Help me remote control 8070

[Saberwing40k]

i must have been out of my mind. i tried to make 8070 remote control. while i was building it. intially, i was going to use 4 xl motors to propel it, but that did not fit. the next revision with only two motors made gears grind . so i ripped out the stupid gearbox to make room for a different steering mechanisim. which does not work. there is simply not enough room for the self centering mechanism to work. i am wondering if anybody has any advice for making this model go really fast, because i want it to be able to do doughnuts and burnouts and stuff.

to sum it up:

1.) advice for the steering.

2.) is 2 motors enough to move the model if i gear it 1:3?

3.) has anybody else used 4 xl motors in a creation? if so, are there any pitfalls i might encounter?

any tips are appreciated. i'm just doing this:

p.s. there are no pics because i did not feel like dragging out my camera, as it is quite late where i am.

[rm8]

I think 2 xl motors is enough for 8070. Model is heavy, so much power (4 xl's) + weight can destruct axles at acceleration or stalling at obstacle. 2 xl is good but you have to mount it as close as it is possible to driving axle. May be the best place for 2 xl's - at the both sides of 5x7'frame which containing differential. Also it s better not to use diff. If possible try not to use long half axles to each wheel or substitute them by something more hard on roll, for example connectors (2 stud length) with axle holes at ends. (If not understand i can show what i mean)

If you have 2 buggy motors you can also test them ( without diff). I think they will be good and very fast for flat surfaces.

As for donuts or drifting, wide rubber 8070 tires+ weight = good grip. It is hard to make them slide. You have to make rear axle lighter than front..of coure make the whole construction light. So put battery box close to front axle or under the bonnet substituting V8.

And another way to make rear wheels drift: take transparent adhesive tape and cover rear whells by it;) also try using rc buggy motors

Good luck. Show us the result

Edited January 2, 2012 by rm8

[allanp]

I don't think you'll get doughnuts or burnouts unless you used plastic wheels (no tyres on them) or build a smaller car. But the best motor for this would be RC buggy motors. Check em out at philos technic motor comparison site. The problem with using these is that require lots of power, best suppied by the RC reciever unit that comes in most of the sets as the motors do. It's big and bulky however, it contains the batteries, the RC reciever stuff and also a servo motor at the front for steering.

[Cwetqo]

I am buliding similar sized car with rc motors and tires from 8070 and it drifts without problem. I am using large receiver rc battery box from rc race buggy, which is best for those motors, but wil certainly not fit intoo 8070 chasis. Unfortunately i dont have extension cables to try it with rc receiver and battery box.

[DLuders]

@ Saberwing40k: sewgway posted this detailed, 12-minute

on a ""Simple Step-by-Step Guide on How To Motorize the Lego Technic 8070 Supercar. The standard 8070 is a remarkable set, has lots of interesting functions and realistic features. This video is aimed at those who are tired of the standard model and want some extra features. You will need the standard 8070 Supercar set, plus:

* 1 [Lego Power Functions] XL motor

* 1 IR [infrared] Receiver

* Some Technic Liftarms and axles

* A pair of scissors

You may also want to consider PCTS99's two-part YouTube video set on "Lego 8070 Supercar with extra PF motors to steer and drive detail view."

and

(showing it in action).

Edited January 2, 2012 by DLuders

[Saberwing40k]

I don't think you'll get doughnuts or burnouts unless you used plastic wheels (no tyres on them) or build a smaller car. But the best motor for this would be RC buggy motors. Check em out at philos technic motor comparison site. The problem with using these is that require lots of power, best suppied by the RC reciever unit that comes in most of the sets as the motors do. It's big and bulky however, it contains the batteries, the RC reciever stuff and also a servo motor at the front for steering.

how, exactly, are the buggy motors better than xl motors? from the same data sheet you mentioned, by any objective measure, xl motors are superior, as an xl produces 14.5 n/cm of torque, versus 2.48 by the buggy motors, because the buggy motors rotate much faster. also, they are far less efficent. what's more, i do not own any. oh yeah, and in order to drift, i wrapped the rear tires in little track links.

