Can a brick be successful?

[Eventorizon]

Errrr no, I think Endeavour can be shown as a testimony to that. Yes, if you use something like 2 screws to hold armour on then you are definitely going to run into problems. In Endeavour though, we used somewhere between 100-125 (possibly more) M4 screws to hold the whole thing together. I think its something like 26 screws alone to hold one motor down. At the champs last year (2013) we took 2 major hits on the side armour and all we got was a bit of a graze, no "panel ripping off" which is what you seem to be describing. Screws are definitely strong if used properly...

Yes 100+ screws were needed to make it effective. Or you could use 20 bolts with washers. Just my view after NST ripped Conker 1 apart and that was held together with around 16-20 screws per pannel running perpendicular to one another in pairs.

Defector was originally Hanibalito 4. (May have spelt that wrong) It's design was proven over years in other machines.

[daveimi]

Yeah just thought about making something like a double sided snow plough to deflect the energy rather than try and absorb it.

It's the spinners that have come on leaps and bounds, and no one has any real answer to it. With everyone building spinners I feel the need to champion the low tech approach lol.

[Garfie489]

It's the spinners that have come on leaps and bounds, and no one has any real answer to it.

I say the answer is Minimoth

[mrsam]

Using screws to hold Hdpe together didn't work for me, it obviously works for Endeavour but to me it just didn't feel strong enough and i ended up with a fair few breaking off when i was tightening them which left bits of screw stuck in the chassis. Besides a pack of 20 high tensile bolts is like £4.00 so i can't see a reason not to use them.

[SamO]

Meh, I guess just all comes down to build technique and doing would you feel comfortable doing...

[Ellis]

I find screws (talking wood screws) hold into HDPE very well. Like in wood they weaken if taken out and in several times. For structural plastic-plastic joins that need to come apart I like barrelnuts, and experiments with custom threaded inserts seem good. Both using M6. Might try some smaller ones (M8 OD and M4 ID) soon.

[Flag Captured]

It's the spinners that have come on leaps and bounds, and no one has any real answer to it.

HardWired 2 Evo will Nothing's ever immune though, no robot is ever safely counted out as the loser either - look at HardWired II for example, took a win against Ironside and Binky by pure fluke alone. The best way to combat spinners as far as I see it is to be able to control them, soon as you can push them about and keep away from the spinning device, they're a lot less scary. Even less so if you can force it to stop. Take good armour and ability to control the fight, and you'll have the best shot at beating the spinners. I think my plans for Hardwired 2 Evo will fill that brief, but it's all up in the air at the minute. And it inevitably won't, either in the end.

Low tech is a good way to go though, low tech and cheap means much easier repairs... if you were to concentrate your electronics in a small central box, then make a few layers of wooden armour with a good enough air gap you'll maybe only ever need to replace the armour. Which is easily done because it's cheaper than the equivalent.

The only other school of thought is taking a solid brick of a machine (hardox etc) and adding disposable armour like hdpe to soften impacts and therefore less chance of your structure getting damaged. Both have been used to good effect, but as said before good construction is vital, really. Definitely use angled steel pieces to keep your structure at the corners, and try not to have any 90 degree ones though that is tough with this sort of construction... as for keeping it together, high tensile bolts are a good bet, woodscrews work OK too but I'd guess it all comes down to how and where you use them... Well thought out design should solve those problems though! If you go through with a build, keep updating your thread on it and I'm sure people will be more than happy to advise as you go!

[MikeNCR]

For screwing directly into plastic I'm a fan of "plastite" screws. ( http://www.mcmaster.com/#plastite-screws/=sdaz58 )

The other option that works pretty well is "nutstrip" ( http://www.fingertechrobotics.com/pr...?prod=NutStrip ) as you just have to match the hole pattern on whatever you're bolting together and you can do all of your panels quickly as 2d profiles which means you can quickly make spares and change them out when they get damaged.

[chris knee]

just a thought from a novice at building bots....what about doing propper dovetail joints and glued and screwed to hold hdpe together

[mrsam]

Dovetail joints *could* work i guess but tbh just having some sort of bracing for your corners ( steel/aluminium angle ) seems to work very well as it prevents the joint from being pulled apart, plus the fact if you have to replace multiple panels on the fly making new Dovetail joints would just take too long unless you brought infinite spares. I wouldn't recommend using glue though, if nothing else it makes it difficult to replace a damaged panel because you'd have to try and yank your chassis apart.

[daveimi]

Mmm dovetail joints! What do you think about a flat square but so that one corner is the front? Erm so I suppose its a diamond. So one corner is your ramming point etc., would the 45 degree angles sloping away deflect or just give a spinner a nice big juicy corner?

[mrsam]

Can you put up a picture of what you mean?

[Ellis]

That would give you an ideal getting-hit edge for horizontals, and verts will get hits regardless. Also with anything but a flat front you won't be able to push a thing as nothing will stay in front of you, which will get frustrating fast. That isn't to say spinners will deflect, only way to deflect is with angled faces, hence wedges being so popular.

Finger joints, dado/rabbet joints etc are all good but as mentioned aren't easy to cut and get the full benefits. And nothing I know of sticks properly to HDPE. A finger joint which is bolted well would be pretty strong.

[typhoon_driver]

Can't glue HDPE effectively. It can be "welded" or in other words melted together. I'm a bit dubious about the strength but some have had great success with it.

[daveimi]

The robot on the right here looks like a good shape for fighting spinners?

http://www.robowars.org/wikka/SchmackOff

Obviously with covered wheels and some other changes etc.