Help with choosing parts for a first robot, please.

[maddox10]

HDPE doesn't hold thread.
Ranglebox is just easy. Other solution is to use L angle and nut and bolt.

I have seen other solutions , like IKEA Tnuts or other fibreboard/MDF connection methodes.

[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.

[dotDominic]

Right, so I'll use a combination of M6 Ranglebox and bolts with barrel nuts.

Thanks very much for the responses!

[Flag Captured]

Both Ellis and Sam (Tormenta 2/Rango, Hatchet respectively) use barrel nuts in HDPE and swear by them. If you install them right, they're excellently strong! And as for the Ranglebox threaded rod, again used right it's really nice stuff. Think it held Tormenta 3 together this year, and I think Mario's used it on (Nebelwerfer?) to nice effect. Really handy!

[Ellis]

Everything except the wedge on Tormenta 3 is held together with M6 Threaded Bar and barrelnuts.

[mrsam]

Hatchet was all m6 barrel nuts in 20mm hdpe this year and it all held up amazingly well, put it this way, it fought 8 spinners at this years world championships and it's still in one piece.

[Rapidrory]

It did also have a large chunk of hardox on the front which may have helped :P but yeah it can work pretty well...

[dotDominic]

Perfect, thanks very much!

[dotDominic]

Ok, so, finally managed to get come CAD stuff done. Took much longer than it should've but here's some pictures of what I intend to build. The design is pretty basic, and I hope you'll excuse the crudeness of the model as I haven't really done anything like this before.

[EDIT] - The photos should be viewable here:
https://www.flickr.com/photos/131745614@N05


The size of the robot is 40cm Width, 36cm Length, 10 cm Height (Including Wheels).

Probably could be more compact but I'm not really sure how much space the wires, removable link, fuse, Battery mounts or ESC mounts are going to take up. I will probably need some sorta spacer between the wheels and the bulkheads but I'm not sure how thick that'll need to be yet, so I've not put it in the diagram. So yeah, if anyone has any opinions or has noticed any major problems with this design I'd really appreciate the responses, thanks!
Should be able to finally get the flippin' drill chucks off this afternoon, too!

[Garfie489]

Just to say i cant see any of the attachments, not sure if thats a problem with the site.

If you have links to the pics, you can use [img] [/img] aswell - just put the link in the middle, can even be a facebook picture link such as below for example

Link: https://fbcdn-sphotos-h-a.akamaihd.n...81220408_o.jpg

[img] https://fbcdn-sphotos-h-a.akamaihd.n...81220408_o.jpg [/img]

(Without spaces)