4 ms·

I haven't looked to far into this project, you might be able to gain a decent amount of stability with better materials like 3d printed plates instead of cardbo

I haven't looked to far into this project, you might be able to gain a decent amount of stability with better materials like 3d printed plates instead of cardboard. (This is a place where CF filament actually makes sense, it's one of the most rigid printable plastics)

semi-extrinsic 7y ago
Or you could just laminate that cardboard with some fiberglass and epoxy, on both sides. A roll of 5cm x 3000 cm fiberglass woven cloth is $9 incl shipping on ebay. Buy some two component epoxy at the local hardware store, like 10 fl. oz. for $15. Cut your cardboard and fiberglass to whatever size and shape you like. You're going to make a sandwich: fiberglass, cardboard, fiberglass. Wear disposable gloves. Cover your benchtop in two layers of cling film. Put your sandwich down, carefully rub epoxy into the top fiberglass, two layers shrink wrap on top, flip the thing over, rub epoxy into the second fiberglass, more cling film. Put it in press with some weight, leave overnight. If your cardboard has some thickness and good compressive strength, the strength of the resulting sandwich is probably such that you won't be able to break a 10 cm long stick with your bare hands. 3D printing is cool. But for random repairs around the house, or building strong flat things like this, epoxy and fiberglass is the bee's knees. We've built stand up paddle boards with this technique, just replacing the cardboard with XPS plates. No vacuum bagging required, really. (Of course it would give further strength and much improved aesthetics.)
- pierrec 7y ago
  Regarding the solidity of this technique, these days a lot of indoor climbing holds are made of fiberglass held together by epoxy, with a thin layer of textured plastic on the outside. These are generally called fiberglass volumes. The material is so solid that a meter-wide hold is actually just an empty shell with a thickness of a few mm. This easily withstands a heavy dude jumping onto it sideways (in fact, that's what it's there for!)
- penagwin 7y ago
  I'm a huge fan of Peter Brown on youtube, I've been wanting to get into using epoxies for various projects, it's just that I live in a small apartment, I'm not sure where to start, and I know I'll need ventilation. I'm biased towards 3D printing simply because I already have my own printer, so it's simply the fastest method for me (not including print time, but epoxies have to cure anyway).
  - jessaustin 7y ago
    If ventilation is challenging, use less epoxy at one time. Also there's nothing wrong with leaving the room and waiting for the vapors to clear out.
  - semi-extrinsic 7y ago
    Ventilation/offgassing is a fairly minor concern, especially for small projects where you don't get much heat release from the reaction, and you are not baking it. Your kitchen extractor fan is probably enough. You can try it out with a small test, say total amount of epoxy equal to 2 tablespoons, and see how that goes. I would actually expect more of a ventilation requirement from your 3D printer! Here is one set of safety recommendations for working with ABS/PLA: https://www.safety.rochester.edu/ih/3Dprinters.html https://www.safety.rochester.edu/ih/3Dprinters.html But if you are really worried, go get a 3M 7502 mask with a 6001 organic vapor cartridge. These are cheap. That's what the manufacturer (West System) MSDS says to use in case of no ventilation. Skin contact is a bigger concern. 1 in 5 develop dermatitis upon skin contact, and some get more severe allergic reactions. So wear good gloves, blue nitrile ones that fit well with decent thickness, not the cheap latex stuff.

semi-extrinsic 7y ago

Or you could just laminate that cardboard with some fiberglass and epoxy, on both sides. A roll of 5cm x 3000 cm fiberglass woven cloth is $9 incl shipping on ebay. Buy some two component epoxy at the local hardware store, like 10 fl. oz. for $15. Cut your cardboard and fiberglass to whatever size and shape you like. You're going to make a sandwich: fiberglass, cardboard, fiberglass. Wear disposable gloves. Cover your benchtop in two layers of cling film. Put your sandwich down, carefully rub epoxy into the top fiberglass, two layers shrink wrap on top, flip the thing over, rub epoxy into the second fiberglass, more cling film. Put it in press with some weight, leave overnight. If your cardboard has some thickness and good compressive strength, the strength of the resulting sandwich is probably such that you won't be able to break a 10 cm long stick with your bare hands. 3D printing is cool. But for random repairs around the house, or building strong flat things like this, epoxy and fiberglass is the bee's knees. We've built stand up paddle boards with this technique, just replacing the cardboard with XPS plates. No vacuum bagging required, really. (Of course it would give further strength and much improved aesthetics.)

pierrec 7y ago
Regarding the solidity of this technique, these days a lot of indoor climbing holds are made of fiberglass held together by epoxy, with a thin layer of textured plastic on the outside. These are generally called fiberglass volumes. The material is so solid that a meter-wide hold is actually just an empty shell with a thickness of a few mm. This easily withstands a heavy dude jumping onto it sideways (in fact, that's what it's there for!)
penagwin 7y ago
I'm a huge fan of Peter Brown on youtube, I've been wanting to get into using epoxies for various projects, it's just that I live in a small apartment, I'm not sure where to start, and I know I'll need ventilation. I'm biased towards 3D printing simply because I already have my own printer, so it's simply the fastest method for me (not including print time, but epoxies have to cure anyway).
- jessaustin 7y ago
  If ventilation is challenging, use less epoxy at one time. Also there's nothing wrong with leaving the room and waiting for the vapors to clear out.
- semi-extrinsic 7y ago
  Ventilation/offgassing is a fairly minor concern, especially for small projects where you don't get much heat release from the reaction, and you are not baking it. Your kitchen extractor fan is probably enough. You can try it out with a small test, say total amount of epoxy equal to 2 tablespoons, and see how that goes. I would actually expect more of a ventilation requirement from your 3D printer! Here is one set of safety recommendations for working with ABS/PLA: https://www.safety.rochester.edu/ih/3Dprinters.html https://www.safety.rochester.edu/ih/3Dprinters.html But if you are really worried, go get a 3M 7502 mask with a 6001 organic vapor cartridge. These are cheap. That's what the manufacturer (West System) MSDS says to use in case of no ventilation. Skin contact is a bigger concern. 1 in 5 develop dermatitis upon skin contact, and some get more severe allergic reactions. So wear good gloves, blue nitrile ones that fit well with decent thickness, not the cheap latex stuff.