LEGO RC Tank Project (WiP)

[Voodoo Hand]

Finally had the time to start on my personal LEGO project, and this was planned in real LEGO instead of MLCAD version!

To start out it should show that I am capable of doing much with not much LEGO at all.

Many take me for granted and don't think I can actually do much, the truth is however that

I don't have the space to sit down and use my LEGO as I want to. But also the lack of

actually owning the right bricks and right ammount is the problem as well.

Now I want to finally realize my ideas for making a tank that is working on multiple areas.

Due to not owning the right things before, I couldn't do much in this. But now I can actually

do something. I warn everyone that my model will NOT be in color theme since

I don't have that much LEGO in real life. So please don't state the obvious, just focus on the model itself!

The Idea

The general idea is to have a RC tank created from LEGO as the title suggests!

But besides the obvious, there is more to the project then just another MOC!

- RC controlled Tracks (WORKING!)

- RC controlled Turret (not created yet)

- RC controlled barrel (not created yet)

- possible other RC controlled features!

Yes it is simple, but we all had to start somewhere! Besides, my model has space enough to expand later on!

One of the very first photo's!

Links

MOC Pages Link

Brickshelf Link (when active)

[Porty]

This was actually going to be my next project once I get 9398 and 8110.

[timslegos]

Looks good so far. i can make one suggestion though, i would move the motors closer to the wheels that are being driven. the longer the axles, the more likely they are to bend and warp and twist. otherwise looks great!

tim

[88high]

Good job! I wish I had som larger treads:) my only suggestion is to raise the bottom of the treads for better ground clearance over rough terrain. Suspension would be cool too! Keep us posted :)

[DLuders]

@ Voodoo Hand: I like the wheel bogeys on your tank:

If your tank is not running in a straight line, it could be that the Lego Technic Treads are not "matched" to be the same on each side. There is a difference in the ability of the newer tread pieces to bend around the sprockets, so one side of the tank could encounter more friction (and thus, turn a bit via skid steer). You should both read this TechnicBRICKS article about the "New(er) Sytle for Wide Link Treads":

The 57518 Technic Treads have appeared since 2007, and one can select parts from older (~2007-2009) Technic sets to get the older type treads (per this Bricklink webpage). One can alternate old/new/old/new Technic Tread pieces to get around the problem of tight bends:

[Lipko]

I don't think the new style links make a big difference, since they are hinging in the different direction to where the extra material is added. It seems to affect the abilities of the thread when it's turned inside out, but not when used normally.

[Voodoo Hand]

@DLuders:

Oh thanks for that tip! Sure will look for that! Should likely solve the problem! lol. However, bad side is that the tracks will become shorter then. So i likely need to redesign/rethink things to get it working properly.

@timr:

I was actually thinging that as well. However, they do need to be raised up else they will likely hit the ground or get the tank stuck on something else. So i may need to figure out how to solve that little problem.

@88high:

I tried to get in suspension but couldn't figure that one out. Besides that, I have the problem that I do not have enough rubber bands to cover each wheel either. So I guess I'm stuck with this for the moment. I need to get out to get some food anyways, I may just as well look around for rubber bands in stores. Perhaps I find something usefull there!

@Porty:

Good luck with your project!

I been thinking to completely start all over again, since there are multiple problems with the current design.

- tracks that refuse to go in a straight line

- tank is a bit narrow for it's length

- I'm not satisfied with the batterybox location

- engines may need to move a little

- possible to add suspension gear 9if I can find the right bricks and rubber bands)

But let me know what you guys and girls think. Perhaps some help or suggestions to get it back on track?

Sets owned that may be a solution:

8265 - Front loader (not ripped apart yet)

8275 - Motorized Bulldozer (ripped apart)

8043 - Excavator (ripped apart)

8284 - Dune Buggy or Tractor (ripped apart)

8285 - Tow Truck (untouched still)

8448 - Super Convertible (untouched still)

[Rikus]

@88high:

I tried to get in suspension but couldn't figure that one out. Besides that, I have the problem that I do not have enough rubber bands to cover each wheel either. So I guess I'm stuck with this for the moment. I need to get out to get some food anyways, I may just as well look around for rubber bands in stores. Perhaps I find something usefull there!

You should try to use torsion bar suspension, for the small wheels, as Sariel did in his Leopard 2A4 tank.

This is a very effective and simple system, much simpler to implement than using rubber bands and other.

[Voodoo Hand]

You should try to use torsion bar suspension, for the small wheels, as Sariel did in his Leopard 2A4 tank.

This is a very effective and simple system, much simpler to implement than using rubber bands and other.

