Wheel matching

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
newarcher
Pine Head
Pine Head
Posts: 59
Joined: Tue Dec 05, 2006 6:47 am
Location: Atlanta

Wheel matching

Post by newarcher »

I bought two PWD car sets to be able to mix and match the parts.

I have only two matching mold wheels....mold 2. From reading, I found that I should put them on the back of the car.

For the front tires, I have molds 1, 4, 7, 8, 11, and 15.

Which would you use? We must have four on the floor.

Thanks,
New
Gameday
Master Pine Head
Master Pine Head
Posts: 277
Joined: Mon Mar 13, 2006 12:50 pm
Location: Madison, WI

Re: Wheel matching

Post by Gameday »

newarcher wrote:I bought two PWD car sets to be able to mix and match the parts.

I have only two matching mold wheels....mold 2. From reading, I found that I should put them on the back of the car.

For the front tires, I have molds 1, 4, 7, 8, 11, and 15.

Which would you use? We must have four on the floor.

Thanks,
New
New, I'm not up-to-speed on the current, best mold numbers to use but here are some thoughts:

1) I recently bought some packages of just wheels and axles at our local BSA store. They were very inexpensive and I ended up with several sets where I had at least 3 matching mold numbers (we can have a raised wheel).

2) I've been working with my son showing him how to use the Pro Wheel Shaver XT. Once we put the wheel on hub tool and spin it, we quickly identify those wheels that are out of balance (much side-to-side motion) and we discard them. After trimming the sides and then shaving the wheels to ensure they're round and flat, they all seem excellent. So, in that case I'm wondering how important it really is to have matched mold numbers.
newarcher
Pine Head
Pine Head
Posts: 59
Joined: Tue Dec 05, 2006 6:47 am
Location: Atlanta

Re: Wheel matching

Post by newarcher »

Game,

We can't shave the wheel or narrow it in any way. Ream the bore, yes. Cone the inside hub, yes. Polish the bore, yes. Prep the outside hub, yes. But can't round them.

New
User avatar
sporty
Pine Head Legend
Pine Head Legend
Posts: 3344
Joined: Sun Feb 13, 2005 1:00 am
Location: rockfalls, Illinois

Re: Wheel matching

Post by sporty »

okay,

I might get some static over my reply.

But here it goes-


mold matching is prefered as they asume that the odds are likely, that the dimensions are the same or very close.

Also, somewhere on here, there is a posting on the various #'s. Which ones are better.

However, I do believe since the year is hard to define. That sometimes you may find mold # that was good one year. But bad the next.

Unless you are in the side at the place they are made.

I would wonder how often the runs are done, how old the wheels are before they are even put into the boxes or how long the boxes sat around.

So it's i-deal to have mold matched wheels. But do not focus on it, if that mold # you have a set of. Turns out to be not as good as a non matching set that you put together.

Then use the better wheels.

I have had good luck and bad luck. Meaning I have built several cars with matched wheels non matched wheels. with the same wedge design, shape/ weight and placement.

As close to identical as I could get and ran into the wheels that did not match and had less done to them. Be the faster car.

From a quote from Down and Derby. The fluke affect !


Something else to think about, unless each wheel was checked with a micrometer. Then it's hard to say just how matched they really are !

Thats why, I feel the sellers of matched wheels. Most of the time allow you to pick the # of the matched set. But do not list are say which # of the matched set is better than the others.

If they did, I am sure they would charge for the time, that it would take to use a micrometer to check the inner and outer specs, width.

Just thinking fast here, I would asume there is over 12 checks that would need to be done on each wheel. Very time consuming.

Sporty
Teeeman
Pine Head Legend
Pine Head Legend
Posts: 1577
Joined: Fri Apr 01, 2005 1:40 pm
Location: Huntsville, AL

Re: Wheel matching

Post by Teeeman »

Here is the short list in order of wheels I compiled from this forum some time ago, bear in mind the defective molds that produce the "bad" wheels are supposedly fixed...

Scout stores sell boxes of 5 nails/wheels, and we've been known to sort through 20 boxes and make up the 8 we want with hesitant permission from the folks working the store (heheh!)... I gave each boy in our Den who showed up to our workshop a free box of sorted "good" wheels.

-Terry

(sorted from top = best, bottom = least favored)

Good wheel mold numbers:
2
12
17
5
(alternates)
4
3
11
10
18


Bad wheel mold numbers:
13
8
18
"I dunno..." - Uncle Eddie, Christmas Vacation
GILLS
Master Pine Head
Master Pine Head
Posts: 115
Joined: Tue Mar 30, 2004 8:33 pm
Location: Nashville, Tn.

Re: Wheel matching

Post by GILLS »

Hey Newarcher, welcome abord! I dunno if this will help clear things up for you or muddy the water some more, check out these two links and see if they will help you.
http://www.maximum-velocity.com/5453.htm, http://home.simplyweb.net/bosworth/what's.htm --Type in this second url address, for some reason it isn't picking up the last five charactors.

These two gentlemen have put some time and effort into pointing out similarities and dissimilarities between the different wheel mold numbers.

[Moderator Note - Looks like the apostrophe is the problem in the url]
mcgyver
Apprentice
Apprentice
Posts: 11
Joined: Sun Mar 20, 2005 6:26 pm

Re: Wheel matching

Post by mcgyver »

If speed is what you are looking for, then you are barking up the wrong tree. We inspect all wheels individually. Just because a wheel happens to be #13, don't disqualify it. And 2 #13 wheels are not necessarily going to be the same size. Whenever you try to teach being meticulous with your sons, don't generalize. This is a science project not a game of odds.
User avatar
2kids10horses
Master Pine Head
Master Pine Head
Posts: 424
Joined: Thu Feb 17, 2005 11:57 am
Location: North Geogia

Re: Wheel matching

Post by 2kids10horses »

newarcher,

Can you sand the wheel to remove the mold mark? If so, you are misintrepreting the "round wheels" prohibition.

