bending plexiglass...

[Everfalling]

i'm working on a mod that'll have windows that will be requiered to bend a little over a curved surface. i was wondering if there is any good way to bend plexiglass into place, like securing it against its will in a bent position with bolts or screws, or actually melting it a little to soften it and mold it into place. or, if not plexiglass, is there any other material i could use for the windows that would bend?

 

[Tiny]

You just heat it up while it is laying on the curvature that you want.


Or you call these people.
http://www.waterfountains.com/acrylic__spheres.htm

 

[Everfalling]

You just heat it up while it is laying on the curvature that you want.


Or you call these people.
http://www.waterfountains.com/acrylic__spheres.htm

that's a bit of an overkill for a few small windows...

what should i heat it with? and how hot to make it juuuust a little malluable. i dont want it fully melted.

 

[ray4389]

I usually pore a bit of kerosene of it and then use a grill lighter and let that burn out.

DO OUTDOORS!


















No seriously I would try a heat gun made for removing paint. They cost maybe low as $20 high as $60?

Don't use anything with a flame it will char it. The heatgun is a suped up blowdryer that will give you 3rd degree burns in miliseconds. Treat it as you would a torch. It's a torch of it's own magnitude.

GOOD LUCK!!!

 

[ryuji]

The heatgun is a suped up blowdryer that will give you 3rd degree burns in miliseconds. Treat it as you would a torch. It's a torch of it's own magnitude.

mmmm bacon

 

[delbert]

I have some experience bending acrylic. How thick is the piece you want to bend? Straight bend or compound curve?

 

[ryuji]

i think there is a good guide for it on bit-tech, or there is a guide that was referenced from there, i remember looking at a case mod and finding a good guide on how to bend

 

[sarbz]

http://www.justwebspace.com/packnheat/thumbnails.php?album=2&page=1

 

[delbert]

Slight curve with thin material I'd use an oven


Sharper bend on thicker acrylic I'd use a heat gun.

example
edit:lol sarbz beat me to a link of my own stuff.

 

[sarbz]

Slight curve with thin material I'd use an oven


Sharper bend on thicker acrylic I'd use a heat gun.

example
edit:lol sarbz beat me to a link of my own stuff.

I love that work log...very good work! Thanks for sharing it with the rest of us!

 

[Everfalling]

I have some experience bending acrylic. How thick is the piece you want to bend? Straight bend or compound curve?

not sure how thick, i'm just piling up information for the future. umm... donno what a compound curve is. see this pic? all those red areas are gonna be small windows looking into the case. if you can picture this 2d layout in 3d, you'd see how they curv with the sphere. that moven thing is an interesting idea. seeing as the pices i'll be cutting out will be metal anyhow, i think i could do that fairly well.

 

[delbert]

if you can picture this 2d layout in 3d, you'd see how they curv with the sphere.

Struggling a bit but if its a sphere then I think I understand. Sort of.

donno what a compound curve is.

curves in more than one direction. A cylinder curves in one direction. A sphere curves in two. Compound curve is harder to pull off for sure.

 

[Everfalling]

i wonder. could i do something like, taking a large piece of plexiglass, set it inside the sphere after i cut the holes, shove it all into the oven, and instead of just getting the curv, letting the plexiglass melt out of the holes and fill them instead of having to get the right curv, then cutting to size? granted, the windoes would look kinda like a bubble trying to ecape out of the slots, but it might be easier... only problem is keeping the glass flush with the rest of the curve of the sphere instead of melting out of the holes. hmm

 

[delbert]

sounds like you need more af a vaccum forming process

 

[Ice Czar]

curves in more than one direction. A cylinder curves in one direction. A sphere curves in two. Compound curve is harder to pull off for sure.

and likely requires a buck with both male and female dies or vaccum forming

http://www.media.mit.edu/physics/pedagogy/fab/moldguru/selker.html


there are some faitly affordable vaccum forming setups (like for laminates \ woodworking shop equipment)
the trick being the heat youd need to employ as well

you might be better off doing some spin casting with an optical resin for a sphere

 

[Thrash]

You are making a window in the exact size and shape of the pieces of metal you will be cutting out, correct? Lay the plexiglass on top of the piece that has been cut out, then heat it so it forms to the cutout.

 

[Everfalling]

yeah that's what i was thinking, more or less. but like delbert said, it's a compound curve. unless i'm exact, it could happen that the glass either falls out of place, or melts odd when settling down into the piece of metal... we'll see, but it's something to think about.

 

[Ice Czar]

i wonder. could i do something like, taking a large piece of plexiglass, set it inside the sphere after i cut the holes, shove it all into the oven, and instead of just getting the curv, letting the plexiglass melt out of the holes and fill them instead of having to get the right curv, then cutting to size? granted, the windoes would look kinda like a bubble trying to ecape out of the slots, but it might be easier... only problem is keeping the glass flush with the rest of the curve of the sphere instead of melting out of the holes. hmm

there is always grinding and rebuffing the plex to an optical finish

 

[AreEss]

Here's an off the wall idea...
Why not get "scraps" that are thick enough that you can grind them to fit, and then repolish?

 

[Everfalling]

Here's an off the wall idea...
Why not get "scraps" that are thick enough that you can grind them to fit, and then repolish?

hmm..maybe... but i'm not entierly sure how much of a curve i'll need, so i donno how thick of a pice i'd need to get... plus where do you get scraps of plexiglass?