Adding a Friction Brake to an Old Track

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Oddzilla
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Adding a Friction Brake to an Old Track

Post by Oddzilla » Wed Sep 07, 2011 10:37 am

A buddy game me a two lane wooden track that he built a while ago. It's still in great shape, but the end is just a foam box. I'm working up plans to add a friction brake on the end, but what would be the ideal length?

I have it designed at 3 feet, but will that be long enough? Currently, I have the farthest end raised (in the design) to 1/2" so the gradual raise from track height goes over 2 1/2 feet in length. Would it be best to design it at 4 feet? Is 3 ok?

Here's a prelim design (which was measured and designed to attach to the end of the current track).

Image

I've got a better drawing made up, just only have this one in image form. The design itself isn't a problem. It's just the length of incline that I want to make sure I get right the first time so I don't have to redo it.

Although, it would be neat to see how far a car could launch. :D



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Re: Adding a Friction Brake to an Old Track

Post by psycaz » Wed Sep 07, 2011 11:35 am

Since you're just into the design stage, you may want to design in side walls, end wall, and a wall seperating the two lanes. Makes sure cars stay in their individual lanes in the stop section and don't damage each other should a wheel come off.



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Re: Adding a Friction Brake to an Old Track

Post by Darin McGrew » Wed Sep 07, 2011 12:56 pm

My (admittedly limited) experience is that the stop section is almost never too long, and almost always too short.

If I were buying a track today, then I'd buy an extra stop section to create a double-length stop section.

If I were building a track today, then I'd have an entire section of track (the same length as all the others) dedicated to the finish gate and stop section. Thus, all but about a foot of this end section would be the stop area.

Yeah, it should be overkill. But that extra length in the stop section is relatively cheap, and will save a lot of grief over the years.

I'd also build a stop section where the track drops out from under the car, rather than where the center rail rises. I think the cars can start braking more quickly and more safely that way.

I like psycaz's suggestion about walls. I'd make them thin, somewhat flexible, and easily replaceable though. And I'd make an extra set or two, and save the templates and specs in a safe, well-labeled location so more sets can be made when needed.



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Re: Adding a Friction Brake to an Old Track

Post by Scubersteve » Wed Sep 07, 2011 4:51 pm

I built a 4' stop section for my church's track where the bottom drops out and the guide rail is 1" tall and covered with foam weatherstrip. It also has a 2x2 end rail covered with a double layer of foam. I thought 4' would be plenty...it wasn't. A week ago at an exhibition race my own car hit the end so hard that the weight came out of it. Darin is right, the longer the better.


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Re: Adding a Friction Brake to an Old Track

Post by FatSebastian » Wed Sep 07, 2011 9:18 pm

Oddzilla wrote:Would it be best to design it at 4 feet?
The short answer would seem to be "yes".
Oddzilla wrote:I have it designed at 3 feet, but will that be long enough?
A slightly different question. Starting-gate height is a big factor determining how much energy must be dissipated by the braking section. 4 feet high is typical; if your starting gate is lower than usual you might be able to get away with a shorter braking section. The "grippiness" of the braking material is another factor, usually some kind of high density foam or rubber strips. Another factor is how quickly maximum pressure is applied to the belly of the car (short versus gradual rise), as you note. Still another (lesser) factor is the length of the staightaway.

Bestrtack notes that their stop section is 40" (3 1/3 feet) long, but my impression has been that, as PWD cars and tracks have become faster over the years, vendors have been tending to make their braking sections longer. This post contains a photo of the newer Microwizard stop section, which appears to be much longer than our older wooden Piantedosi track of similar design.

With all of that said, I agree with the earlier posters that 4 feet (or more) should be a better design than 3 feet. Also I would think that you might want the wheels to raise off the track relatively early, so that the maximum pressure is applied to the belly of the car for as long as possible. This may require a less gradual rise. I have only built one braking section before, and it was for a low-height practice / demo track, so it was not a very demanding application.



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Re: Adding a Friction Brake to an Old Track

Post by BallBoy » Wed Sep 07, 2011 10:24 pm

I have a BestTrack and the stop section is as FS indicates above. It is generally very effective at stopping cars, however I do occasionally have a car that goes the distance on the stop section. If you are going to err, please err on the side of making the stop section too long rather than too short. I also agree with Psycaz's suggestion that there be dividers between the lanes to prevent derailing cars from bumping into each other.



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Re: Adding a Friction Brake to an Old Track

Post by rpcarpe » Fri Nov 04, 2011 7:03 am

Some tempur-pedic type foam for the end of a brake section makes a great absorber of all that energy.


