Small Red RC Racecar

[Jurgen Krooshoop]

The racecar-story continues.

After finishing my Yellow racecar I had to make a second car so they could race against each other.

Unfortunately, red was the only colour og which I had enough parts to make a second racecar. It had to

be the same scale, it has the same wheels and wheelbase, is also powered by the 8878 rechargeable

battery and has the front bumper with shock absorbers. It has PF front & rearlights

But there are many differences:

* The new red car is driven by a RC race-buggy motor with 2:1 gear reductionn, while the yellow one

uses an XL-motor geared up 1:3. This makes the red car considerably faster, both in accelleration

and top speed.

* The chassis is quite different and stronger.

* The return-to-centre steering uses shock-absorbers. It's based on a design by Mahjqa.

* This represents a mid-engine car while the yellow one was a front-engine car.

* This one has wing-doors instead of normal ones.

* No rotating steering-wheel this time. The hood was to small to fit in a good system.

* It was possible to place the receiver lower, not sticking out anymore.

* Although the same scale, it's smaller (35 x 18 x 12 studs. But it's built with slightly more parts

(772 in total, also counting the customized handset)

In the end, I like this one even more than the yellow one. I hope to make some race-footage in the near future.

Instructions

Again I've made full step-by-step building instructions. They can be downloaded on my website www.jurgenstechniccorner.com

If any of you find some errors in these files, please let me know, so I can correct them.

Some more pictures:

I hope you like it (and even build it ).

Edited October 31, 2010 by Jurgen Krooshoop

[Silcantar]

That's pretty cool. Not exactly a fair race, though, is it? You're going to have to build a second version of this car, or level the playing field a little somehow! Does this return-to-center steering work better than the version on the yellow car? (The yellow car uses a hockey spring, right?) From the video it looks a little better. I think that the system you used here seems to be one of the more elegant and efficient return-to-center systems I've seen. Plus, it doesn't use any of those rare hockey springs!

[mahjqa]

Great work once again. What impresses me most are the detailed building instructions, you've put a lot of time and effort in those.

I may steal borrow your huge rear wheels at some point. Not only does it look badass, it also simplifies the end gearing a great deal.

Do you have any issues using the PF rechargeable battery in combination with the RC motor? With my sneaker I had some problems where the controls would become unresponsive, and if the motor got stalled, the entire battery may shut off until it's been recharged.

That's the kind of thing you don't want in a race.

So, for now, I've gone back to PF XL motors.

(And thank you so much for giving me credit)

Edited July 19, 2010 by mahjqa

[Jurgen Krooshoop]

That's pretty cool. Not exactly a fair race, though, is it? You're going to have to build a second version of this car, or level the playing field a little somehow! Does this return-to-center steering work better than the version on the yellow car? (The yellow car uses a hockey spring, right?) From the video it looks a little better. I think that the system you used here seems to be one of the more elegant and efficient return-to-center systems I've seen. Plus, it doesn't use any of those rare hockey springs!

It isn't a fsir race, you're right. But until I get my second Buggy-motor (I only have one now)

The steering-lock is a bit smaller on the red one and the return-to-centre works aprox equally good on both systems. And those hockey-springs can be easily be found on bricklink, that's where I got two of them.

Great work once again. What impresses me most are the detailed building instructions, you've put a lot of time and effort in those.

I may steal borrow your huge rear wheels at some point. Not only does it look badass, it also simplifies the end gearing a great deal.

Do you have any issues using the PF rechargeable battery in combination with the RC motor? With my sneaker I had some problems where the controls would become unresponsive, and if the motor got stalled, the entire battery may shut off until it's been recharged.

That's the kind of thing you don't want in a race.

So, for now, I've gone back to PF XL motors.

(And thank you so much for giving me credit)

Haven't had any real problems with this setup (yet). The only thing I've noticed so far is that the receicer "drops-out" sometimes for about 2 seconds. This propably has to to with a safety-system, which drops the output-current of the receiver. The LED on the receiver stays on.

[Zerobricks]

RC motors are much better suited for fast cars, even though thir power output is more or less same as XL ones. I Really like these little cars, I may be forced to make one too

[Jurgen Krooshoop]

Big thanks to Blakbird for making very nice renders of this model:

[Silcantar]

Big thanks to Blakbird for making very nice renders of this model:

That's amazing. Those could not look more real.

[Jetro]

I hope you like it (and even build it ).

Love it - good looking, fully motorized, complete instructions: must build!

Haven't had any real problems with this setup (yet). The only thing I've noticed so far is that the receicer "drops-out" sometimes for about 2 seconds. This propably has to to with a safety-system, which drops the output-current of the receiver. The LED on the receiver stays on.

