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< Home < Tips Area < Tool Building < Planing Forms < Swelled Butt Rods
Just wondering if the Co. Bootstrap forms, with the extra push/pull bolts between stations at the large end, work well for making swelled butt rods? If I recall correctly, that's why they're there, to help with swelled butts. I keep looking at my collection of Leonard tapers and wishing I had a form that would accommodate them, but the Golden Witch and Wagner alternative are out of my reach. (Bill Benham) That’s a great question Bill. I just made my own forms and was thinking of doing the same thing. I tried to do it with just the 5" stations and it almost worked. I think if I put some more push pulls in I can accomplish the same thing. I believe the high priced forms have the groove cut out wide for the swell. It looks like Bootstrap put extra stations in just for that reason. If you have a set of forms you might want to try the same thing! It took me about 4 days to make my forms. They're 72 inches long, 3 inches wide and 1 inch thick. (Bill Tagye) I have a set of Lon Blauvelt forms with the same extra bolts in the butt end. You can do a swell with this set up, but not too short and not too radical. I typically go around .060 in 5" (per strip) and could probably go more. One thing I've found, if there is any tendency for the forms to cam on the dowel, meaning the surfaces getting uneven, cranking them open for a swell will make it worse. I have to do some interesting things with my wrist to keep the strips true through the swell. (John Channer) Frank's form do swelled butts well - the key is that they use 3/4" wide metal - the wider the forms the harder it will be to deviate from a fairly straight taper - the fellow that mentioned that he is building a set 3" wide will discover that "flexing" that much steel will be a challenge to achieve a swelled butt. (Wayne Cattanach) The forms are done and to my surprise work awesome! I did everything by hand except I had the forms surface ground, which I recommend. I noticed some where ,where someone cut slots in the forms to help them flex. Would this help or should i just make another set of forms? (Bill Tagye) Before I cut slots in any forms - I would first start using them as they are to make the rods you wish. Leonard's and T&T's are classic examples of a swelled butt and then the other world of Jeff Wagner with his very dramatic and decorative ones. But for the most part the world is not a swelled butt. Get to know what rods you want to make before tackling what may or may not be an issue. An illustration of the difference in bending would be this example. At the lumber store pick up a 2x4 flat wise and then put pressure on it to bend it. Then stand the 2x4 up on end and add the same pressure and notice now it doesn't bend as easily. (Wayne Cattanach) If you do cut the slots, I would suggest drilling a hole first and then slotting to the hole. I don't know if you would see any stress cracks in the form but stresses tend to build up in corners, like the corners at the end of the slots. Round holes have no corners and the stress is evenly distributed. (Tim Wilhelm)
Looking for some answers from the deep thinkers. A friend of my brother has a CNC milling machine and has offered to do some work on my planing forms. The set I have were made by Lon Blauvelt and has several 2 1/2" stations in the last foot but this only allows a moderate swell in the butt even over 5"(2 stations). I'd like to have the form modified like the Wagner forms that would allow a .120 swell over 2'' (over 2 1/2" would be acceptable if that's all the station allows). My biggest question is do I need to have the groove cut deeper as well? If any of you use the Wagner forms could you check the depth in the swell area and see how much it changes per inch. Any suggestions about the best way to do this or pitfalls to avoid are most welcome. (Will Price) Am I missing something here? I would have thought that the only way to make a swelled butt form would be to make the grooves deeper. Not that I ever thought about it before this moment, either..... Have never had any yen to build rods with swelled butts, I guess. (Peter McKean) You don't have to cut the groove deeper. You want to flex the bars .120 over two inches & then back to parallel. To do this you have to make the form more flexible. I've suggested a "weak section flexure" before and there's a picture on Todd's Tip Site of what it looks like. Look under Contraptions - Planing Forms. If it were me, I'd make a 12" bolt-on extension for the forms with the flexure built in. (Ron Larsen)
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