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Re: Adding a Friction Brake to an Old Track

Post by rkniffin » Thu Jan 05, 2012 10:04 am

First off, I want to thank everyone. I've learned alot, my son has done fairly well and we've been able to help some other people with what I've read on this site.

A couple of years ago, we added a stop section that had the wheels drop off, but the cars slid across way too fast. Last year, we put strips of rubber toolbox matting on the stop section, but it just is not durable. By the end of the race, it flaked enough to start being an issue. Can anyone recommend a material I can put on top of the stop section lanes that works well to stop the cars and is somewhat durable (will at least last a single derby).

Thanks,

Rich



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FatSebastian
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Re: Adding a Friction Brake to an Old Track

Post by FatSebastian » Thu Jan 05, 2012 10:29 am

:welcome: Rich!
rkniffin wrote:Can anyone recommend a material I can put on top of the stop section lanes that works well to stop the cars and is somewhat durable (will at least last a single derby).
This topic seems close to that question. (I suppose that toolbox liner can vary greatly in quality - have you tried different kinds?)



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Re: Adding a Friction Brake to an Old Track

Post by rkniffin » Thu Jan 05, 2012 11:20 am

FatSebastian wrote::welcome: Rich!
rkniffin wrote:Can anyone recommend a material I can put on top of the stop section lanes that works well to stop the cars and is somewhat durable (will at least last a single derby).
This topic seems close to that question. (I suppose that toolbox liner can vary greatly in quality - have you tried different kinds?)

Thanks for the quick reply. We have not tried any other material than the toolbox liner we tried last year. We did a little testing just to see if it would work last year and it did stop the cars pretty good. Just didn't hold up. We use the track once a year, then it goes to someone's home to be forgotten about until the next year. I really don't have a place to set it up, nor really the time or resources to test a bunch of different materials. I figured if someone had found something that worked well, I would just get it and try it this year. It's my son's last derby, so i wanted to try and get it resolved before leaving the pack.

I will try the McMaster-Carr stuff and see how that works.

Thanks again. Much appreciated.

Rich



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Re: Adding a Friction Brake to an Old Track

Post by rpcarpe » Thu Jan 05, 2012 12:00 pm

Here's an idea... sandpaper.
I use a small square (1"?) of 26 or 40 grit sandpaper glued between the rear axles to help brake the car when it comes to the 'wheels' off stop section. You could put strips of 26-40 grit paper down on the strips, and then give everyone a small (1") piece for their cars.

Harbor Freight sells 26 grit, check your Sunday paper or a Reader's Digest for a 20% off coupon. I've never seen their sandpaper go on sale with other coupons.


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Re: Adding a Friction Brake to an Old Track

Post by Darin McGrew » Thu Jan 05, 2012 12:09 pm

Our stop section uses the non-slip safety tape. It holds up great (it's designed to be walked on), although I haven't compared its stopping ability for derby cars to other materials.



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Re: Adding a Friction Brake to an Old Track

Post by FatSebastian » Thu Jan 05, 2012 12:21 pm

rpcarpe wrote:Here's an idea... sandpaper. [...] You could put strips of 26-40 grit paper down on the strips...
:/ Might gritty sandpaper damage the car's nose and underside (and possibly other areas if a car bounced and landed unfavorably)? Also, sandpaper has a tendency to wear away such that I wonder if there is risk of quickly reduced efficiency, not to mention getting a bit a sand in a wheel bore.
rpcarpe wrote:I use a small square (1"?) of 26 or 40 grit sandpaper glued between the rear axles to help brake the car...
:| I used to think that was a nifty construction tip until I became personally responsible for maintaining a track. (Such practices may have even contributed to rkniffin's flaking problem.)
Last edited by FatSebastian on Thu Jan 05, 2012 12:55 pm, edited 1 time in total.



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Re: Adding a Friction Brake to an Old Track

Post by gpraceman » Thu Jan 05, 2012 12:54 pm

I've seen the rubber non-skid strips at Lowes and Home Depot that would likely work.


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Re: Adding a Friction Brake to an Old Track

Post by ciodude » Fri Jan 06, 2012 2:53 pm

I'll chime in on a few things. I agree with Darin and others that have said the longer the better. Cars are getting faster and traveling further. Psycaz’s idea for containment walls or a barrier between cars is a fantastic idea! I’ve seen more cars damage after the finish line (mainly from cars bouncing back) than I have in the lengths before. Please no sandpaper – I think the risk of damage to the car is too high.



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