"Pinecar" brand wheel modification help

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WI_Dad
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"Pinecar" brand wheel modification help

Post by WI_Dad » Tue Feb 21, 2012 7:56 pm

Sorry in advance for the long winded post but I figured if I was going to ask for help I should provide as much information as possible.

I'll start with what brought me here. My son, Ryan age 12, is in is 4th year of Boy Pioneers and we have been working hard on his car for the last few weeks. We have had a lot of fun working together and the kid is much more mechanically inclined than I ever was at 12. We are using almost the exact same design that won his Train's race, took 2nd at District, and was a participant at International last year.

So we had "time trials" last Sunday night which is a bit of a misnomer as the timing software was not running and the kids simply had a chance to test run their cars. We did quicky pick out who the competition was and tried to get on trial runs against them. We have some competition this year and split heats with a couple of the other top cards.

The car is pretty much done at this point using the Pinecar kit we were given. The single piece axles are highly polished and very well glued into the body so doing anything with them would really be difficult. The car is right on 5.00 oz of weight and puts the center of gravity at about 7/8 of inch forward of the rear axle. It is a 3 wheeler with the driver side front not making contact and the car pulls to the left about 2 inches per 4 feet on a flat, level surface.

The only thing we have not done is any wheel modification. It never crossed my mind as we had acheived good success last year without any. We have two really good wheels (by Pinecar wheel standards) in the back, the wheel touching in the front is decent and the "floater" is iffy at best. We run on an alluminum rail track.

I have been reading about possible wheel modifications on here for hours and am not sure what would be best for out situation. I saw the video about making "razor" style wheels with a drill press and a sharp chisel. I think I could pull that off if I practiced a couple times first.

Is this the best possible modification for our car? Is there any way I can ensure the "roundness" of our wheels without a lathe? I would be very grateful for any help.

Last year's international race was in Minnesota and we just couldn't make the drive so we have no idea how his car fared except that the got a participant ribbon. This year's international race is at our own church and would give him the chance to race 3 times if he makes the cut. He has such a blast racing, all I want to do is give him a shot at it.

Again, sorry for the long winded post. And I have read old threads and used the search function but it honestly only raised more questions as it pertains to our car.

Our rules are pretty liberal as far as wheel modification with the only restrictions being :
5. Bearings: Wheel bearings and bushings are prohibited. Metal or
plastic washers and spacers are considered bushings and not allowed.
Axles and wheels provided in the kit must be used. Wheels
may be modified. Axles may not be cut.
may not be cut.
7. Design: The finished product must have 4 wheels.
8. Attachments: All cars must be made from a normal official Pinecar
Derby Kit sold by the National Office (4 wheels, 2 axles and pine,
wood block). Paints, stickers and decals may be added. No other
commercially prepared products may be added to the design of
the car. Pipes, windshields, fenders and other attachments may
be made from parts of the original block that were cut away.

Complete rules here: http://www.lutheranpioneers.org/linked/ ... 20size.pdf" target="_blank

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FatSebastian
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Re: "Pinecar" brand wheel modification help

Post by FatSebastian » Tue Feb 21, 2012 8:17 pm

:welcome: WI_Dad
WI_Dad wrote:I saw the video about making "razor" style wheels with a drill press and a sharp chisel. I think I could pull that off if I practiced a couple times first. Is this the best possible modification for our car?
Your rules say "wheels may be modified," so if you could make razor wheels then that should be a huge benefit! Not having any experience with Pinecar wheels, I still might offer two potential cautions, however.

1. Your rules say "Wheels must remain outside of original block width." I'm sure this rule exists to ensure that cars fit over the center rail, yet there would be the question of whether having the hubs recessed into the body would violate that rule.

2. The Pinecar wheels do not have a solid sidewall but are truly spoked. I wonder if they would survive the cutting process without significant warping or breakage. At the very least, use a really sharp chisel and work patiently. (I also wonder if a hacksaw blade might work instead of a chisel? :thinking: )
WI_Dad wrote:Is there any way I can ensure the "roundness" of our wheels without a lathe?
The homemade razor wheels call for a Pro-Wheel Shaver, which is a "hand lathe". Of course that could/should be used to ensure roundness.



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whodathunkit
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Re: "Pinecar" brand wheel modification help

Post by whodathunkit » Tue Feb 21, 2012 8:54 pm

Max-v also had.. or did have a wheel accuracy / wheel concentricity gage by derby tek tools at one time.
That worked on Awana -BSA- Pinecar wheels also.

That would measure the "roundness" (known as run out) within one-thousandth
of a inch. (I haven't seen it on his site lately.)

Good luck with your pinecar wheel mods. WI_Dad.
Last edited by whodathunkit on Tue Feb 21, 2012 9:13 pm, edited 1 time in total.


What type of automobile can be spelled the same forwards & backwards?

tjeffrey
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Re: "Pinecar" brand wheel modification help

Post by tjeffrey » Tue Feb 21, 2012 9:01 pm

Wow! I finally feel like I can offer something!!! I've been racing with the pinecar single axle kit for several years. Since I have 3 kids close in age I've built a bunch of these cars. Our rules are similar in that the wheel mods are OK.

