Vitamin K builds a Track! (slowly)

[Vitamin K]

I also need to figure out what I'm going to mount the first section of the track to, since that one will need to flex. Maybe 1/4" plywood or even 1/8" masonite? (with wooden crossbeam supports at the end and various locations along the length.

Have you considered just making another "ladder section" with less rigidity? For example, 1x lumber is stiffer when the longer dimension is vertical, but more flexible when rotated horizontal. There are also composite products like PVC trim that are thin, lightweight, and sometimes more flexible than wood (and although a little more expensive, it doesn't splinter and is maintenance free, and it wouldn't require tons of material if making a ladder shape).

I guess I need to do some experimentation. The piantedosi tracks are 3/8" thick and they bend fine, but anything thicker than that, I worry won't bend easily, even if cut in a ladder configuration.

The PVC is definitely a possibility, but I'm not entirely convinced that thin masonite would be a bad idea at this point, since I really just need something for the track sections to sit on, while the wooden cross pieces provide support and attachment points.

[FatSebastian]

I guess I need to do some experimentation. The piantedosi tracks are 3/8" thick and they bend fine, but anything thicker than that, I worry won't bend easily, even if cut in a ladder configuration.

Yeah, I wasn't suggesting 1x lumber specifically for this application, just citing that as a familiar example of how lumber orientation changes rigidity. There are likely thin lumber options on the trim aisle of your favorite big-box store, some of which may be composite, but I guess it just depends on how much curvature is desired...

The PVC is definitely a possibility, but I'm not entirely convinced that thin masonite would be a bad idea at this point...

Still other options might include thin luan plywood, or wooden paneling. I have personally found fiberboard less satisfying to work with than plywood / wood paneling. Masonite (HDF) is great for something that needs to bend a lot, but I cannot speak to its durability in the long run (I seem to recall that it sags / buckles more than plywood under its own weight if not supported, and may not like humidity). But if going the HDF route, pegboard is an even lighter version of fiberboard... The underlayment and track panels together are going to be more rigid than either one individually.

Excited to see what you come up with !

[Vitamin K]

No real progress to report yet (getting ready to travel this weekend), but I did find some footage of a "Challenger" track on Youtube.

Is it me, or the starting ramp as shown in the standard design here really long?


https://youtu.be/EGWNptT34X0

[FatSebastian]

Is it me, or [is] the starting ramp as shown in the standard design here really long?

It is long relative to both the Best Track and the Micro Wizard Freedom (you can see a drawing of the latter in Micro Wizard's Track Assembly manual). I wondered if the Challenger track in the video might have been built with the transition a little closer to the finish line than the standard plans dictate; but if so, it can't be much closer based on the positions of the latches.

In principle, a longer incline increases the time to reach maximum speed, which would make for slightly longer elapsed times - not necessarily a bad thing for a ~3 second event. And it's also probably helpful to lessen the severity of the transition angle and makes it easier to see the cars from the audience.

[exoray]

In principle, a longer incline increases the time to reach maximum speed, which would make for slightly longer elapsed times - not necessarily a bad thing for a ~3 second event. And it's also probably helpful to lessen the severity of the transition angle and makes it easier to see the cars from the audience.

I suspect it might marginally lower the number of 'non-finishing' cars as well on a normal-length track, but that track looks extra long...

If that is a standard-sized basketball court, there are 56 feet between free-throw lines, meaning that track from the start gate to the finish is about 62ft and I suspect that to be the case as that 62ft estimate would align with an 8-section Challenger build vs 7 sections...

[Vitamin K]

In a few places in the plans, it states that the minimum recommended length for the Challenger track is 46.5', due to how fast the track is, which it attributes to the polished aluminum surface.

But I'm wondering if maybe they suggest so long a track because it literally uses two of the sections on the initial slope. It's a really long time on the incline.

I only intend to use a single section for the incline, bent into a circular curve.

[FatSebastian]

the minimum recommended length for the Challenger track is 46.5', due to how fast the track is, which it attributes to the polished aluminum surface.

Track speed will be primarily governed by the height of the starting pins above the flat, usually in the neighborhood of about 3-1/2 to 4 feet high for most track designs. (Beta Craft track sections come in bundles of six, which appears to be the minimum length they recommend?)

