Bending plastics for a small robot

[strombom]

Hello!

I am building a small robot and want to bend three small plastic parts at 90 degrees.

http://bildz.altronix.se/mekpro/platta.jpg

http://bildz.altronix.se/mekpro/robot.jpg

I tried with a hot-air-gun but the result was dissappointing:
http://bildz.altronix.se/mekpro/bend.jpg

Have you got any ideas how to do this ?

/Johan

[ViperTX]

Generally you bend with a heating strip, which in the US we find at most Plastic's supply houses. You'll have to experiment on how long you have to let the plastic heat-up as the plastic that you're trying to bend is pretty thick, but it can be done. The hot air gun doesn't cover enough area without getting some areas too hot....causing the bubbles in your bends...the plastic was melting.

[strombom]

Ok, but I think I will try once more with the hot air gun, warming a little slower and building some sort of jig...

/Johan

[j m]

I have only bent plastic sheets using a heating strip type thing like vipertx describers it was a few years ago. I was surprised at how lower tempter it started to melt. I don’t know if your hot airgun came with the nozzles to channel the heat into a strip they basically look like a piece of squashed pipe which if you don’t have you could probably make one [ if your airgun is like mine although it is surposed to be variable heat it seams to have 2 tempters on or off ] and if you were to make one I think I would make it 2 or 3 inches long and drill holes in it to losses some of the heat.

[High Seas]

Have you tried an oven? Be careful - test a piece - watch temp and have a way to catch any mess. Vacuum formers use the oven to heat (thinner yes). But to bend my 8mm windows we used a large propane fired oven (looked like a 2meter x 4meter barbie), then clamped the warmed (not melted polycarbonate) over the form to get shape. Maybe use a male + female former to get shape or small bending jig. Use tongs or gloves maybe oversize the piece then trim to shape.
Jim
Oh yes - the women should be sent out window shopping or something when you do this!

[greybeard]

I'd go with HighSeas -lay the 3 plastic pieces over the edge of a flat metal plate with a small weight on them to prevent them falling off.
Raise the oven temp to the lowest setting (assuming your in the kitchen ) then as soon as they slump, turn the oven off and leave to cool with the door open.
John

[strombom]

I wonder what my food will taste like...

http://bildz.altronix.se/mekpro/oven/oven.jpg

I put it on 100 degrees celsius... will raise it if that is not enough.

Edit: 150 degrees celsius (300 F)

/Johan

[greybeard]

If you get any flavours, it'll be from the particle board

[greybeard]

Hammer the particle board into small pieces and serve with cold milk and sugar to taste

[strombom]

particle board = bad smell

http://bildz.altronix.se/mekpro/oven/oven2.jpg

/Johan

[strombom]

woho

it's getting soft

http://bildz.altronix.se/mekpro/oven/oven3.jpg

/Johan

[strombom]

gah, i forgot it

http://bildz.altronix.se/mekpro/oven/oven4.jpg

http://bildz.altronix.se/mekpro/oven/oven5.jpg

will give it another try some other day

/Johan