one of these Rockler clamps, a bit of experimenting (like I just did) will confirm all my hyptothesis below.... I will post the pix again again...





Just to be clear, forget the front front of the clamp, erase it from your mind... the 3 clutch rings (another new name for these discs :-) work very similar on this clamp, as the one we are reverse engineering, except in reverse. Here, the default position is spring loaded locked (of course it's only a one-way lock and that is the KEY issue). When you push the the top of the clutch rings towards the acme threads, its free floating. This woud represent the default position for the new vise we are discussing.


as the rack pushes the clutch rings, they first cock n bite, as seen in the efault position in the pix above. As the rack continues to push the clutch rings, the biting is complete, now the shaft is pushed away, clamping the work piece. In the above pix, this would be analgous to me pushing the rear blue component forward, towards the acme threads, and YES, it works with EASE, which is how it clamps.... like a ratchet.


Now, during the tightening process, the shaft is rotating inside the clutch rings. And guess what, when the above blue component is locked, I can freely spin the shaft with no resistance. Viola.....

When you loosen the hand crank, the rack releases the clutch rings to their spring loaded default position, which is free floating in either direction. (again, the opposite vs. the above pix)

After experimenting with this clamp in the shop, I think this clutch ring concept was the basis of the invention. I noticed my shaft (bar) is still in good shape, and it was very low cost, which is evidence the shaft will not be destroyed to the point of causing bearing damage.

So where is the hole in this ?


How exactly the shaft turns the pinion is not very signficant, this can be accomplished many ways, no sense tackling that issue. Keyway still makes the most sense to me.

OK, so now, no cammed pinion, no keyway for the disc clutchs.... very simple, very low cost and should be quite effective.

Where is the fly in the ointment now?

[George Neill]

No offence, but you have explained the blatently obvious. What isn't readily apparent is the method in which the pinion is rotated. That alone is the key to the new vice.

[Will Blick]

Don't worry George, no offense taken.....

> What isn't readily apparent is the method in which the pinion is rotated. That alone is the key to the new vice.


I could not disagree more.... how the shaft turns the pinion gear is NOT what makes this invention novel and unique. As mentioned, there is several ways this can be accomplished.... IMO, you are missing the novelty of the invention...

[george wilson]

George,I say the real key to the vise is actually how the 3 rings grasp the shaft. Rotating the pinion is a very simple matter. The genius is in using tapered rack edge to cause the rings to tilt more and more until they grasp the shaft. It is indeed a re-use of the old multiple clutch bar clamp,re cycled into a new application,and very cleverly,too.

Will, there was no reason for the guy to start being smart alec. He is sounding like that 15 year old who told someone else to "not waste my precious time" in a post a few months ago. He has 63 posts,is obviously a newbie here,and doesn't know who he is dealing with. Seems like many newbies pull some stunt like that.

[george wilson]

Will,I think you and I are on the same path here,though George has changed my mind on a point or 2.