newbie ? "missile" pics added

[davet]

Hello all. My son and I built our first ever Pinewood Derby car last year and went to Districts with help from the posts on this site so thank you. His rig was a camouflage 8-wheeled tank with soldier on top waving a flag.


My question is this: I ran graphite last year and would like to try the oil this year. I bought a bottle of Ny-Oil but haven't opened it yet. If I use Ny-Oil or Krytox will I have trouble with graphite contaminating it during the races as most everyone else will be running graphite? Advice on it's use is welcomed also.

[Speedster]

Hi davet. Welcome to DT. Guess What? I don't know anything about oil. However, would you send a picture of your son's car for us to see? Thank you.

[TimInOhio]

Hello all. My son and I built our first ever Pinewood Derby car last year and went to Districts with help from the posts on this site so thank you. His rig was a camouflage 8-wheeled tank with soldier on top waving a flag.


My question is this: I ran graphite last year and would like to try the oil this year. I bought a bottle of Ny-Oil but haven't opened it yet. If I use Ny-Oil or Krytox will I have trouble with graphite contaminating it during the races as most everyone else will be running graphite? Advice on it's use is welcomed also.

Welcome to Derby Talk, davet, and congrats on your success so far. You will find a LOT of info and help here at Derby Talk.

There have been reports of cars running oil that are contaminated by the graphite on the track from other cars. Oil contaminated with graphite will work against you. But, if you can run oil in a non-graphite environment, you will generally find faster times. I've never used Ny-Oil, but the Krytox I have used is very fast.

Good luck.

[davet]

Best of Show. Not bad for our first car. He did the major cuts, designed the look, painted and polished axles.

[Speedster]

Nice looking vehicle. He did a good job. Thanks for the picture.

[rpcarpe]

Nice tank! Glad you guys figured out the raise the extra wheels.
Our town has a good deal of military/federal gov't so we see a tank or two every derby.
Usually, the tank design does NOT lend itself to good speed.

Welcome to DT, keep up the good work!

[Darin McGrew]

I like the photo! Thanks for sharing!

As far as graphite contamination of oil, a lot depends on how much loose graphite the other cars are shedding. If the check-in crew doesn't accept cars with excess graphite, then there won't be as much to contaminate your oil. But I've seen people try to check in cars with loose graphite everywhere.

[FatSebastian]

As far as graphite contamination of oil, a lot depends on how much loose graphite the other cars are shedding.

In a couple of scout races that I managed which were dry-lube only, I found it necessary to use a telescoping duster to occasionally clean off the track, as the track would develop a visible layer of very fine dust. (It was a fun spectacle to see someone trot out and run along the track pushing the duster.)

[Ickabod]

a couple of scout races that I managed which were dry-lube only, I found it necessary to use a telescoping duster to occasionally clean off the track, as the track would develop a visible layer of very fine dust. (It was a fun spectacle to see someone trot out and run along the track pushing the duster.)

No video?!

[davet]

Sounds like I should stick to the best powdered lube. I was going to oil because I sold our treadmill and I'd hate to get graphite all over the treadmill at work. I polished the axles to 3000 then used jewelers polish.

[Speedster]

Me again, davit. Lots of questions. Did you race for speed at the Districts or were you entered for "Best Design" only? Did you place 1st or 2nd in the race in your Pack? We don't know your skill level. If you are just beginning I would recommend Troy Thorne's new book, "Building the Fastest Pinewood Derby Car." A couple of geniuses from Derby Talk have helped Troy write this book. Oil is not a "Silver Bullet". If you know how to prepare a car with it (which I think is not easy) it might give you an edge but everything else has to be perfect. Tell us about yourself and your experience in building a car. What is it your son wants to accomplish? Does he want nothing but "Speed" out of his car? There will no doubt be info with the "search" feature that will answer a lot of your questions.
If you are presently in adult Pro racing, please disregard all of the above.
Cheers
Speedster

[FatSebastian]

I was going to oil because I sold our treadmill and I'd hate to get graphite all over the treadmill at work.

Using a treadmill is not recommended because it causes unnecessarily wear. An inclined tuning board is preferred.

[davet]

I used the treadmill because it didn't contaminate my wheels. After the Pack race I relubed and tuned it on a board but it seemed that no matter how much I swept or wiped it I kept getting dust sticking to the wheels. I may varnish or seal the board and use it again.

I am an amateur for sure. Never built a car before but got a book and used many tips from that. I'm not sure where we ranked in our Pack. The times were being flashed so fast I couldn't keep up and we never got a Pack rank list. At Districts during our Tiger's race there were 2 heats where all 4 cars were .5-.6 seconds faster than the next fastest cars. They were running heats so fast that nobody said anything. Our Den leader and I noticed the first heat then when it happened again it was with a different set of 4 cars where all again were .5-.6 seconds faster. I think there was a malfunction in the timing and possibly caused by camera flashes at the finish line. When the Wolves ran it happened again but this time an official noticed and re-ran that heat. The second run of that heat gave average times. I explained what happened to my boy and he was disappointed but I tried to turn it into a learning experience. At both Pack and Districts there was a large following for our tank as it was the only car with more than 4 wheels. When he took it out of the box at weigh in at Districts it seemed there was a fair number of parents (dads) hanging out there watching what was coming in next. He took it out and immediately we hear, "It's got 8 wheels. He's got an unfair advantage!" I wondered if he thought I had 8 motors hooked up to it. I watched the official monitoring the area where the cars were stationed and he picked it up several times and showed to different parents wanting to see it. It then got on to winning races. I don't know who enjoyed it more, my boy or me.

