I’m not planning to try this but was more curious about the pressures it would create for forming. The first thing I’d try would be either hydro forming or a mold that compresses rubber using a suitable hydraulic press to fill the form.
I think that the actual speed that the pressure was applied, as well as the area applied to, needs to be considered. Some jobs are better done at low speeds, others really fast!
The cartridges, they strike me as a source of "Really Fast"!
Be worth considering the videos posted that use these cartridges as the motivating force driving really light weight projectiles, at supersonic speeds...
I’m not planning to try this but was more curious about the pressures it would create for forming. The first thing I’d try would be either hydro forming or a mold that compresses rubber using a suitable hydraulic press to fill the form.
I was at a school that was making Rans RV-7's, IIRC, and they used a LOT of CNC cut formers for making rib elements for their production.
They used a 100 ton, four post press, and hard rubber a the platen to form them against.
You put a sheet of aluminum on the rubber platen, and pressed it, then you had to cut the formed parts free.
Gonna depend on the area of the metal, and the volume of the displacement needed, I think.
The math is a little beyond what I can do in my head on a good day, but as I see it, as you increase the area, and the displacement, the resultant force applied soon runs out of effective pressure.
Seems to me that most parts small enough to form with as limited a pressure source (volume wise), would be better candidates for direct pressure forming in a hyd press.
I have seen these cartridges being used for breaking rock. Drill a hole with a hammer drill, blow out the dust, add a few cartridges, and insert a close fitting heavy punch, which is then struck a sharp blow with a hammer. Seemed gyppo as all hells, and a great way to lose an eye, but that was how they were being used there.
Like when we were kids putting match heads into a 22 cartridge and crimping the end before hitting with the hammer, enter (innocence whistling here) or taking the 303’s apart for the cordite.
Like when we were kids putting match heads into a 22 cartridge and crimping the end before hitting with the hammer, enter (innocence whistling here) or taking the 303’s apart for the cordite.
We were busy making bottle rockets out of CO2 cylinders (only 'some' exploded!), and various tape wrapped fire and stink bombs from strike anywhere matches, never got around to trying match heads in the .22's, and nobody had a .303, so no shells to play with...
Did have a friend, whose father did some blasting, so we did play a bit with fuse and caps... No missing fingers...
Ohh man as does often happen when someone makes a post that causes me to start reminiscing over long past incidents of less than well thought out happenings.
A couple of examples....We had an old barn on the place that a lot of sparrows used as a weather shelter and I used to knock out the knots of the shiplap siding and insert shotshells into the holes so just the shell base & primer was facing outside . A buddy of mine & I would stand back 20 ft or so with a .22 and when a flock of sparrows flew into the barn we would shoot the shotshell primer with the .22 and it would explode inside the barn...I dont think many sparrows were harmed but we sure made a lot of noise.
Another fav pastime back then was to drill the nose out on .357 mag bullets and fill with pistol powder , then glue a primer to the bullet nose...when fired against something hard ( usually field stones) some of them would make a secondary explosion.
Some folks might think of this as dangerous ( as my old man did when we got caught and everything usable for our enjoyment went under lock & key....long before the feds mandated lock-ups), nobody ever got hurt .
Ohh man as does often happen when someone makes a post that causes me to start reminiscing over long past incidents of less than well thought out happenings.
A couple of examples....We had an old barn on the place that a lot of sparrows used as a weather shelter and I used to knock out the knots of the shiplap siding and insert shotshells into the holes so just the shell base & primer was facing outside . A buddy of mine & I would stand back 20 ft or so with a .22 and when a flock of sparrows flew into the barn we would shoot the shotshell primer with the .22 and it would explode inside the barn...I dont think many sparrows were harmed but we sure made a lot of noise.
Another fav pastime back then was to drill the nose out on .357 mag bullets and fill with pistol powder , then glue a primer to the bullet nose...when fired against something hard ( usually field stones) some of them would make a secondary explosion.
Some folks might think of this as dangerous ( as my old man did when we got caught and everything usable for our enjoyment went under lock & key....long before the feds mandated lock-ups), nobody ever got hurt .
I used to have a bottle too. But it got all used up by the time I was 18 spilling it on the floor, my bed sheets which was my work bench at the time, and filling in the life lines in my palm cuz I loved to roll it in my hand.
Apparently, I should be dead by now, but all that really happened was lots of hair, and some extra height.
