How to prepare pinewood derby car body for gluing axles in place
Before even starting the process of tuning, a builder needs to address the following. If I am drilling my own axle holes, how do I keep the axles in place? After all once I install them, I will not be able to drill through the metal.
A series of holes need to be drilled prior to painting, prior to installing the wheels and axles. It is not crucial to make them perfectly spaced, or in a perfect line. What is important is that you leave room from the edge so that the glue doe not accidentally leak on your wheels.
Pinewood derby axle glue holes
Pinewood derby axle glue holes
Graphite Wheel Channel Pinewood Derby Body
Unless you build a lot of cars, one of the problems you will quickly find out is that with drilled axle holes, there is practically no way to add graphite to the hub once you have installed the wheel and gapped them properly.
Here's a builders tip. Add a graphite lube channel. With the BSA slots, you have wood removed that allows you access the inner wheel hub. With Drilled body you literally run into a brick wall. So just add some angled channels that allow you to to get to that spot. I do mine with a rotary tool. This can easily be done withe a file or some sand paper. I just like power tools
If you accidentally take off too much and end up in the axle hole, no worries, just remember that with the BSA blocks, there is an entire slot all the way across the body. It's not going to hurt a thing.
Pinewood derby axle graphite channels
Pinewood derby axle graphite channels
What glue to use to glue Pinewood Derby axles and wheels
Super Glue or CA glue is glue of choice for many years. Just remember this stuff is super runny or liquid, a little will go a long way and I have ruined many wheel sets because of this. Little drops, I mean little. And make sure your car is nice and flat so that it does not run into the wheel. It WILL.
Expert builders are now choosing RED locktite screw thread anti-vibrate treatment. They apply it the same way as super glue. It seems that it penetrates the wood better and it literally locks the axle in place. Not going to move the tune job. So if you are out of super glue, or want to give that a try I highly reccommend it.
Derby Dust Asset Wheel
To the new to novice builder there can be great confusion in wheel choice. What does all this technical info mean? What does my Pack allows? There is no blanket BSA rule that cover all wheels. Each local PACK determines what wheels can and cannot be used.
Below is a run through of each wheel we offer with the as much info as we can provide. If you have a properly tuned car, then speed will be based mostly on wheel weight. The lighter the wheel, the faster the car. Proven concept, not mathematical.
Please take note that wheels are massed produced through injection molding system. There are too many factors to mention why each wheel is its own unique wheel as much as we want them to be the same. They are not machined from a solid mass. This just means that every wheel is different. Only one company makes the wheels, everyone else machines them to make them faster. Every company that machines wheels tries to make the sweetest lemonade they can make based on an average. There will always be outliers. If you think you have an outlier, please contact your wheel manufacturer prior to leaving feedback. I am more than positive no matter who machined your wheel they will make it right. The industry needs this leeway to continue to grow.
Derbydust.com introduced the Asset wheel to the market in 2012. We are the first to bring to the market a wheel that is hand selected to be as close to perfect as we can tell. We are the first to offer a flawless wheel hub. We saw a need to make a new wheel because of the new rules at the pack level. We asked ourselves how can we provide a better wheel if everyone has to play by the same rules. If the wheels must remain basically the same weight as factory, what can we offer to make sure you still have a leg up in the mix. We have had great results with this wheel set.
All measurements are averages and may not be actual per your specific wheel.
AWW- Average Wheel Weight
MIB- Matched Inner Bore +/- 0.0005"
OD: 1.174" Bead/Tread present (target goal may be +/- .001")
AWW: 2.56 grams ( ranges being from 2.53-2.61)
Outer Hub: 2 Step, concave head (allows reduced wheel gap)
Inner Wheel Edge: Factory
Inner Wheel Hub: Factory
Inner Hub Bore: Flawless Bores
This wheel has had the outer diameter reduced by machining with cnc lathe for a uniformed tread consistent with the alignment of the hub. Custom delrin chuck ensures no damage done to the wheel. It will have bead/tread present. Flawless Inner bores. The wheels have been sorted for any manufacturing flaws. Meet Most pack requirements. However it will not meet the 1.180" outer diameter requirement. All BSA lettering in tact.MM, MIB available.
Pinewood Derby Wheel INNER BORE
First process in determining whether or not a wheel can make this "cut" is the inner bore. We first inspect the inner bore using a digital inspection scope. Only wheels with flawless inner bores are used for this wheel set. Because of this quality control, only 2 out of 10 wheels will meet this requirement. EVEN the BIG NAMED wheels do not have this type of quality. This ensures you have the best possible wheel to start with. There is no need in doing all the following modifications if your wheel fails at this requirement.
Pictures are of wheels that did not meet our standards. Many wheels have this void straight from factory which causes unknown wheel travel, binding, and wobble. It is caused by the ejection pin from the injection molding process.