Here is my triage of your situation. If you are not willing to pull out the axles and partially redesign the car do NOT go for razor wheels. They are without a doubt the fastest option but they also require several modifications to the car and axles. Here is why, if you cut off the tread you have essentially moved the inner surface of the wheels out and wider. This means you have a lot more room for movement before a wheel hits the center rail - you don't want that, bad things can happen. So, to counteract this effect you need to inset the area of the car where the hubs touch by 5/32". This means using a 1/4" forester bit centered over the axle hole or slot and moving the wood back 5/32". This now brings the outer edge of your newly shaped razor wheels back to an appropriate distance from the center rail. The next problem you have is that the axle now is too long! Since you've moved your wheels toward the center of the car, the ends of your axle will extend too far. This will now leave you with too much gap for your wheels. If your axles where not glued in the solution would be to cut your axle on one end and then make a new groove with a file for your little plastic hub cap.

So, given the axles are glued in and the alignment set, my suggestion number 1 is to lighten the wheels and then add some weight to the back of your car. We used lightened wheels on my daughters car last year and she was third overall out of 485 cars. She only lost to her two older brothers who had razor wheels! The benefit of lightening the wheels is that you will be first down the ramp. Assuming you have done all the other stuff well you'll keep that lead on the straightaway. I've lightened them two ways. The first is the best, but has not been received well on this forum, is mount a router upside down underneath you drill press table. Put a 1/4" flat bottomed bit into the router. Put your wheel mandrel into the drill press with the open part of the wheel facing toward the router. Now, carefully line up the depth of cut in two dimensions - a) determine the depth to move the drill press down and onto the router bit. You can take out some of the back wall but don't go too far. b) you need to determine how much of the tread to take out. You can be pretty aggressive. Now turn on the router and drill press, make sure that as you look at the drill press you have this system set up with the router bit on the right side of the wheel, IE - the router and drill press are running in opposite directions. Now SLOWLY move the wheel onto the router. Too fast and you warp the wheel. The problem here is that the natural runout of the drill press will result in an out of balance wheel. This can be solved by stopping the process, loosening the mandrel, rotating the wheel on the mandrel a quarter turn, and running it again. Do this three times on each wheel and you should be good. It's not a perfect wheel, but it is much lighter and quicker than the kit wheels. I suggest a couple test wheels first, once you get the system set you can crank out a bunch of wheels in a hurry.

If you don't have the equipment I just described, put the wheel into the mandrel and then hold an exact knife on the inside edge of the tread. It takes some time but you can pull a lot of plastic and weight out of those wheels. You will need to do some balancing afterword. The best solution I've found is using clear nail polish.

Lightened wheels are the way to go.

One additional suggestion is some fenders on the back. They can be made, painted and glued onto the car without too much hassle. There are some people that have much better instruction than I on how to do them.

Best of luck!



WI_Dad
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Re: "Pinecar" brand wheel modification help

Post by WI_Dad » Tue Feb 21, 2012 9:17 pm

Thank you for the welcome. :mrgreen:

I would agree that having the wheels outside with hubs recessed would fit the letter of the rules if not the intent. However, it would create a problem with the one piece axle in that the hub cap would leave a lot of play between block and cap. This could be avoided by pushing the cap through the end of the axle and applying a dot of glue to hold it in place. Unfortunately, going that route at this stage would be very difficult as the axles have been hot glued in place.

As far as cutting without damaging or warping the wheel, I had to sand some width out of a wheel on a car two years ago. My first attempt failed and I damaged the wheel spokes. On my second attempt, I was more patient, applied very little pressure and let the tool do the work which took time but gave a good result and ended up with a wheel about 2/3 as thick. Had to do this to make up for the mistake of sanding the hub down to far and having the wheel rub on the side of the car.

I like the hacksaw blade idea and will try both tools. I have a few extra wheels from last year's build that I can practice on before giving it a go on the race wheels.

My concern with the razor wheels is lost stability if I don't get it right and lost time due to wiggle. The cars natural pull might keep it toward the rail and prevent some of that problem. Right now, with the car as is and about 6 test runs, the car runs well down the track and with no noticable wiggle.

The way our stages of competition are set up, each boy can automatically compete in the local and district races with the top 6 from each district going to the international derby. I would like a chance to do some test runs but I don't know if that can happen.

Worst case scenario, we can try the razor wheels at the local race and if they fail, go back to regular wheels for district and take our chances. We will just have to make sure that any weight we add to offset reduced wheel weight can be easily removed.