I had an Uncle who worked at one of the refineries in BC we got it from him they were always testing workers for mercury contamination rotating the staff until levels drop.
Vises arrived today (well they got here Tuesday, but I haven't had a chance to get to the post office).
Packaged well, Sure glad they put those air packs in there.....
A fair bit smaller than a 6"...
First impressions are that they are decently made for the money. Nice surface finishes on the ground surfaces. Typical import sharp corners everywhere. They should send some complimentary bandaids. I will inspect them Monday at work to see how dimensionally accurate they are. I'm glad I didn't go with the 3" although A 5" might have been a bit better, but I think these will be just fine for my needs.
I literally did nothing other than take it out of the box, and set it on the table to snap those pics. About 1:00 today I started feeling like I was coming down with something, No energy/strength and head cloudy. As of now, I'm just fighting to stay awake on the couch shivering. Our whole shop is out sick right now except for me and one other guy, so It was only a matter of time I guess. I have no energy or desire to go out and play with them tonight. I don't trust my surface plate and all my good metrology equipment is at work anyway, so it'll have to wait until then. With any luck this cold will devour my entire weekend, and I'll be right as rain come Monday morning........I was really hoping to do some blacksmithing for Christmas presents this weekend, but might have to give them coal instead.
If I'm feeling a bit better tomorrow, I'll check them out a bit more. If not I'll model them up, and figure out some of my fixturing ideas.
After spending the day holding the couch down, I finally snuck out to the garage to have a poke at them. Here are some teardown pics and thoughts......
Not sure where to start, but I'm both impressed, and not impressed.
Cons
-Some poorly milled surfaces where IMO they should be ground. Or at least better surface finishes. The sliding surface of the moving jaw, and nut are pretty poorly done. The nut looks like it was done with an angle grinder, and the ball/ramp is simply as cast.
-The fit of the fixed jaw is a bit loose. Didn't put an indicator on it, but there is a thou or two of slop there. It's also cast, which I was not expecting. I will probably remake it completely from solid.
-There is no thrust bearing and the screw is a bit rough. Not bad, but not great
-The moving jaw fit pretty well. There is a tiny bit of wiggle, but not much. That's a bit tougher to correct, and may result in a more extensive repair.
-The mounting faces for the hardened jaws are just milled.
-I have not checked anything dimensionally yet. But I have my doubts about a few things, like squareness of the jaws etc......
-The jaws, themselves are not hard. Files cut them very easily.
Pros
-The actual bed appears to be a well made casting. Dimensional accuracy yet to be determined, but it appears to be an adequate bed for a vise of this size. Plenty stout enough, with no major design flaws, or obvious weak points. Fits the table of the Tormach perfectly.
-The milled surfaces can be ground. There is enough meat in all the right places for me to finish grind them. I expected this, and am not surprised
-There looks like there is enough room in there for a thrust washer should I decide it needs one. Screw action didn't seem that bad without though, but time will tell in use. Not a super smooth, spin with one finger, type of fit.
-Price. Keeping in mid the overall price of $150 delivered, I don't think it's a bad "kit" to start from. I do think there is plenty of room to improve things, but at what point do they create something there is no market for? Is there a big market for high precision import 4" milling vises? I doubt it.
Right off the bat, I'll probably remake the entire fixed jaw. There are no holes to flip the jaw over to the back for gripping wider stuff, and the fit isn't as good as it should be. I can re mill the key area in the bed, and refit a much better jaw in there. I'll up the size of hardware from m6 to m8 as well. There's room. Plus I want to tap some holes in the top, and sides for fixturing items, so the extra meat from being a solid will be much better.
The moving jaw is a bit tougher to correct. There ARE tapped holes to flip the jaw over, so that's good, but the overall fit and finish leave a bit to be desired. I don't want to remake that, BUT, I'll see what I can do with it. I'll see what the indicator says there.
I'll leave the final decision as to whether I'm sending them back or not up to the indicator. I don't mind doing a bit of re work, or re making of parts like the fixed jaw (I was kind of planning on it anyway), but if the whole thing is a warped parallelogram, and I have to spend a few hours on the grinder to correct geometry, then It's going back. That's my line in the sand on this one. If they're flat, and square and all I have to do to the bed is match grind them for height, that's fine.
Math/memory error on my part. They were only ~$125 delivered. Plus I just noticed they are now $99 instead of the $109 I paid, so I wrote them to see about their 30 day price match guarantee. Should be a $20 store credit coming my way.
