Graphite selection/testing?

[geauxturbo]

Seems to me the best way to test this is with a 5 oz metal car. Thread the ends of the axles and axle holes. Use the same wheels and axles. Clean between tests. Or produce many sets of wheels by the same method and reuse the same axles. Since they screw in, they will be aligned the same each time.

The car is metal so that moisture wont effect the weight. Run it down an indoor climate controlled track and see which is fastest. Sort of the KISS method.

If you want camber, you can make the car on an IFS/IRS type platform with camber adjustments in screw type fashion with a dial on the screw head so you can accurately repeat adjustments. You could do the same with toe.

Metal is just easier to make precision equipment out of than wood. Yould could set up multiple gates or a high speed camera and take acceleration and veocity readings the whole way down.

Of course, i hardly understand much of what was written above so maybe I'm way off.

[sporty]

There is a guy who does the testing of the all american soap box derby wheels, who uses this type opf equipment. I forget his name. But he would be the one to work with on this.

All of the wheels at the all american soap box derby world championships, are tested and matched up with equal wheels. Contacting the all american soap box derby, would likely lead you to a why to contact him and something could come from that.

Now that would be Stans greatest achievement.

[Stan Pope]

Too many variables! Would take too many years. I'm 70, for goodness sakes ... I don't have enough years left! With as many variables as are in a whole-car test, it might take multiple lifetimes!

Besides it is structured to test a whole lot more that the "graphite selection" topic asks for.

Seems to me that if you know the static and sliding coefficients of friction and lifetime under the range of PWD pressures, you know all you need to know about graphite as a lubricant!

[resullivan]

I think how the car runs down the track is so variable that if you could some how do it with no rails (maybe a flat piece of glass) and ensure each car is staged exactly the same you would get better results. I don't know what tools are out there, but if there was a way to just spin a wheel on a nail with the exact amount of pressure and measure the max speed of the wheel with each lubricant?

[davem]

Some of my tests

http://www.derbytalk.com/viewtopic.php? ... max#p45337" target="_blank

The track has a lot to do with which lubes work best.
Oils (Krytox) show better performance at higher temps / speeds. High pitch (read that as faster) tracks help them. Low height tracks really hurt them.

But - if you are just looking at graphites (w/o the affects of bore / axle prep) - see my old post above.

[Speedster]

I wish I were 70 again, Stan. You are a youngster.
Folks might want to read Chapter 9 - Friction and Lubrication in Doc Jobe's big green book. The graphite from Hodges Hobby House was the fastest at that time. Has something to do with the big flake. My book has a date of 2004. I have been using Hodges graphite for 27 years and have had wonderful success. I'm still using it .
This forum is full of championship racers. A good way to pick a graphite is if everyone would let us know what graphite they use and the procedure they use in lubing their wheels and axles. Everyone might want to pay close attention to what Sporty has to say. I'm certainly going to pay attention.
Cheers
Bill

[Stan Pope]

I have been using Hodges graphite for 27 years and have had wonderful success. I'm still using it.

Hey! That's how old my pouch of Hodges "Moly G" is! Turned out that a pouch of it lasts a lot more than one Cub Scout's racing career!

[sporty]

I have always shared what I do.

The bore prep process that I do.

As mentioned elsewhere on the forum with videos and ect.


However a brief re-cap:

I use .055 carbon fiber rod, a wrap micro-mesh adheasive backed, 6,000 grit, 8,000 grit, 12,000 grit.

I use drill press at lowest speed setting, which is about 650 rpm.

I polish the wheel bore with the rods/ micro-mesh. When done they look like black ice, nice and shiny.

I prefer a bore oI.D. of .0965 for stock bsa axles.

I then use hodges to burnish my bores, extra fluffy, extra absorbant pipe cleaner.

I dip the pipecleaner into the hodges and also fill the wheel bore up.

I insert pipecleaner, turn on drill press and run for 5 seconds. I repeat this 3 to 4 times, on both sides of the wheel.

Thats it.

Then once the axles and wheels are on the car. I use hobb-e-lube. I tilt the car onto its side and add some in and finger flick the wheel, so it lifts up off the axle head and allows the graphite to get farther down into the bore.

I rotate the axle and repeat. I do this 3 to maybe 4 times. 1/4 rotation at a time. Im only adding a small amount.

I know when I have enough, when I can start to feel the wheel as i lightly turn it with my finger begin to show grip / friction from the graphite in the bore.

Now some use plast-x to polish the bore or micro gloss / polish from micro-surface.com or from a pwdr vendor.

Some also use novus 2.

Those methods are usually done with a q-tip that matches the bore size and using a cordless drill for slow rpm.

That add a dab into the wheel bore and insert the rod thats in the cordless drill and work the wheel bore up the rod and back, 2 times and and from the front and back of the wheel bore.

Clean with warm water or 90% iso alcohol, let dry or blow dry and then burnish the wheel bore.

Then some use liquid glass (legends on the wheel bore and let dry and polish lightly with a pipecleaner then burnish with graphite.

Sporty

[Speedster]

There you have it, Folks. The man with the trophies has spoken.
Thanks Sporty. You are very generous.
Cheers,
Bill

[cubmasterbob]

I simply can't decide between the white or standard graphite powder{yeah, rookie here}.
I think I need to take a stroll on over to see Sporty's pinewood races some day...we're talking here about a full council wide race next year if we can get enough tracks together and a place to do it...all those in 3 fires...too bad Sporty isn't in our group...wait a minute, he's too dang fast...hmm, guess it's a good thing he isn't in our group then!!!

[sporty]

Ahhm thanks for the kind words.

Im not so sure im all that fast, every race can bring a different out come. I help people. but I sold my track and timer last year. My days of full out racing are over with. Just fun stuff.

Sporty