Ideas appreciated.

[Chances R]

I built this pedal tractor pulling sled this winter and am having problems with the measuring wheels. It seems that due to the sled changing direction (not always being pulled in a straight line) the measuring wheel is put in to a bind from side to side pressure's and the measuring wheels internal parts and axle parts break down after about 25 runs down the track. I have noticed that some sleds place the measuring wheel against the sleds rear wheel. The problem with that is it is not a true dimension. Of course money is a problem and I am sure there is no one out there that wants to sponsor the fancy lazer readers like the big boys use. Thanks

 

[art]

To have it run off the rear wheels would leave it cleaner and you might just have to use a multiplyier to get the right distance. Other wise for what it is off it would be for the same for all. If the two were the same diameter the number should be the same!

 

[Tig]

How about if you turn it around and hinge or pivot it so that it will run like a caster. Have a look at a caster wheel and try to recreate that geometry.

 

[athomp]

The problem with that is it is not a true dimension.

 

[Iplayfarmer]

To have it run off the rear wheels would leave it cleaner and you might just have to use a multiplyier to get the right distance. Other wise for what it is off it would be for the same for all. If the two were the same diameter the number should be the same!

Running it off the rear wheel is an excellent idea. You shouldn't need any kind of multiplier if you put the outer circumfrence of the sled wheel in contact with the measuring wheel. Every inch of the wheel equals one inch of ground travel equals one inch of measuring wheel travel. You'd eliminate your sideways torque and potentially get the measuring read-out higher up and easier to read.

 

[jayste]

I'm with farmer. Run it against the rear wheel. Also, takes away the original problem of pulling off to the side.

Jay

 

[RobJ]

I think the big boys use the lasers because they are the most accurate. Someone traveling in a S down the track is going to cover more ground in the same distance than someone pulling in a straight line. With this type of measure, the guy driving in the S is going to win. I'd protest that!! If I'm the other guy.

 

[Chances R]

Running it off the rear wheel is an excellent idea. You shouldn't need any kind of multiplier if you put the outer circumfrence of the sled wheel in contact with the measuring wheel. Every inch of the wheel equals one inch of ground travel equals one inch of measuring wheel travel. You'd eliminate your sideways torque and potentially get the measuring read-out higher up and easier to read.

You know I guess I just firgured with the tire turning against the measuring wheel it would throw everything off. I will give the measuring wheel to sled tire a shot. Thank you all for opening up my eyes.

 

[mcd176]

Are those rubber bungies holding the sled to your truck?

 

[Iplayfarmer]

I'm with farmer. Run it against the rear wheel. Also, takes away the original problem of pulling off to the side.

Jay

I have to make sure credit is given where it's due. For the record, the wheel to tire idea was Art's first. I just expounded a bit about the merits of the idea.