My boy decides what the car design will be. I only tell him that we aren't going to cut the top of the block off then glue some plastic model onto it. Whatever he picks we carve and try to make that as fast as we can. I only have a bench grinder, 3/8" drill, drill press and a sander. Our hollowed out missile design this year was turned on the bench grinder. It weighs 2.0oz without wheels or paint yet. It's what he thinks looks cool.

Our race is next Saturday but we've all been sick so we're behind schedule. Should we polish passed 2000-3000 grit? Which powder lube should I use? I've read that with powder if the axles are too smooth it doesn't last that long. Sorry, it's long but I'm reliving last year.

[FatSebastian]

He took it out and immediately we hear, "It's got 8 wheels. He's got an unfair advantage!"

You might enjoy this then.

I only have a bench grinder, 3/8" drill, drill press and a sander.

No saw?

It's what he thinks looks cool.

That's what matters most.

Should we polish passed 2000-3000 grit?

Here's a related topic. Note that grit definitions vary depending on the standard, so it ambiguous to call out grit numbers without also citing the convention being followed. I would say that most systematically polish to ~2 microns with Micromesh down to 12,000 grit (or close to that; a few go much further). Go as far as you child is willing.

Which powder lube should I use?

Are you asking about graphite versus something else? Or which brand of graphite? Or...? Lots of advice on DT about lube; I'm not sure where to start!

[sporty]

Davet,


Welcome to Derbytalk and thanks for sharing the pictures and a summary of where you are at and want to be at.


My initial thoughts, is that, at this point and time, your child is focused on looks and not so much about speed. and there is nothing wrong with that.

But it does, help provide us with enough info. So we try and not push onto you the other major factors in pwd racing.


I think, since you are primarily done with the build. Im not so sure there is a ton of info we can provide that will help you this year. but some is still available for you.


It is easy to get over whelmed, with so many different ways and processes that can improve a cars performance. Some stuff out there is what I feel a bit off the mark of the realm of what really works and does not work.


Much of what people share on here and including myself, comes from my own testing and expierence, but it is also related to how I do things. So thats a important part in the process.

Meaning, just tossing out a lube to use, is useless unless you are able to or willing to, do to the process'es that are prefered with that lube.

On average, many people tend to like hobb-e-lube, max-v lube, hodges lube and another, not allowed to mentioned here.

Those seem to be the top 4 prefered graphites. But a key factor in all of them or for that matter any lube, is how you prep the wheel bores.

You asked about axle prep, different sand paper, has different grit ratings. so mentioning 2,000, 3,000 or say 4,000 grit. may not be a true indication of what micron level it is. many of us prefer a 1 micron level or lower. in regards to polishing of the axles.

Then I have often ran into many times over the years, that people can tend to not use the sand paper correctly and often end up going backwards on the polishing part of the axles.

A few examples, applying to much pressure, not moving the sandpaper- leaving it in one spot to long. not using enough water or to much water or using the piece of sand paper long past its effective sanding range.

So, as you might now wonder, what the heck, but also in the process, understand why we sometimes ask some pretty odd questions.

The key to a better performing car, depends on many areas of the car, from good axle wholes, alignment of those axle wholes, tuning of the drift, if you know what a rail rider is and if you run a rail rider. or a straight runner.

Then you have axle size, axle prep, wheel bore prep, wheel o.d. prep. good wheels, bore size. so forth.


it sounds more complex then what it is.Sadly these days, parents tend to turn to kits or pre built or pre prepped wheels and axles.

Often these short cuts, do provide a quicker and easier solution to those parents and families, but most often, they dont know what they are getting or what makes it better or if it indeed is better than doing it yourself.

So, i recommend, you develop a plan, of what you and your son would like to do, for the short term and the future. tools and what you really want to learn or beable to do and understand.


I say this, another example, you can do a good bore prep and graphite prep, but if those wheel bores are not all the same size and are larger size then what many prefer. the car will not perform as well as it could.


Now the good thing, is a 2oz car before even adding weight, is a car, that is nice and pretty, but it is handicapped with not being able to add so much weight to it already in key areas.

So, what I mean, is that dont fret it being perfect, untill you are ready to get into the 10/12 gram range of car weight. Dont mean either, give up. But realize you can shoot for perhaps a top 10 or under finish or best of show or best of design.

Wish a race fast approaching, look to pibk up and learn a few things you can do now and focus more next season or after the race is over with.


What do you do for bore prep ? what grpahite have you been using ?


Sporty