Newbie looking for help

[coony278]

I have been lurking around on this site for the last few months gathering info for my sons car. I decided to join just cause I like the derby cars so much and hoped maybe to get some more info.

A little background.... our first years car just sucked ! It was too tail wieghted and the front end bounced down the track and I just didnt know.

2nd year did pretty good won our pack champion came in secound at district and dead last at council/images/boards/smilies/frown.gif

This looks like a a repeat if my son and I dont figure out what we are doing to not get the best speed out of his car.

Our pack race was yesterday, he won by the skin of his teeth ! His car is really not any faster than last years car by the timers. Only by a few thousandths. But I dont think you can really go exactly by the timers, as I am sure the track changes everytime it is moved.

Here is a pic of his car

We are running by basic cub scout rules that come in the box with the car.

He polished his axles to 3000 grit in progressive steps then used a diamond polish compound to finish off.

Wheels I used a wheel shaver on them to true them up. really didnt remove much material,

Then he polished the wheel bores and then used a wax on the bores. And then burnished the bores with graphite. Iam not real sure this was the best way , thinking maybe the wax and graphite wasnt a good combo ? thoughts ?

He also read about putting graphite on the tread , which we did and I now hae read that this was probably not a good idea?

Also he wanted the blue wheels which are not good castings numbers that I hae read to be good and they are not matched castings, but we did true them all up to the same?

The car is an all 4 wheels on the track car and is tuned to where it doesnt steer either direction oer 4 feet.

So my thoughts to get him to where he wants to be , which is competitive at council is.

Change the car to a 3 wheel on track car, Fix a new set of wheels for it that are a matched casting set, and make it a rail runner ?

Is this going in the right direction ? Is rail running worth the effort ? He and I would really like to be competitive at council this year and not suck hind tit as we did last year LOL

Any input/help would be greatly appreciated ! Thanks for a great site to share and talk about derby cars! They are ery addictive !

 

[5KidsRacing]

You would be way faster with a 3-wheel railrunner than with what you have now... Not even in the same ballpark.

 

[IAE Racing]

Congrats on your pack win. Nice looking car. Are the rules the same at district and council? If I remember correctly, OOB rules would allow for a lightened wheel.

Your car design would easily allow to lift a front wheel (NDFW) and use a bent axle to steer, which will be a gain. I'm not sure how the wax you used compares to DD4H process but is to be used with graphite. Allow for 4" drift in 4'

If time allows, your rear wheels could be canted. It might be difficult to redo depending on your skills. Looks like your car is probably rear weighted. What is the COM?

Definite no on graphite on the tread.

 

[5KidsRacing]

I think he can win council/images/boards/smilies/smile.gif

 

[The Iceman]

He can win it!! Unless someone sneaks in some Oil! Now I'm a Newb but I've learned alot in a short amount of time!!!!

Here is a really really Fast version: (from a newb that kicked some)

1. Rail Rider Learn it, Race by it. (I learned my first Pinewood derby and had the 3 fastest cars there)
Note: Axles: fill the holes and re-drill if you need to! (Raise one front wheel, move the axle hole if you need to)
2. Axles and tires (check your rules!!) Buy from Derbydad4hire, if you don't have the money then go buy a new set and rework them.
Note: learn the trick with Walgreen brand qtips (Studio 64) and novus 2 polishing (buy that on Amazon)
how? cut the tips off and put in wheel with Novus 2 on them, really really slow (it will squeak) go the length of the qtip 3 times then eyeball them!
Then clean up, then use one thin coat of turtle wax.(red rocket if you have time to order)
buff the bores with a 1/4" strip of tee shirt till shiny)
then work a bunch of graphite in. (read about Burnishing if you have time)
3. Rear Wheel alignment. Straight as an arrow!! (check roll back and forth and wheels should never touch the body)
why? Because the rears has 3 degrees Negitive cant in the rear. Use folded Wax paper to adjust the nail if you need to!
4. and Finally for Next year, Read this article from 5kidracing, it is an awesome write up that I'll be handing out at when I run a speed class next year! http://5kidsracing.webs.com/cubscoutbuildtips.htm

 

[coony278]

Thanks a bunch for the replies folks!

We have plenty of time before district race , alomost a month. So he could build a new car if needed.

I have a pro axle press so , should I use it to bend my nails or is it better to drill the canted holes?

