Suspension or no suspension?

[clarkdef]

haha yeh sure is!

Well im not sure if it would beat yours, my buggy is pretty slow. lol and turning radius isn't the best.

I put an axle in them and it doesn't do much. I have an idea to make a thin washer and see it that helps.

After testing it the steering needs a bit of work, not quite return to center if you know what i mean.

Hopefully my bigger 81mm wheels will arrive tmr.

Wide is nice and stable, but doesn't make good turns, don't ask me why haha. When I ran a previous car at 12.6volts it throttle steered which was nice, though I don't do it for long because I don't want to hurt the electronics. That play is annoying if you find a fix let us all know. I was thinking of gluing the tri peg onto the wheels!

Here's my car, just to see how the steering is incorporated, along with some fun testing

^rear axle is direct drive with no diff. While it may reduce cornering (unless it starts to drift ) it helps keep stable at top speed and there is minimum power loss.

^when suspension is compressed (such as when hitting a bump at high speed or going over rough terrain) there is some toe-in, which is perfect because it will keep the car straight and it wont lose control

I may make a video today or tomorrow if I have time.

EDIT: I tested inside because I knew I'd crash eventually with the poor IR signal And I did, but a near full speed crash will make anything with lego fall apart, in this case the front axle assembly separated from the rest of the chassis. As for steering-everything is perfect except the steering rack came out so one tie-rod separated from the rack but not the hub, but trust me, at top speed, along with some small jumps, this holds together perfectly during a crash I actually think sections coming apart is better, since it absorbs the impact instead of the pieces at the very front taking all the force and possibly breaking.I like the setup in your video a lot, it could be used for a large scale stadium buggy or baja truck.

Well my ultimate plan is not to crash, but just steering was ripping me a new one. You got a decent sized battery on there!

Put a bumper on the front! :D

[Doc_Brown]

Wide is nice and stable, but doesn't make good turns, don't ask me why haha. When I ran a previous car at 12.6volts it throttle steered which was nice, though I don't do it for long because I don't want to hurt the electronics. That play is annoying if you find a fix let us all know. I was thinking of gluing the tri peg onto the wheels!

What? how did you manage 12.6 volts into the RC unit I assume? That's crazy, and nothing melted? :P

@MrNumbskull13

Great model, but I dont like the look of the the front suspension just to be honest, just seems messy. On the other hand I love your rear wheel setup! Fantastic!

[MrNumbskull13]

Umm I didn't make that xD

[Someonenamedjon]

What? how did you manage 12.6 volts into the RC unit I assume? That's crazy, and nothing melted? :P

@MrNumbskull13

Great model, but I dont like the look of the the front suspension just to be honest, just seems messy. On the other hand I love your rear wheel setup! Fantastic!

There might be a DC/DC inside.

[clarkdef]

What? how did you manage 12.6 volts into the RC unit I assume? That's crazy, and nothing melted? :P

@MrNumbskull13

Great model, but I dont like the look of the the front suspension just to be honest, just seems messy. On the other hand I love your rear wheel setup! Fantastic!

3 cell lipo battery, when fully charged each cell is 4.2v that drops to 3.7v after time, but gotta test under the high volt scenario. Very powerful at this voltage, however I will not use my current lipo because it does not fit into the unit.

I am looking at putting 3 of these http://www.hobbyking...o_Pro_180_.html into the unit, I have measured up and I am sure 3 can fit, at least 2 can fit without modification to the unit.

I have done the math and this battery can deliver enough amps to power 6 buggy motors without a voltage sage, they will drain fast doing that though.

Oh and I am not sure if anything will melt yet, I have a half broken unit, it was sent from bricklink broken . Anyway I am conducting tests with that unit, I will update on my findings, I can tell you that the buggy motors are very hungry, so hungry in fact they stall themselves as they overheat, this isn't good treatment, don't let it happen.

To avoid this you want to make sure that they don't struggle too much, under a lot of load they pull high amps from the battery and over heat themselves until they stall. It's good to have a clutch, maybe wheels spinning in the tyres, using a lot of motors is good 3 can spin the tyres under most conditions.