It is generally true that the treads can't be reshaped to have a U shaped profile (or a V shaped profile or H shaped profile). The idea is the entire surface of the wheel should lay flat on the track.

When the posters are referring to a "round wheel" they are describing one that has a constant radius. That is the wheel is round and balanced.

If you are allowed all the wheel mods you described, I would bet you could use the Pro Wheel Shaver to produce a "round wheel with a flat tread".

Ask the Pinewood Chairman for an interpretation.

2K10H
newarcher
Pine Head
Pine Head
Posts: 59
Joined: Tue Dec 05, 2006 6:47 am
Location: Atlanta

Re: Wheel matching

Post by newarcher »

Well, I bought the last tool I can afford this year. Maybe I will buy a shaver next season.

I coned the hubs, polished the bore, worked the outer hub, and I will sand a little bit on the outside of the wheel.

Buying the extra car set is a good idea. We found that the hub on a couple was overly tight. We found a couple that were so badly out of whack when we spun them on the axle, they would wobble.

So now I have four matched wheels that spin about the same amount of time and spin true.

New
User avatar
2kids10horses
Master Pine Head
Master Pine Head
Posts: 424
Joined: Thu Feb 17, 2005 11:57 am
Location: North Geogia

Re: Wheel matching

Post by 2kids10horses »

I'm the Cubmaster, and I went to our Scout shop and bought this year's kits to give out at the December Pack meeting.

Guess what? The end flaps are glued this year! I can't remember if last year the end flaps were glued, or if there was a tab that tucked in.

But, since they're glued, that's going to prevent folks from going to the scout shop and cherry picking the wheels from the kits, and weighing the blocks!

(You can still buy wheels separately.)
User avatar
sporty
Pine Head Legend
Pine Head Legend
Posts: 3344
Joined: Sun Feb 13, 2005 1:00 am
Location: rockfalls, Illinois

Re: Wheel matching

Post by sporty »

Glued ends on the boxes.


You were talking about the block, axle, wheels ??

My son got his kit the other day and it was just the flap, no glue.

So my sons kit, might be from last year.

Sporty
Gameday
Master Pine Head
Master Pine Head
Posts: 277
Joined: Mon Mar 13, 2006 12:50 pm
Location: Madison, WI

Re: Wheel matching

Post by Gameday »

I went to the scout shop two weeks ago to get an extra kit and I also noticed that the boxes are glued shut.
User avatar
gpraceman
Site Admin
Site Admin
Posts: 4926
Joined: Fri Jun 20, 2003 12:46 am
Location: Highlands Ranch, CO
Contact:

Re: Wheel matching

Post by gpraceman »

Gameday wrote:I went to the scout shop two weeks ago to get an extra kit and I also noticed that the boxes are glued shut.
They probably got tired of Dads picking through the boxes looking for a matched set of wheels and the lightest block. :lol:
Randy Lisano
Romans 5:8

Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
User avatar
Go Bubba Go
Pine Head Legend
Pine Head Legend
Posts: 1190
Joined: Sat Nov 18, 2006 12:09 pm
Location: Northern, Illinois

Re: Wheel matching

Post by Go Bubba Go »

Please don't run me off, fellow Scout guys, but I typically buy my kits and wheels at a local hobby store where the manager allows me to open and sort through the kits and wheels prior to purchase.

For the 6 step Construction Demo model I built recently (see MaxV posting - I hadn't joined DerbyTalk yet), I was able to sort through about 25-30 kits and find 6 nice blocks of similar shade and grain that didn't have gouges in all the wrong places, so to speak. Oddly enough, as I was sorting through some kits recently I found 1 block that had some green paint coloration at the grain (it didn't look intentional) and 1 block that had a dark finish/stain coloration at the grain (again, it didn't look intentional). I showed these to the manager so that he could determine whether to return them rather than have another customer get a "surprise" when they open their box, especially with the tainted green block. They would probably paint over it anyway, but the initial gut reaction would likely be "hey, that guy sold me a junk kit".

Back on topic - the manager has also allowed me to sort through and match up wheels at the store. While he is an "airplane" guy and his employees are much more experienced with scale aircraft and RC equipment, they are very much "into" their craft and understand the desire to be selective about raw materials. Either that, or maybe he just figured that with his liberal return policy, if I don't sort through them at the store, I would buy 50 boxes, sort them out at home, and return the 46 I didn't want later. He's right :D.

p.s. (note to self: steal weighting, paint, aerodynamics ideas from the airplane guys. Also a good place to buy various grades of Balsa).
"Who's Grandpa's neighbor?"... Phil Davis, Down and Derby
User avatar
gpraceman
Site Admin
Site Admin
Posts: 4926
Joined: Fri Jun 20, 2003 12:46 am
Location: Highlands Ranch, CO
Contact:

Re: Wheel matching

Post by gpraceman »

Go Bubba Go wrote:Please don't run me off, fellow Scout guys, but I typically buy my kits and wheels at a local hobby store where the manager allows me to open and sort through the kits and wheels prior to purchase.
I promise. We won't run you off. At least not yet :lol:

Since the boxes are now coming glued shut, then it looks like you (and others) will have to use the derby merchants to get mold matched wheels, unless you really want to buy a lot of stock from the local Scout Shop. Of course, mold matched wheels don't gaurantee that they will not be out of round or otherwise have a problem.

Though, if you are looking for the lightest block, you may just have to weigh a whole bunch of unopened boxes to see which is lightest. I wouldn't image that the weight of the wheels, axles, rule sheet and sticker decals would vary by much.
Randy Lisano
Romans 5:8

Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
Post Reply