How to build a scale model - tubing choices.

[NTwoO]

Hi guys,

I want to build a scale model of a garden chair I am planning to build. The real thing will be 304 with 50 and 60mm tubing. If I say want to do a 1:10 scale model, what thickness tubing must I use to come close to the real thing, preferably in mild steel? I'm aware of the bending stiffness going at the 4th power, so tubing of 5 and 6mm is not realistic... or is it?

 

[chunkolini]

Would it not be easier to use solid bar at this kind of size?
is the model to look lie the ful sized chair or to have the same properties eg flex etc?

Just a thought, Chunko'.

 

[NTwoO]

Well, I thought of doing it for a discussion piece for a final design and also to test it to destruction and have an idea what the strength would be. With the mass to be carried decreased by a 10th and the lever arm also by a 10th, the cross section running at the second power, maybe a direct scale is the correct approach. Maybe a scale 1:5 is more constructable.

 

[Shox Dr]

For the full size chair you would not want to be using tube with a wall thickness greater than 1.2, otherwise it's going to be a pig to move about.

The Problem you have making a 10th scale model is the OD is going to be 5 to6mm with a wall of 0.12mm

Good Luck fella

 

[NTwoO]

It'll be as good as possible without buying a miniature jewellery tig welder and ordering special tubing. The material will be 1-1.5mm 304 for the real thing. A rough estimate would be good. Is the idea of using 5, 6mm tubing for a 1:10 scale version correct?

 

[chunkolini]

Could you braze tubing at that scale, it might be a 'fun' option but it would sharpen up your skill set.

Chunko'.

 

[Shox Dr]

Does the scaled model HAVE to be made from SS, if not Wood would be a better choice, or as someone else said round bar. I TIG .9mm SS all day long, and it warps for fun if you are not careful. Trying to weld 0.12 will be a nightmare, esp if the fitt-up of the tubes or not to perfection, for a start where are you going to get 0.1/0.2mm rod from, in a small qty

 

[Ratty]

The Problem you have making a 10th scale model is the OD is going to be 5 to6mm with a wall of 0.12mm

I can get st/st tubing 4.98mm with 0.16mm wall (6 gauge), 5.46mm with 0.179mm wall (5 gauge) and 6mm with 0.20mm wall (4 gauge). Let me know if you need contact details.

Tigging that will be fun!

 

[NTwoO]

As said, I think making it from mild steel would give a good impression of the proportions etc. Welding that thin wall stuff would make you go dotty, that's why I think a start with 6mm tubing with 1mm wall would give a reasonable impression of the end result.