Homemade manual square tube bender

[Tuomas]

Are you noticing any flex in the side plates or are they staying tight against the center die.

I haven't.

As you see "arms" supports the package on vertical direction.



Also i have to take back my previous post.
If you look those pictures closely, you notice that i mounted that lower edge support plate wrong side up. blaah...
That's why i got different results with the widht.


Also i made a little improvement, just drilled a hole through the whole thing, now i can lock the used "slot depth", and get similar results every time.



Now when comparing deep, or shallow slot. Only difference can be seen from this picture:


Somewhat similar, only difference is that deeper slot handles little bigger force before it starts to loose its shape.

I think that the result is now somewhat best that i can get with the manual bender with radius this tight, and i wanted to get tight radius.
( without need to use plenty of time for bending ).




Personally i am satisfied... Now i just need to make stronger vise mount.

[Frontier Forge]

Brilliant! What a great idea. Heck of a job, mate!

[Tuomas]

Brilliant! What a great idea. Heck of a job, mate!

Thank you very much.

[Whitworthsocket]

Very good work Thomas.
Try putting the weld on the side. (Neutral axis). It may or may not make a big difference. However it's good practice to put the seam or weld on the neutral axis. To minimise any chance of the weld splitting

[Whitworthsocket]

If you want a really small radius. You can fabricate a vee block with slightly tapered sides out of say 10mm plate. To use in a hydraulic press. Then make a "nose" from polished 25 x 8 mm flat bar to push on the inside (topside) of the steel tube. The die needs to be lubricated.
It's probably better to call it a "crush" bend. It did not take too long to set up and it worked very well.
I am not sure if I kept it when I moved workshops but if I find it I will post an image.

[Tuomas]

Very good work Thomas.
Try putting the weld on the side. (Neutral axis). It may or may not make a big difference. However it's good practice to put the seam or weld on the neutral axis. To minimise any chance of the weld splitting

Thanks!

Sorry about answering little late. But, my English ain't very good.. I am not sure where you suggested to add welds?

Its always good to practise welding, but i rather don't practise for pieces that i'm working on.
Anyway, i like to use welds only in those places where its required.

That might sound weird, because i have worked with metals over 20 years, and have two graduates about welding.

Actual bender is designed so, that there is welds on every direction,
those plug welds and seams on the ends of the split square tubing " locks " possible movements on the sideways, also there is that curved plate on opposite edge of the square tubing.

Those makes structure so strong, that at the point when welds could possible split,
it is lost its shape and most likely is unusable condition anyway.
I try to plan and use welds as strong as the materials are, to avoid unnecessary distortion.

[Tuomas]

Here is one example where i use this.





Result was a referee's chair for pull ups competition.

[Tuomas]

I made the pull up stand too. I post some pictures later, If one is interested.

Here is a clip about in use.
New national Record in Females 52 chinups: https://www.instagram.com/tv/CWyX_v9...dium=copy_link

Idea in the stand is to lift shorter pullers to reach the bar, and then lower it down, to allow free movement of feets.