Build Journal : Shark Track

pratman2 Friday, 8/5/2022

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  This project is a little over a week in the making thus far.  I have 2 young boys who love playing with cars.  I stumbled across die-cast racing on Youtube and thought what a great project for us to do together.  They get to race their cars and dad gets a little more of his big kid energy out as well.  We already had lots of orange track we bought years ago from thriftstores and a Crash Racers figure 8 set from last Christmas.  I have a 3D printer as well to help out.  I mocked up a couple of tracks with what we had and after a few mini tournaments, I decided this would be worth doing.

I'm always on a budget, so I started with building a table from pallet wood from work, which makes up about 95% of the table.  I wanted to have a back wall with studs so I could screw in peices of wood at any height to work as brackets that support the elevated straights.  What I like about this is that when we decide to build a new track we can easily take down the old one and re-use parts.  It got me to thinking all three sides with a pegboard may not be a bad idea.  Overall dimensions are just under 8ft x 2.6ft.

This is in a spare bedroom so keeping the table compact as possible, but also having good speed and as much track as possible was important.


This is the current mockup with (2) Crash Racers sets and orange Hot Wheels track.  This isn't a very original layout as I sort of pieced together ideas from this site using the limited amount of track on hand.  I 3D printed a start gate and (2) SR1 flat 45° curves from Spool Heads.



I will be augmenting this track with more 3D printed parts.  I worked up some pre-visuals in 3D Builder to guage how many peices of each type of track I would need and how well they would fit together.

*The purple piece will not have a divider, I used it for dimensioning only.


I'm currently printing the green banked 180° turn by TBTech which will replace the Crash Racers parts.  I hope this will allow the cars to perform a little better in the first turn and gain a little more speed for the rest of the track.  I think the lane divider will end after the second blue SR1 45° turn, but I may toy with it being the first 45°.


The boys love sharks so I had an idea to possibly try a shark catchbox at the end of he track.  I'm not sure how far i'll get on the theming portion once the track is finished, but I like thinking about the possibilities.  I have other ideas as well for additional features, whatever is built has to withstand the rath of small kids.  At the very least I am planning on using cardboard to "skin" the wood structure once the track is finished which we'll then paint as a rocky beach scene.

Here is a little test video I did in slow-mo (sorry first few seconds are blurry), was able to catch a sweet pass on the back stretch.

Shark Track - Test Footage


Discussion

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Track looks great and the cars seemed to run well.

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GryphonSoul 8/5/22

Looks like a cool track. Going to be some exciting races once it's done. :)

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Rusty 8/6/22

That's shaping up to be a Shark,umm, I mean ,Sharp Track!!!

this is looking pretty darn great to me! I love the 3d renderings of the track. I also recently got into 3d printing and will be printing a few new track pieces of my own. I'm excited to design some custom one-off pieces. Keep us in the loop as the track comes together. I'd love to build a car and send your way for upcoming races :) 


  • There are some pretty good 3D files out there, but still plenty of need for custom peices as there isn't quite a complete system yet that I've seen. The SR1 stuff is a good start, but I'll be customizing some of those files as well to suit my needs. — pratman2
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Mike70 8/11/22

This gives me some inspiration to stop procrastinating and build a track! I appreciate that you gave the dimensions as it gives a better picture of the room needed for a build. Keep up the good work!


  • No problem. I think 8ft long is the best place to start with these parts, but I ended up a little short because the pallet wood I used needed to be trimmed down a little due to edge damage. So the track hangs over a couple inches on the ends. — pratman2
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pratman2 8/12/22

Some progress updates:

Finally got the 180° turn printed and it works quite well, nicely designed.


Also got some 45° curves printed.  I extended the outside wall on this model as a prelemenary step to see how bad I would need them to be banked; answer is quite a bit.  I'll be modifiying these and may also tweek the wall angles to line up better with Hot Wheels and Crash Racers straights. 