I was looking at the rules

YOCONA AREA COUNCIL BOY SCOUTS OF AMERICA

PINEWOOD DERBY RULES AND SPECIFICATIONS (2010 Revision)

These are the rules for Yocona Area Council races. Rules may differ, so be sure to read and abide by the

rules for your race. The Pinewood Derby is open to all Cub Scouts (including Tiger Cubs). The intent is

for the boy to have the satisfaction of building his own car from the materials kit. Guidance and

assistance should be given by capable adults. Encourage adults to remember that this race is for the

boys and not for the adults. ( Packs may have a separate Pinewood Derby competition for adults.)

The following lists of Rules and Specifications were adopted by the 2000 Council Program Committee to

govern District Pinewood Derbies and Council Pinewood Derbies. Revisions made by Pinewood Derby

Committee.

Rules:

1. Each car must be constructed from the original equipment found in the BSA Grand Prix

Kit #17006 and/or BSA approved parts. (No Hobby Lobby Car Kits, etc.)

2. The cars are to be made by the Cub Scout with assistance and guidance from the

parents/guardians.

3. The race will be double elimination. District Races and individual Pack races can make

their own choice on how they want to run their race. The Council race will be a timed

race.

4. After the car has been registered and assigned a number the Cub Scout will not be

allowed to handle the car until after the race. No cars will be registered after the race

begins.

5. Rules for the construction of the car will be the same as those found in the BSA kit

#17006 as well as the rules specified here.

6. All cars should be built during the current school year. Same car that qualified in District

has to be used in the Council race.

7. Cars that fail to cross the finish line or interfere with other cars during the race more than

one time will be eliminated.

8. Failure to comply with any rule or specification will mean automatic disqualification.

*Remember ALL decisions by judges are Final.

Racing Specifications:

1. WIDTH - The overall width of the car shall not exceed 2 ¾ inches.

2. LENGTH - The overall length of the car shall not exceed 7 inches.

3. WEIGHT - The car weight shall not exceed 5.0 ounces (or 142 grams). No loose

material of any kind is permitted in the car. The car may be hollowed out and built up to

the maximum weight by the addition of wood or metal only, provided it is securely built

into the body. The official race scale shall be considered final.

4. Wheel bearings, washers, and bushings are prohibited.

5. Axels must be placed in grooves provided on kit. No moving forward or backward. No

Solid Axle. Axles should be inserted into the axle slots provided in the car kit.

6. The only modifications of wheels accepted will be the removing of mold projections from

the center seam of the wheel. No narrowing, grinding or reshaping of any kind and “No

special wheels” permitted. No coning of inside hub/no v-cut/no California cut/ no h-cut.

(Please look at the example at the end of this document)

7. SPRINGING – The car shall NOT ride on any type of springs. YOCONA AREA COUNCIL BOY SCOUTS OF AMERICA

8. DETAIL – Details such as steering wheels, drivers, decals, painting, etc. are permissible

as long as these details do not exceed the maximum length, width, and weight of the car

and are securely attached.

9. ATTACHMENTS – The car must be free-wheeling, with no starting device.

10. INSPECTION - Each car must pass inspection by the official inspection committee

before it will be allowed to compete. The Inspection Committee has the responsibility to

disqualify those cars that do not meet these specifications.

11. Only dry-powdered graphite may be used as lubricant. *It’s suggested that each boy

bring a box or bag to help keep graphite off the floor and himself.

It only states where to put the axles not what kind you can use? I might as well buy him a good set of axles. And while iam placing the order with derby dad might as well get him some good wheels also!

Theres no wonder we got out butts handed to us at council last year /images/boards/smilies/frown.gif I just didnt learn enough. /images/boards/smilies/smile.gif

 

[coony278]

One other question , why is the canted rear wheels faster seems like it make the wheel ride on the head of the nail real hard , maing more friction ?

 

[Kinser Racing]

There's some great advice here. From personal experience I have found that some "waxes" can slow your car down. So a proven "wax" is important. In regards to the canting of the rear wheels. It does cause it to ride harder on the axle head, but it's a little like rail running. It helps keep the wheel in one place not vibrating back and forth between the car and axle head. It also reduces a lot of vibration. If you wanted to replace your wheels and axles you can gain some speed there also. Stick around and check stuff out. /images/boards/smilies/thumb.gif

 

[speed bump]

I helped build a car last year for that council race. It got in the top three. Three wheels touching,rail runner. it was a 1/4 plank car with com of 5/8 inch. You can gain a lot more speed !!

 

[The Iceman]

One other question , why is the canted rear wheels faster seems like it make the wheel ride on the head of the nail real hard , maing more friction ?

One of these Pro guys can chime in if I'm off too much!

Canted rears = Rides on Edge (less surface area) and keeps the wheel away from the body!.