I only intend to use a single section for the incline, bent into a circular curve.

Using only a single 8' section, back-of-the-envelope geometry suggests that the transition would need to be totally level after roughly a six-foot distance (depending on how high the track starts). It seems like it would require a rather steep starting incline...

The curves of the Piantedosi Oars and Freedom tracks use two sections fastened together, with the latter half of the second section contacting the ground to level out the transition. Had those designs not added dead weight to pull down the curve, their incline lengths would look more like the Challenger.

[Vitamin K]

the minimum recommended length for the Challenger track is 46.5', due to how fast the track is, which it attributes to the polished aluminum surface.

Track speed will be primarily governed by the height of the starting pins above the flat, usually in the neighborhood of about 3-1/2 to 4 feet high for most track designs. (Beta Craft track sections come in bundles of six, which appears to be the minimum length they recommend?)

I only intend to use a single section for the incline, bent into a circular curve.

Using only a single 8' section, back-of-the-envelope geometry suggests that the transition would need to be totally level after roughly a six-foot distance (depending on how high the track starts). It seems like it would require a rather steep starting incline...

The curves of the Piantedosi Oars and Freedom tracks use two sections fastened together, with the latter half of the second section contacting the ground to level out the transition. Had those designs not added dead weight to pull down the curve, their incline lengths would look more like the Challenger.

Oh, really? I guess I'm misremembering how those tracks go.

You don't happen to know where I might find a diagram of the Freedom track sections?

[Vitamin K]

I had originally thought to build the first section of the track on a more flexible base, while having the other sections be more rigid, but now it seems to make sense that I would, at the very least, need to have the first and second sections of the track flexible.

For consistency, I think the entire track ought to be built the same. Just need to come up with a mounting schema for the track sections that allows the flex I'm after.

[FatSebastian]

You don't happen to know where I might find a diagram of the Freedom track sections?

This earlier post points to the location of Micro Wizard's assembly manual, which has a diagram showing where the section joints reside on an assembled track.

This post shows a picture of the first mated joint, raised off the floor.

[Vitamin K]

You don't happen to know where I might find a diagram of the Freedom track sections?

This earlier post points to the location of Micro Wizard's assembly manual, which has a diagram showing where the section joints reside on an assembled track.

This post shows a picture of the first mated joint, raised off the floor.

Excellent! Thanks!

[Vitamin K]

I think that these plans will prove quite useful as a rough guide to follow for the starting section measurements and such. The basic design of the starting gate is not bad either (gravity powered, like I prefer).

[FatSebastian]

I think that these plans will prove quite useful as a rough guide to follow for the starting section measurements and such.

The Cub Scout Leader How-To Book might serve as another dimensional guide for the starting section (See pg. 6–28, or 242 of 288); I believe it was the starting point for the Piantedosi Oars wooden track.

[Vitamin K]

So I have been chewing on how I want to approach this track build. I'm sort of stealing inspiration from both the Challenger plans and some of the well-known wooden track plans. I really want the gentle curve of the Freedom-style track, versus the "fixed curve" of the Best Track style.

Right now, what I am considering is to have the track sections resting on 1/8" masonite (hardboard) with sections of wood below to anchor the bolts into (the masonite sandwiched between). I would like to retain the aluminum "tongue" and the draw-pull clamps for joining the sections.

Here are some drawings of what's in my head. (Roughly).

Detail on the track joins



Layout of the track sections



(larger link: https://imgur.com/rLQ9nmh )

One thing I'm grappling with a bit is how to get an approximation of the shape of the track for vertical legs of a given height and position. Is there any geometry solver that might help with this?

Anyhow, open to any thoughts, remarks, criticisms, etc.

[exoray]

One thing I'm grappling with a bit is how to get an approximation of the shape of the track for vertical legs of a given height and position. Is there any geometry solver that might help with this?

I can pretty much guarantee there are some online sites or CAD packages, or even art packages that will do that, for me, I'm old school, I would probably build a scaled track out of tagboard and mock up what I wanted it to look like, as long as you kept scaling to a standard architectural scale you could then measure off the mockup and do a temporary full sized test after that...