Avoid:

Quick backward and forward type movement

Trying to push something, like a tree!

A hill that sounds hard to get up... gear it down!

Or play it safe and use 2c lipo

P.s the suspension I used is pretty ugly!

Edited August 14, 2013 by clarkdef

[Doc_Brown]

Thanks for the info! those batteries are cool, good for PF stuff too, 750mh is almost perfect draw.

I can imagine they are hungry! cant wait to see more of your experiments, glad you have a "test" unit too.

So you literally wire 3 together and the voltage adds, just like AA's?

Thanks for the link, I might get them as they are really cheap! and I have an awesome lipo charger doing nothing much. lol

[clarkdef]

Thanks for the info! those batteries are cool, good for PF stuff too, 750mh is almost perfect draw.

I can imagine they are hungry! cant wait to see more of your experiments, glad you have a "test" unit too.

So you literally wire 3 together and the voltage adds, just like AA's?

Thanks for the link, I might get them as they are really cheap! and I have an awesome lipo charger doing nothing much. lol

I typed out a reply where is it?...

You can draw a lot of current from these batteries, a constant 26.24amps, which will drain them instantly. I bought some and they are being shipped. Might pay to let me test them first as there could be an unknown with them.

Not sure how they will fit in the pf box??? The plastic fins inside are very restrictive on room, plus no vents.

Yes just put them in series, two in series 7.4-8.4v and three in series 11.1-12.6v. If you want the speed go for three, motors life span will reduce though.

Can the motors in the buggy housing be replaced in case of failure? They look to be a standard sized motor.

[1974]

You can use high power LIPOs and you may get it to run, but LEGO is not made for this. You can certainly not run 26A through standard LEGO wires. Also, the drivetrain will suffer badly. Look at real RC vehicles, they're not made of feeble ABS joints. They're made of metal and composite parts. For a good reason

Yeah, you can get your one minute youtube fame with a LEGO vehicle going 30km/h but it'll be toast after that

Go buy some real RC cars instead

LEGO is great for making intricate constructions, not for making badass high performance wannabe RC cars

There might be a DC/DC inside.

There is not. The new V2 receiver features the DRV8833 H-bridge driver with a working voltage of 2,7-10,8V (absolute max is 11,8V!)

There may be a diode in series giving a 0,3-0,7V drop (low if it is a schottky), but anything above 11V is really pushing it

The old V1 has even lower voltage limit and also much lower current output

philohome.com has all the info/datasheets

[clarkdef]

You can use high power LIPOs and you may get it to run, but LEGO is not made for this. You can certainly not run 26A through standard LEGO wires. Also, the drivetrain will suffer badly. Look at real RC vehicles, they're not made of feeble ABS joints. They're made of metal and composite parts. For a good reason

Yeah, you can get your one minute youtube fame with a LEGO vehicle going 30km/h but it'll be toast after that

Go buy some real RC cars instead

LEGO is great for making intricate constructions, not for making badass high performance wannabe RC cars

There is not. The new V2 receiver features the DRV8833 H-bridge driver with a working voltage of 2,7-10,8V (absolute max is 11,8V!)

There may be a diode in series giving a 0,3-0,7V drop (low if it is a schottky), but anything above 11V is really pushing it

The old V1 has even lower voltage limit and also much lower current output

philohome.com has all the info/datasheets

I am stating what can be constantly drained from the battery, no lego motor draws 20 plus amp so yeah, also you can draw high amps through lego wires, you just need to stack them in parallel lol.

You are right about the current limiter, but motors will only draw what they need, and two large motors won't trip it pfs current switch, the advantage is light weight battery box. lighter than that rip off lipo one lego sells.

Also please don't tell us what lego is for, I see a challenge and it is stimulating my brain, that's the goal of the toy, isn't it?

[1974]

There are causal readers of this forum that might go; Whoha, I just need some bigass LIPOs and my car will lightning fast! .. and then, why is my wires melting, why is that motor smelling burnt, whoha flames, mom house is on fire!

