pic: Track System

[FierceRabbit]

Originally Posted by RTTComanche17

Beware of (ab)using these track systems. My team (1662) thought about using them but decided against it for a cople of reasons:

1. Track material falls off. Last year we saw 753 at the davis regional and they did very well, bt they (ab)used the eystem so much, tread/track material started to fall off in pieces. This also happened this year where a team on our alliance (dont remember number) left a three inch long by inch and a half wide piece of material on the field.

2. These belts break if (ab)used too much. Just ask 997. In their 6th qualifying match sat. morning at the championships, they were pushed from the side and a belt snapped, leaving one side of the robot disabled. they said it took an hour to change both belts.

3. Teams do not gear them low enough. This year and last year, we have been able to psh or at least stop any robot with tracks. last year we had very low gearing with 4 two inch wide by 8 inch diameter IFI wedgetom traction wheels. We pshed 753 arond no problem. They did have more traction than us, but they were geared so high that they pulled too many volts when they lugged thir cims down low, their robot wold essentially shut down to protect itself, enabling them to be moved across the entire field.
This year we had 6 two inch wide 6 inch diameter IFI wedgetop wheels with a lowered center wheel and a bit higher gearing for mare speed and manuverability. Of the three track systems we encontered this year, we pushed two and stood up the third (they couldnt move us, we couldnt move them).

We love traction wheels We havent benn moved in the last two years!!
A track system cold definately outpush us if you designed them right.
Instead of 5 fps and 15 fps(most teams end up locking them in low gear anyway), try 2 fps and 6-8 fps or 3 fps and 9 fps.

Just tying to provide a little insight, thats all.

1. Track material falls off Last year it happened yes....but not This year? To an OutbackTrack at least. Interesting. Outback fixed the problem with a thicker track and beveled edges this year.


2. These belts break if (ab)used too much Both Belts snapped. Only because the force of the robot going sideways and the tracks moving forward put a wedge between the lower layer of the track and the drive wheel, Snapping the belt instantly. This problem can be fixt by enclosing the plastic layer of the belt more, allowing it not to move. At all, side to side.

The simplicity of the track system 997 is using allowed them to change out 2 belts completely in less than 45 minutes. In the past I have seen this take up to 3 hours. for just one track : /

3. Teams do not gear them low enough I would have to agree with you that the Gear ratio for a track system needs to be refined. The amount of traction a system like Outbacks needs the implementation of a well designed 2-speed gearbox. @ 2fps that track system would push anybody. I have yet to see a well geared track system be pushed by a wheel driven drive train. With 2 fps for lower and 7 for high gear. Driver practice. Good game.


***

For the most part teams tend to avoid using a track system for a drive train because it is a real pain in the As(s) to make them right. It is not the same as throwing 6 wheels/sprockets onto some axles and slapping a chain down. But, through trial and error a well designed Tred/Track system (in my opinion) has proven to be the most efficient if you want reliable traction/power.



FierceRabbit.
Maxwell.

Well, I've been listening to the people who may actually consider buying transmissions once we swing into gear to sell them, and so I've designed another one (Did it in the last hour. I got bored and inspired, and have mad CAD skillage....). The new one has a low speed of 4 fps, and a high of 10. Drivers will most likely stay in high gear most of the time, and when they hit a pushing match, they will shift down to be able to torque.

[pakratt1991]

Well, I've been listening to the people who may actually consider buying transmissions once we swing into gear to sell them, and so I've designed another one (Did it in the last hour. I got bored and inspired, and have mad CAD skillage....). The new one has a low speed of 4 fps, and a high of 10. Drivers will most likely stay in high gear most of the time, and when they hit a pushing match, they will shift down to be able to torque.

This was going to be one of my suggestions to Sam for next year, Just change the final gear ratio so that when we need to push, we can push anyone, and in high gear we don't flail around trying to drive something that is too fast, 4:1 and 10:1 sound perfect to me

Also, the cost for the entire thing is only $1,200. The belts alone are 300 apiece so 1/2 of what a team would pay would be for the belts alone. For the quality of and time put into this drive train it is well worth the $1,200

[Alpha 997]

Originally Posted by 114ManualLabor

Well, I've been listening to the people who may actually consider buying transmissions once we swing into gear to sell them, and so I've designed another one (Did it in the last hour. I got bored and inspired, and have mad CAD skillage....). The new one has a low speed of 4 fps, and a high of 10. Drivers will most likely stay in high gear most of the time, and when they hit a pushing match, they will shift down to be able to torque.

4fps still might be too high for pushing. 3 or 2 fps would ensure victory in a pushing match. 10 fps sounds about right. If the robot is not top heavy. 15 fps, like 254 had, would be sweet.