Problems turning

[Daniel_LaFleur]

Originally Posted by Bochek

sorry, the drivetrain is the banebots 56mm gearbox with a CIM and 4wd.

basically the standard kitbot chassis but with added sprokets and chain to make it 4wd.

so replacing the rear wheels with omni's could prove a good solution then?
and i would still keep it 4wd correct?

- Bochek

This will work well (we've used it in the past).

A inexpensive alternative is putting zipties on the rear set of wheels. Putting about 10-20 zipties on each wheel (equally spaced) will reduce the traction of those wheels. The more zipties, the less traction. As with Omniwheels, as your traction goes down it becomes easier to push you around.

[Dominicano0519]

Originally Posted by Daniel_LaFleur

This will work well (we've used it in the past).

A inexpensive alternative is putting zipties on the rear set of wheels. Putting about 10-20 zipties on each wheel (equally spaced) will reduce the traction of those wheels. The more zipties, the less traction. As with Omniwheels, as your traction goes down it becomes easier to push you around.

uhh we had a bad experience with zip ties in the Philly regional

In New Jersey they said it was perfectly legal; while in philly we ended up shaving all of the treads from our tires and waxing them every match becuase they said nothing mechanical could be added to the tires.

[Gdeaver]

This years KOP wheels are flat. We drive on a 3d surface. The edges of the wheels tend to dig into the carpet. The skyway wheels Are slightly v shaped and not as grippy. The tend to turn better. Unfortunately, having the power of 2 cims to a side and tank drive makes things much better. We are using skyway wheels this year. They are cheap and adapters are easy to make. We also bought IFI AL sprockets for weight.

[Daniel_LaFleur]

Originally Posted by Dominicano0519

uhh we had a bad experience with zip ties in the Philly regional

In New Jersey they said it was perfectly legal; while in philly we ended up shaving all of the treads from our tires and waxing them every match becuase they said nothing mechanical could be added to the tires.

Sorry to hear that you weren't allowed to use them.

Last year I saw a good number of teams here in New Hampshire using Zipties.

As long as they can't damage the carpet, I don't understand why they can't be used. Can anyone post a rule as to why zipties cannot be used on the tires?

[Springman]

If you are using the stock banebots gear boxes, the first thing that I would do is replace the existing planetary gear set in the stock unit to the 4:1 gear in the change kit (available from banebots.) This will give you a 16:1 ratio vs. the stock 12:1 ratio. This will not negatively impact your weight issue, and depending on how accessible your gear boxes are, this swap can be made in 10-15 minutes easily. In addition, if you have reduction between your gearbox shaft and the sprocket at the tires, you can change the sprocket sizes to further increase your reduction. You will be giving up some speed everytime you make a change. If you do decide to buy omni wheels, you may want to buy extras. Several teams have had issues breaking the omnis in a 4WD configuration. The kitty-corner wheel configuration may help the breakage issue. The simplest test to perform on a drivetrain is to, on carpet, push against a wall. You should be able to spin the tires without tripping the breakers. Some simple things to check are:

1. Are you using the right fuses (40Amp.)
2. If so, are the fuses tripping when you are turning? If so, you will have to make a mechanical change.

[Al Skierkiewicz]

Originally Posted by Dominicano0519

uhh we had a bad experience with zip ties in the Philly regional

In New Jersey they said it was perfectly legal; while in philly we ended up shaving all of the treads from our tires and waxing them every match becuase they said nothing mechanical could be added to the tires.

Dom,
This has come up before but I do not understand the inspector's decision without talking with them. As long as the mods meet the rules they should have been allowed. I have recommended this fix for teams who were having a problem and couldn't find a fix quickly. Tywraps obviously are allowed since they are supplied in the KOP. More accurately the rule is...


<R34> ROBOT wheels, tracks, and other parts intended to provide traction on the playing field may be purchased or fabricated (“traction devices” include all parts of the ROBOT that are designed to transmit any propulsive and/or braking forces between the ROBOT and the playing field). In no case will traction devices that damage the carpet or other playing surfaces be permitted. Traction devices can not have surface features such as metal, sandpaper, hard plastic studs, cleats, or other attachments. Anchors (i.e. devices that are deployed/used to keep one’s ROBOT in one place and prevent if from being moved by another ROBOT) can not use metal in contact with the carpet or other playing surfaces to “stay put.” Gaining traction by using adhesives or Velcro-like fastener material is not allowed.

As long as the lock part of the tie is positioned to the inside of the wheel, there will be no "hard plastic stud" in contact with the surface. A little hot glue to hold it in place doesn't hurt either. There is other possibilities as outlined above but this does provide a quick fix.

[TheFuhr]

Ahhhh the four wheel pneumatic drivetrain...
Such a horrible idea...
We used that last year and never will again.
Broke so many chains jerking around the field.
We installed castors but they only make the jerking smoother.
My advice, use two omni-wheels, its the only way to save yourself.