Boring Brick

Done a bit more today, started on the wheel guards, heres a couple of pics of them just placed
http://i921.photobucket.com/albums/a...ps3ff06bfb.jpghttp://i921.photobucket.com/albums/a...ps97a0b6d5.jpg

Looks great!

Nice :)
Looks a bit like a truncated T2 from RW Series 3, cool shape to it.

Looks good! Why boring brick though? It's anything but at this point! Liking those wheels and arches particularly!
Are you still having the axe on it too?

Thanks guys, yes axe is still going on when I get round to it and at the start it was supposed to be just a brick but it evolved a lot

Made a start on the axe supports today and im not sure whether to have bearings pressed in or to just have the shaft run straight into the hdpe bulkheads, what would people recommend?

Press in the bearings

I'm led to believe that Inertia XL just had the shaft run straight into the HDPE bulkheads for its spinning disc, and if that's true I'd guess that you wouldn't need bearings for an axe but don't quote me on that!

Edit: Of course, you need to make sure that your bulkheads are thick enough, I think they're usually about 20mm thick for spinners but again, don't quote me on that

Inertia XL ran into Nylon bulkheads with a 20mm bolt. With HDPE you really aught to use bearings or bushes as the HDPE will wear away quickly if you don't where as nylon is harder and designed to have things slide against it.

The orginal Inertia XL used a 20mm bolt as the shaft running directly on the 20mm HDPE Bulkheads and lasted 2 years in this configuration, the second one had bearings press fitted into the bulkheads but these needed retainers as they had a habit of falling out.

The newest one is all Aluminium so a different structure entirely.

HDPE isn't a bad bearing material in itself, and with 20mm thickness, just drill a 20mm hole and put the shaft directly in that. If it wears out, you can put in bushings or bearings. Just make sure there is enough material all alround, otherwise it will rip trough.

I've got 15mm of hdpe, hopefully that would be enough? I might just run the shaft straight into the bulkheads and if im not happy ill press some bearings in

15mm HDPE should be fine, as should running it without bearings. Obviously since it's an axe, the shaft won't be rotating as much as it would if it was a spinner so it shouldn't trouble you really, but it will wear down over time. As Mario said, when that happens, you can then look at bushings/bearings but, to be honest, you'll probably end up moving onto a new chassis long before that happens.

Awesome thanks for all the advice

Finished bolting the wheel guards together, i had intended to finish the axe mounts but i've been called into work early. I just couldn't resist taking a picture with the axe on it though, http://i921.photobucket.com/albums/a...ps59f48e18.jpg

As others have said, this is far from a boring brick. I love the shape!

edit: also, I agree with others about it being fine just running into the 15mm HDPE. With a smooth shaft like that I don't think you'll see any wear at all across the lifetime of a robot.

The name will have to change i agree, i'm just finding it hard not to think of something predictable or too clichéd. If Tomohawk wasn't already taken i would have had that because of the shape of the axe but alas back to the name drawing board.

It's pretty tough to find a name, but what I did was just keep an eye out for cool words that pop up or song/album titles generally go well. Mine got its name from two sources funnily enough, one was an album called Hardwired and when I got round to building the thing properly the components were all hard-wired together so it couldn't be anything else really!

Either that, or try searching for synonyms on Google - I typed 'axe synonyms' in, and one of the suggestions was Abandon (from 'to axe' something) which actually sounds a really cool name, if it's not taken!

That's a great idea I hadn't thought of that, might give that a go

A quick search came up with Hatchet and I think that sounds good as a name


Edit: I also forgot to mention that i weighed the bot as it was in the last picture and it's only 6.6kg!, so that leaves me with a maximum of 7kg for the axe supports and mechanism, the scooter motor, a 30 amp electronize, the top panel and with that much weight left to spare i reckon i could even squeeze a scoop on the front.

Nice one, sounds a pretty awesome name! Looking forward to seeing the machine with the axe mounts on it too - the axe is a lot chunkier than I thought it was, going to be a force to be reckoned with!

The axe is pretty beefy, all credit goes to Mario he did an amazing job on it, it won't be the fastest axe around but it's pretty heavy so it should hopefully be a good balance of speed and power

More work on the axe mounts today, still not quite finished i still need to cut some angles as is customary on this bot but here it is all fitted together, http://i921.photobucket.com/albums/a...psfd67690d.jpg

Chunky! This is a really cool build. Love the angles!

By the sounds of things you don't have weight to worry about, may be worth adding a hardox wedge to the front that has a back plate you can bolt on to cover the whole of that front, gives spinners something to hit and if you get under people can give you a few more hits. Doesn't need to be overly large, just may help in both attack and defence

I was planning on adding a wedge to the front if the budget allows however hardox might be a bit too expensive for now so it will probably just be stainless

Hatchet is now all wired up and ready for a drive test, so once the batteries have finished charging expect a very bad one handed driving video :lol:

New video as promised, my driving really is awful at the moment http://s921.photobucket.com/user/mrs...c3e1b.mp4.html

Is there a mixer in the robot? It could also be a trim issue , since it went straight backwards. I've found with. 2WD robots that they go straight one way and often veer off the other way, hence Satanix having a Gyro.

No mixer in there and all the trim buttons are centered, I'll have a play around with them and if it still happens I can *just* get it to go straight with some fiddly driving

Ajust the grub screws in the grum screws so the wheels have the same amount of turn by hand before you can feel it bite, this will help with accuracy a bit.

Deffo want to look at adding a gyro but could just simply swap the motors round for now to improve the forward motion, who needs straight reverse anyway hahaha

That TX you have does not have internal mixing, nor do your speed controllers as I understand. Put one in to save you driving diagonal (I can't drive diagonal for toffee!).

Just practise a lot :D

I always planned on adding a mixer as it is really difficult driving diagonal and there wouldn't be much point having the axe if i can't actually drive well enough to hit anything, as you said Niels practice ALOT!

Considering your robot drives round the front it may not be a bad idea to add a gyro for ease of driving, but it's up to you.

I'll see how it handles with the mixer but a gyro is definitely on the cards at some point

It's a common issue with robots that have their wheels at the front, they tend to be a pain to drive forwards (spinning round like that) but they reverse remarkably well. It's the opposite for robots with rear-wheel drive; the robot will go forwards like an arrow but tends to spin off to one side on reverse. There is a scientific explanation behind it to do with acceleration and the robot's centre of gravity but I'll be damned if I remember fully what it is.

The problem is exacerbated by the Electronize speedos. Because it's relay control, they'll click on at different rates before applying proportional control so if one's clicking on marginally before the other then it will give bias to that side of drive. By the time the other one kicks in, the spin is already happening and hard to correct. Add to the fact that the drive motors are facing opposite directions so while you're driving forwards, one motor is spinning in the opposite direction to the other, and electric motors that aren't neutrally timed will go faster in one direction than the other.

The best thing to do is sit down with your robot (wheels off the ground) and move the transmitter stick forwards and backwards slowly. Watch the wheels and see if one starts turning before the other; use the rotary controls on the top of the Electronizes to make fine adjustments to when the wheels start turning so that they're as close to starting up together as they possibly can. It won't fix the problem but it might help lessen it. The alternatives would be a gyro (as mentioned) or even switching to a dual ESC or some TZ-85s in the future, basically something that has much finer control than Electronizes.

Thanks Jamie I'll give that a go, the electronize will probably be the first thing to go when I rebuild/upgrade Hatchet as they definitely aren't the eaaiest things to use

Looking very good so far! Any idea which events you plan to bring it to?

Thank you, for the moment it's just going to GSL but hopefully I'll be able to get to some more events if I can get the time off and some way of getting there.