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3d printed slotcar track.

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  • #16
    Originally posted by HO RacePro View Post
    I watched your YouTube video. Two sections of one-lane track does not a proof-of-concept make.

    And judging only by what I can see on the video, it does not look like the joint between your two track sections is level. If that is indeed the case, it is probably out by twenty thousandths or so. I wouldn't expect to see an offset less than that in your video. Twenty thousandths is a lot.

    Your joiner system seems to work well in two dimensions, but it does not constrain things well in the vertical dimension. You need something rigid to do that.

    The underside of your track sections also tells a story. All the dithering back and forth -- clearly evident in your video -- to build up the structure does not happen quickly. And the walls are thick -- something common in 3D designs. A legacy of the inaccuracies of the early technology. Yes, I admit they can be made thinner. As thin as injection molded? And as straight and smooth? I wonder.

    As for your copper tape -- I have my doubts about being able to maintain contact between your track sections long-term. Good contact requires sustained pressure. Copper tape makes a lousy spring. You can use the elasticity of your track-joining system to provide pressure, but two issues. First, elastomers aren't all that good at being springs either. They tend to take a 'set' over time. Second, a multi-lane track section -- say 4 lanes wide -- will have many strands of copper tape to keep in forceful contact. Unless the ends of the track sections are dead flat across their width you are going to see a lot of variation in their contact force, dimples or no.

    I've built tracks with both copper tape and braid, tracks that have joints. Tracks that have lasted for years, or even decades, without contact problems. Good contact requires forceful contact.

    And every project is entirely about its cost. Bright eyes go dim really fast when you show what their fantasy is really going to cost. A lifetime practicing engineering has proven to me you can never ignore the dollars. You can't ignore time either. Clients get restive about delivery dates, even if they knew the score going in.

    Look, I understand your enthusiasm for the potential of 3D printing. Industries are doing spectacular things with it, and it is slowly emerging from one-off models into volume production of working, finished hardware. It is revolutionizing the aerospace industry. But there is a world of difference between hobby printing and industrial printing. The methods used in industry have gone far beyond the hot-glue-gun-on-a-gantry.

    I understand the potential. But let's see what can be done right now. Try making a simple 4-lane flat oval track.

    And please don't complain it will take too long or cost too much.

    Ed Bianchi
    FYi I have been producing and selling 3d printed functional parts for over 6 years now. I am fully aware of what is capable and not capable of, and how much time and money it takes. This is not a pipe dream. With my experience I would never complain about time or money. I have been thinking about this for well over 3 years now.

    Although I have pointed out several times that what I am doing is not meant to replace what we have, you insist on comparing it to what we have. I will not be making a 4 lane oval, I already have one. I will be making a 1 lane oval, then I will be making a 1 lane rally track. Then maybe I'll make a 3 lane oval, and turns will be high banked and the slots will squeeze together. Maybe I'll make a loop. Maybe I will make turns that actually allow the outside lane to drift without falling off or having to ride up on to a snapped on extension. The point is, I can do whatever I want.

    As I pointed oit in the video, I am going to make a few improvements to the joiner system, and any offset will disappear. Try waving around an HO track or scalextric track the way I did in my video and have it stay together. Let's be real here, my first prototype is already better than any snap together commercially produced track. Tolerences of 3d printing can go beyond .004, depending where on the print, it's all in the design. The height of each section will be exactly the same. On the road surface, there is no offset, it is 100% smooth. I even countersunk the height of the copper so it is perfectly flush with the surface. As I also pointed out, if you are making a permanent track, all joints can be glued with CA, and the copper can be soldered. So worrying about the elasticity of the TPU, is a none issue. Besides, if the TPU lost it's elasticity, and they won't, installing new ones is cheap and easy. Having said that, I would be willing to bet that my joiner will be just as good as scalextric. My current 4 lane oval constantly has conductivity problems between tracks. I am not relying on the copper to act as a spring. It is an interference fit, and will have constant pressure which is more than I can say for scalextric track, or any HO track I have owned. They all have conductivity problems, and need to be cleaned and maintained. My design gives the option for it to be permanent by gluing and soldering.