Which ones are those? Have a picture for me please?

[Rikus]

Which ones are those? Have a picture for me please?

You can find more info about this system, applied to a tank, on Sariel's website.

HERE

You'll find a lot of useful info on Technic building and on Tank building on his site, too.

Of course, as Sariel says, there is the possibility that the axles used for this purpose cuold be damaged, but the results are excellent.

Otherwise, you should try using simple "pendular" suspension system to the wheels, linking them in couples with a liftarm, with a friction-free pin in the middle.

Edited March 28, 2012 by Rikus

[Voodoo Hand]

You can find more info about this system, applied to a tank, on Sariel's website.

HERE

You'll find a lot of useful info on Technic building and on Tank building on his site, too.

Of course, as Sariel says, there is the possibility that the axles used for this purpose cuold be damaged, but the results are excellent.

Otherwise, you should try using simple "pendular" suspension system to the wheels, linking them in couples with a liftarm, with a friction-free pin in the middle.

Ok thanks for that link! Will look into that after I get back from buying some food!

[Scorpion]

Wow, Voodoo Hand, your project is eerilly similar to the first iterations of my own effort! With some differeces, of course: the location of the engines and the battery is switched and I used M-motors instead of XL (silly me, that poor thing couldn't even turn in the grass!).

Curiously, my own tank also can't run straight! I guess it has something to do with the fact that one of the engines is "reversed" on the remote. Is that also the case in your project?

I'm also trying to make a full tank, turret and all! I guess I better step up my game, the competition's closing in! :p

Best of luck for your project! Oh, and just a hint for the suspension: shock absober.

[Voodoo Hand]

Wow, Voodoo Hand, your project is eerilly similar to the first iterations of my own effort! With some differeces, of course: the location of the engines and the battery is switched and I used M-motors instead of XL (silly me, that poor thing couldn't even turn in the grass!).

Curiously, my own tank also can't run straight! I guess it has something to do with the fact that one of the engines is "reversed" on the remote. Is that also the case in your project?

I'm also trying to make a full tank, turret and all! I guess I better step up my game, the competition's closing in! :p

Best of luck for your project! Oh, and just a hint for the suspension: shock absober.

This project is indeed in very early stages, I first want to finish the chassis to perfection. Or at least close enough to that. But tracks on a bigger vehicle (such as a big tank) need the XL motors, since the M motors will not be able to do much. You can try to make a smaller tank which can use the M motors

Making the engine in 'reverse' does not matter, or should not at least. It just does the same thing otherway around, thats all. For shock absorbers, unfortunately I don't have enough of those at this time. I did buy some rubberbands, which are just a little bigger then the official LEGO rubberbands. So I should be able to do something with that.

I also working on full design with turret, but thats far later in the project. My project is not for a competition though, but perhaps later on when it's nearly done!

[Rikus]

About the problem on the tracks, going unevenly in forward, you can try this:

Step 1: look at it in forward and in reverse, if it turns in opposite directions, the problem is that the torque of the two motors is different if they turn CW or CCW. To solve this, simply add a 1:1 gear to one of the motors, so they will turn in the same way to go forward/reverse.

Step 2: If the first fail, simply invert the connectors on the RC receiver and try it; if the tank turns in the other direction, the problem is in the receiver (this cuold happen, but is very unlikely)

Step 3: This time, try to invert motor positions and make a test; if the tank turns in the other direction, the problem is in the motors (different performance), you have to find another motor or you can try applying a 1:1 gear to one of them, to introduce some friction and lower performance of that motor.

If none of the above works, it could be a problem with link friction... in this case all I can think is to check if both of them are mounted in the same way on the wheels...

[Voodoo Hand]

About the problem on the tracks, going unevenly in forward, you can try this:

Step 1: look at it in forward and in reverse, if it turns in opposite directions, the problem is that the torque of the two motors is different if they turn CW or CCW. To solve this, simply add a 1:1 gear to one of the motors, so they will turn in the same way to go forward/reverse.

Step 2: If the first fail, simply invert the connectors on the RC receiver and try it; if the tank turns in the other direction, the problem is in the receiver (this cuold happen, but is very unlikely)

Step 3: This time, try to invert motor positions and make a test; if the tank turns in the other direction, the problem is in the motors (different performance), you have to find another motor or you can try applying a 1:1 gear to one of them, to introduce some friction and lower performance of that motor.

If none of the above works, it could be a problem with link friction... in this case all I can think is to check if both of them are mounted in the same way on the wheels...

First time for the dentist, then ill check your suggestions out! Thanks for the suggestions!