Improving the stop section
- Curse You Red Baron!
- Master Pine Head
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Re: Improving the stop section
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.
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.
- FatSebastian
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Re: Improving the stop section
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!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.
Re: Improving the stop section
Agreed!
Sandpaper vs. Anything creates grit/dirt/something you DON't want near your precious wheels and axles.
Sandpaper vs. Anything creates grit/dirt/something you DON't want near your precious wheels and axles.
My wife started a new support group... Widows of the Pinewood Derby.
- Stan Pope
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Re: Improving the stop section
"Bounce" is why I moved from "foam" to "memory foam."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...
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.
Stan
"If it's not for the boys, it's for the birds!"
"If it's not for the boys, it's for the birds!"
Re: Improving the stop section
I have four foam pads that get used each year... I'll let y'all know when they stop stopping. Uh, when they fail.
My wife started a new support group... Widows of the Pinewood Derby.
Re: Improving the stop section
Any tips on where to get scraps of memory foam?
- FatSebastian
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Re: Improving the stop section
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.chromegsx wrote:Any tips on where to get scraps of memory foam?
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.
Re: Improving the stop section
gpraceman wrote:I assume they removed the plastic end stop, correct?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.
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.
Re: Improving the stop section
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.
Stands to reason, if you must have a bumper at the end of the track, memory foam is a good choice.
- whodathunkit
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Re: Improving the stop section
I like what was said in chapter 2 of your new book.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.
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.
What type of automobile can be spelled the same forwards & backwards?
Re: Improving the stop section
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?
Maybe check for an upholstery place in town?
My wife started a new support group... Widows of the Pinewood Derby.