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Kabutoni

3D Modeling; The Future

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Kabutoni

You only need working pickups on a trailer when it is pushed by the motor car and used as a control trailer. For the headlights to work, they are needed anyway. The lack of trailer pickups is one of the biggest problems with Tomytec kits as most of the emus are motor-control trailer sets. It's not a surprise that Tomix trailer bogies have the all wheel pickup even on middle cars. If you skip working head and tail lights, then there is no real need for the trailer pickups. By the way, i think you might have to provide a way to route the power from the two powered bogies to the motor, so adding a 3rd seemed like any easy task, unless there is a way to use the pickup strips from the original motor frame.

 

The thing is that I don't want to force the user to cut any original parts. I don't know why, but that just seems inappropriate. However, there are very little options in terms of providing power to the motor. The most simple solution is to provide very thin (0.3mm?) sheet metal strips like in the Tomytec units. If I do that, I might even add these to the unpowered bogie for good measure...

 

Another problem are the usage of bogies made by Tomix (or any other brand), as they are too wide for the low body type of this tram. For this project, I have had to adjust the bogies to be able to slide under the body and create an illusion of being able to fit there. The body has also been made thinner where the wheels might touch the sides.

 

Other than that, your desin looks fairly professional and i'm looking forward to it. The minimum turn radius will be an important value. (considering the R140 and R150 turnouts available on the market)

 

ps: You might want to design an unmotorised base frame for the motorised half, so the model could be assembled as a rolling, but unpowered set. (so it could be used as a trailer coupled to a motorised one)

 

Thank you. I want to make it useful, as well as create a clean design. The turning radius is indeed a problem, as I want it to be able to turn on R120 as well, since that is the minimum turning radius on T-Trak layouts. With this design, it might be impossible though... R140 is however quite a must, I agree, but the original tram doesn't have to negate extremely tight curves, as it was planned as a heavy-rail line, rather than a light-rail line.

 

P.s. the current setup allows for roughly a R313 curve, which is unnacceptable. The turning radius of the bogies are less of an issue than the design of the connection.

 

post-188-0-43460100-1432302290_thumb.png

 

Pak Hantu posted an interesting link earlier with a design that I'll incorporate here. It's a bit complicated, but will guarantee a tight turning radius. If the bodies can negate a tight curve, the bogies should be able to join in as well. If this fails to reach below R140, I'll call it a day on that behalf of the design.

Edited by Toni Babelony
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HantuBlauLOL

Imho you can make the radius even tighter with a wider and rounded shape connector than the one in the link I posted before, the mech I still the same.

 

post-2495-0-25541200-1432309551_thumb.jpg

 

Sorry for my bad drawing, drawing from a touch screen sucks for me. I hope you understand what I mean.

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kvp

An easier solution could be to slightly increase the distance between the cars while keeping the connecting pin centered. That would automatically increase the turning radius of the trailer part. I think this is what Tomytec did with the portrams.

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Kabutoni

Increasing the middle part is maybe the last solution, as it would mess-up the visual balance of the train. Even if it's just a few millimeter. The mechamism is also very different from the Portrams, as the portrams have only two axles per car, instead of 1,5 bogie.

 

I'll experiment a bit more with different connections and adjusting the body for better movement next week.

 

P.s. if this problem has been solved, I will further develop this into an unpowered set as well. For myself, I'd like to have a few unpowered sets as static display models, as well as trailers.

Edited by Toni Babelony

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Kabutoni

A very quick and simple solution. Browsing the web inspired me. Lego jacob bogie designs in particular.

 

Screen_Shot_2015_05_24_at_14_18_46.png

 

The middle bogie needs a redesign to allow for small curves (lower sides and the pins further away from the bogie centre, but this is probably the best, most simple and elegant solution with the least moving parts and least chance of breaking. It however only allows for one driven bogie, unless you install two motors.

 

I was thinking to develop a Modemo style driving system, but that might be too much for this project. The upside as well is that power pickup is possible from both front ends. :)

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HantuBlauLOL

Only one drive bogie? You must put over 60gr of ballast above that bogie to make it capable to climb a 2% grade. Also you need to use traction rubber on 2 of 4 wheels on that bogie. This is what I've done on my BB204.

