# Bending the lighting support gantries

**URL:** <https://discourse.southlondonmakerspace.org/t/bending-the-lighting-support-gantries/4790>\
**Category:** Projects\
**Created:** [26 January 2017 09:33 UTC](https://discourse.southlondonmakerspace.org/t/bending-the-lighting-support-gantries/4790 "2017-01-26T09:33:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![RichM](https://discourse.southlondonmakerspace.org/user_avatar/discourse.southlondonmakerspace.org/richm/32/2991_2.png) [@RichM](https://discourse.southlondonmakerspace.org/u/RichM)\
**Post date:** [26 January 2017 09:33 UTC](https://discourse.southlondonmakerspace.org/t/bending-the-lighting-support-gantries/4790/1 "2017-01-26T09:33:08Z")

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Some people were asking about how I was intending to bend the 50x50 box section for the lighting support gantries. I made a start yesterday. Here are some pictures!

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/4/495f01a30d05d5beb3a6f310cde6dcbcbab50ab0.jpg)

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/b/b1f9864903562f45f8d63419dc872d83f0cfdd09.jpg)

The bending jig is a piece of channel bolted to the bed of the flypress. The flypress just converts the kinetic energy on the big red ball to a squashing force, but importantly there is an adjustable collar that restricts the maximum stroke. I’ve set it to just impart a little bit of bend each time.

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/d/d670360e64b6a1d57ed9f8c55d139e64974f7480.jpg)

We’re going to need bigger pins…

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/8/80c18204dc45fe4e672d187af9edb7d4d01fb2ce.jpg)

That’s better. 20mm pins, sleeved with a couple of different bits of tube that conveniently fit inside each other.

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/1/1e2ac2942b6da1afcae43179ebc91dcc2121d098.jpg)

So I put chalk marks at even intervals along the tube, and squish it a little bit at every mark. It dents the tube a bit (not so much of a problem for solid) but ends up with a smooth-looking curve.

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/d/da47aa86a5bb3831cf7f2556c469b84824f12917.jpg)

Each time I run the tube through the jig, I move the collar on the press up a bit so it bends a little further each time.

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/9/90442d6aef83b61b571d74032876318cb07168e1.jpg)

Gradually we sneak up on the right curve, measured against Dermot’s template.

 ![](https://slms-discourse.s3.dualstack.eu-west-2.amazonaws.com/original/2X/e/e68c4eddad7d223299c13f43a4dc36d730484d7b.jpg)

Until we’re there.

Repeat times four, or until it’s dark.

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**Author:** ![tomnewsom](https://discourse.southlondonmakerspace.org/user_avatar/discourse.southlondonmakerspace.org/tomnewsom/32/2_2.png) [@tomnewsom](https://discourse.southlondonmakerspace.org/u/tomnewsom)\
**Post date:** [26 January 2017 10:43 UTC](https://discourse.southlondonmakerspace.org/t/bending-the-lighting-support-gantries/4790/2 "2017-01-26T10:43:59Z")

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Nice 🙂  
I’ve seen this done with rollers to get a smooth curve, but that’s a single-use tool…