# H-Drive Issue

IQ fields are hard plastic, not squishy foam like VRC.

Still though it clearly does not have enough traction. This can be remedied by moving the wheel down. If moving it down more off centers the base, the robot is likely too heavy

just a technicality, but i believe a better explanation would be one that relates traction. it’s not the height that matters, it’s the how much traction the individual wheel has, compared to it’s acceleration; just because something has more normal force doesn’t mean it necessarily has more traction, cuz traction in newtonian is essentially Ff=μN. in fact in this case, it may not even have to do with the height (although it’s undoubtedly much more plausible), it could be the friction coefficient of the rollers themselves that’s lacking- yet either way, the main issue mr banjoman has is with traction

5 Likes

Well yeah that’s true, and a good point. But assuming that it’s the same type of wheel being used all around, and one of them isn’t significantly more worn than the others or something, I think it’s reasonable to assume the wheels have pretty similar coefficients of friction.

3 Likes

Just a few things to note that may or may not be useful:
-Yes, the field is hard plastic but if your field is on carpet (even the hard kind in schools) it can have a significant impact. We built a kind of lattice out of wood which helped a ton
-the overall weight of your robot does matter too but if your bot isn’t really heavy it shouldn’t matter much
-the balance could be an issue. even if your wheel is in the center, having all of the weight on one side will make the bot tip just enough
-linty wheels could be another thing. try wiping them with rubbing alcohol
-speed ratio could be too high resulting in not enough torque. anything above 2:1 has never worked for us
-the hole you’re using could already we worn down causing a bit of give
bonus tip: add a square lock plate (the kind with the square hole) to the inside of your wheels using two-standoffs to give them two points of contact with the shaft.

So basically, h-drives are stubborn little things. But I still love them. I can do my entire driver skills with only two turns!

6 Likes

Just don’t use WD40 though, because it is illegal in IQ.

i dont know how to do that- i have never used google drives
do macs even have google drive?

1 Like

one has omni wheel in the centre and the other had tration wheel in the centre.
Note- the four drivetrain wheels are standard traction wheels.

you need to turn link sharing on in settings of the files. we can’t see anything when we press the link

[quote=“Ethan5956F, post:18, topic:83934”]

it should work now…

can you send a close up pic of the strafe wheel from the front? i want to see how it’s mounted

it definitely doesn’t have enough traction, and as other said it looks like it’s because it’s not close enough to the floor

the omni one or the traction one?

another issue…your wheels are all canti’d. dunno if this is normal in iq or not, but it’s bad practice in vrc. it might not make a difference for the 4 main wheels, but it’d definitely make a difference for the strafe one

1 Like

both

All 5 wheels should be omni wheels. The traction wheels will provide way too much drag when trying to move sideways.

8 Likes

You have a few main issues.
One - all the wheels need to be omnis. The traction wheels won’t strafe as they have lots of…traction.

Second is there is no weight over the strafe wheel, so it’ll not have much grip. Even if all your wheels were omnis, it would arc rather than strafe.

Edit: sniped by @holbrook

4 Likes

what does that mean?