WXB- F23 Tail post

[wingnut]

Anyone have any foolproof method for bending the tail post components? I bent the WIX- F23 doubler strap I my big vise with a 1" piece of pipe to get the 1/2" radius and with the help of a cheater bar on the handle it worked but my advisor suggested clamping the parts down in a exact location on my bench and hammering them over a pipe until they submit. Any thoughts would be appreciated. I have the option of taking everything to the chapter hanger and using a press but getting them all located and bent precisely isn't necessarily guaranteed doing it that way either. Thanks. Pat Murry

[GordonTurner]

If you mean the big Y pieces and the one thick straight piece, used the basic harbor freight press successfully. Purchased several long deep sockets in various sizes for the radius, cut a V notch in a piece of hardwood. Align the bend centerline of the piece over the center of the V, then tape the correct socket (remember radius versus diameter) in top of the piece, aligned with the bend line, and press the socket into the piece. Has worked perfectly every time. Have your protractor handy and work carefully UP to the right bend, do not go past. I find unbending very difficult and imprecise.

Gordon

[Bryan Cotton]

Check out my thread. Page 1:
viewtopic.php?f=39&t=578

There was more but photobucket seems to have deleted them.

[Bryan Cotton]

A couple more comments: I would not hammer those pieces. They are sort of important. My later bending jig was a couple pieces of oak screwed to a piece of plywood. My bending mandrels are huge bolts bought from Lowes Depot. I screwed the oak to the plywood so the huge bolt would just slip into the gap.

[Bryan Cotton]

There is a later picture on page 12:
viewtopic.php?f=39&t=578&p=6035&hilit=Arbor#p6035

[Rynoth]

I was successful with all of my tail post/spar bends using the 4(6?)-ton harbor freight press, a wooden block with a wedge cut out, and either a socket or pipe of appropriate bend diameter(radius).



Generally speaking you want to make as few attempts to bend it as possible (due to work hardening) so I question the hammer method. My typical method was to bend it until it was at or just barely beyond the called-for degree of bend, release pressure and see how much the spring-back was. Then apply pressure again and push it though the called-for bend + springback amount. This got me very close and I could make minor tweaks from there.

Draw your bend line on the part and extend that line around the corners so you can spot the ends of the line while placing your socket/pipe into position. Apply a little bit of pressure then check alignment again before continuing.

[wingnut]

Thanks for all the responses. I tried clamping the thinner Y down and hammering it over a 1" pipe but the clamps wouldn't stay put as soon as I started. I got no results in the few attempts I made and I didn't think using a bigger hammer was going to get it either and even if it finally relented it wasn't going to work on the thick one. I basically did what you all recommended but used the pipe in my big vise on the back of the pieces and the wood on the front and with a 30" cheater on the handle I bent them. The worst part is every time I thought I had it, when I relaxed they would be shy a degree or two, but I got them and they seemed to sandwich together pretty nice. Hopefully it's close enough to right. Wasn't it John Monnet that said were building airplanes not watches?

[dbdevkc]

I found bending the "hockey sticks" precisely to be a challenge. The other pieces have bends that are straight across the piece which is easy in comparison. If I were to do those hockey sticks again, I'd create a wood jig that would hold the piece to be bent so it could not move as the pressure is added to create the bend. Additionally, I would add supports to that jig that would hold the pipe in alignment with the bend line. Then put the actual bending pressure using a hydraulic press, although a larger arbor press would work if the jig can fit under the press. Without the jig, it seems that either the hockey stick piece or the pipe would move slightly when the bending pressure was added.