[MOC] Tractrike RC2 Record Racer 35 km/h+

[zux]

What's the speed in the other direction please? Just checking if that's not a downhill ride test.

[Marxpek]

@zuxI have only done 3 runs yet, on a flat (like the most of Holland) asphalt road here : https://www.google.nl/maps/@52.497985,6.1206633,20.25z?hl=en 2x in one direction and 1x in the other, 28,9km/h , 30,9km/h and the last 32,71km/h, so the answer to your question at the moment is 30,9 km/h.

But i will try to push it further and i will do that in both directions while filming it from my bike, i will also include the full gps data from the bryton gps computer, which will show speed-data, the track, elevation of the track and much more, but i am waiting for some spare time on a day without rain, which rare here at the moment..

I will update the topic soon with some more detailed pictures of the car, i did some weight reduction, its not pretty, but that's not my goal.

[Marxpek]

@zuxLooking into the gps data on the 32,71 run, that went slightly uphill, 1% gradient. so i'd be better of riding the other way ;)

[Marxpek]

Well here is the final result:

Not much besides some weight reduction has changed, but my camera setup has been expanded with an action cam giving some nice footage here.

The video does the talking, i'll shut up...

[MangaNOID]

Ok so that's pretty cool but it looks like it accelerates off the line quite quickly as well. Does that mean you could gear it up a little more for more top speed or have you tried and what you have is the limit before the 'tipping point' of no acceleration? 

EDIT: actually I think my question is more like What is the calculated rpm of the drive wheel so I can know the difference to the actual on track rpm at 35kmh. Thanks!

Edited June 18, 2017 by MangaNOID

[mocbuild101]

35 km/h!!! I can't believe how many times have you broken the/your record!

I think you really have reached the top speed of Lego, or at least for non-modified motors...

[Marxpek]

13 hours ago, MangaNOID said:

Ok so that's pretty cool but it looks like it accelerates off the line quite quickly as well

It really doesn't, keep in mind that the action cam is low to the ground so it looks a lot faster, with the action cam on it it becomes unstable, so i never went over 25km/h with it attached, it takes about 150-170 meter before it reaches top speed with the gps computer on. it is a bit over-engineered to prevent destruction with every crash so it is a bit on the heavy side. Sometimes it already gives me troubles with the thermistors in the motors, needing them to cool down.

 

13 hours ago, MangaNOID said:

What is the calculated rpm of the drive wheel

what exactly do you mean by this? how fast the wheel could spin in theory? (Philo's info again) fast output= 1700 rpm geared up 2,5x= 4250 rpm without load. 107mm diameter wheel: theorectial speed: 84,7 km/h... But with 35km/h it should be something like 1740 rpm that was actually reached.

8 hours ago, mocbuild101 said:

35 km/h!!! I can't believe how many times have you broken the/your record!

I think you really have reached the top speed of Lego, or at least for non-modified motors...

Hmm, i doubt i reached the roof on this, i went about this the raw power way. the next build will be more about finesse and lightweight construction, risking total destruction upon the inevitable crashes.. 

Gotta keep pushing further ;) first with more finesse, or maybe later ill just add more motors :D.

[MangaNOID]

1 hour ago, Marxpek said:

 

 how fast the wheel could spin in theory? (Philo's info again) fast output= 1700 rpm geared up 2,5x= 4250 rpm without load. 107mm diameter wheel: theorectial speed: 84,7 35km/h it should be something like 1740 rpm that was actually reached.

Yes that's it thanks. I was just really interested in the real world difference to calculated to see the affects of aerodynamics, rolling resistance etc.

[mocbuild101]

Hey @Marxpek, it looks like you have some competition! 

https://rebrickable.com/mocs/MOC-8658/Summse/348-kmh-black-speed-record-breaker-worlds-fastest-remote-controlled-2-motor-lego-car

[Marxpek]

@mocbuild101

Yeah i do finally we already met on youtube and i sent him here ;) Although he made me go back to the boring way; slick wheels, lightweight all that crap, i actually used his exact steering setup in one of my concepts about a year back, but i found it to be risky (it wants to crash).

