Fastest LEGO Technic Car!

[mwnilsson]

Saw Sariels Trike on youtube at 20km/h and tought I might beat that or at least I give it a go. This started my pursute to building

Lego Cars for one purpus: to go as fast as possible this is the models I made:

My first car that beat sariels and all the motors I had then! Also my first youtub video at 37 years old. But i found som L-motors on

ebay and made my next car :-)

Had made LPE engines som years prior to this when I discoverd they exsisted on youtube and made a car of those to.

But then I learnt that the most powerfull electric motors lego made was the buggy RC Motor so I discoverd Bricklink!

(But found a cheaper supersonic RC on ebay) so then I made this:

And then I found this forum and tought I whanted to share my own creations (or MOC as I have learnt the term is)

[JJ2]

@mwnilsson Welcome to Eurobricks!

They do indeed break the speed record but they don't steer, is that to make them as simple as possible or not enough space? Maybe a simple 7L gear-rack and 12T gear would work.

[technic_addict]

I didn't think the L motor would be able to compete with the buggy motor, but there you go!

Assuming you used V2 IR's?  Would you gain any extra speed by using LiPo's instead of battery boxes?

[offroadcreations]

Whenever I see something that says "Fastest Lego Car," I think that it just uses some Lego and 3rd party RC parts, not fully Lego. However, I was pleasantly surprised to see you only used Lego here (and pneumatics, but I like that), so congratulations, and welcome to Eurobricks!

[mwnilsson]

@JJ2 Thanks! Well all lego steering has som play in them and that would generate som friction and loss of speed!

@technic_addictyea I whent whit the L-Motor because the XL-motor would have to be geard up by 4 gears instead of 2 so less friction. In the first car I have 2 V1 and in the second 1 V1 and 1 V2 (just to try it out) As far as I know Lipos are 7,2V or like max 8,4V maximum charged as usual Alkaline battery out of the box is lik 1,66V (9.96V for 6x) but the weight is higher. Dont have Lipos but i think that the extra voltage would be better so assumably less speed in a Lipo car..

@Offroadcreat1ons Thanks! Yes I think it should be original lego parts only and not modifyed! Exept for LPE these are so slow when not modyfied that its patetic:-)

 

 

Edited March 30, 2017 by mwnilsson

[Lakop]

I like what you're doing. Your last model certanly looks the best, but I think you need "slicker" wheels. Try and get more grip and maybe lose some weight from the cars. You've got a challenge on your hands and I look forward to more.

good videos.

H

 

[J_C]

31 minutes ago, Horace T said:

I like what you're doing. Your last model certanly looks the best, but I think you need "slicker" wheels. Try and get more grip and maybe lose some weight from the cars. You've got a challenge on your hands and I look forward to more.

good videos.

H

 

extra weight means better traction, weight is your enemy for acceleration, not so much for top-end max speed (Trust SSC was over 10tons  ). low weight means less traction.

 

[Boxerlego]

Try this Dual Battery Box Out. See if you can get more speed from your Creation, Its so Powerful it Destroys Electron Theory. Tutorial Link

 

 

Edited March 30, 2017 by Boxerlego

[Lakop]

the right amount of weight in the right area will no doubt provide the traction. Its an interesting experiment with lego and those battery packs.

H

[Sariel]

Not to spoil the fun, but the Lego speed computer is wildly inaccurate. I've seen it give readings different by 20% and more at exactly the same speed. This is not to say that your cars didn't go that fast - it's just that in the future you may want to try something accurate to measure the speed. Personally, I recommend strapping some lightweight Android phone to the car, with GPS enabled and this app running: https://play.google.com/store/apps/details?id=pl.com.digita.BikeComputer&hl=en

Edited March 30, 2017 by Sariel

[Jurss]

10 hours ago, mwnilsson said:

Well all lego steering has som play in them and that would generate som friction and loss of speed!

So why You don't use these tires then?

[Didumos69]

49 minutes ago, Jurss said:

So why You don't use these tires then?

These are too big. He uses the smaller motorcycle wheels.

This one fits and has a racing tread:

Edited March 31, 2017 by Didumos69

[mwnilsson]

@Horace T Thanks!  Thinking of getting covers for the wheel sides but it would mean more rotational mass and more weight resulting in more friction so i dont know.  Wheigt saving could be don but at the cost of rigidity and aerodynamics so its a hard traderoff and I dont know what will result in higher speeds. 

[Lasse D]

It's great to see that the goalpost has been moved. Congrats.

BTW. Will you consider making an attempt at trains as well? It would be awesome to see new records here :)

[Jurss]

5 hours ago, Didumos69 said:

These are too big. He uses the smaller motorcycle wheels.

This one fits and has a racing tread:

In last video is that bigger size, even with motocross tread

[Didumos69]

Just now, Jurss said:

In last video is that bigger size, even with motocross tread

You're right, sorry about that. At least we now know there is a racing treat for both sizes.

[mwnilsson]

17 hours ago, J_C said:

extra weight means better traction, weight is your enemy for acceleration, not so much for top-end max speed (Trust SSC was over 10tons  ). low weight means less traction.

 

I dont need better traction. A so high geard buggy motor dont have that power to spin the wheels. I dont have bearings (like the thrust ssc)  so the more wheight the more friction and less power to generate speed. 

