Building a Jig for the Jetpack Harness

Soundwave

Hunter
So, after unsuccessfully trying to bend some conduit for the jetpack harness it was time for a jig.

All I needed was a standard hand saw, a coping saw, some wood screws, and a couple of half inch planks.

Using Rafal Fett’s templates to determine the inner diameter of the 180 degree bend I got to work.

The jig will consist of a base plank which is the larger piece pictured. Fixed to the top will be the circle piece, or the die for the bend. The plank from which the circle was cut has been cut down the middle length wise. These two will form a channel to hold the conduit in place.

Filling the conduit with sand and sealing both ends will prevent any collapsing and kinking within the area to be bent.

More pics and whether or not this succeeds to follow!

*Update*
Just finished the basic assembly of the jig. Tomorrow I’ll add two cross pieces to keep the conduit in the channel while bending.

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So, today was not the success I had hoped for. But I learned two things.
1) I think the pipe will need to be bolted to the jig to prevent it from riding up as it is being bent.
2) I think the sand I have is too coarse preventing a tighter pack within the conduit.

The good news is that the jig was strong enough, and didn’t buckle or crack.

Gonna grab another length of conduit soon, and the hardware to bolt it down. More to come...

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Ouch! Try using water instead of sand. Put it in the freezer until frozen to see if that helps. That is what I used and it bent smoothly. I like your jig design. Also, not sure if the conduit may be giving you trouble as well. I used hollow aluminum stock for mine. You can get it at Home Depot, Lowe’s, etc. Good luck.

PS. What size pipe are you using? Looks a little big. It’s hard to tell from the pics. You don’t want it too large or it may not fit under you back armor properly.
 
ShortFuse Thanks for the input and recommendations. I’m using 1/2 inch outer diameter aluminum conduit. It’s the closest size I could find to what the template calls for. Unfortunately I don’t have a freezer that is large enough. But I suppose I could leave it outside over night during a freeze. Hmmm...
 
I made a very similar jig, but I used an aluminum pipe filled with sand and the ends tapped shut. No problems. If you are using steel, try heating it w/ a gas torch.
 
So, I managed to get a little closer today. It still ended up with kinks in the bend, though. The pressure inside was just too much for the marine formula jb weld which leaked by. I have another length that I’m going to try corking the ends with before sealing them off. Hopefully that will prevent leaks that prevent a clean bend.

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When you bend the pipe and it kinks, you're compressing the water into a smaller space. You can't compress a liquid, so it's going to find a place to come out.
Your round part of your jig needs to be curved to contour the pipe to hold the outer wall of the pipe intact. If you have access to a torch, you might try heating the conduit across your bend radius with a torch until it's red hot to anneal the steel to make it softer, and then try bending it after it has cooled. Or if you could find something made out of metal to bend it across, you can anneal it and do the bending over while it is still red hot......
 
I think if I can get a good seal on the ends of the pipe that will prevent the kinks. Like you said liquids can’t be compressed. It was the leak at one end that allowed water out. The conduit I have is aluminum, so it’s pretty soft already. The round portion of the jig does have a bit of contour to it as well. Unfortunately I don’t have anything that could follow the pipe around the bend. I’m pretty confident that with a proper seal on both ends I can get a clean bend.
 
Soundwave, instead of using conduit try using the stock aluminum tubing from Home Depot/ Lowes. The walls of the conduit may be too thin to make the tight bend. I just bent mine over a landscaping timber I had set in a vise. Slow steady pressure is the key.
 
Soundwave, instead of using conduit try using the stock aluminum tubing from Home Depot/ Lowes. The walls of the conduit may be too thin to make the tight bend. I just bent mine over a landscaping timber I had set in a vise. Slow steady pressure is the key.
Thanks, ShortFuse! I’ll have to give that a try.
 
I still haven't made my frame for myself yet. I'm glad you're figuring this out for when I have to do it Soundwave! Keep me informed with updates!
 
Well, since these posts I’ve tried a couple o more times with no luck. I’ll be packing up the jig, and will put my name in the hat for one of BigDane’s harnesses.
 
I hate to hear that. Not that I didn’t want BigDane to get business, I’m just always pulling for the scratch builder. Sorry you weren’t having luck with your harness.
 
You could also try an actual pipe-bender. I'm going to try making one myself one of these days and was going to try my hand at it using that.
 
I hate to hear that. Not that I didn’t want BigDane to get business, I’m just always pulling for the scratch builder. Sorry you weren’t having luck with your harness.

You could also try an actual pipe-bender. I'm going to try making one myself one of these days and was going to try my hand at it using that.

Thanks, guys. I’m not too terribly disappointed, because I had fun trying to figure it out. But unfortunately I’ve got limited room and access to tools. With the proper setup it might have worked out. Now it’s time to refocus and move towards getting the armor fitted up to the vest, and then painted!
 
You could also try an actual pipe-bender. I'm going to try making one myself one of these days and was going to try my hand at it using that.

Pipe bender would work excellent, especially with the conduit. I had good luck with bending it by hand over a landscape timber set in a vise. A coworker has a pipe bender and that was going to be my next option, if I was unsuccessful with my first try.
 
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