Chassis thickness.

[Barks]

Hi all.
New here.
Didn’t think I would ever build a garden railway but I’m doing it.
Anyway just a quick one.
I’m on the verge of buying cut metal body and chassis parts for an 08 shunter.
They have been cut correctly from the online drawings however the chassis has been cut from 5mm mild steel instead of 8mm.
That’s only 1mm off being half thickness.
Anyone care to say if it would be fine or too weak.

Regards
Barks

[drewzero1]

Welcome to the forum! It sounds worrisome, but I'm more familiar with plastics and wood. What scale are you working with, and what kinds of loads/stresses will the locomotive be expected to handle?

[Barks]

Hi.
Thanks for the welcome.
Sorry I didn’t say. It’s 7 1/4 gauge. The drawings state 8mm thickness and most other locos are the same 8mm.
It will probably be battery direct motor drive and pulling around 6 adults max.

Cheers
Barks

[Phil.P]

It might be a problem, for 'stiffness' of the chassis, but I would have thought you could add a couple of lengths of angle section, if this proved a problem.

Only other thought, is if it has been cut 'wrong', any tab and slot construction, will need more fill, when welding.
Overall dimensions, will be 'off' by 3mm,as well.

Phil.P

[Barks]

Thanks Phil.
Yeah it’s a difficult one.
Chassis will be half the weight which means less traction.
Stiffness and flex.
Also as you say if the axle boxes slot in to 8mm I would have to mod as they will be loose.

Thanks all
Barks

[Phil.P]

This wouldn't be one of the two sets of laser cut parts, listed on a certain auction site, would it?

Near Nottingham, so was sorely tempted..

Phil.P

[Barks]

Yes Phil.
The set not assembled.

Cheers
Barks

[Old Man Aaron]

Back in my 7¼" days, I seem to remember most steam and coupled-wheeled diesel locos at my club had frames of around ¼" / 6.4mm thick.
8mm seems slightly overkill to my mind, but the extra weight and rigidity certainly wouldn't go awry.

5mm does sound a bit flimsy; but I think could be made to work, with (as you've mentioned) packing if needed.
Certainly would want extra bracing though.

[FWLR]

I agree with Aaron, bracing is a must now and the width like Phil.P says the overall dimensions will hurt you when building it. You could put thicker right angle corner pieces to make the dimensions better and stronger. No harm in looking at that mocked up and seeing if it helps, I think it would and nobody would be the wiser...