HDPE and perspex

muchalucha · Post by **muchalucha** » Mon Mar 30, 2009 12:33 pm

Any body at robots live would have seen my dear thants get launched 20 feet across the arena and land out side as well as it get smashed by battle axe (vendetta , vendetta) all because my crappy tamiya connector fell out . so i was thinking , loads of other people used hdpe and perspex , where could i get about 5 - 10 mm sheets of this stuff in the uk and which is better for my feather , ive never used this stuff before so any advice is good advice

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Simon Windisch · Post by **Simon Windisch** » Mon Mar 30, 2009 1:37 pm

I use this stuff.

Simon

muchalucha · Post by **muchalucha** » Mon Mar 30, 2009 2:54 pm

thnaks for the link , that stuffs not to expensive at all

Post by **BeligerAnt** » Mon Mar 30, 2009 7:57 pm

Perspex is a well-known brand name of acrylic sheet. Acrylic tends to shatter when hit, so is generally useless for robots. If you want clear plastic, use polycarbonate. HDPE is much cheaper, it doesn't have the same impact strength (on paper) but it is more flexible than polycarbonate, which should help to absorb the impact.

DirectPlastics Online (see Simon's link above) also sell HDPE in a range of thicknesses. I had no problems when I ordered from them.

teamocean · Post by **teamocean** » Tue Mar 31, 2009 9:04 pm

HDPE is definately the better option over polycarb, we used polycarb on the old whirlpool and ended up replacing the side panels after each event, we then replaced it with some 20mm HDPE and it has been more than strong enough ever since. We also used 5mm HDPE covers on Aftershock which have been welded together which is attached to a steel frame which can deal with spinners reasonably well.

We buy all our HDPE from direct plastics too- I would suggest looking in the stock clearance section- there are sometimes some good bargains to be had!

Remote-Controlled Dave · Tue Mar 31, 2009 11:18 pm

We use 20mm HDPE in our current heavyweight, and I'm building my new one out of it, so it's definately strong enough for a featherweight.

Will (or Gary), how exactly do you weld HDPE? Is it a complicated process or fairly easy?

leo-rcc · Post by **leo-rcc** » Wed Apr 01, 2009 2:31 am

Dave26 wrote:We use 20mm HDPE in our current heavyweight, and I'm building my new one out of it, so it's definately strong enough for a featherweight.

Will (or Gary), how exactly do you weld HDPE? Is it a complicated process or fairly easy?

HDPE is welded with a hot air welder (and adding some hdpe as filler). All our feathers and the top of our Heavyweight Obsidian is welded HDPE.

Flippt · Post by **Flippt** » Wed Apr 01, 2009 7:18 am

Whats the cost for such tool, or can you make one yourself with a modified end for a hot air gun?

Remote-Controlled Dave · Wed Apr 01, 2009 10:55 am

That was gunna be my exact next question Joacim. lol

Post by **BeligerAnt** » Wed Apr 01, 2009 9:19 pm

For welding RONNY's bodyshell (1mm) and chassis (3mm) I used an old soldering iron bit. The technique took a bit of mastering, but once I got it right it is really strong.

I would expect a hot-air gun could be pressed into service for bigger jobs. A variable temperature might be useful, I suspect a standard paint-stripping tool might get a bit too hot. HDPE melts at 130C by the way, and from what I've read you have to avoid overheating it.