Test Track

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
User avatar
ohiofitter
Master Pine Head
Master Pine Head
Posts: 693
Joined: Sat Feb 03, 2007 10:30 am
Location: Uniontown,Ohio

Test Track

Post by ohiofitter »

I'M Going to make a test track,,,I know the starting mechanism is a simple lever action But does anyone have a pic of this so I can study thank you
GrantnHayden
Master Pine Head
Master Pine Head
Posts: 114
Joined: Sun Mar 11, 2007 8:11 pm
Location: Fenton, Michigan

Re: Test Track

Post by GrantnHayden »

User avatar
gpraceman
Site Admin
Site Admin
Posts: 4926
Joined: Fri Jun 20, 2003 12:46 am
Location: Highlands Ranch, CO
Contact:

Re: Test Track

Post by gpraceman »

GrantnHayden wrote:Follow this link:

http://www.rahul.net/mcgrew/derby/track/
I wouldn't recommend that start gate design, since it is held closed and takes human power to open. The problem comes when the human is not consistant opening the gate, which can actually affect the race times (if using times scoring). I saw this personally with the old style Piantedosi start gate (fortunately, they redesigned it).

A better design is one that is held closed with some latch or catch and then pops open when released. Then the human only needs to release the latch/catch. This type of gate will open far more consistantly.

http://home.simplyweb.net/bosworth/trac ... CK_RELEASE
http://home.simplyweb.net/bosworth/trac ... m#pictures
Randy Lisano
Romans 5:8

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.
quadad
Master Pine Head
Master Pine Head
Posts: 494
Joined: Wed Jan 23, 2008 11:51 am
Location: SE, WI

Re: Test Track

Post by quadad »

I think that link has a great example, but it looks to me like too much work for a home test track. :(

Any other simpler ideas that would still be repeatable and not make the cars jump ?

Thanks !
GrantnHayden
Master Pine Head
Master Pine Head
Posts: 114
Joined: Sun Mar 11, 2007 8:11 pm
Location: Fenton, Michigan

Re: Test Track

Post by GrantnHayden »

I am going to modify the design that I posted above and this next URL is to another thread here that shows pics of another design. Have fun!

http://derbytalk.com/viewtopic.php?t=37 ... race+timer
User avatar
cubdad
Pine Head
Pine Head
Posts: 99
Joined: Wed Dec 26, 2007 6:59 pm
Location: New York, NY

Re: Test Track

Post by cubdad »

Here are pictures of the starting gate I use. It was quick and easy to do, especially as I did not have to drill the Aluminum plating.

The gate is normally open and you must use your finger to keep it closed until you are ready to release the car.

Track times are sensitive to lubricating the main dowel were it sits in the 2 uprights. Track times are also sensitive to the strenght of the rubber band. However, once the dowel was treated with graphite and I used a very strong rubber band the track times became very repeatable and stopped drifting from day to day. Increase rubber band strenght till the vertical dowel snaps against the horizontal retainer with a solid thwap reminiscent of a mouse trap. The cam was made by drilling wood stock with a hole saw then using a spade bit to make and offcenter hole in it. It must be glued to the horizontal dowel or it will drift and cause maddeningly weird test results trough out the day.

I will one day get to making a proper connection to the switch.

Image


Image


Image


Image


Image
GrantnHayden
Master Pine Head
Master Pine Head
Posts: 114
Joined: Sun Mar 11, 2007 8:11 pm
Location: Fenton, Michigan

Re: Test Track

Post by GrantnHayden »

That is very nice. Great creativity and workmanship! Simple too. I like simple.

- Todd
User avatar
joe
Master Pine Head
Master Pine Head
Posts: 554
Joined: Sun Jan 23, 2005 12:09 pm
Location: Kansas
Contact:

Re: Test Track

Post by joe »

How cool that is! I just have to shake my head at the ingenuity. Did you make the aluminum track too!
User avatar
cubdad
Pine Head
Pine Head
Posts: 99
Joined: Wed Dec 26, 2007 6:59 pm
Location: New York, NY

Re: Test Track

Post by cubdad »

Thanks. Hope you find parts of use.

I should also mention that it turns out that the dowels are not straight (who knew?), so after measuring and cutting everything very accurately, the gate was binding slightly on release cause the dowel was little warped. That was fixed by decreasing the OD of the dowel a bit for the part that went into the far upright.
User avatar
cubdad
Pine Head
Pine Head
Posts: 99
Joined: Wed Dec 26, 2007 6:59 pm
Location: New York, NY

Re: Test Track

Post by cubdad »

and to answer your question Joe, the track plating was ordered from betacraft here:

http://www.betacrafts.com/catalog/default.php

The material underneath is plastic (vinyl?) 3"x1" house trim from Home depot sold in lenghts like 8' at Home Depot.
Derby Dad for 3
Apprentice
Apprentice
Posts: 22
Joined: Fri Jan 18, 2008 1:02 pm
Location: Freehold, NJ

Re: Test Track

Post by Derby Dad for 3 »

Cubdad, that is fantastic track for testing! It is exactly what I am looking to do.

Did you find the plating easy/natural bending in creating the tansition? Also, how did you fasten the plating to the plastic/vinyl underlayment?

Anymore pics you'd be willing to share (i.e., transition, finish)? They help the technically challenged people like me a lot!

Thanks!
Mike
User avatar
cubdad
Pine Head
Pine Head
Posts: 99
Joined: Wed Dec 26, 2007 6:59 pm
Location: New York, NY

Re: Test Track

Post by cubdad »

Derby Dad for 3 wrote:Cubdad, that is fantastic track for testing! It is exactly what I am looking to do.

Did you find the plating easy/natural bending in creating the tansition? Also, how did you fasten the plating to the plastic/vinyl underlayment?

Anymore pics you'd be willing to share (i.e., transition, finish)? They help the technically challenged people like me a lot!

Thanks!
Mike
Both the plating and the vinyl trim wanted to bend into a smooth catenary, that was easy. I used #6x3/4 pan head phillips screws (I meant to use #8) to fasten the plating to the vinyl. The #6 seem more than strong enough. I'll post pictures in track section in a little bit. Thanks for asking. Hope its of use.
User avatar
cubdad
Pine Head
Pine Head
Posts: 99
Joined: Wed Dec 26, 2007 6:59 pm
Location: New York, NY

Re: Test Track

Post by cubdad »

Derby Dad,
I just put info about the test track in the track section of this board.
Thanks.
User avatar
ohiofitter
Master Pine Head
Master Pine Head
Posts: 693
Joined: Sat Feb 03, 2007 10:30 am
Location: Uniontown,Ohio

Re: Test Track

Post by ohiofitter »

Cubdad can you add on to this track if you wanted to.
User avatar
pack529holycross
Master Pine Head
Master Pine Head
Posts: 555
Joined: Wed Dec 26, 2007 4:25 pm
Location: Dr. Phillips, Florida
Contact:

Re: Test Track

Post by pack529holycross »

I would say that the starting mechanism on the BESTTRACK is very efficient, and the entire "construction" manual shows you detailed pictures of its function - Hinge, pins, Angle bracket, springs, and lever to hold it in the closed position. very simple and very reliable.

Nicholas
Post Reply