Any recommendations for car design? Help appreciated...

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derbypain
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Re: Any recommendations for car design? Help appreciated...

Post by derbypain »

I tried reaching out to Sporty (Pm) with a question on the rear cant amounts (he does not note the can't amounts for rear wheels in his blog) but have not been able to make contact. Is he still active on the forums? If any of you have an email address and would mind asking is he doesn't want made public we would appreciate.

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gpraceman
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Re: Any recommendations for car design? Help appreciated...

Post by gpraceman »

Sporty moved on and hasn't been on the forum for awhile now.

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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.
derbypain
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Re: Any recommendations for car design? Help appreciated...

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OK. Thanks for letting me know. We have assumed a cant of 2.5 degrees but wasn't sure since his 4 on the floor version goes against what most people describe as their preferred methods today associated with 3 wheel cars.

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Vitamin K
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Re: Any recommendations for car design? Help appreciated...

Post by Vitamin K »

2.5 to 3 should be fine for the rears. It's getting the fronts properly adjusted that is more critical.
derbypain
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Re: Any recommendations for car design? Help appreciated...

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That is what we assumed as well. We are using lighting boys alignment method for the rears and tonight will get the front all dialed in. Question on tuning the front....... If we tune the DFW first to be 3" of drift (like a 3 wheel car) and then add the NDFW to get 3 1/2" total does that sound like the right process of how to perform the tune. This assumes all four will touch which may require several iterations of test as well.

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derbypain
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Re: RE: Re: Any recommendations for car design? Help appreciated...

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derbypain wrote:That is what we assumed as well. We are using lighting boys alignment method for the rears and tonight will get the front all dialed in. Question on tuning the front....... If we tune the DFW first to be 3" of drift (like a 3 wheel car) and then add the NDFW to get 3 1/2" total does that sound like the right process of how to perform the tune. This assumes all four will touch which may require several iterations of test as well.

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Well tuning is complete and the car has been checked in for the district race tomorrow... Thank you all for the advice and great feedback. Here are some pictures right before we turned it in. She weighed right at 5.000 oz, DFW had .59 oz, NDFW had .09 oz, total front weight of .68oz, 3 3/4" of drift on a 4 foot board, all four wheels touching and passed inspection. DFW had just over 3" of the drift.... My son is so proud regardless of how it performs... It took us forever to get it tuned with very small amounts of adjustments and multiple axles to find the right set that created the right drift and four touching. Thank you Sporty for the blog as it certainly was a great additional guidance.

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davet
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Re: Any recommendations for car design? Help appreciated...

Post by davet »

That'll be the coolest looking car on the parking rack for sure! You certainly dotted every "I" and crossed every "T" on that build. Can't wait to see how you guys do.
derbypain
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Re: RE: Re: Any recommendations for car design? Help appreciated...

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davet wrote:That'll be the coolest looking car on the parking rack for sure! You certainly dotted every "I" and crossed every "T" on that build. Can't wait to see how you guys do.
My son and I are as well... He is cautiously optimistic since this was our first effort at rail riding... I am sure we will have fun either way... Thanks again.

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Re: Any recommendations for car design? Help appreciated...

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Well guys what can I say.... Disappointing is a word... Car was sliding back and forth in the rear all over the track about 10-12 ft before the finish. It was fast through transition and then it looked like the brakes were put on. Got the car back and the DFW axle which we glued in place was not in the position we had it after tuning. Not sure what happened and why the glue did not hold in place. We still had a great experience and we still appreciate all your help. There may be another district race in our area in May and if so we might enter just to see if the front wheel placement was the cause. The DFW wheel when we got the car back appeared to be set with toe out rather than toe in. The NDFW appeared to hold as we set it with slight toe out. I think the front wheels started fighting and slinging around the back. I am just not sure what happened but I guess that is racing. Good luck to you all on future races. Truly appreciate your feedback over the last few months.

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davet
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Re: Any recommendations for car design? Help appreciated...

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That's too bad. We had a rear axle slide nearly all the way out after 2 trial runs before a Pack race. We had glued them in just about an hr before the race. We drill 2 holes under the axle and put glue in the innermost hole at each axle then push the axle in. This way the axle is being slid into the glue. One time we installed the axles and then just put a dab in the hole underneath and it wasn't enough to hold it.
We've seen cars get handled pretty roughly at Districts. Maybe a bad seam knocked it out of alignment.
Win or lose, your boy learns something.

You probably came out ahead of the faster teams anyways because you and your boy spent a ton of time together on the car. That, he'll remember for the rest of his life. The loss will be forgotten. The way I see it, you guys had a successful derby. Well done.Image
derbypain
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Re: RE: Re: Any recommendations for car design? Help appreciated...

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davet wrote:That's too bad. We had a rear axle slide nearly all the way out after 2 trial runs before a Pack race. We had glued them in just about an hr before the race. We drill 2 holes under the axle and put glue in the innermost hole at each axle then push the axle in. This way the axle is being slid into the glue. One time we installed the axles and then just put a dab in the hole underneath and it wasn't enough to hold it.
We've seen cars get handled pretty roughly at Districts. Maybe a bad seam knocked it out of alignment.
Win or lose, your boy learns something.

You probably came out ahead of the faster teams anyways because you and your boy spent a ton of time together on the car. That, he'll remember for the rest of his life. The loss will be forgotten. The way I see it, you guys had a successful derby. Well done.Image
Thanks Davet... We did have good time building. We met a guy who owns a 42' 4 lane best track. He asked us to come over so we could see how it would have run based on the original settings. We may take him up on it to see but either way you are absolutely right. Successful either way.

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Re: Any recommendations for car design? Help appreciated...

Post by Speedster »

derbypain, Did you by any chance roll the car down a level surface after the race to see which way it drifted? The DFW definitely sounds like the problem.
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Re: Any recommendations for car design? Help appreciated...

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Yes.. We did... After the race it was drifting to the right (DFW was on the right side and tuned to drift left about 3 1/2") and you could see how the NDFW and the DFW were fighting (wobbling) . I believe that due to weight and transition it did not show up on the track until the latest 10 - 15 ft of the track in the straight away. We have fixed it when we got home and plan to take to a track to see how it would have run. Back wheels were aligned using Lightening Boys rear alignment and appeared to hold as glued.

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