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Fireball Tool Style Vice - Metric Edition 
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Inspired by:

https://www.youtube.com/watch?v=tUJbz9Ih13Y

and

https://www.youtube.com/watch?v=VcbTopj5u7A

A collection of ideas and price / sizing research and specs/details to suit a non-imperial non-US world:

So for a kiwi vice build, this: select inside box size, laser/water cut sides and jaw parts and end caps etc, use matching flat-bar for top and bottom, use shim stock to create desired clearance, clamp/sandwich up, and weld sides to top/bottom, press shim+tube out, reinsert tube/front jaw, profit.

Three reasonable sizes for sliding front jaw main tube are:

  • 150mm x 50mm x 5.0mm
  • 125mm x 75mm x 6.0mm
  • 100mm x 50mm x 6.0mm

However if we assume we want a decent size screw/thread AND that we'll do it the fireball tool way, kinda similar to the way I did the vice stand/table, then 50x5 leaves less than 40mm by the time you take the seam height (x2) out of it, and 50x6 leaves less than 38mm minus seam (x2) so the only appropriate size, then, is the probably the second option, 125x75x6.

The tube I used in the vice stand/table build was 42.2mm OD and 35mm ID and if we want approx 25mm thread inside there, then anything smaller than that doesn't leave much wall thickness after tapping to retain strength.

  • 75 - 12 = 63 - 6 = 57mm between weld seam and equivalent on other side, max.
  • 50 - 12 = 38 - 6 = 32mm ditto
  • 50 - 10 = 40 - 6 = 34mm ditto

Next step down is 33.4mm OD and 26.6 ID which only really supports M16 leaving 5.3mm on each side of the thread. M16 would be okay on a smaller vice, but if we're trying to show metric in a similar light to Fireball tool, then it won't cut it :-D

So with 57mm to play with, next and final step up in pipe that still fits in there is 48.3 OD with ID of 40.94 which means no easy-fitting engineering rounds to press into it and either machined nuts or a sloppy fit squared up before welding. And we don't need more than 35mm ID to hold ~25mm thread anyway, really.

So then, 125x75x6 + 42.2 OD API schedule 40 seamless pipe plus either nuts or 35mm engineering round drilled and tapped as I did in the vice stand, but a larger thread.

top and bottom would therefore be 75x40mm, 75x25mm, 75x20mm, 75x16mm, 75x12mm, or 75x10mm

otherwise they'd be 50x25, 50x20, 50x16, 50x12, 50x10 instead

Refs/examples of 42.2 and 35 tube/bar:

https://twitter.com/FredCookeNZ/status/ ... 8773940224
https://twitter.com/FredCookeNZ/status/ ... 8575535104

For welding the sides to the top and bottom a bit of shim stock on the top and one side would be used:

0.5 or 0.8 or 1.0 mm shim stock to provide clearance while welding it up? tighter the better, until it jams and you need to file it to give clearance

divide by 2 for average gap on both sides so 0.5mm x 2 will be a little loose, but pretty good, and 0.25mm x2 will be pretty snug with oil/grease in there, or maybe perfect with a coating of wax instead?

Fireball guestimated about 1/16 of an inch play in his which is about 1.5875mm plus or minus his guessing error. That makes me think 0.5mm shim stock pre-greased before clamping would be ideal for a nice close tolerance fit once pressed apart post welding.

Hmmmm, if you used say 12mm plate for the sides (ample strong in every direction), and really thick top/bottom flat bar, and only welded top of top and bottom of bottom, then you could tap and drill to allow cap screws to pull the sides in along the length to take up some of the play with flex of the side plates. Interesting idea.

Next up, what sort of threaded rod: Thread details, all black low grade:

• M16 x 2 @ 1m = $23
• M20 x 2.5 @ 1m = $35
• M22 x 2.5 @ 1m = $88
• M27 x 3 @ 1m = $294
• M24 x 3 @ 1m = $78

And fine pitch, grade 8.8:

• M16 x 1.5 @ 1m = $137
• M18 x 1.5 @ 1m = $224
• M20 x 1.5 @ 1m = $161

Un-discounted prices, so likely better than that!

Fireball used 10 TPI 2.54mm pitch 1" threaded rod.

M20x1.5 would be pretty nice, but slow - use power tool for speed?

m24x3 or m20x2.5 or m16x2 or m20x1.5 for me, I think, value for strength/clamp ratio

Friend said: "For more clamp you could use a cheater bar. Fireball's vice showed more than enough strength for that."

True! So given that, M24x3 for strength of weld, and use a bigger handle for more clamp rather than a higher leverage from finer pitch thread. That's 8.46 TPI for the imperially minded.

Forward and reverse movement will be supported by proper thrust bearings, not straight metal on metal contact, just like the vice that inspired this.

Aside from all metric, and welded outer tube construction differences giving us a tighter fit up, I would futher like to enhance the front jaw stability by keeping more tube engaged in the outer tube when the vice is fully open. IE, longer/deeper outer/inner tubes so there's still say 200mm engaged when the thing is fully open. Fireball did 16" or 400mm opening, so if we bettered that at 500mm and kept 200 inside and say 100 outside for the front jaw structure then we're talking 800mm+ of inner tube and 700mm deep of outer welded tube or more.

Another thing I find weird and even wasteful about his setup is how narrow his jaws are for such a monster vice: 5 inches. May as well have them wider IMO. With big openings the angle will be slight and side forces equally slight. With small openings there'll be ample strength to hold the direct side forces applied by clamping at one extreme or the other. I have a 6" vice that opens about 200mm and another 5+ inch vice, so naturally 8+ inches or 200+ mm would be the target giving ample room for long vertical pieces to be clamped without fouling the tube. In comparison his 5" vice opens 400mm. Does not compute.

In his vice test vid you can see it bowing under many kg of load, so a bit thicker jaw-backing and steel removable jaws would be the ticket IMO.

Given his outer was 4x3 and his wall thickness 0.25 then his inner tube for the front jaw was just 2.5x3.5 inches, or about 63.5x88.9 - far smaller than my evil intent :-D

No intent to build this anytime soon, just wanted to record the research I did for anyone else wanting to play and so I don't lost it to the depths of free slack conversation short-memory.

Thoughts welcome! :-)

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Thu Oct 03, 2019 2:40 pm
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Thread comparison:

FireballTool: 25.4mm OD 2.54mm pitch
Record No6: 24.6mm OD ?.??mm pitch
BrassRecord: 28.6mm OD 3.7mm pitch
MyIntentHere: 24.0mm OD 3.0mm pitch

That makes me happy with the above choice of M24x3 threaded rod. Ample strength, quick enough movement, sufficient clamp force by hand, and monster clamp force by bar.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Thu Oct 03, 2019 3:06 pm
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