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What is the best screws for screwing HDPE sheets together? I used standard wood screws but they didn't seem to get that good a grip. is there any particular type of screw I should be using or thread type? I plan on screwing 12mm hdpe together.
Ta
Billy
As thick and coarse as possible.
Particle board screws I guess
http://www.usifaz.com/Web%20Site%20P...crew%20nkl.gif
The thinner piece is drilled trough with the same size as the outer diameter of the tread. The thick piece is predrilled with the inner diameter. And don't overtorque.
i found large wood screws work fine
something like these?
http://www.screwfix.com/p/timco-velocit ... -200/95274
I just use chipboard screws, seem to work fine.
I used wood screws of some sort (I think they were standard) and when put together well they make for one heck of a connection, to the point where on several occasions our cordless drill/screwdriver (one of the lucky ones that still serves as a drill!) couldn't undo them.
In my materials lectures we have been researching processes like laser and sonic welding as well as extrusion welding for HDPE. I was hoping that I could hire an extrusion welder and build the armour for my robot with that but I cant find any companies that hire them out. Any ideas or is it overkill?
i would say yes overkill, use some screws
Quote:
Originally Posted by Eventorizon
I own a handwelder for HDPE, but it seems the welds are more brittle than the mother material.
I learned to back the welds uo with some bolted in/on supports.
There are a few robots about that have 'welded' hdpe shells , you can use a really powerful hot air gun and hdpe welding rods
Skink is entirely made of such plastic.
The joins are tongue and grooved, then tapped m5 and scewed together with countersunk allen screws.
A bit over the top perhaps but it has lasted five years!
Problem with wood type screws is they don't always find the same thread when you take them out and put them back, so you end up with little or no grip and your bot coming to pieces in the arena!
Mike.
has anyone ever pressed a brass insert into the hdpe which is threaded and allows an m5 etc bolt to be screwed in? rather than taping the hdpe itself
i used these on my bot
www.ebay.co.uk/itm/M4-X-10mm-Hex-Drive- ... 500wt_1054
I believe there's a topic about this in the fw section a while back.
how did they work out?
heres link:
viewtopic.php?f=111&t=4378
well i think there holding it together well it dropped off the work bench and it only scratched the plastic but the structure is 20mm hdpe and rg1000Quote:
Originally Posted by billy breach
I didn't use them in the end- now I have decided just to screw the bolts into the grow with a powerful drill to in effect tap a hole in the hdpe. If you look towards the end of my pneumatics thread (aroun page 8 I think) madox showed a good solution
Page7 its on and a very good idea