RC Chassis V4-Success!

[z3_2drive]

Ok, after figuring out some video problems I am going to post about my final satisfaction out of my Four chassis builds. While V4 may be slower (slower output), It is extremely robust, simple and has the best handling out of the Four .

It is powered by four Buggy motors and steering uses the servo motor. Electronics-wise it uses the same hobby-grade motor controller, receiver and transmitter that I have mentioned before and my custom battery. These are the only non lego parts

Performance is great, and a couple days ago during some play I managed to barrel-roll it, only knocking the project box containing the electronics a bit loose

For now I only have the video to show, but I will upload pictures soon

[Rishab N]

Wow that is really fast! Are the pneumatics for the suspension?

[Junpei]

Yes, kind of like the ones I have made:

They act as dampers for the shock absorbers, although they are not really needed due to the slack in lego pins, liftarms, etc.

Awesome job on the chasis z3_2drive! It's a lot bigger than I expected.

Edited November 9, 2013 by TwentyLeggedHen

[z3_2drive]

Yes, they add stiffness and smoothness to the suspension which it really needs-the rigid structure allows the dampers to actually help a lot Thanks for the compliments!

Edited November 9, 2013 by z3_2drive

[Lakop]

That's fantastic. I like that you've adapted a radio control motor into it and your video is great.

H

[bricky300]

Could you post a picture or more how you connected the Lego Servo to the Rc system?

[Ralf]

Wow, really nice and very fast

But the lifetime of the parts at that speed is not really long, or?

There are no bearings and plastic on plastic........ short lifetime i think.

[z3_2drive]

Thanks to all of you, pictures will come soon, right now I'm very tired and as for part wear-it's actually pretty good this time around, only some slight dust at the portal hub area, which can be solved with a bit of lithium grease but it's not necessary. The main wear and tear comes if the car "bottoms-out" and the two perpendicular axle/pin connectors underneath the front axle get scraped. Other than that, this is one tough Lego chassis!

EDIT: To put it in perspective, if you think it's fast, this model is noticeably slower than V1 and V3, those were complete speed demons! But, V1 and V3 had much higher wear on parts with their independent rear suspension, and parts sometimes broke, along with the wheels/suspension being wobbly-which lead to not-so great handling. V2 was a test chassis that I had a great front end idea with but terrible rear axle, only ran it once...but V4 combined the best of all 3, improved on each aspect, and is great fun without any hassles!

Edited November 9, 2013 by z3_2drive

[clarkdef]

That's pretty awesome, I like the fact you decided on rwd, nice little slide I think it was doing here and there. The car also looks hella smooth over the bumps. This is the best RC Lego car I have seen so far. How will you do the body?

[z3_2drive]

That's pretty awesome, I like the fact you decided on rwd, nice little slide I think it was doing here and there. The car also looks hella smooth over the bumps. This is the best RC Lego car I have seen so far. How will you do the body?

If the ground is dusty or slightly wet it can hold drifts around large turns with some slight counter-steer Thanks! But I think any more weight would reduce acceleration, Unless I use a bunch of flex axles which I don't have much of one color.

[clarkdef]

If the ground is dusty or slightly wet it can hold drifts around large turns with some slight counter-steer Thanks! But I think any more weight would reduce acceleration, Unless I use a bunch of flex axles which I don't have much of one color.

Yes very true, I had a largish chassis which was fairly fast, but I had to gear it down once I added the body.

[tibivi]

I like that very much, i like how fast it accelerates

I tested my attempt for building a hobby rc car out of lego yesterday, it doesn't accelerate so fast, but i have only used lego pieces and it reaches about 25km/h

I'll post it here when I get the time

Great car you have!

Tibivi

[zux]

But I think any more weight would reduce acceleration, Unless I use a bunch of flex axles which I don't have much of one color.

What about rollcage body made from axles and connectors? This shouldn't be heavy at all and ther's a lot of ways to create your style.

[piterx]

holy ...!

well done :D !!!

not 100% lego but surely impressive eheh

[skriblez]

Man that car is fast! Great work :)

[trekman]

Now that is one serious RC car. Well done, but I would fear that in a long term setting there is going to be some meltdown somewhere...

[Rockbrick]

ground-huggingly amazing!

each time it comes back from the end of the road you must wonder how many pieces fell off - at least with IR PF controller you see them fall off as you are never that far away....

[legomuppet9]

Looks like a lot of fun, nice work!