Derby Dust Asset Wheels have inner hub free of voids.
Pinewood Derby Wheel Tread
Stock Pinewood derby Wheel Tread
Machined pinewood derby wheel tread
Derby Dust Pinewood derby wheel tread
Next step is to make a uniformed, flat tread as addressed by most packs. Mold marks are removed while retaining near full tread/beaded edges. Outer wheel diameter will always be 1.170 or greater because of our machining process. Milled using CNC lathes makes the treads nearly identical to factory casting. We have a dedicated lathe for this process. The axis is fixed and never moves. What this means is that all wheels that we produce have the most consistent repeatable wheel that we can offer. There is no other way to do this. We can control all the variables By doing so, rough edges are not present on our wheel tread.
Compare the outer treads of these three wheels. First is stock, the second is the leading aftermarket seller, the last is ours. Even the most expensive aftermarket wheels have this tell-tale sign. With that in mind, we figured out a way to machine our tread to near identical to uncut wheels.
For the 2016 season, we have now improved this process by replacing the mandrel with a dedicated delrin chucking system that grabs the wheel by the inner hub. This ensures that machine work done is parallel to the hub and that any and all wheel wobble is now almost always eliminated... There is always an outlier.
This process has to be done with a cnc machine. If you try to do it by hand then you get a cut in the wheel similar to the one in the middle. It's called the "fingernail" test by the experienced judges. Run your fingernail across the wheel and if you can feel the grooves, then you know it was machined.
Pinewood Derby Wheel Go / No Inspection
To keep this wheel compliant with 99.99% of packs. We have to address the following.
We do not reduce the width of the wheel. Since most packs do not allow this modification. Most are very descriptive about this modification.
We do not "true" the edges as that changes the width of the wheel which makes it illegal according to 90% of the pack rules.
We do not modify the inner hub portion that is closest to the body. Since we do not reduce the width of the wheel, there is no need to trim this area to make it appear to have the same gap.
Pinewood derby Speed Wheel Hub
Outer hub is modified. As per most packs rules, they allow this modification by addressing it. Or do not address it as a violation of rules to modify this area.
Increased outer hub diameter. We increase the diameter of the hub by 0.0015 inches. This decreases the outer axle hub rub/friction. By opening up this area, this modification allows the wheel to travel in a more true circular motion around the axle verses an elliptical rotation. Better, more true rotation of the wheel because the head of the axle will not rub while during rotation.Outer hub is retained. Per pack rules
Beveled outer hub. This modification decreases friction (Red area in picture). We have chosen to have a wider point of contact between your axle and wheel. We feel the larger outer ring provides a more stable wheel travel when compared to just a rounded hub as most aftermarket wheels utilize. This helps the first time builders get the most speed and tuning out of their wheels. We also find that it eliminates most wheel wobble when installed on a 1.5-2 degree negative canter.
We also leave this as a 2 step hub. This allows for factory axle head depth. This also allows for proper wheel gap when using the axle tuning pliers. With a recessed rounded hub, you can no longer gap the wheel and adjust the axle with the pliers. You will have to tune your car, then push the axle in to reduce the wheel gap which can lead to undesired movement of the axle which will change your tuning work.
We also find that this type of profile allows for a larger area of graphite reserves (green area in picture). Why not store more lube for the upcoming races?
Here's the answer to the million dollar question. What do I suggest? First I say check you rules...... Then use the following advice.
So my choice: Physics car body 3-wheel racer. Lead Weight. 3k bent axles (3x 2.5, 1x 1.5), pliers, Wheel Polish kit or service, Derby Dust graphite. You will have to choose what wheels you want to play by, but they will determine speed of car second to tuning the axles correctly
Pinewood Derby Tuning is the Key
So you are going to need to focus mainly on tuning or adjusting your axles. You want your car to go down the track as straight as it can without going side to side. Easiest way to do this is 3 wheels touching and make it ride along the center strip. So you purposely make it track to the high side. Takes time. Not technical, Not complicated, just time. The correct tool-- axle pliers. This $25 purchase is the difference between a headache and a breeze. what you will need is 4x bent axles so that you can do this: for 4 wheels I always suggest 3x2.5 1x1.5 angles
If you have to do 4 wheel tuning....
Pinewood Derby Speed Axles
3k for graphite with break-in
100K for oil or graphite with just dust and spin. You are substituting the lube for a higher polish metal.
Bent axles will be fastest (rail riding) however each axle needs to be adjusted (tuned) so that it steers the car down the track and not side to side. Each axle will have to be adjusted: Watch the tuning video above...substitute treadmill for tuning board if needed. Bent axles for the wheel to ride in one spot and also change the amount of tread presented to track. Ice skates vs rollerblades just the inner part of wheel will touch. (red wheel).
