Boring Brick

[mattsdragons]

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

[razerdave]

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!).

[Niels - Team K.a.L.M.]

Just practise a lot

[mrsam]

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!

[razerdave]

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.

[mrsam]

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

[RogueTwoRobots]

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.

[mrsam]

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

[Danny B]

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

[mrsam]

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.

[mrsam]

Adjusted the ESCs and gave it another drive test, seems a bit better but the batteries are going a bit flat so it's quite slow http://s921.photobucket.com/user/mrs...3a7dc.mp4.html

[mrsam]

Main axe sprocket and mixer ordered today and axe motor will be with me next week courtesy of Mario and Dave Weston so expect an axe test video mid to late next week

[mrsam]

I've now got a mixer in the robot and it all works fine but now it won't failsafe, I've tried rebinding but it hasn't worked, any help would be great

[Revsmin]

You still after a gyro for it? Looking great BTW, what axe motor you using?

[mrsam]

I'll see how it handles when the mixer is all sorted and it's tested properly, and a 300 watt scooter motor