Improving the stop section

Discussions on buying, building or rehabbing a race track. Topics like plans, materials, tools, construction, finishing, commercially available tracks, and so on.
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Curse You Red Baron!
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Re: Improving the stop section

Post by Curse You Red Baron! » Thu Jan 17, 2013 11:27 am

Ickabod, your idea sounds like a good one, as long as the stuff you use doesn't grab the stop section contact surface... if it grabs, then you could have the car flipping. They sell grip-eeze (sp?) in a tube to put on the sole of toddler socks so they can walk without slipping - I still have a tube from my boy's younger days and I'm thinking about trying it on an experimental car.

We used to have a very poor stop section, cars bouncing etc, so I constructed some simple ramps with fuzzy velcro on top to raise (1/4 inch) and slow the cars as they slide on the velcro while in the stop section, and then finally hit the foam. Worked really well the first couple of years, most cars didn't make it to the foam at all - but the velcro is getting a bit worn and faster cars can bounce if the foam at the end is set up poorly, so I've been thinking about sandpaper or something like that to help slow us down... it's probably time to replace the velcro anyways, or build something better.



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FatSebastian
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Re: Improving the stop section

Post by FatSebastian » Thu Jan 17, 2013 12:04 pm

Curse You Red Baron! wrote:They sell grip-eeze (sp?) in a tube to put on the sole of toddler socks so they can walk without slipping - I still have a tube from my boy's younger days and I'm thinking about trying it on an experimental car.
Interesting! I have read about people using "puffy" or "dimensional" craft paint to create a non-slip surface for fabrics; this would be an interesting experiment with derby cars. It would certainly be better than sandpaper!



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Re: Improving the stop section

Post by rpcarpe » Thu Jan 17, 2013 12:32 pm

Agreed!
Sandpaper vs. Anything creates grit/dirt/something you DON't want near your precious wheels and axles.


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Stan Pope
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Re: Improving the stop section

Post by Stan Pope » Thu Jan 17, 2013 1:00 pm

Curse You Red Baron! wrote:... but the velcro is getting a bit worn and faster cars can bounce if the foam at the end is set up poorly...
"Bounce" is why I moved from "foam" to "memory foam."

As I understand the physics, "bouncing straight back off of a hard surface" requires that the car absorb about twice the energy as "stopping dead at a hard surface." Foam changes the energy dissipation but I suspect that the relationships are the same... If the car displaces foam 1/2" and bounces back vs. car displaces memory foam by 1/2" and stops.

Our experience using memory foam at last year's district races was positive. I think that there were no incidents of cars doing other than "stopping dead" and I think that there were no instances of damage, even to my grandson's "more delicate appearing" rail car.

Next job ... figure out how often the memory foam pads need to be replaced.


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Re: Improving the stop section

Post by rpcarpe » Fri Jan 18, 2013 9:42 am

I have four foam pads that get used each year... I'll let y'all know when they stop stopping. Uh, when they fail.


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Re: Improving the stop section

Post by chromegsx » Fri Jan 18, 2013 10:19 am

Any tips on where to get scraps of memory foam?



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FatSebastian
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Re: Improving the stop section

Post by FatSebastian » Fri Jan 18, 2013 11:35 am

chromegsx wrote:Any tips on where to get scraps of memory foam?
Earlier in this thread I suggested a pillow as an inexpensive source. We went that route because we weren't able to find another (free) source.

We have seen memory foam used in the packaging of some shipped electronics, but nothing that was of adequate size and shape for this application. Some mattress stores may have free samples, but again, our experience has been that these samples tended to be of inadequate size and shape.



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Re: Improving the stop section

Post by DerbyDash » Fri Jan 18, 2013 1:05 pm

gpraceman wrote:
DerbyDash wrote:Thanks for the videos. Based on the comment I made in my other post about this issue, we are seeing some of the same things...cars flipped up or over and off the track. We have seen various parts of cars (wings, spoilers, etc.) get broken off when this happens. They have put blankets at the end of the stop section but it didn't stop the issue from happening.
I assume they removed the plastic end stop, correct?

The end stop protects the edges of the aluminum from getting dinged up, but I would not want cars to hit it. Best to remove it.

Correct but the blankets at the end have NOT helped. I hope they are able to use something else this year to stop the cars from getting damaged.



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SirStorm
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Re: Improving the stop section

Post by SirStorm » Fri Jan 18, 2013 1:35 pm

An interesting note about "memory foam". It has been found that memory foam absorbs energy in relationship to speed. The motorcycle industry uses it as flexible armor in protective pants and jackets. At high velocity it becomes ridged an yet softens as the velocity slows. I have tested this in relationship to my knee pads and it holds true. My padding is 1 inch thick an yet does not bottom out if I "fall" to my knees on a concrete floor. There is no bounce.

Stands to reason, if you must have a bumper at the end of the track, memory foam is a good choice.



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Re: Improving the stop section

Post by whodathunkit » Fri Jan 18, 2013 7:20 pm

DerbyDash wrote:
gpraceman wrote: I assume they removed the plastic end stop, correct?

The end stop protects the edges of the aluminum from getting dinged up, but I would not want cars to hit it. Best to remove it.

Correct but the blankets at the end have NOT helped. I hope they are able to use something else this year to stop the cars from getting damaged.
I like what was said in chapter 2 of your new book.
about a flat bottom car haveing more brakeing area vs a car that has an arch between the wheels.

I haven't ever tryed this: but i wounder if a rubber spray coating like flex seal would work if it were to be sprayed on maybe in 2 patch areas under the car body.


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Re: Improving the stop section

Post by rpcarpe » Tue Jan 22, 2013 1:24 pm

Answering the previous question: I got the memory foam from a manufacturer in my area. They might be willing to ship to you, hit my e-mail link and let me know if you're interested.

Maybe check for an upholstery place in town?


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