I was wondering if anyone has attempted this before. I couldn't find anyone on youtube who has tried it.
I'm currently working on a prop with a lot of moving parts. But for the ones connected to a linear actuator, it needs to be as light as possible to be within the range of the motors torque limit. However my concern is that if it gets dented then it will be a problem when it's in motion. Thus why I need to make it tougher.
I only have one set of this cardboard cut out since it was laser cut as I don't have easy access to do it again. Also the cardboard can only be one layer thick due to limited room thus stacking it is not an option. So this is something I need to get right the first time. I'm currently experimenting with scrap pieces layering it with glue. Results are okay-ish. But then I thought about expanding foam and wondered if I could fill in the internal areas.
Thoughts? Opinions? Other ideas?
Expanding foam shot into the tiny grooves of a piece of cardboard won’t be very strong. Expanding foam is pretty brittle unless it’s very thick. It might make the cardboard a little stronger, but I’m guessing it won’t hold for very long if torque is applied to it, and crack into a bunch of smaller pieces.
Without seeing what you’re building to get a better idea of the forces that will be applied, it’s tough to give any other advice.
I'm currently working on crescent rose from RWBY. Specifically the scythe and armor plating at the end of the barrel. I already laser cut the pieces out of cardboard. I have all the moving mechanisms figured out and ready to install. I just need the make the cardboard stronger that in the event of an accident I don't have to worry about it being dented out of place and unable to fold back together.
The expanding foam has more chance to destroy the cardboard than do any good.
If you are using glue, add some tissue paper or news paper with the glue to make a paper mache it’s not too heavy and not thick but can make things very rigid.
That is my very last option as I don't want to do paper mache if I can avoid it.
Id use mod posge but nighthawkinlight on youtube has some pretty amazing ways of making cardboard as strong as wood
Id personally also suggest mod podge on Eva foam its way easier to work with and very lightweight and doesent tend to break in the same way cardboard does :) its incredible stuff and you can add foam clay on top of it for some extra style and to hide things and just generally make it way easier to work with. But overall anything you slap mod podge on will get stronger
I usually work with elmers glue. But for mod podge, would I just put it on directly or mix with water and repeatedly layer it?
If you're making a Crescent Rose, could you switch out the cardboard for pvc pipes instead? I think they'd hold us better than cardboard. Either that or wooden dowels?
Side note I am curious to see your folding mechanisms as I also plan on making a Crescent Rose someday.
Most of the body is made from PLA plastic that I 3d printed. All the electrical components were integrated in when I put it all together. The only cardboard pieces are the blades and the exterior plating of the scythe end. I just need to make the cardboard hard enough to resist any dings that it might encounter. Not to mention it has to be cardboard to get it within the weight limit of the motors torque.
Ah, motor torque. Yeah, I've had that problem before.
Hm, I wonder, can you PlastiDip cardboard to make it more durable? Like the spray on kind?
use Foam core board... same thickness as regular corrugated cardboard
Cut the shapes out of foam board using your laser cut cardboard as a template. Light and rigid, and you can sand the edges to get smoother curves. If that's still too heavy, you can skeletonise the foam board, then cover the holes with a layer of facing material laminated on, maybe some kind of vinyl sheet. You should be able to get it significantly lighter without sacrificing too much strength.