Looks like you will not be able to drill your own holes, so I'm guessing you'll have to bend all your own axles. My rules are about the same as yours for axles and wheels.

Wheels= I used The Dynasty BASX set of 4 from John here. Trued up!
Axles= 'Axles should be inserted into the axle slots provided in the car kit.' Sounds like you have to run BSA Axles now I don't think John (derbydad4hire) has any true BSA Slotted axles. (correct me if I'm wrong guys) then I would run Pro BSA 2 Groove Axles from DerbyMonkeygarage.

COG, = someone other than me will have to chime in for this standard wheel base setup. If it was extended wheel base then I would of said run 3/4" cog with 4" per 4'.

weight, Hog as much wood as possible. Then reposition all the weight around the rear axle. These guys strive for 2oz behind the axles and the rest in front. Note: slide the front weight forward till you get your cog. Then cover then the bottom with aluminum furnace tape. (or packing tape)

Axle prep I do= 400, 600, 1200, 1500, 2000, 6000, 8000, 120000, leather then clean and a shot of Pledge. Yes I had to redo my Pro BSA 2 Groove Axles from DerbyMonkeygarage after the first pass starting @1200.

Remember all this is a really fast walk through!!
.

 

[coony278]

All good stuff thanks for the info , my CG is at 3/4" in front of rear axle right now, the car has tungstun for weight its all in the lower back section of the car.

 

[Chief]

Do not bend the rear axles, drill the block canted keeping the slots in tact. Only bend the front dominate axle after polishing

 

[The Iceman]

Do not bend the rear axles, drill the block canted keeping the slots in tact. Only bend the front dominate axle after polishing

Ahhh Drill the slots??

You would probably use Elmers glue to set when you know your right on!!!

 

[The Iceman]

All good stuff thanks for the info , my CG is at 3/4" in front of rear axle right now, the car has tungstun for weight its all in the lower back section of the car.

Lets see a Pic of the Bottom!

 

[bracketracer]

Do not bend the rear axles, drill the block canted keeping the slots in tact. Only bend the front dominate axle after polishing

+1 I like to drill the holes a little higher than the slots, shave off the bottom of the block, then deepen the slots with a 1/16" end mill until they connect to the drilled holes. That way I'm drilling into solid wood but we still meet the rule about using the slots. Works good, and you don't need to use glue so you can pull the wheels off to reprep easily.

 

[Obsessedderbydad]

Your rules ate strange. But just another guy trying to make it fair for everyone. I think John can tell you what to do with that Axle Pro bender /images/boards/smilies/smile.gif

 

[coony278]

Here is a pic of the bottom of the car

I guess when you say that John will tell me what to do with the pro axle bender is to throw it away?

I talked to the guy that finished second in the den this evening. He said he did nothing to his nails or wheels , makes feel that our car was slower then I even thought /images/boards/smilies/frown.gif

 

[coony278]

here is a pic of the track we run on. Its really old ( about 25 years). Its rough and in need of some help imo . Our car is in the closest lane.

 

[coony278]

Ok had a free day today , I got to thinking about what eeryone said above.

So I quickly threw together this car this morning. Cleaned up a set of nails with a file and smoothed with 400 grit paper.
2 deg cant in rear , left front not touching and bent an axle for the right front to steer by.

I have a 30 foot test track that I built.

Holy crap , the junky back to the future car with no graphite, lost to my test car by one car link. I was amazed. I run them several times and it was the same every pass.

I then put graphite on the wheels , iam talking a quick spnkle on a 3 wheels spun them a couple of times.

I re ran the race. OMG the back to the future rail runner smokes my test car by 2 car links every race.

I can not believe I have fought rail runnning for 2 years of the derbies. Thanks guys for the above advice. I was too simple mineded to beleive it worked. Thanks for opening my eyes.

Now I just have to get it dialed in, no wonder we always got smoked at the races, I was just too ignorant to see the light /images/boards/smilies/smile.gif

THanks

 

[The Iceman]

Here is a pic of the bottom of the car

I guess when you say that John will tell me what to do with the pro axle bender is to throw it away?

I talked to the guy that finished second in the den this evening. He said he did nothing to his nails or wheels , makes feel that our car was slower then I even thought /images/boards/smilies/frown.gif

When I see that the first thing I think of is Wow look at all that wood that could be routered out and put to the back. This was my Kintergardners (My first Wedge) that was faster than the fastest cubscouts. 3.06 42 best. And below is some I'm working on for Mid-America race. (my updated Wedge) /images/boards/smilies/smile.gif