Help with choosing parts for a first robot, please.

[dotDominic]

Ok, so I was looking at these on Ranglebox.com: http://ranglebox.com/mechanical-products/

Just wondering if this is needed to join HDPE together, or can HDPE sheets be bolted directly to each other, without any joining elements? If it is necessary, would it be the M4 or M6 threaded bar I'd need?
And also, how would one go about cutting the bar to size? Is an angle grinder necessary?
I know this was mentioned on this thread by Flag Captured a while ago now - sorry for not asking about it sooner!

I'm a little bit away actually building much at the moment as I'm still having problems with the drill chucks from hell. None of my local shops had torx screwdrivers, but I'm going to a hobby shop in another town tomorrow so hopefully I can get this sorted!

[Eventorizon]

Ok, so I was looking at these on Ranglebox.com: http://ranglebox.com/mechanical-products/

Just wondering if this is needed to join HDPE together, or can HDPE sheets be bolted directly to each other, without any joining elements? If it is necessary, would it be the M4 or M6 threaded bar I'd need?
And also, how would one go about cutting the bar to size? Is an angle grinder necessary?
I know this was mentioned on this thread by Flag Captured a while ago now - sorry for not asking about it sooner!

I'm a little bit away actually building much at the moment as I'm still having problems with the drill chucks from hell. None of my local shops had torx screwdrivers, but I'm going to a hobby shop in another town tomorrow so hopefully I can get this sorted!

Rangle Box is just Aluminium so you can cut it with a hacksaw with no problem and then file the ends neat, even Wet 'n' Dry sandpaper would do, its much softer than steel.

HDPE can hold a thread, it has been done but given that tapping it requires a Tap and a turning tool and a drill of a specialist size, ege 6.8mm for an M8 bolt, I would suggest using barrel nuts for some parts too. Then you just need a drill and 2 normal drill bits, and M8 for the bolt to go in and a M12 for the barrel nut for example. A combination of that and Ranglebox will allow you to deal with almost any joining situation.

The M6 Ranglebox is aimed at the Featherweight class where as the M4 can be used strategically in feather but I would say lends itself better to the beetleweight class.