 For sure it gives better results, but i like the raw power, but hey... cannot be picky if you want to be the fastest, so i left the raw power for what it is and went the finesse way.

 He also made a new category for his record, (fastest 2 motor Lego) something i will not do, i want to be the fastest period,regardless of the partcount.

But know that i have a new, not fully tested design but its shows promising results. I will keep you updated.

Edited June 24, 2017 by Marxpek

[TechnicSummse]

4 hours ago, Marxpek said:

 He also made a new category for his record, (fastest 2 motor Lego) something i will not do, i want to be the fastest period,regardless of the partcount.

Basicly @mwnilsson "opened" this category ;)

But i picked it up, because i dont want a chalange like: who can buy the most buggy-motors/rc-parts, that would just be stupid.

And i think its a good solution, to classify it by the amount of used motors/rc units, since then evryone "fights with the same weapons" ;)

 

[mocbuild101]

Just now, Marxpek said:

But know that i have a new, not fully tested design but its shows promising results. I will keep you updated.

Great!

And the battle is on... and I'm going to join in!

[Marxpek]

9 hours ago, TechnicSummse said:

who can buy the most buggy-motors/rc-parts, that would just be stupid.

sorry to tell you, but racing always has been about who can get the best parts, combined with the best setup. Racing is an expensive hobby, if you don't spend you don't win.

And i WILL add more motors if I have to, it is the challenge I set myself and i will stick to that. Fastest Lego with no modifications, by whatever means.

[TechnicSummse]

2 minutes ago, Marxpek said:

sorry to tell you, but racing always has been about who can get the best parts, combined with the best setup. Racing is an expensive hobby, if you don't spend you don't win.

And i WILL add more motors if I have to, it is the challenge I set myself and i will stick to that. Fastest Lego with no modifications, by whatever means.

Ok... so in in real life 700HP F1 cars race vs 20HP karts? ;)

Thats the reason why there are different classes. To compare things on the same level.

And for me, building LEGO-technic, is to reach a specific goal within a set frame. In this case, this will mean.. reaching higher speeds then someone else, with the same motorpower.

 

[Marxpek]

Well i should not have said "racing",

That's not what we do here, it is the land speed record, in the real world that is about who can buy the biggest jet engine and strap it to some wheels the best way.

[Aventador2004]

On 6/25/2017 at 1:05 AM, mocbuild101 said:

Great!

And the battle is on... and I'm going to join in!

I would too, and what marx said above is correct. Look at f1.

I am going to use l motors.

Edited June 26, 2017 by Aventador2004

[TechnicSummse]

48 minutes ago, Aventador2004 said:

I am going to use l motors.

Comparing L-motor vs buggy-motor in this chart...

http://www.philohome.com/motors/motorcomp.htm

... shows, you would need 4 L-motors to get the same mechanical power then 2 buggy motors, while they consume the same amount of power.

But you would need a 4,5 times higher gearing... meaning a 2-gear-transmission wont work anymore, you will need a 40:8 upgearing + another 20:12 for example.

 

[Aventador2004]

25 minutes ago, TechnicSummse said:

Comparing L-motor vs buggy-motor in this chart...

http://www.philohome.com/motors/motorcomp.htm

... shows, you would need 4 L-motors to get the same mechanical power then 2 buggy motors, while they consume the same amount of power.

But you would need a 4,5 times higher gearing... meaning a 2-gear-transmission wont work anymore, you will need a 40:8 upgearing + another 20:12 for example.

 

I am using that ratio currently, but two l motors, so that is the l motor idea done.

[TechnicSummse]

13 minutes ago, Aventador2004 said:

I am using that ratio currently, but two l motors, so that is the l motor idea done.

Well you can use 2 L-motors per side, 4 in total... should givie you similar results then using 2 buggy-motors. But with the geartrain, and additional axle-beam-friction (wich you need at the geartrain) you wont come to the limit.

But 4 L-Motors still could reach 30+ i guess :)

 

But at the end... 2 buggy-motors are cheaper then 4 L-motors.. arent they?

