There are several simple modifications that would make the vice cheaper - stronger - lighter + simpler to manufacture. I haven’t written a full design review yet. Would you like to discuss on this forum with input from other engineers?
Would any of these modifications be improvements?
Just my first impression, a shoulder bolt and a couple drilled, tapped, and counter bored holes are probably cheaper and pivot as good or better than the registering ledge you have drawn that would need a more complicated machining operation on both pieces.
Also, I prefer to not need a tool to pivot the vise and the handles being in the way hasn’t been an issue yet on my fairly new vise, but there may be others who rarely ever swivel it and may like the lower profile head on your bolts.
That said don’t think I’m being a downer, always good to think about ways something would work better for you and seek out feedback from others about design ideas. It’s entirely possible the next reply will be 180° from what I’ve said.
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Thanks for the prompt reply.
My reasoning was that the time to machine the registers would easily be cheaper than machining a complete shoulder bolt, its recesses & tapped hole. The large radial locating surface diameter is more robust, coupled with the larger bearing clamping surfaces will lead to better clamping. Both the base of the vice and the top of the swivel base will already be set to be machined flat, so adding a recess and spigot will not increase cycle time significantly. Casting a 4" diameter hole in the swivel base where no strength is needed will reduce the casting weight and have less material to remove.
What did you think to the wedging of the nuts in the casting & their outward forces into the casting? The red lines show where the cracks propogated from in the tests. Reverting to traditional standard high tensile T bolts eliminates the outward forces allowing much higher torque from a spanner. In turn, this will give much stronger clamping using cheap tested standard components instead of 6 bespoke parts ( excluding the tommy bar balls ).
I can see how T nuts in the base could improve the clamping force without creating the wedging force that could crack the casting.
I suspect that machining T slots could be more cost intensive than cleaning up a V groove, if nothing else the tooling would be cheaper and more robust leading to a longer life.
With your system all of the critical features that must work with each other (the slot and pivoting elements) can be machined from a single side, which could a big help to maintaining their concentricity, so it may have an advantage there. Though drilling an tapping holes on a CNC mill is a crazy fast operation, and shoulder bolts are made by the thousands, so they can be cheaply purchased and/or replaced due to damage or wear, so I’m still not sure if there is a cost or design savings to the pivoting being controlled by a machined pair of shoulders VS the current shoulder bolt method.
Possibly the best solution I see is the T nuts AND shoulder bolt, but that’s likely to add some sort of cost just from the t slot possibly costing more to machine.
I believe that the vee groove is finished cast and not machined. I would expect the same for a tee slot. There does not seem to be an entrance relief to get either tool into the cast groove. If they were machined, tooling costs would be similar and the price spread over many thousand parts.
The cutter doesn’t have to be the full with of the slot, it only needs a shoulder deep enough to cut the T or taper, so the wide end of the cutter is the width of the top of the slot, and the narrow end correlates to the depth of cut in the T slot or taper.
That said, I don’t have proof they finish machine the current slots, perhaps @Fireball_Jason can shed some light on that. If they’re not machining them into spec, I’m not sure how they get them to fit so well. Generally a sliding fit that good requires at least roughly if not decently machined surfaces.
Good call, I missed that. In which case I would certainly machine the underside of the tee slot where the tee bolt clamps. Rotating the part and using a turning tool is another option.
Well, we’ve discussed several design details of the vise. Are you ready to address some of the others? fireball2-Model.pdf - Google Drive
I do prefer the tubular type of vise like the Wilton. The lack of corners, ease of manufacture and the look appeal to me. I would love any comments on my design of my ideal vise. The link is below.
Great discussion. There are many tradeoffs between form, function, cost, and also tradition.
The way we make the swivel handles and the meatball is definitely more expensive, but for us it is the right aesthetic choice.
A fully enclosed rectangular tube is definitely harder to manufacture, and we’re the first company to actually manufacture a vise like that. This is the strongest and most durable design. If we wanted to make a copy of the Wilton bullet vise, we certainly could, and a tube would certainly be easier, but it veers away from our main objectives.
Thanks for looking at the design. One challenge was to omit the hole in your rectangular box to make the screw and bearings completely sealed.
Another challenge was to allow the anvil to reach the end of the vice. I suspect your thin cover tube could get damaged.
The last drawing included fillets at the high stress points. Using a register and a recess for guiding the swivel instead of the shoulder bolt. Also reverting to traditional tee bolts to eliminate the outward pressure from the wedge nuts.
Thanks again for taking the time to critique my design.
During our first hammer rig testing of the vise, the part that broke was the casting around the center pivot bolt.
Putting T-slots in the base would probably require machining as casting it would probably not yield the same consistency.
One thing about castings it that complexity does not mean impossible. Complexity raises cost by increasing defects and thereby decreasing yield rate.
Complexity can also add cost directly if it requires more manual work or steps like coring.
Good points, I’ll use them to try to clarify some of my decisions.
I watched the testing video & saw where the early fracture point was. Looking at the cut away image on the website, it shows that this fracture point is around 9x thinner than the thickness of the ( blue ) area above. However the base ( green ) is also subjected to shear & tensile stresses, yet is so much thinner. This is another reason why I decided to concentrate on reinforcing the area. The same fracture path using tee nuts is now about 50% of the jaw thickness, almost 5x thicker than the wedge design and without any outward stresses. I expect this style will make the dome nuts the first yield point as they are the cheapest and easiest to replace.
Combined with the male & female mating circular recesses the shoulder bolt can now be completely discarded.
The same cut away image shows the open hole in the dynamic jaw that I decided to remove to keep out grit from the screw,nut & bearings, as mentioned in my previous post.
If the tee slots are not able to be cast accurately enough, then they should be machined. A core similar to the wedge shape currently used would remove most of the material prior to machining. I suspect a T shaped core could be used that only leaves material on the underside of the tee slot where it engages with the tee bolt. Considering that the casting is already on a mill or lathe for other machining operations, it is only an extra skim cut.
Link to Fireball hardtail cut away image. - cut away section vise.jpg - Google Drive