Help with choosing parts for a first robot, please.

[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)

[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]

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]

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!

[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.

[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, thanks. I've tried to jolt it loose again on low torque but it still won't budge. :/ Luckily I had the drills delivered, and one of the drill cardboard boxes has this big bash in it. Hopefully I can pretend the drill has been damaged as a result and I can exchange it for another one. :P

[Max]

I assume you are leaving the motors in the drill casing when trying to remove the chuck? You should always remove the chuck before disassembling the drill as it gives you a better lever to undo the screw than just trying the grip the motor.

[dotDominic]

Yes, I've been leaving the drill assembled in it's casing when trying to remove the chuck. For the other 3 drills, I've had to use the Allen Key Hammer Whacking technique to unscrew the chucks once the screw was out, and for that I clamped the drill by it's casing.

[dotDominic]

Hello, just starting to sort out the wiring and stuff, and I was just wondering what would be an appropriate rated fuse for this LiPo battery, please:
http://www.hobbyking.co.uk/hobbyking...mah%204s%2030c

I've read that the fuse has to rated lower than the maximum current draw of the battery, but how much lower is necessary? I obviously don't want the fuse to be rated too low.

Also read that using Maxi fuses with the holder from technobotsonline can also be the removable link. Is that reasonably straight forward to set up? I've also noticed that the wire in the holder uses 8 awg wire, whereas the rest of my robot will use 12 awg (with the exception of the battery which uses 10 awg.) Does mixing wire ratings cause any problems or is it ok?

Not started building much yet but I pretty much have everything except a few bits and pieces, so hopefully progress should speed up soon!

Thanks!

[dotDominic]

Ok, so the other day I was trying to increase the bore of those Blue Bearing Boys wheels to 14 mm, so I could hammer in the Brass Inserts needed to attach the wheel to the drive shaft of the drill motor. (Finally got the damn screws out about a month and a half ago!)

But my drill made literally no impression on the plastic of the wheel. Pretty much right after the bit made contact with the wheel it stopped, leaving a few very minor cuts in the plastic. It's a relatively cheapo Black & Decker drill (Coincidentally it's the exact same model I was initially going to use for drive motors.), but I'm not sure if it's the drill's naff-ness that's at fault or some cruddy drilling technique of mine.

Just wondering how anyone else has gone about doing this? Is there some way of doing it or is it more so a matter of buying a drill with more oomph? Do I need something high-end for this sort of thing? Any help/responses would be really appreciated, thanks! (I hope you guys aren't getting sick of all us new folks asking so many questions!)

Also, just to show that I am actually building stuffs/making some progress here's snaps of the 99% complete battery mount thingy, and also slight changes/more details to the design of the robot. (Hopefully it looks marginally less boxy and basic now, though it still omits the fuse, link and LED.)

https://www.flickr.com/photos/134836804@N02/

I still need to drill holes in the base of the battery mount so it can be bolted to the base of the robot. Annoyingly my drill (or my potentially shoddy technique.) couldn't get through the 3 mm aluminium. :/

Again if there's anything horribly wrong with anything I've done so far please say so!

I'm also thinking of naming the robot Venator (Means "Hunter" in Latin.) if it's not been taken already.

Thanks for reading if you've made it this far. Sorry this post was so long!