[z3_2drive]

ground-huggingly amazing!each time it comes back from the end of the road you must wonder how many pieces fell off - at least with IR PF controller you see them fall off as you are never that far away....

Hahah with most lego models that's true, but I built this to last, as I said it even barrel-rolled and not a piece came off pictures will be soon by the way, I'm quite busy lately. Thanks for all the positive feedback! And as for the meltdown, I've been running this setup for a couple months, and all the parts, from the battery to motors to cables, are running perfectly This model has a dust cover under the rear axle to protect the motors just in case. Edited November 13, 2013 by z3_2drive

[Alasdair Ryan]

Are you going to make a body for it?

Why does everyone wear flip-flops?

[z3_2drive]

Are you going to make a body for it?

Why does everyone wear flip-flops?

Possibly; it's Florida and it's not a public place

[z3_2drive]

The long-delayed pictures:

^the dust guard keeps the motors safe

^the battery fits very snug between the beams.

And if you were wondering, the batteries used to make the pack are similar to these: http://www.ebay.com/...=item43bedcd4a8

^the rear of the chassis does bend a bit under full compression.

^the pneumatic pump provides some extra stiffness when engaged, just like the large cylinders at the rear.

the front subframe is angled up in order to have positive caster without weakening/complicating the suspension and increases overall handling capabilities-the car can drive straight even when you remove the steering links

^I pulled off the symmetrical look I wanted

Here are some new photos with a few tweaks/add-ons I made:

^at the time of the photo there was a very light drizzle, so I put on the top motor-cover.

^everything is nice and protected so there is no damage, but I still only tolerate the lightest of rains as to not risk anything...

The black lego wire in the center is the servo wire, connected to the motor controller. You simply need to know which of the 4 sub-wires control the servo's movements and connect them properly. After that you can change the steering direction while mounting the servo or on the remote control.

^these are the only parts that ever get damaged-as you can see they are easily replaceable-no shame in being lost during battle

^I even went ahead and covered the end of the lego extension wire that connects with the end of the servo's wire.

And finally a burnout on the wet ground

Hope it answered any questions or helped you in your own RC-MOC pursuits!

Edited November 16, 2013 by z3_2drive

[clarkdef]

Very awesome man, so the pumps communicate? I remember back to an anti dive system in a race car, where the front was somehow mechanically linked to the rear, and under heavy braking when the front dived downwards, it would pull the rear down as well, just as a anti roll does left to right this car did front to back. The reason for this setup was because of a lot of down hill braking. Anyway it looks like you came up with a similar idea, yet you have reversed it so when it dives the back raises?...

Also yes the castor at the front is an awesome way to get a return to center, it's a must in my cars, because of the slack in the steering. Those tyres you have would make the return to center very good I would imagine, better than my balloon tyres, do you think this is the case? Balloon vs flat.

[z3_2drive]

Very awesome man, so the pumps communicate? I remember back to an anti dive system in a race car, where the front was somehow mechanically linked to the rear, and under heavy braking when the front dived downwards, it would pull the rear down as well, just as a anti roll does left to right this car did front to back. The reason for this setup was because of a lot of down hill braking. Anyway it looks like you came up with a similar idea, yet you have reversed it so when it dives the back raises?...

Also yes the castor at the front is an awesome way to get a return to center, it's a must in my cars, because of the slack in the steering. Those tyres you have would make the return to center very good I would imagine, better than my balloon tyres, do you think this is the case? Balloon vs flat.

the pumps and cylinders are not linked together, but the torque of the motors causes the rear to go down under braking and raise with acceleration, as the suspension is always somewhat compressed when driving(like in real cars), a perfect balance between soft and stiff. The switches just switch between normal and extra-soft. As for tires, these Unimog tires keep the car more steady and under control, especially in wet conditions. As for return to center I believe it makes no difference, but balloon tires IMO result in less wheel-vibration when steering. This is because they can lean while the flat unimog tires skip across the surface, if you know what I mean-since Lego rubber is extremely hard and plastic-like, so the tires can't deform when turning. Non lego tires would be perfect but you would need a good balance between soft and hard to get the best handling. And non lego tires tend to weigh more Edited November 16, 2013 by z3_2drive

[clarkdef]

Ah! Well it's a cool system and you gave me the idea that the dampers could make it work as well as act as dampers, but those small ones are just so expensive. I hear ya about Lego tyre weight being very light, I actually prefer that to grippy as it means less stress on the control arms etc.

It is nice to see you have allowed for extension in the suspension for negative elevation, very nice!