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DFW wheel angle and edge

Posted: Wed May 09, 2018 11:22 pm
by AaronS
:| I have a couple of DFW questions. 1: At what point does the angle of degree on the DFW become less productive with reducing friction on the track rail? A more severe angle is going to make a smaller footprint on the rail with less contact area. But will the axle begin to take on more friction between itself and the car body or wheel bore? 2: Would it be beneficial to taper the wheel's inner edge toward the inside to make a smaller diameter point of contact against the track rail? A smaller circle's edge would be less travel on the rail and less of a foot print . What are your thoughts? Thank you.

Re: DFW wheel angle and edge

Posted: Wed May 09, 2018 11:54 pm
by AaronS
For question 2, I meant to ask will the steeper axle angle cause the wheel hub to rub too much on the car body? I wasn't sure because as a car travels the length of the track, the DFW is lightly touching the track rail maybe enough to cause the wheel to migrate to the axle head? Thoughts on this?

Re: DFW wheel angle and edge

Posted: Thu May 10, 2018 5:28 am
by Vitamin K
I usually run about 7-9 degrees on the DFW.

What I've heard the league racers say is akin to "As much bend as you can put on the front axle and still be able to get the wheel on."

Re: DFW wheel angle and edge

Posted: Thu May 10, 2018 4:34 pm
by AaronS
Ok. I have my daughter's car set at 5 degrees for the DFW. It's a combination of axle slot can't and 2.5 deg bend in the axle. Just a degree or two of turning and it will go from 2" drift to 5" drift in 4' on my tuning board. Our drift is set at 3" in 4'. It seems to work very well with the rear wheels tracking equidistantly on either side of the rail. We are excited to race here in a couple days! Thank U Vitamin K for your advice.

Re: DFW wheel angle and edge

Posted: Thu May 10, 2018 4:52 pm
by AaronS
Vit K, have U been able to test run the different angles of
dfw degree on your car? If so, how much of a difference has it made in your times? Just curious as I have much to learn. Thank U .

Re: DFW wheel angle and edge

Posted: Thu May 10, 2018 8:02 pm
by Vitamin K
AaronS wrote: Thu May 10, 2018 4:52 pm Vit K, have U been able to test run the different angles of
dfw degree on your car? If so, how much of a difference has it made in your times? Just curious as I have much to learn. Thank U .
I haven't really. I have theories on why a lot of bend is better than a little, but I haven't been able to do any real comparison testing.

Re: DFW wheel angle and edge

Posted: Thu May 10, 2018 10:42 pm
by AaronS
Ok. Sounds like the greater bend is more advantageous. I'm not sure anyone has successfully tested what the DFW rail pressure actually is, but I gave it a shot about a month ago and found an approximate way to measure it. With a DFW weight of 14.3g, I got an approximate measurement of 1.6g of wheel-to- rail pressure. I'm not sure how to use that info. yet, but I'm thinking it could be tested with various weights to possibly come up with an avg. percent value. Haven't explored it enough to get a consistent value, as different cars may affect the results.

Re: DFW wheel angle and edge

Posted: Fri May 11, 2018 4:30 am
by Speedster
I think as the degree of cant is increased the toe-in adjustment becomes more sensitive. If I'm understanding Physics correctly, a knife edge on the inside rim of the dfw would still have the same amount of friction, it would simply be moved to a smaller area.

Re: DFW wheel angle and edge

Posted: Fri May 11, 2018 5:06 pm
by AaronS
Ok. Thanks Bill, that makes sense. See U at the race tomorrow!☺️

Re: DFW wheel angle and edge

Posted: Fri May 11, 2018 6:59 pm
by Speedster
Aaron, I wish your Team the very Best.
It will be interesting to see what the Top Eliminator car looks like and what time it turns when racing in the finals.