Toys are for stimulating yes, but there's a limit. You do not put a V8 big block in a VW beetle without changing the drivetrain, chassis and body to make it work. Can't do that with LEGO, sorry

I'm not telling YOU, I'm telling the rest

[clarkdef]

There are causal readers of this forum that might go; Whoha, I just need some bigass LIPOs and my car will lightning fast! .. and then, why is my wires melting, why is that motor smelling burnt, whoha flames, mom house is on fire!

Toys are for stimulating yes, but there's a limit. You do not put a V8 big block in a VW beetle without changing the drivetrain, chassis and body to make it work. Can't do that with LEGO, sorry

I'm not telling YOU, I'm telling the rest

Good point, thought you were trying to kill my joy. Oh and don't tell Nicjasno that, you will seriously kill his joy.

[1974]

I won't, he's a pro

Good luck and do be carefull

[clarkdef]

Update: The new suspension that I have come up with is very tough.

Pros

- It can easily handle direct small to medium crashes on the control arms and tyres.

- It is compact for it's scale.

- It is attractive.

- The steering is like a one way valve, so the shock won't get fully transmitted to the steering servo.

Cons

- Hardly any turning angle, rely s on throttle steer technique.

- Big tyres are needed because of ground clearance, big heavy tyres.

- Ok amount of travel, doesn't allow for pot holes.

I will post pictures sometime tomorrow of how I did the wheel carrier using the crawler hub and how it is possible to get a close pivot point, almost in the wheel. Here is a link to a video of me testing volts and toughness of the setup. I use a power supply to simulate different battery configs, the buggy unit is a test unit the steering is broken and it stutters at low voltage so please don't feel to sorry for it.

Please if you are a mature person and believe that lego is more precious than your first born son do not watch this video. Contains slight abuse towards lego.

http://www.youtube.com/watch?v=0sI5rwfAjxw

[Doc_Brown]

Dang that looks fast! Very impressive.

Well I don't have a first born, So cool with me!

[EyesOnly]

Wow that is really fast and strong.

[clarkdef]

The car was running at 11v there, the wheel spin is nice but I don't like that axle tramping, sounds horrible.

[MrNumbskull13]

THAT THING IS RAPID. I'm making an RC trophy truck ATM, the first thing I'm going to do is make the independent suspension for the front, if I come up with any good ideas I'll let you know. :)

[clarkdef]

THAT THING IS RAPID. I'm making an RC trophy truck ATM, the first thing I'm going to do is make the independent suspension for the front, if I come up with any good ideas I'll let you know. :)

I'd love to see it. I would like a tough suspension system that uses these wheels http://www.bricklink.com/catalogItem.asp?P=86652c01 wheels, I love the balance of these wheels and weight.

[clarkdef]

Update: Ok I have built my hill climb car 'The Lobster" and the suspension is strong, the only thing that falls off the car in crashes is the bumper, which is designed to take impact. My small lipos have still not arrived... So just been using some rechargeables... They suck!

This is a 3 wheeler or inverted trike, with only two buggy motors, 4 motors with two units was hard to stop and the weight helped to destroy the car. I use 3 wheels for a heap of reasons, less rolling friction, less weight, the rear wheel being bared from either side.

Suspension conclusion is a medium no! It doesn't work as it should, probably because there are no actual dampers/shocks to stop the spring oscillation haha so any bump it hits the chassis has to absorb, which makes it bounce around anyway.

Haha maybe not that bad! But ya know... Car is heavier, steering is less accurate because of all the play.

I have no idea how to post pictures?..

[JoeKaydear]

@ clarkdef: Here are tips on how to post Flickr images: http://www.eurobricks.com/forum/index.php?showtopic=82980&hl=pictures .

How to Upload Pictures to Brickshelf: http://www.eurobricks.com/forum/index.php?showtopic=18347&hl=pictures

How to "Deeplnk" Your Pictures from Brickshelf: http://www.eurobricks.com/forum/index.php?showtopic=5448&hl=deeplink

[clarkdef]

Hmmm it keeps saying "you are not allowed to use that image extension" when I try to post...