New Tool Suggestion

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mossk
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New Tool Suggestion

Post by mossk »

Our rules are very specific when it comes to wheel modification. I’ve seen several vendors have 3.3 gram wheels, 2.2 and 1.0 gram wheels (the standard BSA wheels are 3.6 grams). Our rules state you can do some light sanding to remove the mold mark but you may not remove any significant amount of material to reduce the weight of the wheel.

Can someone come up with a pass/no pass tool that can be used at check ins that will detect modified and/or purchased wheels? I’m thinking of a small piece of metal with a slot cut in it the proper width. A legal wheel would not fit in the slot while an illegal wheel would fit in the slot. It would have to be used carefully so you don’t change the alignment when looking at the wheels.

Where is the wheel mass removed in the 3.3 gram wheels? Will a tool described above detect them?

Randy – anybody?
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Re: New Tool Suggestion

Post by OneHour »

Short of having a caliper there to measure the wheel's inner and outer diameter, there isn't much of a device that will detect a light-weight wheel that is mounted on the car already. Having the pictures there is a good start. Even if you have a caliper there, you will have to define the specifications of the wheels.

The advice that I usually send out before the races to the parents in my pack is that if they are that desparate for a trophy, they can save some moneys and purchase a 1st place trophy for their son for a fraction of the costs of those wheels, body, or car. The trophy would twice as big as the one that the Pack/District gives out and let other kids who do not have the means for those advantage compete fairly.

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Re: New Tool Suggestion

Post by pwdarchitect »

mossk wrote:
Where is the wheel mass removed in the 3.3 gram wheels? Will a tool described above detect them?

Randy – anybody?
The 3.3 gram wheels are wheels that have been lathe turned on the exterior side of the tread surface, which, IMO, would weigh about the same as a wheel that has been turned utilizing the Derbyworx Pro-wheel shaver, a tool that a Cub Scout team can easily purchase and use to get a good set of wheels. With lightly sanding using sand paper there would be less of a chance to ensure the wheel treads are true to the bore.
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Re: New Tool Suggestion

Post by mossk »

I was thinking of a more definitive tool. Either pass or no-pass. You obviously can’t weigh the wheels once they are put on the car. A caliper would be fine but a good one would cost a lot of money – but a simple piece of metal (maybe aluminum) with a pre-cut slot in it could be sold very inexpensively.
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Stan Pope
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Re: New Tool Suggestion

Post by Stan Pope »

mossk wrote:You obviously can’t weigh the wheels once they are put on the car.
Are you sure about that?
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Re: New Tool Suggestion

Post by mossk »

Stan, I guess you could come up with some sort of jig that would hold the car off the scales while letting the wheels hang since there is a little slack between the wheels and the axles. But since everyone has puts the axles in the slots (we have to use the slots) at a different hight it would have to be adjustable. Have you have already drawn up plans to do this.
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Stan Pope
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Re: New Tool Suggestion

Post by Stan Pope »

mossk wrote:Stan, I guess you could come up with some sort of jig that would hold the car off the scales while letting the wheels hang since there is a little slack between the wheels and the axles. But since everyone has puts the axles in the slots (we have to use the slots) at a different hight it would have to be adjustable. Have you have already drawn up plans to do this.
Only concept. :) Since ther is "slop" in the axle/bore interface, it must be possible to isolate the wheel. Suppose car belly sits on slat of adjustable height and that a scale sits under one wheel, blocks under others. Car slowly lowered until scale registers. The scale should show three readings:
0 when wheel off the scale,
1/2 to 2-1/2 oz when belly is off the slat, and
actual wheel weight in that +/- 0.002" in which the axle hovers in the bore.

Control the slat height with a hinge on one end and a large knurled nut on the other!

Variant ... those little CenTec pocket scales are so cheap that you could put one under each wheel! :)
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Re: New Tool Suggestion

Post by Bulldog »

mossk wrote:I was thinking of a more definitive tool. Either pass or no-pass. You obviously can’t weigh the wheels once they are put on the car. A caliper would be fine but a good one would cost a lot of money – but a simple piece of metal (maybe aluminum) with a pre-cut slot in it could be sold very inexpensively.
I tend to think that the cost of developing and machining a gauge might be more expensive than a caliper- You din't need anything too fancy- the tread of a wheel that has been machined as to lighten the wheels should be easy to spot- you can usually pick up on it with the naked eye. The cheap caliper can be used just to confirm.

