Modeling Corrugated Sheet Steel

[milwiron]

Has anyone modeled corrugated sheet? I'd like to come up with a way to make enough 2.5" scale sheet for a small cab roof. It only needs to be one sided but somewhat durable. The best I can come up with is grinding a form cutter and milling the corrugations one by one in 3/16 or 1/4" aluminum.
I don't think making a forming die for my 20 ton press would do it, even one row at a time.
Make a polyboard pattern and follow board and have it cast? I just dunno.
Any thoughts?
Thanks much,
Denny

[Dick_Morris]

Look at food cans. The spacing may be too close for your scale though. Two cans from my pantry (small refried beans and larger enchilada sauce) have 1/8" and 3/16" rib spacing.

[makinsmoke]

Hi Denny,
Smaller scale guys have used gear material in lengths, in a roller.

The teeth run crossways too the length of the material. I don’t know how long you can buy it in. Just find the pitch you are looking for to mimic corrugated metal.

Put two lengths in a roller and adjust the depth for the material and look you want.

Take care,
Brian

[rudd]

That's a good idea.... Spline profiles might work even better.
OP, do you have a dividing head to go with the mill?
https://www.grobinc.com/cold-rolled-pro ... ne-shafts/
https://www.grobinc.com/cold-rolled-pro ... pur-gears/

[Dick_Morris]

If you decide to mill them a ball end mill and radius end mill would approximate the the profile without having to make your own tool.

[milwiron]

Thank you guys. I do have a dividing head, cutting splines isn't an issue, I would need to build a roller. I thought about ball and corner rounding end mills which I have but every corner rounder of mine has a large center spud that forms the full radius, it would have to be heavily modified.
Thinking out loud here...
Looking at numbers, something I didn't do before I originally posted and I apologize. A small to mid size real world corrugation of 3 inch pitch x 3/4 inch depth would scale (2.5") down to a linear pitch of .625 and a height of .156. Not as scary as I thought in 18 ga. steel.
With a 20 ton press I've smooshed 10 ga. steel flat bottom U channels about 10 inches long.
So, doing a couple of corrugations, indexing the sheet then doing an entire sheet that way should be within my 18 gauge sheet smashing capabilities.
Thank you again, ya'll kick started my brain.
Denny

[amadlinger]

Hi Denny,

I'm not sure it this would fit the bill, but have you considered corrugated pipe jacketing material? McMaster and others sell rolls of it. I believe this is the material that Russ Eldred used to simulate corrugated sheathing material on the buildings on his railroad (White Creek).

https://www.mcmaster.com/insulation-jac ... orrugated/

See, for example, 4479K22.

Sincerely,
Adam

[milwiron]

Thank you Adam, I've seen the stuff and forgot it existed. For a cab roof it will need some backing for strength but that shouldn't be difficult to do.
As my second loco build I'm building a Chloe detailed out as a way-way-back, backwoods logging engine with no particular prototype in mind. It'll be more of a plantation engine meets two man logging operation.
My first build was a CP173 which taught me the most important lesson of how much I disliked polishing brass and bronze. So, Logging Chloe will have lots of detail but almost nothing shiney.
Thanks again,
Denny

[makinsmoke]

Not sure what the backing is they refer to. 5 ft length. If you don't need more than 2-1/2 feet in length you could double it. Course I guess it depends on which direction the corrugations run...

[Greg_Lewis]

If your cab roof will have a wood underside, consider laminating some of that 1/16 thin plywood the aircraft hobby folks use to make up the thickness you need and then attach some corrugated to that. Thus thin metal could be used which would be much easier to work. I did the laminated technique but used flat sheet on top to match my prototype. I used the metal repair shingles Lowes sells in the roofing dept. Dunno what gauge they are.

[Chris Hollands]

I'm sure you can buy model corrugated sheet I have seen it before for model houses or something not sure of the scale but there is probably different scales out there too - you tube is a good option

[milwiron]

Hi Chris,
The largest scale corrugated I found was 1/12 for doll houses.
Saw the YouTube videos earlier and have the ability to make a sheet metal roller but was trying to avoid that if possible for a 16" x 18" sheet. Other videos/methods for HO and O gauge buildings don't much apply.
Thanks much,
Denny