Derby Talk

Just thought I'd share my totally original attempt at creating a wheel weigher, (tounge planted firmly in cheek )

Thanks for the direction Teee!


Notice the inspiration in the background of the first pic!




Just happened to have an old lab jack stuck away in a box that works pretty well for the scale, although it's a little loose.



Yes, the weight shown below is an accurate weight



Again Teeeman, thanks for the design inspiration. I'm sure this should make an interesting impact at our district race coming up in a couple of weeks.

BTW- only one small thing I changed. When using a normal shim to raise the wheel, there wasn't much travel before the nail head hit the shim, making the reading a little difficult. I switched to using a thick washer to lift the wheel and it made it a lot easier.

For anyone interested, the 4" clamps were $2 apiece at HF, the wood was scrap laying around. Total time was only a couple of hours!



Steve

Looks like it would work to me

one question, what are considered to light of wheels

Very nicely done....

Way cool!

Go get ‘em at inspection!

2.1g eh?




The jack is a neat idea… what was it from again or did I miss that?

The nice thing about this approach is you don’t need totally smooth operation in the jack or whatever you use to lift the platform…

you just need it to be stable when not being adjusted… and the reading will “settle”.

We too used a plastic washer for a short time but found it easier with the flat surface… I did make a surface to go on the scale… to “flatten out” the dip in the scale that is probably there to help keep objects from rolling off… but hurts in this application.

-T

(P.S. no using my idea for making money!... !... my idea remember!... but welcome to use it for the greater good )

just a question.. did you wiegh that wheel off the car to see if your measurement is correct? It looks to me from your picture.. that you are weighing the wheel, the axle, the wheel on the other side of the car, etc.

pack529holycross wrote:just a question.. did you wiegh that wheel off the car to see if your measurement is correct? It looks to me from your picture.. that you are weighing the wheel, the axle, the wheel on the other side of the car, etc.

Yes, that is the weight of just that wheel. The way it works is that you raise the scale just to the point where the wheel is no longer resting on the nail head, but before it touches the body. So, in effect, the wheel is floating, being supported only by the scale.

(you can't tell from the picture, but those are MaxV "H" tread wheels, and they really do weigh only 2.1g!)

Gotta love adult races!!!

3 Cub Dad wrote:Just thought I'd share my totally original attempt at creating a wheel weigher, (tounge planted firmly in cheek )

Thanks for the direction Teee!


Notice the inspiration in the background of the first pic!




Just happened to have an old lab jack stuck away in a box that works pretty well for the scale, although it's a little loose.



Yes, the weight shown below is an accurate weight



Again Teeeman, thanks for the design inspiration. I'm sure this should make an interesting impact at our district race coming up in a couple of weeks.

BTW- only one small thing I changed. When using a normal shim to raise the wheel, there wasn't much travel before the nail head hit the shim, making the reading a little difficult. I switched to using a thick washer to lift the wheel and it made it a lot easier.

For anyone interested, the 4" clamps were $2 apiece at HF, the wood was scrap laying around. Total time was only a couple of hours!



Steve

But the University of Kansas Physics Department lab jack is priceless!

GravityRacer wrote:But the University of Kansas Physics Department lab jack is priceless!

ROTFL!!!

Actually I think it was $5 back when I was a TA and they were cleaning out the old labs! Never knew what I would use it for other than an interesting umm, "beverage" holder in the dorms! (way back before they changed the drinking age!) It's amazing the things we keep!

Last night, I was playing around and found it very easy to weigh the wheels, while on the car, just using the el cheapo Harbor Freight $12.99 scales. Simply hold the car on the side, lower the car with the wheel on the scale surface until you feel the weight come off the axle head. There's enough slack in the body to inner wheel hub placement to get a good measurement of weight. Nothing too tricky. I wouldn't want to do it for every car but if there are suspicious looking wheels, it is a quick and dirty way to weigh them.

3 Cub Dad wrote:

GravityRacer wrote:But the University of Kansas Physics Department lab jack is priceless!

ROTFL!!!

Actually I think it was $5 back when I was a TA and they were cleaning out the old labs! Never knew what I would use it for other than an interesting umm, "beverage" holder in the dorms! (way back before they changed the drinking age!) It's amazing the things we keep!

Yet another guy with physics degree? Given the number of people on this board, that's starting to stretch the limits of probability...

GravityRacer wrote: Yet another guy with physics degree? Given the number of people on this board, that's starting to stretch the limits of probability...

Actually my degree is a Bachelors in Mechanical Engineering with a minor in Aerospace Engineering. However, since graduation and passing the EIT, the only thing I use my HP calculator for is expense reports and budgets!

PWD, it's the exact same process, only the stand allows you to adjust it for anyone to see!

Don't feel bad! I don't do any scientific programming anymore, haven't in a few years. I do some computation, but I use a handheld with some statistical capability, left over from when I taught high schools physics and math, and had to do the "curve" thing. Other than that it's canned stuff, even the CFD stuff for high power rockets.

Great tool but it seems there would be a lot of time added to check-in if used.

IMHO a good eyeball on a set of wheels will tell if they need further inspection or not and if so, a digital caliper to check for O.D., I.D., and width (backed up by spec rules published) would work just as well.

3 Cub Dad wrote:...since graduation and passing the EIT, the only thing I use my HP calculator for is expense reports and budgets!

HP calculator?

I'd completely forgotten about those accursed instruments. I'm trying to remember if I ever learned the "secret reverse entry sequence" of the initiated or not...

Boy, wish I could remember half of what I've forgotten (well, the useful half LOL).

Bubba

Go Bubba Go wrote:HP calculator?

I'd completely forgotten about those accursed instruments. I'm trying to remember if I ever learned the "secret reverse entry sequence" of the initiated or not...

All us old compiler writers remember Polish Postfix AKA Reverse Polish notation! Utter simplicity ... arithmetic operations performed in the order encountered!