Home is Where the Track Is

My only steady hobby is racing my RC car. It’s a blast to drive, but I am pretty terrible at it.

Now that I can keep it off the walls (mostly), I am working on laying down consistent laps. I ham having making and significant improvements because I can only make it out to Mike’s one day a week to practice. Couple that with the fact that they’re changing the track layout almost weekly and you’ll undertand my dilemma: I’ve basically plateaued.

Since I am not able to make it to the track as often as I’d like, I’ve decided to try and bring the track to me.

My Christmas toy this year was a Mini-Z Sports. I opted for the Sauber C9 since I am a fan of the Sauber F1 team.

Anyway, the idea behind getting the Mini-Z – besides having another cool toy :) – was to turn laps at home. Sure, it’s not 100% like-for-like with my 1:10 F1 car, but they are both essentially pan cars. Here is a lengthy, but thorough description of what a pan car is, for those who are interested.

Long and short, they should drive similarly. Even if not, I would still be refining my hand-eye coordination, as these Mini-Z’s are pretty quick and nimble.

Now that I had the car, it was time to focus on making a track for my garage – taking into account these key limitations:

  1. The end product had to aim for as high of a Wife Acceptance Factor as possible
  2. Make setup and teardown as quick and simple as possible
  3. Part of hitting #1, above, is amount of room the solution takes up when put away
  4. Try to replicate an ozite carpet surface, as closely as possible
  5. As always, minimize cost
  6. Finally, I’ve only got 13′ x 21′ of usable garage space to play with

Options Considered

With that in mind, it was time to focus on the two key items for the track:

  1. Track surface/material
  2. Track walls/dividers

Track Surface

Being the obsessive person I am, I spent way too much time reading many accounts of others’ experiences with their home tracks. Ultimately, a few front-runners for the track surface emerged.

  1. RCP: This is far and away the #1 track surface for Mini-Z’s in the US (though carpet is the choice in Asia)
  2. EVA Foam Tiles: EVA Foam is the stuff they make those interlocking tiles for kids playrooms, gyms, etc. from
  3. Rolled rubber/neoprene/etc
  4. Canvas
  5. Tar paper
  6. Carpet

RCP

RCP is popular because it has high levels of grip. It also gets cool points for the Lego-like “snapability”, not to mention the rails to keep the cars on the track. RCP is the most professional-looking out of all of these options, hands down.

I passed on RCP for a few reasons, though:

  1. Cost: Professionalism costs :) A typical RCP setup is to buy two of these “Wide L” setups… at $210 a piece retail. I don’t think that includes shipping, either, but I might be wrong. Just seemed wrong to spend ~$500 for a track to drive a $160 car on it.
  2. Space: One Wide L set would be too simplistic of a track, but I didn’t have room to accomodate all of two Wide L’s. So, I’d be paying for track that I couldn’t use.
  3. Grip: Having seen these cars in action at Inside Line Racing, I can say they stick to RCP pretty damned well. That doesn’t fit with my goal of replicating the medium levels of grip found on the ozite at Mikes.
  4. Limited layout options: The shape of RCP tiles is pre-defined. A straight is a straight. All curves are 90 degrees (unless you spend $70-140 for one 45 degree turn). This limits your options on track layouts.

On a side note, the owners at Inside Line Racing are super cool peeps. Definitely stop by if you’re in the South Bay area, even if it is just to watch some laps.

EVA Foam Tiles

The story on EVA tiles was a mixed bag. You had some people saying that they were nearly identical to RCP and others – who also seemed to be higher-skilled drivers, BTW – saying there was a major difference between the two.

In either case, there was a fair amount of prep work that would need to go into the EVA foam in order to get the mold release agent (read: grease) off of the tiles before you could run on them.

EVA didn’t make the cut because:

  1. Cost: Looking around many places on the Internet, the best deal I could find for EVA tiles was in the ballpark of $0.85 per sqft. That’s about 2x the cost of what I ultimately settled on.
  2. Setup/Teardown: I would be looking at 60 or so 2’x2′ pieces that I would have to assemble every time I wanted to drive. Given that I will only have an hour or two here and there, I’d rather spend that precious time driving.
  3. Storage: At 3/8″, we’re talking 7.5 cubic feet (if I’m doing my math right) of tiles to store. Either way, we’re talking a minimum of 2′ in from any of the garage walls, which is quite a bit when you only have about 20′ total width… and you’re trying to fit two cars along with enough space between to actuall get out of the cars.
  4. Limited layout options: Same issue as RCP

Rolled Rubber/Neoprene

These were interesting options, but they ultimately didn’t pan out for a few reasons:

  1. Grip: This would likely be even grippier than RCP. They use something like this in Europe, so there is precedent, but recall that I am trying to approximate carpet-levels of grip.
  2. Cost: Best I could find was about $1/sqft
  3. Durability (maybe imagined): The rolled rubber – at the $1/sqft price point – was chunks of cut rubber, which concerned me about how it would fare being rolled and unrolled
  4. Material width: The widest roll I could find – again, at a reasonable price point – was 6′, but that much more than $1/sqft. I was not keen on having to lay two or three runs of this together and hoping there isn’t a big seam, having to tape them together, etc.

Canvas

I came across a couple of posts where people mentioned using canvas for their track. Honestly, this wouldn’t have occurred to me, but they universally agreed that grip levels were really great.

I passed on canvas because:

  1. Grip: Sounded like the grip was too good
  2. Difficult to lay flat: There would be seams and creases in the material
  3. Durability: On a per sqft basis, the price was similar to my final solution, but I was concerned how well it would hold up over time
  4. Material width: Ultimately, there wasn’t a cost-appropriate setup that would have fit my garage without having to tape multiple sheets together, etc.

