Help with choosing parts for a first robot, please.

[harry hills]

Probably for the best, black and decker are seriously budget. Turn the torque limiter down, then basically try and rattle gun it out. worst case drill off the head of the bolt then remove the rest of it when you get the chuck off but that will require buying a new LH bolt.

[dotDominic]

Ok, so after spending way too long faffing about with these Black and Decker drills, (my nearest hobby shop couldn't help me out either.) I bought some Argos drills and I'm going to sell the Black and Decker ones on eBay. 3 of the 4 reverse thread chuck screws popped out relatively easily. However, even using another cordless drill I can't get this last screw out. Does anyone have any suggestions on unscrewing particularly tight chuck screws?

Thanks.

[dotDominic]

Thanks! Yeah, it's about as basic as it gets but I'd rather play it safe for my first robot. Totally forgot about the LED - thanks for reminding me!
I thought that by having the rear wedge like that I wouldn't have to waste time turning my robot around if an opponent tried to attack from the rear/get to one of the sides. At least in theory anyway. And I'd just have to hope I won't get flipped! I did think about making the wedge like you've mentioned - might change it to that.

Thanks very much for the quick response!

[Garfie489]

Looks good - few things like links and fuses which you already mentioned obviously need adding, though it shouldnt take up much space, just remember you need an LED as well.

Design wise its basic of course, only simple suggestion id make is to make it look like a parallelogram from the side. It means when its inverted you always have one scoop still useable as a wedge.

[dotDominic]

The photos should be viewable here: (This is the same link as the one in my previous post. If people could read that post too, that'd be superb thanks!)

https://www.flickr.com/photos/131745614@N05

[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)

[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!

[dotDominic]

Perfect, thanks very much!

[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...

[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.

[Ellis]

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

[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!

[dotDominic]

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

Thanks very much for the responses!

[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.

[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.