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Just came back from BrickCon where I showcased my model of the Jesko's Lightspeed Transmission, so I figured it's time to start a build thread.

48843144412_4326b2530e_c.jpg
Light Speed by VKTechnic, on Flickr

This will be a car built around the Porsche wheels, giving the model a scale of roughly 1:8.6. This will be my biggest car model yet and hopefully the most feature rich.

Below are the planned functions for this model:

  • 9+R 7 clutch transmission operated with pneumatics
  • Drive with 2 XL motors
  • Front and rear wheel steering (real car has ~5 degrees of rear wheel steer)
  • Front and rear Triplex suspension
  • Opening synchro-dihedral doors, front trunk, and engine cover (hopefully with pneumatics)
  • Active top-mounted rear wing

This project will take me quite some time, especially between my university studies, work, and a few other things, but hopefully starting this build will keep me motivated to build.

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Wow, a 9 + R pneumatic gearbox :drool:

From the image you posted, you show the transmission. Could we have more information on this?

Very interesting specs, can't wait to see progress on it!

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@VKTechnic, sorry, could you explain, why do you need so complex setup? You use servos for controlling pneumatics (according to your words on flickr). Maybe, real car really needs gearbox control module and hydraulics (or something else to shift gears) to be separated. But in Lego car your setup seems to be a little more complicated and overweighted compared to it's possible version. Why not to make a mechanical control of your gearbox via servos directly? Anyway, with pneumatics, you need an automatic air compressor - it adds more weight (again) and needs more room in model.

Edited by romashkaman

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8 hours ago, badmad said:

Hey, thats sounds interesting. 

Do you plan to build the red or white model? 

White car

8 hours ago, grego18f said:

Wow, a 9 + R pneumatic gearbox :drool:

From the image you posted, you show the transmission. Could we have more information on this?

Very interesting specs, can't wait to see progress on it!

I am hoping to do a video demonstrating my prototype soon.

2 hours ago, romashkaman said:

@VKTechnic, sorry, could you explain, why do you need so complex setup? You use servos for controlling pneumatics (according to your words on flickr). Maybe, real car really needs gearbox control module and hydraulics (or something else to shift gears) to be separated. But in Lego car your setup seems to be a little more complicated and overweighted compared to it's possible version. Why not to make a mechanical control of your gearbox via servos directly? Anyway, with pneumatics, you need an automatic air compressor - it adds more weight (again) and needs more room in model.

I don't necessarily need a complex setup, but it's a good engineering challenge. Mostly for fun, but also the packaging of it ends up being actually quite a bit nicer with pneumatics actuating the clutches directly. Based on my current sketches I should be able to fit everything in. I was also already planning on adding in a compressor for pneumatic doors, engine cover, etc.

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Good choice.  I have been tempted to try to build the Jesko but at smaller scale.   It is difficult to replicate that gearbox with the Lego gears available, and to make it operate at lightspeed using pneumatics.  Interested to see your solution.  

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I'll be following this build with interest.

From the pictures on Flickr I think I see you only use one side of the gear selector ring, right? It is an easy solution to have at all times maximum only one gear engaged, but have you thought of a gearbox design whereby you can actually use both sides of the gear selector ring? I've always thought it should be possible to do that with some sort of adder/subtractor mechanism between the front and back gears, but I never figured out how. It would save 5 cilinders, 5 switches and 5 servos I guess.

Or did I misinterpret the photos and do you actually use both ends already?

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3 hours ago, Jeroen Ottens said:

I'll be following this build with interest.

From the pictures on Flickr I think I see you only use one side of the gear selector ring, right? It is an easy solution to have at all times maximum only one gear engaged, but have you thought of a gearbox design whereby you can actually use both sides of the gear selector ring? I've always thought it should be possible to do that with some sort of adder/subtractor mechanism between the front and back gears, but I never figured out how. It would save 5 cilinders, 5 switches and 5 servos I guess.

Or did I misinterpret the photos and do you actually use both ends already?