Tar Paper

I read many accounts of people using tar paper for Mini Z tracks. The issues here were several, and similar to the other “rolled” options:

  1. Longevity. Tar paper (“roofing felt”) simply isn’t made to be rolled and unrolled. Plus, it tears easily.
  2. Cost
  3. Material Width
  4. Grip: From what I read, sounds like the grip would have been too good

Walls/Rails

RCP and (somewhat) EVA foam come with their own rails, which is nice. That said, both are limited in their shape, thus limiting layout options. Besides, they were out of the running due to cost, anyway.

Other posts turned up some good ideas, but here are the ones I passed on:

PVC Pipe

  • Too expensive
  • Inflexible (literally, and in options for layout)

Pool Noodles

  • Same issues as PVC, save flexibility
  • Much more expensive, unless I found them on clearance or something

Garden Hose with Sand

Some people said they used garden hose with sand inside, just to give the hose weight and some “positionability.”

“Final” Product

Ultimately, here is what I settled on:

  • “Commercial,” low-pile indoor/outdoor carpet
  • Garden hose, with dowels to keep the hose straight and give them some weight

Carpet

Carpet won out for the following reasons:

  1. Cost: $0.49/sqft, which was about 1/2 the closest other material
  2. Width: Carpet is available in 12′ rolls, which uses almost all of the 13′ available
  3. Ease of setup/teardown: Roll out and roll up :)
  4. Closest resembelence to ozite
  5. Can get locally, thus not pay shipping costs (which are non-trivial)
  6. This style of carpet is what Kyosho themselves use
    • The folks at Kyosho were kind enough to tell me the following about their carpet:
      • Manufacturer: Shaw
      • Style: “Putting Green” is the name, though it’s not a grass-like pile – and it’s black, not green :)
      • Bought at: Lowes

In the process, I learned more about carpet than I rightly should. Here are the key takeaways:

  1. Ozite is pretty damned expensive – and must be ordered in large quantities, plus comes in 6′ wide rolls
  2. Mini Z’s are pretty sensitive to the height/pile of the carpet, as fibers start binding wheels, get caught in gears, etc
  3. There are three main carpet materials: polyester, nylon and Olefin. You want Olefin for RC cars, as it is the most resistent to generating static electricity.
  4. Ideally, you want a needlepunch carpet, as this minimizes the about of fuzz that comes off the carpet
  5. The outdoor-style carpet has a different type of backing vs “normal” carpet (more on this in a bit)

Here is the carpet I chose, for those who are interested.

An Unexpected Discovery

Reading further, it seems that you really need foam tires to run Mini-Zs well – and I don’t have foams at the moment.

Indeed, the rear was pretty squirly with slicks on the carpet. The front seemed planted, but the rear as all over the place – which is the opposite of my experience at Mike’s, where the rear sticks well, but the front pushes if I take a corner too hot.

I noticed that the backside of the carpet was a rough, semi-rubbery surface. Seemed kind of like canvas in a way. So, on a whim, I flipped the carpet and ran on that.

Oddly enough, the grip and handling were pretty similar to my F1 car at Mike’s.

Here’s a picture of the underside of the carpet to show you what it looks like:

IMG_1265

 

It looks fuzzy as all heck, but the car mainly just comes off with dust – which I understand is an issue with RCP, as well.

Garden Hose

I opted for a hose that was not necessarily the cheapest for a few reasons:

  1. Diameter: It seemed that 3/8″ inside diameter hose woudln’t keep the car on the track
  2. Finish: The cheaper hoses had a rubbery finish, which I suspected would have not let the car glance off the “wall”
  3. Color: Vein, but I liked the dark gray over green or tan :)

I ended up getting 100′ of 5/8″ inside diameter hose, as I needed enough for the perimeter (12’x2 + 20’x2 = 64′) as well as making the walls inside the track.

Initially, I thought I could straighten out the hose by bending it opposite to the way it was rolled up. This helped, but it didn’t work that well. It did not take long for the hose to revert back to a curve/circle.

As mentioned above, I was thinking about using sand in the hose to weigh it down, but I feared that would not address the curling issue. So, I opted to get 4′ x 1/2″ dowels to keep te hose straight. The 3/8″ were 2/3 the cost, but they seemed a bit too flimsy for the job, as the hose was pretty robust and didn’t want to be straight :)

Originally, I just planned on using circles of hose at the corners – kind of like the “dots” you’ll see at most on road tracks. But, I found that the dowels can be used not just to make a run of host straight, but you can use them to hook runs of hose together – including the circles of hose. This allows me to make pretty clean, curved corners, like so:

Of course… Duct Tape

The one major gap with my creation is that any free-floating pieces of hose don’t have enough weight to keep from being knocked around. Even those that are hooked together can be moved over time.

For now, my answer to those issues is duct tape. Keeps with the simple setup/teardown criteria and gives it that DIY feel :)

Here’s a pic of the end result. Again, this is just one of an endless possibility of layouts.

IMG_1252

Future Plans

The main thing I need now is a timing solution. I tried using Easy Lap Counter. It actually worked pretty well, but it unfortunately (and oddly) doesn’t announce the lap times.

Knowing immedialtely how a lap went is the best feedback tool to know what you’re doing right – and wrong. Not having that really diminishes the value of this setup.

So, my next plan is to use the Ping))) sonic rangefinder with my Arduino and modify the sketch for the “Flip Side Dio” so I can use the excellent Flip Side Lap Counter software.

Ultimately, I might retool it to use RFID, but since it’s just me for now, this should work just fine.