[Catalinanmb]

Yes, but the knobbly tires have higher rolling resistance.

[mwnilsson]

19 hours ago, Boxerlego said:

Try this Dual Battery Box Out. See if you can get more speed from your Creation, Its so Powerful it Destroys Electron Theory. Tutorial Link

 

 

This is awsome! But then I need 2 V2 recivers because V1 cant drive Buggy Motors proper

 

BTW is it safe to use the other 2 ports on the recivers to a second engine?

[mwnilsson]

20 hours ago, Sariel said:

Not to spoil the fun, but the Lego speed computer is wildly inaccurate. I've seen it give readings different by 20% and more at exactly the same speed. This is not to say that your cars didn't go that fast - it's just that in the future you may want to try something accurate to measure the speed. Personally, I recommend strapping some lightweight Android phone to the car, with GPS enabled and this app running: https://play.google.com/store/apps/details?id=pl.com.digita.BikeComputer&hl=en

My speedcomputer dispalys my diffrente electric motors at the rpm they are supposed to spin at so i dont think its unaccurate. GPS can be unaccurate at small distances and is best att average speeds there is a wide margin off error. I can se on your video when you take a photo of your gps data standing still it display your speed at 1,8km/h.  Have you tried speedcomputers to mesure rpm to be unaccurate to? or is there something wrong whith the actual calculation in the computer? If i were to use a phone it wouldent be made intire out of Lego.

[Sariel]

1 hour ago, mwnilsson said:

or is there something wrong whith the actual calculation in the computer? If i were to use a phone it wouldent be made intire out of Lego.

Lego speed computer is inaccurate, that's all. It measures speed with a delay, it only measures by certain increments (e.g. by 20 RPM but not 19 RPM) and it often produces wrong results. Try comparing it with other measuring methods and you'll see.

I think people will understand that the phone is for measuring speed only and it's not part of your car.

The GPS' margin of error is far less than that of the Lego speed computer, which is simply a toy for kids, and you can keep it low by making long runs with your car. When I measure top speed with GPS, I make sure to drive at least 50 meters, ideally 100+.

Edited March 31, 2017 by Sariel

[mwnilsson]

9 hours ago, Sariel said:

Lego speed computer is inaccurate, that's all. It measures speed with a delay, it only measures by certain increments (e.g. by 20 RPM but not 19 RPM) and it often produces wrong results. Try comparing it with other measuring methods and you'll see.

I think people will understand that the phone is for measuring speed only and it's not part of your car.

The GPS' margin of error is far less than that of the Lego speed computer, which is simply a toy for kids, and you can keep it low by making long runs with your car. When I measure top speed with GPS, I make sure to drive at least 50 meters, ideally 100+.

So if I where to display max rpm on my speedrun and then self calculate the result would that be ok? so the question is do the lego speedcomputer say 100rpm if it is 91rpm or 109rpm(or somewere in between) it looks so if you messure a electric engine. in that case the margin of error would be if I just tock rpm and for my wheel 0,000256km*20rpm*60 thats +-0,15km/h or 0,3Km/h how you see it

I dont know what accurasy you get on your bike app but min at 16 sattelites conection was down to 3m! and thats fine when you drive at a constant velocety but not if you accelerate the hole time then it would display less.

And lets face it at 20km/h you could run 50-100m but at 30km/h its impossible!

19 hours ago, Lasse D said:

It's great to see that the goalpost has been moved. Congrats.

BTW. Will you consider making an attempt at trains as well? It would be awesome to see new records here :)

Thanks! Sorry dont have any Lego Train parts and have never been a train guy :-)

23 hours ago, Jurss said:

So why You don't use these tires then?

 

23 hours ago, Didumos69 said:

These are too big. He uses the smaller motorcycle wheels.

This one fits and has a racing tread:

 

14 hours ago, Catalinanmb said:

Yes, but the knobbly tires have higher rolling resistance.

They ar bigger and heavier so more drag and more friction.

I would like 2 racing slicks on front :-)

Yea the motorcross tire woud be more rolling resistance but it suited my gearing better.

Edited April 1, 2017 by mwnilsson

[MangaNOID]

what about measuring a distance out on the surface, say 50m and then time that and calculate, (making sure your car is up to top speed before that 50m of course) just time it out on the video playback for better accuracy perhaps.

the you can use an underground smooth carpark like in the Video and no wind interference.

Edited April 1, 2017 by MangaNOID

[TheMindGarage]

The pneumatic one looks really cool! Are the parts all stock (apart from the Fanta airtank of course)? If so, I'm impressed...

[Sariel]

4 hours ago, mwnilsson said:

So if I where to display max rpm on my speedrun and then self calculate the result would that be ok? so the question is do the lego speedcomputer say 100rpm if it is 91rpm or 109rpm(or somewere in between) it looks so if you messure a electric engine. in that case the margin of error would be if I just tock rpm and for my wheel 0,000256km*20rpm*60 thats +-0,15km/h or 0,3Km/h how you see it

It's your choice. I think it's a lot of hassle. If you don't want to use GPS, why not keep things simple: for example, draw marks on a road 10 meters apart and film how fast your car goes from one to the other at top speed, then do the math? This way you don't need to put anything on the car, the camera can simply stand on a side.

Edited April 1, 2017 by Sariel