I'd like to show you my progress on my pneumatic tank.

It includes the following functions:

• Driving
  
• Rotating of turret
  
• Shooting
  
• Barrel adjustment
  

Both tracks can be controlled separately. I used gearracks to transform the linear motion into rotation to drive the tracks.

I used a combination of gears to allow the tracks to move forward by extending and contraction of the cylinders.

Therefore it is ony possible to drive forward.

I limited the rotation of the turret by a 90 degrees to the left and 90 degrees to the right. This allows for the hoses to go through the turntable.

The shooting mechanism shoot when the cylinders extend, and when the retract. This allows for relatively fast shooting.

Do you have any suggestions what can be added or improved, just let me know.

Edited September 19, 20168 yr by KvM

Interesting idea . Any pictures with the progress ? Also , the title should be [TC10] not [TC]

Interesting idea . Any pictures with the progress ? Also , the title should be [TC10] not [TC]

Yeah I know, my mistake. I see it is already changed!

Pictures are just posted, i was struggling to deeplink them.

Your response was too fast for me

Now i see the beautifull engeniering that went into that tank ;)

I cant wait for the vid to see this moving its such a brilliant idea. I'm not that good with pneumatic so i'll ask a dumb question for myself, is the pneumatics strong enough for the weight of the tank to move it?,

Interesting idea and I'm really looking forward to see its progress...!

I had to slow it down to generate enough torque but from the first test it worked OK.

At the moment I'm busy with the bodywork, which is quite challenging for me.

Do you have any suggestions for more functions?

A really interesting project! I think that it has already a good number of functions, but if you want to add more, maybe an openable rear door. Or maybe an attachment for some equipment like a plough or a de-mining device!

Here a short update.

I started with the bodyworks. The drawback of light blue gray lego is the lack of curved panels.

I doubt whether I will make the body more colorfull or just black? Any suggestion?

I will continue to improve the bodywork before I implement the pneumatic compressor and the hoses.

I will probably change the barrel and add plates to cover part of the tracks. Finally I need to add some details.

A belly shot. I need to change the suspension system, which will most probably be a torsion rod based suspension system.

Looks great so far. As for the bodywork, you might mix white, orange and black. Lipko pulled it off to great effect on his telehandler. Not sure how good it'd look on a tank but it's worth a try.

Great progress! I can't help you with the "panel" thing, I not really into it that much... Probably some cool mixture would work on a tank...well at least on a happy tank...

I used gearracks to transform the linear motion into rotation to drive the tracks.

I used a combination of gears to allow the tracks to move forward by extending and contraction of the cylinders.

Can you elaborate on this? If the linear motion is alternating, how do you convert the alternating rotating motion to a one-directional rotation? You said part of it is a rack and pinion, right?

Can you elaborate on this? If the linear motion is alternating, how do you convert the alternating rotating motion to a one-directional rotation? You said part of it is a rack and pinion, right?

Maybe he made a pneumatic engine?

As you can see in the picture of the bottom, I use a series of gears to make sure the end rotation is always the same. This can be realized by a gear which is not fixed in position, but depending on the direction of motion, it is forced towards another gear.

The little cylinder in the rear bottom switches the valves which allows to continue operate the main cylinder extending and then retracting. However due to the mechanism which fix the direction of rotation the motion of the tank is not continuously. I will show it later in a movie!

As you can see in the picture of the bottom, I use a series of gears to make sure the end rotation is always the same. This can be realized by a gear which is not fixed in position, but depending on the direction of motion, it is forced towards another gear.

The little cylinder in the rear bottom switches the valves which allows to continue operate the main cylinder extending and then retracting. However due to the mechanism which fix the direction of rotation the motion of the tank is not continuously. I will show it later in a movie!

That's a very interesting solution! Thanks for the explanation.

Well, I don't know how much interruption this mechanism causes you, but something else I did in college to achieve rotation in a constant direction was use two one-way bearings and a couple of gears. Implementing one way bearings in Lego, though, is probably not too trivial, and could probably only be replaced by a clutch gear with a pin that only lets it rotate in a single direction. However, if you're willing to accept non-purist solutions, one-way bearings will provide a clean alternative solution.

For the mis-colored panels, just replace those parts with plates.

Here another update.

I added an opening rear door and changed most of the panels to white.

Still enough work to do.

Looks better now. But when will you start with the tubes?

Looking good! Looking forward to seeing a video of it in action.