 

Why not use a cardan shaft to the another end bogie instead?

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kvp

 

Lego jacob bogie designs in particular.

I wonder what designs you saw, since quite a few years ago i was one of the first to use this design on my lego desiro, but i have to admit it, that i copied from the original train. The plus side is that you can make a see/walk through connection this way.

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Kabutoni

Only one drive bogie? You must put over 60gr of ballast above that bogie to make it capable to climb a 2% grade. Also you need to use traction rubber on 2 of 4 wheels on that bogie. This is what I've done on my BB204.

 

Why not use a cardan shaft to the another end bogie instead?

 

With every power unit however, weights are provided that the user can put in the shell to weigh down the train. Because these all differ in size per power unit, I can't make a clip-in system for that. Another solution is lead tape (more dense than ballast) that can be put under and on the chassis, as there is enough space for that. Wheels with traction tires can be exchanged from both bogies into one bogie.

 

A cardan shaft to the other side would mean I'd have to develop a drive system for that, of which I don't know if it would work. This is something I can develop later when these models prove to be successful enough. This requires a new way of thinking, as this is more mechanical engineering, rather than just designing a simple train.

 

I wonder what designs you saw, since quite a few years ago i was one of the first to use this design on my lego desiro, but i have to admit it, that i copied from the original train. The plus side is that you can make a see/walk through connection this way.

 

I must admit I didn't look at the type of train, but rather focused on the bogie design and the technical pictures (digital graphics).

 

Anyway, after some experimenting, I've come to the conclusion that to keep it simple, I needed to move the bodies a few millimeters further apart from each other, but that is okay, since the axle distance is 2mm off from the real thing anyway. It's however the maximum I'd like to go, as 2mm in N-gauge is quite a lot. It now just manages to do R177 at least. Let's see if I can push it to R140!

 

Screen_Shot_2015_05_25_at_11_09_38.png

 

P.s. I managed to push it to ±R140, where the car bodies are touching each other, so it's not really a recommended curve to push them through. T-Trak however has R120, but does not recommend this. R140 is recommended, so this model should function.

 

With this out of the way, I think I can slowly prepare the model for printing. The only thing to add will be the articulated centre part, which I think would be best to make out of black paper, as it's flexible and making a rigid centre part is impossible with this setup.

Edited by Toni Babelony

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HantuBlauLOL

an illustration for the drive mechanism i mentioned above

 

post-2495-0-08114300-1432541362_thumb.png

 

wiring? same as usual.

 

the blue articulated part and the bogie below it is separated from the main chassises,

Edited by HantuBlauLOL

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Kabutoni

an illustration for the drive mechanism i mentioned above

 

attachicon.gifmech tram.png

 

Thank you for the illustration, but this new system is more complex, as it has two pivoting points as opposed to one in the previous design. Due to space constraints, it is nearly impossible to do so. The motor barely fits in between the driven bogie and the pivoting point for the middle bogie, so it is very tight already. Also, this train doesn't need to drag a lot of cars, just one extra if the user wants to be prototypical. Adding weights around both end bogies should probably do the job.

 

There is also the option of adding a 2nd motor, since I will be providing the space for that, if needed when the user wants to negate steep inclines with a single powered unit. Since I will not be providing a finished product, this offers a great choice of freedom for the user, without having to compromise too much on the product.

 

P.s. here are two examples of possible solutions:

- http://www.buntbahn.de/modellbau/printview.php?t=5795&start=0;

http://www.modulbau-nuernberg.de/sven/dt8_10/index.html;

 

The first one is elegant and beautiful, but I fear it's too complex to make in N-gauge. The second is far simpler, is easier to make and thus has more potential.

Edited by Toni Babelony

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Densha

But is it now possible to install just one motor? Because both cars of the motorized version seem to have the gaps for a power unit. I don't really see the point in using two power units for just a tram.

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Kabutoni

But is it now possible to install just one motor? Because both cars of the motorized version seem to have the gaps for a power unit. I don't really see the point in using two power units for just a tram.

 The great thing about 3D modelling is that you, as the user, can order the consist the way you like: M+T, M+M, or T+T. Since the moving parts will be available separately from the body, you can just order the body and the trailer parts you fancy. It'll become something like this then:

 

Screen_Shot_2015_05_25_at_21_16_35.png

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Densha

Hmmm what is the large gap in the green trailer for? What kind of bogie will you use for that?

