Pinewood Derby / Derby Worx-Pro Hub Shaver

Pinewood Derby / Derby Worx Pro Hub Shaver: Is designed to shave or remove imperfections from the outter hub of a pinewood derby car wheel. The Pro Hub Shaver will also remove the extra step in the new B.S.A. wheel helping to create a faster wheel.

Category:

Science & Technology

Tags:

• Derby
• Worx
• Pro
• Hub
• Shaver
• 0001

[ideotic]

Ya know, not to start an argument, but when the step is removed it increases the surface area that makes contact with the axle head. With the step, the axle head sits over a gap and touches only its outer head circumference. With the step removed, it rubs against the same plus the inner surface area that was once the gap. This isn't true if you've tapered your head to a bevel.

[Derbyworx]

@ideotic You should never run flat heads, it is like running with the brakes on. See my responses below, but you always want to reduce contact circles to reduce friction, friction is also material passed per revolution, less material = less friction. Case in point, our Derby Worx Pro RSX Needle Axle wheels are 1 car length + in time faster than the same wheel with a std axle. Read more performance tips on our discussion forum from our web and join us on Face Book. Thanks>

[Derbyworx]

@Derbyworx 2, The circle of the step is larger than the circle of the hub, SO the amount of material past or rubbed per revolution is greater (more friction) on the step circle than the smaller inner circle of the hub.

I hope this helps.

Feel free to e-mail me.

[Derbyworx]

@Derbyworx 1,The lever of the wheel would be the distance from the tread to the first point of contact, so by removing the ledge and moving it to the hub (like the old wheel) you have effectively lenghtened your lever (or reduced your braking forces) thus you have a more leverage on friction for a faster start and to overcome braking type friction in the flat of the track.

[Derbyworx]

@ryandlancaster

First off you always taper or "V" the head on your axle so there is no flat, this prevents any flat to flat contact between the axle head and outer hub face. If you do not remove the step, your point of contact is where the taper in the axle head contacts the point in the step, if you remove the step, your contact point becomes the inner edge of the hub bore. Now think about these 2 points of contact for a min:

[ryandlancaster]

@Derbyworx

Can you explain further? Your response does not seem straight forward. What is the effective lever? And how does it decrease the amount of friction if the axle now has more contact with the hub? I'm sure you know what you are talking about, please just explain it a little more.

[Derbyworx]

No, you are moving the friction point inward towards the hub bore (smaller circle) which does 2 positive things. 1, It increases the effective lever (making it longer) of the wheel on the start (faster start) and decreasing the amount of material (friction) per revolution.

With properly preped axles (back angled heads with the Pro Axle Press) it provides the minimal amount of friction possiable.

[realcampusman]

uhh, you are actually creating a larger friction point for the screws

the new wheel design was for more speed and you are basically changing the new wheel desin back to the old

lol

[Derbyworx]

Removing the ledge should not effect the bore diameter. Watch that you are cutting straight and not twisting the wheel on the Pro Hub Tool. This is the same effect we do to all of the Derby Worx / Warp Speed Pro B.S.A.Wheels.

[gpsjetskier]

I beveled my hub shaver such that it's lower in the center then the outer area. This in turn made for a slightly crowned face where the nail head would run on the inner area and not touch the outer. However, the wheels seem to wobble more on the bigger bore as if the added area might help prevent wobbling. Any thoughts?