Crimping lower forks

#21
WOW!, those results are great, some small 1" blocks of foam between the plates at the corners to support the weight while lining things up and I think it would be a winner for those looking to get awesome results without making dies. Thanks for taking the time to do this mrpat, I'll be getting one of these shop presses shortly and a press brake to make my own engine plates.

A2M
 
#22
#24
Yours do look the part and very well I might add, the extra angle in your dies makes the difference, I was just wondering why nobody has tried the "V" notches in those base plates. PatrickCraik, I circled the "V" notch in the press plates of where I'm talking about, seems like a simple way for folks to flatten or crimp their tubing without a lot of fab work and making their own dies.

View attachment 241988
Gotcha,I didnt notice those plates being 2 separate pieces
 
#25
Gotcha,I didnt notice those plates being 2 separate pieces
Pat: Did you happen to notice any "cracking" of the tubing, on the edges, where the folds were tight? Also...about that alignment problem: You could probably just drill 4 holes at the corners of those blocks and use some steel rod to keep them in line. Those rods would, no doubt, have to fit tightly. As an alternative to that, you could perhaps weld some small vertical plates on 3 sides of those blocks instead.


Henry
 
#26
Pat: Did you happen to notice any "cracking" of the tubing, on the edges, where the folds were tight? Also...about that alignment problem: You could probably just drill 4 holes at the corners of those blocks and use some steel rod to keep them in line. Those rods would, no doubt, have to fit tightly. As an alternative to that, you could perhaps weld some small vertical plates on 3 sides of those blocks instead.


Henry
Pat: Did you happen to notice any "cracking" of the tubing, on the edges, where the folds were tight? Also...about that alignment problem: You could probably just drill 4 holes at the corners of those blocks and use some steel rod to keep them in line. Those rods would, no doubt, have to fit tightly. As an alternative to that, you could perhaps weld some small vertical plates on 3 sides of those blocks instead.


Henry
Sorry, but what I meant was weld some small vertical plates on 3 sides of "one" of the blocks.........the "lower" block.
 
#28
Hey Henry, there is some cracking on the sides of the tight bends. Not sure on how to remedy that.
The only real way to keep the tubing from cracking when flattening is to have the dies not be wider than the final width of the flattened tube. Let's say the final width of your tubing was 1-1/2", if the die was 1-1/4" wide it would leave 1/8" on either side for relief. This isn't as noticeable on thinner wall tubing as it is thicker wall tubing. Any die that is wider than the final width of the flattened tubing will do this because there's nowhere for the metal to go and it can only flatten out so much and with no side relief it just keeps getting flattened until the sides crack. To remedy this you could weld a thin piece of steel to the press plates that is less than the final width of the flattened tubing and then grind it to match the notch being used.
 
#29
The only real way to keep the tubing from cracking when flattening is to have the dies not be wider than the final width of the flattened tube. Let's say the final width of your tubing was 1-1/2", if the die was 1-1/4" wide it would leave 1/8" on either side for relief. This isn't as noticeable on thinner wall tubing as it is thicker wall tubing. Any die that is wider than the final width of the flattened tubing will do this because there's nowhere for the metal to go and it can only flatten out so much and with no side relief it just keeps getting flattened until the sides crack. To remedy this you could weld a thin piece of steel to the press plates that is less than the final width of the flattened tubing and then grind it to match the notch being used.
Addicted, thank you. Perhaps we all just learned something here. Pat and I had conversations in the past regarding this cracking problem. I thought heating the tubing would eliminate this problem, but never took the time to experiment doing it.
 

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