HARBOR FREIGHT has several models around $15 or even cheaper.
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Re: New Tool Suggestion

Post by Teeeman »

To lighten the wheels but look BSA stock the vendors are focusing on the following areas:

tread OD reduction
tread ID reduction
hub OD reduction
face disc thinning

Width tampering is very easy to spot even by a relatively untrained eye (if it is dramatic).

We have a simple visual using the bumps to be sure the OD is not beyond our set specific limits.

We used a plastic caliper and cut it to fit the wheel tread by slipping inside the minimum 1-3/4 inch wheel spacing… we measured it with good digital calipers and glued it fixed… it became a “no go” gauge… no go was good, if it easily slipped on, the tread was thinned…

We used 2 strips of aluminum tape on a flat ceramic plate to look for excessive thinning of the wheel width and flatness of the treads.
We also would put a plastic caliper on a wheel to look for square (no treading).

We provided a “too roughened tread” sample wheel to help spot excessive treading.

Visual can spot missing or partially removed lettering, hub OD reduction and tread OD reduction. The tool would spot tread ID reduction.

We used a bright light. I had a magnifying glass available though it wasn’t used much if at all :(

Despite all this, I think some oiled wheels probably got by us… the only inspection I had for that was to look for graphite… if NO graphite spotted, interview the adult… which our inspectors were lax on :(

I am still trying to come up with a perfect and quick inspection… so far no luck.

What I have come up with requires diligent and willing judges, willing to both be trained and to confront any suspect wheel by talking (gently) with the adult guardian of the Scout.


We had one dad this year flat lie in saying they took the wheels straight from the box and put them on the car when they were obviously sanded !
That cost him a VERY thorough inspection by yours truly ;)


Next year I plan to have a small notebook of pics on how to spot tampered non-legal wheels with lots of pics…

and I will make sure either we have 1 lane only for wheel inspection (I got overruled on that this year and we had a less than I wanted inspection in one lane)… or both lanes are equally TRAINED and equipped.

I think building a weight jig to weigh the wheels would be AWESOME!
I just may do that Stan!


To complement the existing rules and dimensions we may put an absolute minimum a wheel must weigh and check 1 wheel at random on each car… a rear wheel since our tracks favor rear weighting and we don’t care much about the carry wheel (not as much, anyway).



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Re: New Tool Suggestion

Post by gpraceman »

Trying to catch lightened wheels can be difficult. The tread may be undercut, but not the edge, so you cannot use calipers or a no-go gauge to measure tread thickness. Anyways, the tread thickness actually varies. It tapers from thinner at the outer edge to thicker at the sidewall, so it comes out of the mold more easily.

Material can be removed around the inner hub, but it is not likely that you can get calipers or a no-go gauge in to measure it with many of the car designs.

Material can also be removed from the inner part of the sidewall, and there is no easy way to measure that thickness.

You can more easily verify tread profile and wheel diameter. Though, you cannot be so restrictive on wheel diameter that it will not allow people to eliminate any out of roundness for the wheel and the mold mark. That likely will allow aftermarket wheels that have been only lathed on the tread to pass.

Unfortunately, I think it's not likely to find an easy way to verify a wheel has been lightened, except visually. Trying to create a jig to weigh each wheel without load seems more likely to slow down the check-in line to a crawl.
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Stan Pope
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Re: New Tool Suggestion

Post by Stan Pope »

gpraceman wrote:Trying to create a jig to weigh each wheel without load seems more likely to slow down the check-in line to a crawl.
Actually, we don't know how long it would take to weigh a wheel. Thus we have no way to know how it would affect the inspection process. I would be content to weigh only the wheels on one side (the same side as the dominant wheel of a 3-wheeler) and, maybe, weigh just one active rear wheel.

The logic for this is that I suspect that mixing wheel weights would be detrimental to performance in the same way that mixing axle-bore friction coefficients is detrimental.

To evaluate, I must build the rascal and see how long it takes to operate it. I already found a simple refinement that should make it rather speedy: Add a "0.009 inch cam lever" between the knurled nut and the belly support slat! Lower the slat until body weight is applied to the scale, then lift the cam lever to lift the body 1/2 the bore slop amount! At 0.001 inch per 10 degrees of cam lever rotation, it should be easy to get zeroed in on the wheel weight.

