Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Holm-Made on October 30, 2008, 09:26:00 PM
-
I'm having an aluminum form milled on a cnc machine. Anyone have pictures of one. The machinist ran the dementions and figures it will weigh about 70 pounds. That's just the bottem. I will have him reduce weight with cut outs but want to know how much material I need to leave. Chad
-
Wow Chad,.. how many bowyers ya think have aluminum bow forms? I think maybe your a pioneer? I've talked about it with a machinist friend of mine but thought I'd wait till I actually knew how to make bows.. :biglaugh: Maybe you should call the "professor"..(mike).. :biglaugh:
Shawn...
-
Dweyer longbow uses those type forms.
Maybe he can give you info.
Deathmaster
-
I thought about it, and went to a few sites looking for the cost of stock. Thats as far as I got, other than some other additional modifications. I'll look more into after we get the boat loads of cash from the redistribution package. :knothead:
Let us know how you make out.
-
If it were my money, I don't think I'd go with a solid billet to start with. Too heavy(and ya pay by the pound!) and why turn most of it into chips if you don't have to? I'd make a weldment...probably 1/4 or 3/16" plate. Cut it out, add some ribs for stability, then finish machine the critical surfaces. A little more labor but a good weld shop could make it happen pretty in short order, I would think.
-
Good point rkmnt2. It is fairly expensive, at least for this garage shop hobbiest.
-
I measure from a straight line to places on the drawing of the bow or an actual bow at 6" intervals. I cut pieces of 1 1/2"x1/4" flat strap to the lengths at those spacings and weld them to a piece of 1 1/2"x1 1/2"x1/4" square tubing on the six inch spacing. Then take a piece of the 1 1/2" strap and pull it down in the middle or handle part of the straps and tack weld it. Flex it down over the pieces of strap and tack weld as you go till you get to the end piece of flat strap. Do the other end. Weld another piece of flat strap onto the first in case you have any pulling on the first piece. Just weld on the edges. It's done if you use clamps. If you use a hose you need to make the other half the same as the first.
These forms are pretty quick to build and easy to copy another bow or a drawing and are very accurate when built with a little care.
-
draco, pics please. :)
-
I'd like to see pictures as well Drago..
I could never afford to purchase an aluminum form. I had a machine shop owner offer a trade for a couple bows. I thought I'd jump on it before he changed his mind.
Thanks, Chad
-
Chad,
Bartering sounds like a great way to get a form as nice as a complete machined one. You can still have him cut the weight down a lot by coring out each side to a similar design like the weldment idea. I'll see if I can draw something up at work tomorrow and shoot you a jpeg
-
here is mine, 0$, nice to have friends (http://i20.photobucket.com/albums/b242/hdc123/DSCN0869.jpg)
-
got to clean that shop up SOON
-
don't do that slinger, your making my shop look good :D
I like the form by the way.
-
SS, How deep is that form. 3 inches? I'm just wondering how much material I need for strength. Chad
-
chad, i will check it and weight it tomorrow, let you know all the specs.
if you use "C" clamps you don't need much for strength, but if you use the air hose it is different, you need more thickness Harold
-
Chad, the form is ,,11/2"x2"x70" and weight is 20# Harold
-
Thanks.
-
I don't have pics, but I do have something like Draco is describing. Bassically it is made of flat stock aluminum bars, I used 1/8 x 1-1/2 stock.
I planned the form out on paper and then placed blocks on a piece of straight wooden stock. I lay down 3 "laminations" of the aluminum stock, and carefully bent all three into the correct shape with clamps and blocks, just like laminating a bow. Then I drilled holes and ran a steel self-threading countersunk screw every few inches. Remove the clamps and blocks and you have a laminated aluminum form. Done the same with vinyl board and wood lathe.
-
A buddy and I made a pattern out of mahogany a few years back and then had forms poured in sand molds. The laminating surface was then machined down. We even went so far as to have heating elements inside the bottom surface of the mold to eliminate the need for an oven. I went through the whole process of patenting and so on. I'll try to get some pics of them in the near future.