Edited June 26, 2017 by TechnicSummse

[Aventador2004]

1 hour ago, TechnicSummse said:

But at the end... 2 buggy-motors are cheaper then 4 L-motors.. arent they?

Yes, but i used most of my budget earlier in the year, so a buggy motor will have to wait.

[Marxpek]

@Aventador2004 @mocbuild101Great to see more people try in the race to be the fastest!

@Aventador2004Really curious about your plans and execution with the PF system, i have my reservations about it but who knows? Try! 

Learn from mine and others mistakes... don't break the amount of Lego i have destroyed ;D

I have also done a giant overhaul on my racer, threw looks and "crash-survivability" out the window, just as the claas wheel. Although a still WIP it very much resembles the first racer i built (sadly i don't have pictures...) but found to be "too dangerous for my small Lego collection", it was a bit flimsy (i normally over-engineer to be safe) So i never went on with this project, but since @TechnicSummse went this way, i feel kind of forced to go light and dangerous (i mean flimsy, i will not risk my rc units...yet ;D). But it is the way to go fast of course, although way more fun, there is only so much raw power can do.

Let's have fun and break that 40 km/h! And pray we don't send too much parts to Lego-heaven, a.k.a dustbin...

[Aventador2004]

1 hour ago, Marxpek said:

@Aventador2004 @mocbuild101Great to see more people try in the race to be the fastest!

@Aventador2004Really curious about your plans and execution with the PF system, i have my reservations about it but who knows? Try! 

Learn from mine and others mistakes... don't break the amount of Lego i have destroyed ;D

I have also done a giant overhaul on my racer, threw looks and "crash-survivability" out the window, just as the claas wheel. Although a still WIP it very much resembles the first racer i built (sadly i don't have pictures...) but found to be "too dangerous for my small Lego collection", it was a bit flimsy (i normally over-engineer to be safe) So i never went on with this project, but since @TechnicSummse went this way, i feel kind of forced to go light and dangerous (i mean flimsy, i will not risk my rc units...yet ;D). But it is the way to go fast of course, although way more fun, there is only so much raw power can do.

Let's have fun and break that 40 km/h! And pray we don't send too much parts to Lego-heaven, a.k.a dustbin...

I am not sure it will hit even 20, the friction is too much, but I am thinking:

• 2 L motors + 1 XL motor.
• Buy a buggy motor.
• Collaborate with someone else (mocbuild said yes).
• Give up.

The last one will not happen for me. Now to stop stalling, 40 is still far away.

Technic summise said his latest prototype hit 35.

I got an idea! I will buy a train motor, gear down, and go for 40!

Edited June 26, 2017 by Aventador2004

[Marxpek]

56 minutes ago, Aventador2004 said:

I got an idea! I will buy a train motor, gear down, and go for 40!

don't rush head over heels into buying things you might spend money on things you will never use... please take a good look at the philo's motor specs page that was linked before, and look at the mechanical power output of the all motors (and compare rpm's also)

 

1 hour ago, Aventador2004 said:

Technic summise said his latest prototype only hit 35.

Only?!? 35 is quite an achievement i think!

[Aventador2004]

11 minutes ago, Marxpek said:

don't rush head over heels into buying things you might spend money on things you will never use... please take a good look at the philo's motor specs page that was linked before, and look at the mechanical power output of the all motors (and compare rpm's also)

 

Only?!? 35 is quite an achievement i think!

i have tracks that i use, but only 1 power car, so i could have a spare use for it. the torque can be regained through gearing. the train motor gets 300 rpm more than the buggy motor, but i can change that easily.

[PorkyMonster]

1 hour ago, Marxpek said:

... there is only so much raw power can do ...

 which brings to mind the reality that going light is very much limited by the collective weights of motors, power source, and pieces of Lego plastic... not to mention that lightness must not result in losing traction too often... whereas if you go the other way - adding more motors, more power, etc., the sky's the limit!!  ok that's just my view 

Edit: Of course, I do understand the fun involved in pushing the frontier while limiting resources.

Edited June 26, 2017 by PorkyMonster