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Kabutoni

Hmmm what is the large gap in the green trailer for? What kind of bogie will you use for that?

One left over from the power unit. This can also provide power pickup. Just remove the sprockets and worm-drive to ensure smooth movement. Waste not what not of the resources you're using anyway.

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Densha

So the wheels will turn even without being driven by the motor? Just wondering whether the gears would block or not. I don't know if if I'm talking any sense.

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Kabutoni

So the wheels will turn even without being driven by the motor? Just wondering whether the gears would block or not. I don't know if if I'm talking any sense.

Yes, the wheels will move freely if you remove worm drive at least.

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Kabutoni

Saw this on yahoo, reminded me of your original project.

 

I think that is a spray mould in a different material than acrylic. Body originally also made by Niigata Sharyō though ;)

 

By the way, DMM stated the body and chassis of the tram have gone into production, so I expect a delivery of the products this week. Upon receiving them, I will immediately review them and see if they are compatible with the Tomytec products. If all is well, I will put them on sale. In the meantime, please keep an eye on the other developments of Kabuto Models next week! ;)

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Kabutoni

A little bump for some great development on this front: http://www.olo3d.net/

 

This is the first kickstarter I've personally backed because I have very very high hopes for this technology. Already we have machines at home you can pour ingredients into and have a finished product come out (rice cooker, bread maker, washing machine, etc.). The Jetson age is very very near.

 

This is a super cheap smartphone 3D printing device for only $99 as the base cost. I think -even with all the costs of the materials, shipping and such- this will be much cheaper than ordering prints online. Now I can prototype literally overnight and speed up my model train development process to an extreme level. If this proves to be successful, at-home 3D printing may be viable within the next few years and will revolutionise modern living standards. Ergo, we can have any train we want, in any scale, etc. as long as there is a printable digital model and the printing device is large enough.

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kvp

If this technology works, then you can actually build a larger machine using a monitor and any fine servo/stepper mech. The catch seems to be light leakage, so a rectangle grid oled screen might work better than a high angle lcd. The biggest limit seems to be the precision of the lifting mech.

 

Based on the video, imho the trick compared to conventional uv cured polymers seem to be the usage of conventional light and 2d lighting instead of mechanical scanning with a laser. It's like high tech candle making.

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Kabutoni

If this technology works, then you can actually build a larger machine using a monitor and any fine servo/stepper mech.

 

Upscaling this technology is actually the next step of this project:

 

Screen_Shot_2016_03_25_at_12_27_27.png

 

Of course, this technology has to be small and affordable to win the public, gain profits, invest and upscale. I presume the 18' amoled screen will be capable of producing amazing results, hence my very positive view of this project. The possibilities it offers and potential impact it can make on our daily lives is simply blowing my mind. This is something people have been dreaming about for years and we (us humans) are so very close to making these dreams come true.

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cteno4

Very interesting, it will be interesting to see how the actual print resolution look and how sturdy and stable the prints are.

 

Of course it will cost me a lot more as I don't have a smartphone!

 

Almost worth it to get one to give it a whirl!

 

Jeff

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railsquid

What happens if you get a call while it's "printing"? ;)

 

Do they have anything resembling a working prototype? Hard to tell from the very slick website.

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Kabutoni

The website has several videos of sped-up printing. Yes, I also deeply hate these kind of modern websites, but the concept and pricing persuaded me to read everything. This I think is quite representative to it does during a ±3:52:00 print session:

 

 

Also, here is the presentation movie of the Kickstarter, explaining the concept a bit and presenting some of the materials. Please don't get bothered too much by the awkward social engagement at the end of the video. It made me cringe.

 

 

I presume these kind of prints will be more sturdy than FUD/FXD, as there is no printing wax involved that leaves microscopical pockets open in the material. This wax-type printing makes the material (acrylic polymer) extremely brittle. This type of printing at OLO however uses only light curing resin, making a solid object possible.

 

You'd have to print during the night and/or get a second phone and/or use an old/unused phone. Don't put your phone on vibration mode during printing!

Edited by Toni Babelony

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