Just did a quick sampling of sizes. Untreated axle dia is about 0.088". Untreated wheel bore minimum dia is about 0.096" That leaves 0.008" of slop and need to lift the axle about 0.004" to neutralize the body's influence on the scale! This leaves some room for error in running down the belly support. Lessee ... at 20 turns per inch that is 0.050 inches per turn (or about 0.0015" per 10 degrees) of the rough setting nut. It should be pretty quick to operate!
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Stan Pope
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Re: New Tool Suggestion

Post by Stan Pope »

gpraceman wrote:Material can be removed around the inner hub, but it is not likely that you can get calipers or a no-go gauge in to measure it with many of the car designs.
Removing material that close to the wheel axis is detrimental to performance! It subtracts little inertia but it increases the body weight (and, thus, the bore-axle friction) of a 5 oz car!
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Re: New Tool Suggestion

Post by gpraceman »

Stan Pope wrote:Actually, we don't know how long it would take to weigh a wheel. Thus we have no way to know how it would affect the inspection process.
If you can devise a quick check, that would be great. I just invision someone fiddling with a jig, trying to get to a no load condition, so the weight can be measured. All the while, the line is backing up.
Stan Pope wrote:I would be content to weigh only the wheels on one side (the same side as the dominant wheel of a 3-wheeler) and, maybe, weigh just one active rear wheel.

The logic for this is that I suspect that mixing wheel weights would be detrimental to performance in the same way that mixing axle-bore friction coefficients is detrimental.
That is true. Not all 4 need to be weighed. I would definitely check one non-raised wheel from the front and one from the rear, as I can see someone using one set of wheels for the front and another for the rear.
Stan Pope wrote:Removing material that close to the wheel axis is detrimental to performance! It subtracts little inertia but it increases the body weight (and, thus, the bore-axle friction) of a 5 oz car!
Maybe so, but if you look at the picture below, to get to 1g, that is an area that they are taking material away from.

Image
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Re: New Tool Suggestion

Post by Stan Pope »

gpraceman wrote:
Stan Pope wrote:I would be content to weigh only the wheels on one side (the same side as the dominant wheel of a 3-wheeler) and, maybe, weigh just one active rear wheel.

The logic for this is that I suspect that mixing wheel weights would be detrimental to performance in the same way that mixing axle-bore friction coefficients is detrimental.
That is true. Not all 4 need to be weighed. I would definitely check one non-raised wheel from the front and one from the rear, as I can see someone using one set of wheels for the front and another for the rear.
Good point ... for a 4-wheeler! Not applicable for a 3-wheeler, though.

What are typical inspection station cycle times? With one server per station, the longest station controls the line flow rate. We need to be able to inspect 100 cars in a 50-minute hour, so any station with a cycle time over 30 seconds needs a second server (inspector).

To achieve consistency in inspection, it is better to reduce the tasks assigned to each station and add stations rather than add inspectors to a station. But, if the inspection assignment for a station is already pared down to a single step, then an additional inspector or a change in the inspection procedure step is needed.
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Re: New Tool Suggestion

Post by mossk »

The problem we had is we had five cars with the Pro Ultra Light Speed Wheels (1.0 grams) and at least one car with the Ultralight speed wheels (2.2 grams). It was very easy to see the 1.0 grams wheels and easy to me to see the 2.2 gram wheels. I cannot visually tell the difference between 3.6 and 3.3 gram wheels based on the picture above maybe I could if I had an example of both.

This is the exact picture I enlarged and printed out except I masked Randy's website information and company name. The masked version of this picture will be in our rules for next year.

Reducing inner or outer face of the wheels should be easy to detect visually. Calipars or a go/no go tool should detect any significant reduction in tread thickness. But we need to know what range of thicknesses the stock wheels have and what the 3.3 gram wheels have. The tool would have to have a tolarance between the two wheels. I would say somewhere just above the 3.3 gram wheels to allow for light sanding. This thickness could then be put into the rules. I have a feeling the 3.3 gram wheels have a tight tolarance since they are lathed with a CNC machine. So setting a measurement just above these might be the way to go.

Undercuting the ID of the tread would be difficult to detect if you keep the outer edge of the wheel intact.
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