    Cost is not an issue here, because you won't be able to buy what I eventually will produce. Cost is also not an issue for some of us because I will release the designs for personal use for free. My goal was to come up with an "openslot" system of track, accessories, and even cars. Others will get involved and design their own pieces, and they can all work with each other. I don't really care if I make money with this or not. I already work 2 great jobs and any money I make from this is chump change. This is more for fun, just like the other pieces I produce, which have financed my hobby 5 times over and provided people with parts no longer produced. I am contributing to my hobbies.

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    • #17
      Oh and if you are going to use this for a permanent track, you can glue all the sections together, then run your copper tape after the fact. No joints at all. I can also counter sink the design enough to use braid.

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      • #18
        Originally posted by antslake View Post

        I will be making a 1 lane oval, then I will be making a 1 lane rally track. Then maybe I'll make a 3 lane oval, and turns will be high banked and the slots will squeeze together. Maybe I'll make a loop. Maybe I will make turns that actually allow the outside lane to drift without falling off or having to ride up on to a snapped on extension.
        Cool. We're all eager to see your results.

        Ed Bianchi

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        • #19
          Originally posted by HO RacePro View Post

          Cool. We're all eager to see your results.

          Ed Bianchi
          Thanks, I am eager to share and appreciate your input!

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          • #20
            I would love a section of track that adds some weird squeeze or pinch to a lane, that's the length of 3 normal straights - a Carrera track insert. I can come up with tons of strange track pieces to make. I hear you loud and clear antslake.

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            • #21
              I think your idea is great. I would love to see some one off pieces, that are not commercially available.

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              • #22
                Hi all. Have not read all these posts but what about a slot insert that could be let into track surface with integral braid slots. This would work best if there is a 3D printer that can do continuous runs but not sure if that is possible. Would do away with tricky task of routing running and braid slot unless you can afford CNC. Not sure whether 3D would be best but it could certainly be extruded. Think such an insert may have been available some years back. It would have advantage in that it could be let into a wood track surface with a simple but not absolutely accurate slot (using filler where fit not perfect or attached to a track bed and some sort of filler used for actual track surface. Regards Chas Le Breton

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                • #23
                  Chas, no need to 3D print your slot insert. That is an ideal candidate for extrusion -- squeezing out a plastic shape like toothpaste out of a tube. Extruding a molten plastic -- like, say, vinyl -- is a classic way to produce nearly endless ribbons of a particular shape.

                  And yes, it has been done already. Sometime back in the '60's a continuous plastic extrusion of slot and braid holder was produced and sold. One of the classic slot car magazines published an article featuring a track made with the stuff. The extrusions had 'wings' that could be stapled down to a plywood base. Then plaster was squeegee'd between the extrusions to build up the racing surface. That track was called the "So-Cal Raceway".

                  It was an intriguing concept, but apparently a one-off. I never heard of it, or any other track like it, again.

                  Extrusion is a very fast and far cheaper alternative to 3D printing. The tooling is simple and very inexpensive as such things go. And there are a wide variety of plastics that can be extruded.

                  Trouble is, when you work through the numbers, it is cheaper and easier to rout a track out of MDF (Medium Density Fiberboard). Folks are still intimidated by the traditional way of creating a slot track, but there is a reason -- half a century on -- it remains the dominant method. It just works.

                  Ed Bianchi

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                  • #24
                    Agree with everything you say Eric. Sounds like my memory is better than I thought. I have only completed one track in last 10 years and it was done with CNC. Have just started a rally track but my routing skills need improvement. Was just trying to add to thread. Regards Chas Le Breton (charlesx)

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                    • #25
                      Personally, I wonder why bother making a direct replacement for something that is already quite good? It would make more sense to apply effort to make something better - such as custom borders or custom pieces that integrate into existing systems but offer features that those systems do not. Example: make a garage track that goes along a pit lane and allows cars parked in the garages to drive out onto the track. Or design curved pit lane track pieces or true "S" chicane pieces. Or make border pieces that have built-in safety walls that look realistic. Instead of trying to replace the whole track, come up with pieces that complement the existing systems in new ways.

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