The hard part with using both ends (at least with pneumatics) is that you have to be able to select the neutral precision precisely. With my current setup, I'm using one switch to control extension of two cylinders. Each output of the switch is responsible for the extension of a cylinder, and once the air is released from the line, a rubber band returns the selector to neutral. This way it only takes 4 servo motors and 4 switches to control the 7 "clutches".

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Too less gears on the picture for the 9+R transmission. Are you cheating? :laugh:

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4 hours ago, Aleh said:

Too less gears on the picture for the 9+R transmission. Are you cheating? :laugh:

No, the engineers at Koenigsegg are the ones cheating ;)

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4 hours ago, VKTechnic said:

No, the engineers at Koenigsegg are the ones cheating ;)

I believe this all is up to Kristian himself  :thumbup:

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Alright, finally an update. Transmission video is still on the to-do list, but I've made some good progress on the rear suspension packaging:

49358885028_d193bb8367_c.jpg
Rear Suspension by VKTechnic, on Flickr

I've had to make a few aesthetic sacrifices compared to my One:1 model to ensure that all the functionality of the rear suspension is there. Two hard shock absorbers per side should take care of the weight of the model, and the long pneumatic cylinder acts as a squat damper. Upper control arm (magenta) and lower control arm (green) are different lengths, resulting in decent camber gain through the suspension travel. Rear wheels are driven (orange) and steered (red). The Anti-Roll Bar (white) is still subject to change, but is currently functional. Next challenge is to connect all the mounting points with some sort of structure...

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Alrighty, another update!

Took some time today to test livestreaming on YouTube. In that livestream, about at the 18:12 mark, I ramble about my progress on the Lightspeed Transmission and do a short demo:

As you can see, the concept works, but there are a few improvements that need to be made (namely, a non-human logic controller). Feel free to take a look and let me know your thoughts!

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On 1/10/2020 at 2:39 AM, VKTechnic said:

Alright, finally an update. Transmission video is still on the to-do list, but I've made some good progress on the rear suspension packaging...

Impressive setup, really good to see something other than a basic double wishbone.

Looks like (and I admit freely I'm a novice so might be wrong) it could toe out a bit as the suspension compressed?

Keep it up :)

 

edit: now I'm not so sure as I realized I don't know which side is the front of the car :laugh:

Edited by amorti

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4 hours ago, amorti said:

Impressive setup, really good to see something other than a basic double wishbone.

I couldn't agree more, i see so many 'supercar' moc's with huge attention spent on the interior and the number of gears.. lots of talk of replicating the real vehicles technicality, then some basic suspension thrown on as an after thought.. i've mentioned it many times as i've never understood why its neglected. There was a F1 moc a while back that had too much sag and was requesting help... F1 cars have heave springs which were missing from the moc, adding them would make it more realistic and fix the sag. Seemed an obvious win win...

...anyway, what i'm saying is, its awesome to see it being treated as the amazing technical element it is. I actually find complex suspension more interesting than gearboxes!! 

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2 hours ago, TeamThrifty said:

... I actually find complex suspension more interesting than gearboxes!! 

The whole gearbox thing reminds me of early mountain bikes where more=better. They went from 21 to 24 to 27 gears all in relatively short order. My hybrid actually has 30 gears, but it's no better than it would be with 20. 

There are some very clever mechanisms being built but they have nothing to do with realistic technology, aren't typically strong enough to accept powered drive, and are kinda pointless to spin a fake motor.

So... If anyone with design skill is reading (not going to lie, I have none), let's see more cool suspension please :)

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Thank you all for the kind words!

15 hours ago, amorti said:

Impressive setup, really good to see something other than a basic double wishbone.

Looks like (and I admit freely I'm a novice so might be wrong) it could toe out a bit as the suspension compressed?

Keep it up :)

 

edit: now I'm not so sure as I realized I don't know which side is the front of the car :laugh:

Steering rack is to the rear of the car, so the suspension will slightly toe in on compression.

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I always like to see technical innovation in models, rather than just a new body on old functions, so this model interests me greatly! Good job!

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