[timslegos]

The r/c motor is way faster than the xl motor, and probably stronger too when you consider the amount of gearing down you could do to the r/c motor.

tim

[DLuders]

According to Philo's "LEGO 9V Technic Motor Compared Characteristics" webpage, the Power Functions has a "Stalled Torque" of 40 Newton-centimeters (N-cm) compared to the 5292 RC Buggy Motor's 12 N-cm. Moreover, the PF XL motor draws 1.8 Amps at the "Stalled Current" load, while the 5292 RC Buggy Motor draws a whopping 3.2 Amps (which often trips the thermistor current regulator).

Edited January 2, 2012 by DLuders

[davidmull]

That YouTube 12 min link for instructions not working ;(

[Alasdair Ryan]

Works for me.

Edited January 2, 2012 by Alasdair Ryan

[DLuders]

@ davidmull: Try this direct link to sewgway's 12-minute YouTube video on "How to Motorize the Lego 8070 Supercar":

. Does the video "not work" for you because of the Pepe Romero music that's part of the video?

[dokludi]

My 8070 MOC:

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=478305

[davidmull]

@ davidmull: Try this direct link to sewgway's 12-minute YouTube video on "How to Motorize the Lego 8070 Supercar":

. Does the video "not work" for you because of the Pepe Romero music that's part of the video?

Still not working wierd,won't load that clip,have u a direct link?

[Jack-Jedi]

My 8070 MOC:

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=478305

best 8070 mod i ever seen

[Finntech]

best 8070 mod i ever seen

Very nice indeed.

[dokludi]

Very nice indeed.

THX ALL!!

[jacobkristensen]

i must have been out of my mind. i tried to make 8070 remote control. while i was building it. intially, i was going to use 4 xl motors to propel it, but that did not fit. the next revision with only two motors made gears grind . so i ripped out the stupid gearbox to make room for a different steering mechanisim. which does not work. there is simply not enough room for the self centering mechanism to work. i am wondering if anybody has any advice for making this model go really fast, because i want it to be able to do doughnuts and burnouts and stuff.

to sum it up:

1.) advice for the steering.

2.) is 2 motors enough to move the model if i gear it 1:3?

3.) has anybody else used 4 xl motors in a creation? if so, are there any pitfalls i might encounter?

any tips are appreciated. i'm just doing this:

p.s. there are no pics because i did not feel like dragging out my camera, as it is quite late where i am.

4 xl motors, mean they can make havok/chaos - the tank i am working on(I have mention several times here on the board) has indeed four xl motors. And that has several times ripped the tank to pieces because they are so strong. But my advise would be to add them, but think about the control setup twice or you gonna have trouble.

I have in several places made the construction so if the model gonna go to pieces by itself(observering the direction the forces it can apply) then it has to ripe/break a piece.

I use what I think is a old technic pro trick, I have two recivers both doing ch1 and then two 8878 batteri boxes powering them.

[TechnicJuan]

Glad I spotted this thread. I have been wanting to PF the drive of the 8070 for quite some time now.

[Nikelodeon]

Hey guys I just stumbled onto this topic and had to register.

I had a go at motorizing this set here using two XL-motors for the drive and one M-motor:

http://www.knicknacknock.com/index.php?title=8070#Motorised_Remote_Control_Lego_8070_Supercar_.28Modification_3.29

Its seems to have all fit in the existing chasiss, steps here:

[Bzroom]

What I've learned about power functions motors: use as few gears as possible with the motors as directly connected to the wheels as possible. In other words, use a motor who's power is appropriate for where you connect it.

It's not a good idea to connect two xl motors behind a complicated gear box. Xl motors could connect directly to the wheels. If you need that much power to turn your gear reduction, you've done something wrong. If you're going to gear down, you should use smaller/faster motors so they can provide the necessary speed, and won't over power your gears. So a rule of thumb, XL on the wheels, or an L under the hood.

This applies to gearing up also, because its really still about torque.

[Nikelodeon]

My model doesn't have any gear reductions. There's one gear up in the power train.