Picture originally published on Derbytalk.com forum
Pinewood Derby Speed Wheels
Lighter the better. Lighter wheels will require use of tuning pliers however to remove axles/wheels.
Polish the bores. Either you or me. Its pretty simple.
Flawless bores will eliminate any abnormal rotation in relation to wheel spinning around axles.
Weight reduced wheels start around 1.7 grams. Have all the lettering. Charlie Bravo
or Black Op's
will be those weights. Charlie Bravo has factory outer tread. Black Op's will have lathed outer tread.
Derby Worx makes a 1.5 and 1 gram wheel, but a little more noticeable machining done to them. Lighter is always better! They are all very fast wheels. Choose what will meet your pack's rules.
Pinewood Derby Graphite Lube
Graphite on graphite has a lower coefficient of friction than steel on plastic. Our theory is build layers of lube on layers of lube. Then you have graphite on graphite peeling off each race. Break In / Lube building process
Winning Pinewood Derby Car with Canopy #3
Winning Pinewood Derby Car with Canopy #3 Car
Winning Pinewood Derby Car designs by Derby Dust
. Here is another beauty. This will be available in either BSA Slot or Drilled BSA Distance. This body weighed 11.3ish grams so we will call it a 12 gram body. I bet if I added a few more pockets up the neck I could get it to 10 grams. But maybe next time.
As always we incorporate winning Design tricks. Super light weight. Center of gravity designed to be around .930" in front of rear axle. Slim Line aerodynamic profile. Wood removed to eliminate wheel rub. Quick start front ends. We always offer 3 wheel riders if desired.
Winning Pinewood Derby Car with Canopy
This one going to be a little complicated in trying to get people to believe that you cubber did it. Lets be honest. SO.... make sure to watch the YouTube video below to have a viable way that it could be accomplished.
Winning Pinewood Derby Car with Canopy bottom view
Winning Pinewood Derby Car with Canopy
Ultra light Pinewood Derby body. These bodies start around 15.5 grams. Pockets and holes everywhere to adjust your Center of Gravity needs.
I got really bored last night and drew up a few canopy cars. Will get them cutout over the weekend. Some will be extended wheel base only. Some will be regular wheelbase. I'm not going to offer both styles for each type of car. Too many bodies! Too hard to test and get COG correct.
Winning Pinewood Derby Car
Winning Pinewood Derby Car (bottom view) with pockets
Winning Pinewood Derby Car - top view And thank you... Wayne.... Your review on the treadmill process inspired me to just mass produce your design.
There is a Video on Youtube that gives you 7 Winning Tips to Pinewood derby.
Our PWD bodies utilize the steps.
1. Center of Mass (Center of gravity) Location. This step is supposed to give you a 36% increase in speed. These canopy style bodies are super light and allow us to maximize weight placement where we want it. Our setup is for a 0.930" COM in front of the rear axle. Then we place weight pockets on the remaining wood sections so that you can tweak what works for you.
2. Lightweight wheels.- Claim is 16% increase in speed, but I tend to think the increase is more like 36% and COG is 16%. I know if I can use a set of 1 gram wheels and tune a car, I will smoke nearly everything. I will beat any car that has factory wheels no matter if I am racing a block of wood. Seriously.
3. Aerodynamic.-- 11% increase in speed. Majority of our bodies are streamlined. With Low weight placement. We also remove wood around the wheel's outer edge to ensure that that part never touches the body.
4. Polished Nails. 10% increase in speed LOL we got that covered. CNC polished nails. Only one in industry that can state their axles are polished my a computer controlled machine.
5. Lift one wheel - 9% increase in speed. All bodies made by Derby Dust have the option of 3 wheel racing at no extra charge. We believe it is the only way to race.
6. Graphite / lube - Do we ever know this! Derby Dust dry lube is a pure graphite with proper flake size and moisture content that will give you a smooth friction-less surface when you follow our break-in process.
7. Other (long wheel Base, car shape, wheel gap, etc) 11% increase. I think this is a BS category. I can get a standard wheelbase to run just as fast or faster than a short wheel base. Car shape is important. Wheel gap is important based on the type of wheel hub. It will differ.
8. Derby Dust's conclusion which was not even addressed........ Fastest car is a tuned car. Regardless of any other option. Focus mainly on tuning or adjusting your axles. You want your car to go down the track as straight as it can without going side to side. Easiest way to do this is 3 wheels touching and make it ride along the center strip. Takes time. Not technical, Not complicated, just time. The correct tool to do this with is a set of axle pliers.
Low profile body with .930ish COG, 3k bent axles (3x 2.5, 1x 1.5) for center rail riding, lightest possible wheels that you can use, Wheel Polish kit to clean up the bores of the wheels, Derby Dust graphite.