Bending Eccentric Rod

[PaulR]

I need to put a small bend in the middle of an eccentric rod. The rod will be either 1/8" x 1/4" flat or 1/8" round bar, I haven't decided yet. The strap side of the rod needs to be offset by just 2.5mm from the valve side. What's the best way to do that accurately by bending or, given the small offset, would it be better to make it from two parts with a soldered or pinned overlap if using flat bar?

I've done something similar using a jig before but I think it was a much bigger offset although I'm damned if I can remember exactly how! 

[Jasonb]

Usual way is to do it in a vice. Two pieces of 2.5mm flat material one either side of the rod an dwith a space between. Then tighten up the vice and that should put a jog in the rod.

[PaulR]

Usual way is to do it in a vice. Two pieces of 2.5mm flat material one either side of the rod an dwith a space between. Then tighten up the vice and that should put a jog in the rod.

Sounds easier than making a jig! Anneal first and do it cold? I'll do some experimentation first

[Jasonb]

Do it cold, the vice will just suck the heat out of a thin bit of metal like that before you can get the vice done up.

[internal_fire]

I'll do some experimentation first

I recommend that you round the inner edges of the flat material. Otherwise it is likely that an indentation mark will show up at each end of the jog.

Gene

[PaulR]

I filed some scrap brass to 2.5mm thick, thinking a softer material would be less likely to leave a mark, and very slightly rounded the edges. The bending was easy, and the result seems accurate enough. There's a slight crease on the inside of each bend but that will come out with a bit of sanding.

Thanks Jason 

[PaulR]

I'll do some experimentation first

I recommend that you round the inner edges of the flat material. Otherwise it is likely that an indentation mark will show up at each end of the jog.

Gene

Thanks, I've learned the hard way - next time I will!

[Sanjay F]

It's still worked out well, I had to do the same operation for the first time on the flame gulper I made a last year