The problem is with the current overload in the IR Receiver. The Buggy motor is a real power hog and the IR Receiver is designed to short out temporally if too much power is drawn. We had a race with cars with a similar set-up and those 2 seconds of complete loss of control made the race completely unpredictable. I later found out that even using two IR Receivers (one for each motor) doesn't do the trick as the battery box has a similar protection system (don't know a bout the rechargeable battery but suspect it may be the same)

[Jurgen Krooshoop]

The problem is with the current overload in the IR Receiver. The Buggy motor is a real power hog and the IR Receiver is designed to short out temporally if too much power is drawn. We had a race with cars with a similar set-up and those 2 seconds of complete loss of control made the race completely unpredictable. I later found out that even using two IR Receivers (one for each motor) doesn't do the trick as the battery box has a similar protection system (don't know a bout the rechargeable battery but suspect it may be the same)

This is a good thing IMO. It's better to have some protections and loose performance (a slight bit) than do damage to (or burn) the motor.

Edited July 25, 2010 by Jurgen Krooshoop

[Jetro]

This ig a good thing IMO. It's better to have some protections and loose performance (a slight bit) than do damage to (or burn) the motor.

I agree it is good - it's just incovenient for this kind of constrctions which is why I wwent back to using a single XL for propulsion: less power, but more control.

[Jurgen Krooshoop]

I just rebuilt my red racecar, but chose to make it in a different colour-combination. It may even look more mean in black/yellow.

Edited August 19, 2010 by Jurgen Krooshoop

[rgbrown]

I later found out that even using two IR Receivers (one for each motor) doesn't do the trick as the battery box has a similar protection system (don't know a bout the rechargeable battery but suspect it may be the same)

Rechargeable battery is the same: http://powerfunctions.lego.com/en-us/Bios/power/8878.aspx

[dolittle]

Hi,

I know that there is a part list at the bottom but since it lacks the part numbers near the items, I would appreciate if you could tell which LEGO sets would be the best ones to purchase in order to be able to build this car with the RC capabilities.

If there are a few sets you can mix up, I would appreciate if you could tell more than one combination.

Thanks,

Noam

[Jurgen Krooshoop]

@ dolittle:

This is a difficult one. 2 important parts of this MOC are the

(1) 8878 rechargeable battery. I don't know if there is a set that has one, but it can be ordered at S@H. The thing is: it's very expensive (over € 55 in my country) and you need an expensive transformer (€ 25 in my country).

(2) RC-race buggy motor. This is an older part and there is no present set that has one, you'll have to get it from bricklink. It's connected to the PF-receiver with an extension wire.

For the rest of the parts: if you have a 8258 you have all the panels you need (assuming you'll build the red version) and most of the standrd parts like axles, gears & connectors, liftarms etc.

I get most of my parts from bricklink nowadays, so I can order specifically what I need without buying a complete set which allways has a lot of parts I already have.

I hope this was helpfull.

[JunkstyleGio]

Whoa!!!

Those renderings are really fantastic...

Shamefully i must have overlooked them earlier!

Well done jurgen! And well done Blackbird!

[dolittle]

@ dolittle:

This is a difficult one. 2 important parts of this MOC are the

(1) 8878 rechargeable battery. I don't know if there is a set that has one, but it can be ordered at S@H. The thing is: it's very expensive (over € 55 in my country) and you need an expensive transformer (€ 25 in my country).

(2) RC-race buggy motor. This is an older part and there is no present set that has one, you'll have to get it from bricklink. It's connected to the PF-receiver with an extension wire.

For the rest of the parts: if you have a 8258 you have all the panels you need (assuming you'll build the red version) and most of the standrd parts like axles, gears & connectors, liftarms etc.

I get most of my parts from bricklink nowadays, so I can order specifically what I need without buying a complete set which allways has a lot of parts I already have.

I hope this was helpfull.

Thank you for that, I will look at bricklink to get the needed parts, I have never used it before as the feel of the site is a bit clumsy in my view - I prefer to buy from "shops" rather than people - but maybe it is my brain causing problems :)

[Jurgen Krooshoop]

Thank you for that, I will look at bricklink to get the needed parts, I have never used it before as the feel of the site is a bit clumsy in my view - I prefer to buy from "shops" rather than people - but maybe it is my brain causing problems :)

The advantage of Bricklink is that you can buy from thousands of people who have Lego for sale, so the choice of parts is bigger than any store I know. Ok the site might not be so advanced & flashy, but Bricklink uses a feedback-system, so you can see if the previous transactions of a specific seller went OK.

[dolittle]

I am mainly inexperienced in using that site, which makes me wary of buying from it.

I will give it a go :)

Thanks for the tip.

[Blakbird]

I am mainly inexperienced in using that site, which makes me wary of buying from it.

If it helps your confidence level, I have had many hundreds of transactions on Bricklink and have never had a single issue. Much better than eBay. LEGO buyers and sellers are generally pretty reliable, and you won't find any other kinds of people on Bricklink.