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Yes sort of, basically thin the corners to allow flex there.
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New vise jaw product
- Thread starter Janger
- Start date
The two screws will be better but angular would be better still.
Really stupid idea. Why does the orange block need to clamp at all? Why can't the blocks float? As long as all the ears are clamped in compression, they will act as an assembly and once the play (let's call it backlash) is taken up, the assembled system will clamp.
Really stupid idea. Why does the orange block need to clamp at all? Why can't the blocks float? As long as all the ears are clamped in compression, they will act as an assembly and once the play (let's call it backlash) is taken up, the assembled system will clamp.
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What can't the orange blocks just float? I think because the orange blocks do two things. The first is clamp the fingers from both ends against the middle vise jaw block. The second though is I think the red bar will tend to flex or vibrate up down and back/forth. Having the orange block locked in place I think would minimize that movement.
Perhaps they will at first, but I would think that once everything is tightened down and they reach the end of their travel in the bigger assembly, they won't move anymore.
Anyway John, I have some medical tests first thing tomorrow morning so I gotta get some sleep. I'll try to catch up tomorrow.
I like these improvements @Janger . I'd also add a vertical slit at the bottom right.
What @Dabbler s slits do is provide for some compression in the other columns. Those big steel columns need to do more than bend a bit - they need to compress. But the big steel blocks cannot be easily compressed with a small screw. The compression will be insignificant. The slits allow for some spatial compression in the gaps not in the steel. I'd make those slits quite long. In fact, size the remaining piece (uncut portion) about the same size as the screw. There is no point in bigger than that anyway. Lots of nuances in there about how fasteners work as well as the distribution of stress and strain in the part.
That said, I think two screws - one on each side - is a superior solution. This allows for 100% compression of the two side columns. As you visualize what the two screws do to the block, I think you can begin to see the issue with the one screw version. The two screws put compression into both side columns, (but still leave the top and bottom uncompressed). Of course the slits help solve that in the one screw version.
In my mind, I am visualizing a simplified finite element model of your parts. That is to say, break the components of the outside block into multiple blocks in your mind. When you do this, you can begin to see how each adjacent element influences the one next to it and so forth around the outside block. If you do this for your original design, you can watch (in your mind) the top bar bending (somewhat like a cantelever) down on the right. But there are only very low forces to pull it to the right as the screw is tightened. The only forces doing that are the restraining forces in the left column that are trying to stop the top bar from bending. They are somewhat like the anchor for the cantelever. But this effect gets dramatically reduced for each leg. In addition to providing space for compression, the slits help turn the hinge points into quasi unrestrained fulcrums for the other three joints.
The two screw version provides raw vertical clamping but no side clamping.
All this said, unless the complete assembly is different than what I think it is, I still don't see why clamping is required at all. I would just make it a vertical slip fit and let the backlash look after itself as the outside jaws are tightened. Think of this a bit like a part put between two (or three) jaws. As the Jaws tighten, the first ones contact the part, and then the part slides until it hits the second, and then the second and the parts slide until they hit the third, and then when no more sliding is possible, compression clamping begins.
Thx John, 'cause I'm still not 'getting' it. From the other pictures, the red bar went 'through' the fingers, not sure where the clamping force comes from. We can take this offline -- I don't want to derail this great thread.
@Janger - please don't take it off line. This discussion is part of the big picture for this novel vise.
If I understand it (good chance I don't - but it's useful to know what others are thinking) the red bar is actually 2 or 3 parts that are tightened longitudinally through the axis of the red bar to clamp all the fingers in whatever geometry they arrive at after adjusting to the profile of the part. This locks the profile in place.
Subsequently the entire finger assembly gets clamped against the part by another tightening mechanism working in the direction of the overall clamp.
Ok here is how this is supposed to clamp the fingers. First picture shows the red bar it is 0.75"x0.75". You can see it is slightly inset against the fingers. Now look at the second picture. The orange block is is 1x1x1". Bolts go through it into the red bar. Because the red bar is smaller and shorter this means as the orange block is tightened against the red bar the orange block pushes against the fingers squeezing them against the green center part of the vise. The other end of the red bar is the same, the orange block at the other end is also tightened in the same manner. Both orange blocks then squeeze the fingers against the immovable center block. see picture 3 to see the vise jaw block.
@Janger, glad it works!
What I am keenly interested in at this point is how the entire assembled vise works. Do you have any drawings of that yet?
Are you using Fusion 3D? I think I may have solved my problem there. I was reading about @Dabbler rescuing an old gaming laptop for his needs and I realized one of my sons has one gathering dust. I may need to add memory, but with a gaming heritage I'm guessing it will run Fusion. It would be nice to have that capability in my shop.
What I am keenly interested in at this point is how the entire assembled vise works. Do you have any drawings of that yet?
Are you using Fusion 3D? I think I may have solved my problem there. I was reading about @Dabbler rescuing an old gaming laptop for his needs and I realized one of my sons has one gathering dust. I may need to add memory, but with a gaming heritage I'm guessing it will run Fusion. It would be nice to have that capability in my shop.
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I think you only need one through bolt. If the bolt goes all the way through from one side to the other, it will pull both orange blocks together simultaneously against the center block. You can use a bigger bolt that way and only have to tighten once.
Btw, I'm still thinking you don't really need that square clamping system. Just take up the backlash and go .....
This has been an interesting read.
I think the 2 screw cap is a better clamping approach to clamp down on the orange blocks. Tightening the caps would be after the horizontal bolt has the fingers tight. I agree with @Susquatch 's comments about V-block effect vertically holding down the cap and his comment to use a set screw to lock the orange block horizontally, but if the caps are very secure bearing down on the orange blocks then the horizontal set screws are likely not required. I suggest adding a keyway to the column/cap to help make the cap more secure on the orange blocks (see the attached crude pic). Note: when tightened down, the cap would not bottom out on the keyway.
Craig
I think the 2 screw cap is a better clamping approach to clamp down on the orange blocks. Tightening the caps would be after the horizontal bolt has the fingers tight. I agree with @Susquatch 's comments about V-block effect vertically holding down the cap and his comment to use a set screw to lock the orange block horizontally, but if the caps are very secure bearing down on the orange blocks then the horizontal set screws are likely not required. I suggest adding a keyway to the column/cap to help make the cap more secure on the orange blocks (see the attached crude pic). Note: when tightened down, the cap would not bottom out on the keyway.
Craig
I don't have any other drawings yet - just this 3d model. Yes this is all Fusion 360. @Dabbler was trying to use Fusion 360 on an older machine - the limiting factor seemed to be RAM. 8GB just wasn't enough. I have 16GB on my 5 year old macbook pro laptop and it works pretty decent.