I replaced all my old Hot Wheels orange track with new pieces.  These 2ft straights from the dollar store surprisingly made a difference.  They also have less connectors and thus bumps for the cars.  Definitely worth the purchase.


At this point I'm mostly trying to solve the problem of the 45 with these crash racer sets (the middle section of the track).  How I wish we hade true 45's and 22.5's in this set.  Here are a few mockups I have been testing.  The other challenge is to keep the cars at a good speed, but not too fast and create opprotunities for passing.  Any tips here would be great.

This one is essentially what I mocked up first in 3D Builder.  The 45's need to be banked and I think the second one needs to have a center divider so the cars open up on the longer straight to a single lane.


This is adding back in the Crash Racers Turn.  The problem here is I had to add more orange track exiting the banked 180° to make everything fit, but even still the peices are not as squared up as I'd like them.  This is where not having true 45° or 25.5° peices in the Crash Racers set makes things tricky.


Lastly, I think I like this setup the best so far, but again I need at least the first two 45's banked and the second one needs a center divider before opening up into the long single lane straight.

I hope once I get a couple of banked 45's printed I'll be able to hone in on the best version.  But before I can do that I've got to get more familier with Fusion 360.

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Playz 8/13/22

Look nice!

with the 45deg open lane sections they are a nightmare to setup. If they have any speed they will need to be high banked to force cars to turn rather than crash into wall. I kinda gave up and only have one kink left.

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pratman2 9/16/22

This track has been a challenge, a lot more work than I had antisipated.  I think I'm about 95% done on the track.  We've just begun to run laps and see how it's doing and making minor tweaks.  I've learned you can make a track too fast which has been interesting to adapt to.  If I had it to do over I think I could gotten away with the track about 6-8" less in overall height.  I'm also toying with the idea of making a loop after the finish line that would turn onto a pit road inside the track.

I've made the hills up top a little shallower which slows the speed down just a bit, but the cars are much more stable on the track and are less likely to fly off. 


I upgraded the two 45deg. turns up top to a larger 300mm radius (I was using 200mm previously).  This makes for a much smoother turn for the cars with less barrel rolls and jerking.


This is what I've dubbed "the part".  This 45deg. Crash Racers style turn took the better part of two weeks to develop, learning Fusion and making test prints.  It's not perfect, but works fairly well I think.  If I get around to making a 2nd version it will be much better.


One area specifically that needs adjustment is the Crash Racers straight exiting a turn.  You can see the right corner is not sitting flat which clips the faster cars that tend to ride high in the turn.  I may use screws or try super glue to make it flush with the turn exit.


   

I've ran out of Crash Racers track for the final stretch, so I'm thinking of using a curagated plastic section for the last couple of feet.


Here's a couple of test videos for the track and "the part".   The 45deg. turn is still not perfect, some faster cars with higher clearance can have issues at times.

Four car Test Lap

The Part (45 deg. Turn) Test 1

The Part (45deg. Turn) Test 2.

Single Car Test

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Russell 9/20/22

This is so cool to see. Glad the SR1 has been helpful. I've updated the SR1 to the SR2, but haven't posted on Thingiverse yet. I'm happy to send you what I have if you are interested. sales@spoolheads.com (I'm not selling the base SR2 designs so don't worry about me asking for money for them). There are a few tracks out there that are using the SR2 designs and I think you'll like it. I'd even recommend using it for some of the straights as well. 

As far as the 45 degree goes, good for you for diving into Fusion 360. Doing banked turns with grooves is a serious pain. From my own testing, I would recommend making the ramps in and out as long as you can. Short ramps in either cause cars to jump or don't allow for the car to turn naturally enough. Crash racers does it great because the ramp it can be almost a full section of flexible track. 

Another thing to debate is if the slope of the short turn is steep enough, are grooves actually needed? They can help, but they can also be problematic. On the last turn in this video, I tried it without grooves to see how it goes. I'm still collecting data before I decide what I think. youtu.be/YW-rb7IjomA

Keep up the great work!