And, a note to self. Be sure to read more info on this board before building next year's car. ;)



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FatSebastian
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Re: "Pinecar" brand wheel modification help

Post by FatSebastian » Tue Feb 21, 2012 9:25 pm

tjeffrey wrote:...the solution would be to cut your axle on one end...
His rules say "axles may not be cut." :(



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Re: "Pinecar" brand wheel modification help

Post by tjeffrey » Tue Feb 21, 2012 9:30 pm

Sorry, missed the axle rule. Yes, you can cut the end of the hub caps off and push them into the axle to hold the wheel in place. My concern is that you are cutting the hub, if you cut the inside of the wheel hub down you will have very unstable wheels. The proper solution is to inset the hub area of the car but since you are glued in place I would not go the razor route at all.

As far as hack saw versus chisel. The chisel is much better. The corner of the chisel is actually what works best. The hack saw creates too much heat and melts the wheels.



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Re: "Pinecar" brand wheel modification help

Post by FatSebastian » Tue Feb 21, 2012 9:33 pm

WI_Dad wrote:the axles have been hot glued in place.
Although we've never done it, reportedly hot glue "can be removed" through reheating. :unsure:
Last edited by FatSebastian on Tue Feb 21, 2012 9:50 pm, edited 1 time in total.



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Re: "Pinecar" brand wheel modification help

Post by whodathunkit » Tue Feb 21, 2012 9:44 pm

WI_Dad wrote:
As far as cutting without damaging or warping the wheel,

I like the hacksaw blade idea and will try both tools. I have a few extra wheels from last year's build that I can practice on before giving it a go on the race wheels.

Worst case scenario,
I like useing a crafters razor saw to cut the wheels down with.
Just take your time and spin the wheel slower in the drill press so it is not
heating the wheel up and melting it.
And let the saw do the work cutting.

Makes for a smoother cut on the wheel and it's whats works for me. ;)
I just cut these down.. just a few min ago..
Image
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Last edited by whodathunkit on Tue Feb 21, 2012 10:21 pm, edited 2 times in total.


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WI_Dad
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Re: "Pinecar" brand wheel modification help

Post by WI_Dad » Tue Feb 21, 2012 9:57 pm

I appreciate all of the input. At this point, I am going to avoid removing axles. It could be done but I don't want to risk damage to the finish which my son is very proud of and I don't think he has the patience to take a step back in the building process at this point.

It seems the razor wheels involve some risk of losing time further down the track that could offset gains at the start.

tjeffrey, your sugguestion about removing material from inside the wheel sounds like the best way to go. I do have access to a router and I think I follow your instructions but I just don't think I could pull that off without ruining every wheel I have. I can give removing material with an exacto knife from the inside of the tread a shot and will play around with that this week to see how it goes.



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Re: "Pinecar" brand wheel modification help

Post by whodathunkit » Tue Feb 21, 2012 10:27 pm

;) I was going to add lighting the wheels as well.. but once more tjeffrey was faster at it then I was.
But I'm going to add put on some gloves also so you don't cut your fingers.
Good Luck to you WI_Dad.

Whoda.


What type of automobile can be spelled the same forwards & backwards?

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Re: "Pinecar" brand wheel modification help

Post by Darin McGrew » Wed Feb 22, 2012 2:21 am

WI_Dad wrote:8. Attachments: All cars must be made from a normal official Pinecar
Derby Kit sold by the National Office (4 wheels, 2 axles and pine,
wood block). Paints, stickers and decals may be added. No other
commercially prepared products may be added to the design of
the car. Pipes, windshields, fenders and other attachments may
be made from parts of the original block that were cut away.
Wow... I've never seen rules that strict about what decorations are allowed before. I find it especially surprising that the rules are so strict about decorations, given how lax they are about wheel modifications. Every one of the 25 cars I've built would have been disqualified by that rule.

I wonder whether self-adhesive googley eyes would count as "stickers"... or self-adhesive pom-poms... or other self-adhesive (but not flat) items at the craft store...



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Re: "Pinecar" brand wheel modification help

Post by whodathunkit » Thu Feb 23, 2012 10:51 pm

Darin, If the car will only competing in craft comptition, it may exceed
the width noted for race cars.


What type of automobile can be spelled the same forwards & backwards?

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Re: "Pinecar" brand wheel modification help

Post by Darin McGrew » Fri Feb 24, 2012 12:50 am

whodathunkit wrote:Darin, If the car will only competing in craft comptition, it may exceed
the width noted for race cars.
:scratching: I don't understand how that relates to the rule limiting the decorations to paints, stickers, decals, and non-commercially prepared items.

According to this rule, Lego drivers are prohibited. Using the label from a real product (e.g., candy bars, Tabasco bottles) is prohibited. Gluing a real pine cone to a car is okay, but a fake pine cone bought at the craft store is prohibited.

And yet, they can modify the wheels any way they want. Am I the only one who finds this odd?



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Re: "Pinecar" brand wheel modification help

Post by macd » Fri Feb 24, 2012 9:18 am

I agree the decoration restrictions seem over the top.
I think perhaps even a real pine cone could be considered illegal. It would have to be a fake pine cone made only from the scraps and sawdust cut from the original block.

I think the author of the rule wanted to keep out "kit cars", but the language goes too far.



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