#11
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Got there in the end!
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Rob Thomas, Cardiff, Wales, UK |
#12
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Well, I've rolled the tube (hard work when you only have one working thumb) and have rolled the cone for the tip. Problem is that I couldn't form the bulging profile of the cone whilst still flat sheet and then roll it due to the lack of the strength required to then roll it into a cone. I've rolled and welded the cone and tried using a heavy ball-pein hammer and a sandbag but that won't get me all the way towards the tip unless I go to smaller (and thus lighter) hammers. No fancy tools available. What would anyone recommend? Slit the cone tip and fold the edges in to curve the tip round more?
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Rob Thomas, Cardiff, Wales, UK |
#13
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Hi Rob.
You can make the piece in two halves. Make a template the shape of the profile you are after and make two pieces that match. Then weld them together. I would form the large end first with the E wheel and then use a rubber band to get the longitudinal shape. Work from both outside edges first then work to the center. Jere
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Jere Kirkpatrick Valley Forge & Welding HEN-ROB Torch Dealer. Teaching The Fundamentals of Metal Shaping www.jerekirkpatrick.com All tools are a hammer except the chisel.....That's a screwdriver. |
#14
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As Jere suggested, it turned out to be easier with the cone in 2 parts. It was hard to work out the best shape to cut the sheet into to get the right final shape. Several attempts! I used the tree stump method with a BFH to get the general shape and then ran it through the tiny English wheel to smooth it. The tip from someone about butting up and then scribing a cut line for the tinsnips also helped greatly. Final imperfections came out with some SifBronze 8 Tig braze.
Very happy with the result. Thanks to everyone who contributed advice, to the website owners and to all the experts on here who pass on all those tips and inspirational pictures. Couldn't have done it without you!
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Rob Thomas, Cardiff, Wales, UK |
#15
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Cone layout tool
I had need to make a cone and recalled Steve Hamiltons post with the disc method. I built off that to make a layout tool that will do multiple cones without needing to cut templates each time. It starts with a gun cleaning rod and a lawn mower wheel. The pens are set to the dimensions of the cone and move the wheel til it hits. There is a mark on the wheel to get 360 degrees. Hose clamps are marginal, have to fix that. I think I can add an eccentric and pivots on the pen mounts to do nonparallel truncated cones.
cone layout.jpg
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Bill Funk |
#16
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Calc
Rob, Google Flat Cone Template calculator. There is another one I used to make angled sections for exhaust pipes, but I'm having trouble finding it.
This one seems ok for simple cones. Regards. Mick
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Michael Henry Sutton |
#17
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Quote:
Same wheel for any cone? What determines the wheel position on the rod?
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Richard K |
#18
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The Omicron beam compass will lay out multiple segments of arc quickly and accurately.
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Karl Heinz |
#19
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Quote:
This device could seemingly work for any cone, however it pre-determines the diameters of the cone ends based on a determined length, which isn't usually practical? To my understanding, the non-mathematical method proposed by Steve H is entirely different in two aspects: 1, it will produce a cone with a determined length, & 2, produce a shape with known diameters at either end.
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Manny Remember that the best of men, are only men at best. |
#20
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Cone layout tool
I guess I should have explained better.
Imagine rolling up the cone with the rod as the central axis. Notice that the position of the pens on the rod are equal to the total height of the cone and the cut off part. Usually known. The distance of the pen from the rod is the cone radius. Also usually known. The wheel goes where ever it needs to touch and rotate. One full revolution of the wheel is a full 360 degrees for the cone. If it is still unclear, I can do a video.
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Bill Funk |
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