Russ


  • Thanks for the comments Russ and for the Fusion 360 video you did for your SR1 profiles. It was my intro into Fusion. I do some hobbyist AutoCAD and Sketchup work but Fusion is quite different. I ended up modifying your profile with higher walls to make the flat 45's (after the 1st 180 turn), but I eventually realized my issue was really too short of a radius and too much speed due to the tracks downward slope going into the turns. So I decreased the slope, printed 300mm turns and had much better results, to the point now I want to eventually reprint them with shorter walls as the higher ones tend to slow wider cars down. This banked 45 is my version 1.0 which is basically a compact "true 45" version of the Crash Racers turn. I plan to eventually rework it. I'm hoping to complete the finish line area and move on to other elements for now. The grooves were definitely the most difficult part of building this piece, but I think in the end I figured out a simple but surely unconventional way to create them. I'm sure it's the kind of thing an pro could do in a matter of minutes. One of the things I want to fix in version 2.0 is to slowly slope up/down the in/out ramps as you mentioned. I realized I need a lot of realestate to make that work properly. Cars that ride low on this turn tend to not have issues, but if they are riding high the chance of trouble increases. I may also increase the bank and width a bit in the middle. I'm still deciding on the grooves. When a fast car hits the grooves just right (see below), it slingshots around the turn which makes for a really fast lap. It can work against a fast car riding high as it prevents them from sliding back down in the turn which can cause issues. I kind of want a little bit of unpreditability in this turn, I think it can make for some interesting racing, but the art of it is not having too much, I'd love to keep it in the 10-15% range. Outside of this 45, the biggest thorn has been the joint at the CR turns exiting into the flexible CR straights, mostly in the corners. I've had to raise up the bottom 3rd of my track since my last post to slow it down just a touch to stop cars from riding high in the last 180 turn and clipping the corner of the straight on exit (the close up shot of the track). It helps keeping the straight flat for a few inches with the turn on exit, but it's not a complete fix. Also on a couple of connections I've heated the flat edge of the straight to help it lay flush with the exit, or even sink in a little, but I would still like it better. I'm mainly trying to minimize the amount of bouncing and swerving caused by the track joint on turn exits. Something I didn't catch onto in my mockups before building my table is track speed and how it can be too fast. Im hindsight I probably could have shaved 8-12" of overall height off my track to make it a little more stable. — pratman2
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pratman2 9/20/22

Example of when the grooves help out a car around the 45 turn.  You can see the car enters a but straightens out as soon as it hits the grooves.  Also notice the slight bump on the exit, still working on this too.

Successful pass through the 45

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pratman2 10/4/22

The track is not perfect but it is built.  Still have some revisions to make on the 3D printed 180 banked turn, low or wide cars with long wheel bases have trouble bottoming out or riding the wall (something I wish I had caught sooner), but outside of that most cars run pretty good.  After painting, on to installing LEDs, a digital finish line and some simple set pieces.


I finally have the track skinned with 2 layer cardboard.  Parts of the panels are hot glued together, but all of the pieces are easily removable.  The large side panels via screws, and everything else with industrial grade velcro.  The work turned out to be a little more teadious than I had hoped, but in the end servicing this track is pretty easy just by removing the needed panel.  This will also make LED installation pretty easy too.  I know in the end it won't be the most realistic looking set piece, but that wasn't the goal with small kids who will be playing with this unattended at times.


I ran into some older pirate themed playsets at the thrift store I'll be repainting and modifying for set pieces eventually.   I've expanded my original shark themed idea into more of a deserted island type theme.


This is a velcro example.  You have to use the right amount so the pieces click in place and hold, but too much and the velcro will pull off the outer layer of cardboard.   I have reinforced some velcro pieces with hot glue so they stay put when removing panels.  Hopefully this will hold up pretty well.

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TC3_Hobby 10/7/22

This is a cool build. I know the kids will love it. 


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