I'm new here.....first MOC, a tank...

[Someonenamedjon]

Here's the video of the ammunition conveyor belt prototype.....really ugly and cumbersome

But it works

[Doc_Brown]

HUGE first post! Excellent work, inspired me to make a tank next!

I can't wait to see more. :thumbup:

[SteveNesta]

Slight update...fitted some cowling around the gun barrel, just waiting for black parts to arrive on Bricklink then I'll photograph and upload....looks pretty good.

I've fitted two large linear actuators at the rear of the tank, which I now think will be a self propelled gun. They will move a ground attachment to dig into the ground and manage the recoil effect of the gun (in real life that is).

However, I need your help....I am trying to find a mechanism that will push back straight, and then downwards at an angle, as though it were extending and then digging in. Have a look at the photos and the videos to see the fixings. There is also a rotating axle underneath along the centre line, connected to the actuators, that can be used to turn something else, such as a mini LA or some other thing. When this mechanism is operating, a set of lights will flash - huge thanks to those who showed me the uses of the PF switch and how to make a small mechanism to make lights flash :-)

130 Mechanism for the lights

131 Mechanism for the lights

http://thumbsnap.com/s/67QVKt2B.jpg

132 Underside showing the power going left, right to large linear actuators and straight down to a spare axle.

133 As above

Videos:

Linear Actuators

Flashing lights

Edited May 12, 2013 by SteveNesta

[SteveNesta]

Update. A few changes.

- Modified the turntable mechanism, made it smaller.

- Added the black cowling around the gun barrel.

- Changed the tip of the gun barrel. Looks more aggressive now.

- Added the panels to the very front of the tank.

Next up - build the topside body work, and see what else can be added. Thinking about a holder for the front end of the barrel, and a retractable small comms tower.

134 - Underside using the elastic band to make the lower part of the bucket retract. Note: Red cowling now replaced in black thanks to Bricklink.

135 - Close up.

136 - Overhead of the bucket mechanism and large LA's

137 - Front end now with panels.

138 - Revised gun barrel with cowling and new front end.

139 - Simplified and smaller turntable mechanism.

140 - full size tank :-)

141 - All the motors in the rear has a rather detrimental effect on ground clearance :-(

142 - Torsion beam suspension is under strain.

143 - Rear stabiliser. The movement and grip from the rubber tips are enough to lift and move the entire tank.

144 - The other side.

145 - General

146

147 - Rear bucket extending

148 - Bucket extended.

149 - Bucket retracted.

Video:

Bucket movement and mechanism

[Erik Leppen]

You're surely a dedicated builder, that can't be denied. Interestinly, when I read the first post I was already thinking, you should go studded for the frame. Fortunately you found that out yourself already :) I like how you combine the two building systems to their full potential.

And the whole thing is becoming to be quite a monster ;)

There's one thing though. I'm not fond of your twisting-axles suspension idea. Even though Technic axles are a dime a dozen, I don't like the idea of a MOC that damages parts on usage. But I guess that's a matter of taste. I would have gone for springs, or bogies of some sort so that even without springs the wheels have some motion to adapt to terrain.

(Same goes for the rubber liftarms on the bucket by the way. Although it makes me wonder why there's a bucket on a tank?)

Anyhow, I like how you're going to put a working gun on it. Youre doing a great job, carry it on :D

[DLuders]

...why there's a bucket on a tank?

When I was stationed in West Berlin, Germany during the mid-1980s, I lived a few hundred meters away from a US Army tank battery. The "combat engineers" had tanks like this, with buckets that could excavate so that the tank could "hunker down" in a pit, out of view.

[legomuppet9]

When I was stationed in West Berlin, Germany during the mid-1980s, I lived a few hundred meters away from a US Army tank battery. The "combat engineers" had tanks like this, with buckets that could excavate so that the tank could "hunker down" in a pit, out of view.

They also have them for clearing the way and DLuders, the correct term is "Hull Down" so they can only shoot at the turret, American tanks are good at that as a lot of them like the T29 have incredibly tough turrets

[SteveNesta]

You're surely a dedicated builder, that can't be denied. Interestinly, when I read the first post I was already thinking, you should go studded for the frame. Fortunately you found that out yourself already :) I like how you combine the two building systems to their full potential.

And the whole thing is becoming to be quite a monster ;)

There's one thing though. I'm not fond of your twisting-axles suspension idea. Even though Technic axles are a dime a dozen, I don't like the idea of a MOC that damages parts on usage. But I guess that's a matter of taste. I would have gone for springs, or bogies of some sort so that even without springs the wheels have some motion to adapt to terrain.

(Same goes for the rubber liftarms on the bucket by the way. Although it makes me wonder why there's a bucket on a tank?)

Anyhow, I like how you're going to put a working gun on it. Youre doing a great job, carry it on :D

Thanks for the kind words :-)

Here's a picture of a tracked self propelled gun with a 'bucket' at the rear...the rubber lift arms just provide a great level of grip.

It's certainly pretty big, at 67 studs in length without the bucket and 24 studs wide body-only. 1.98Kg without battery packs....so far.

The torsion beam suspension is a good use of Lego in my opinion, and the axles don't seem to suffer lasting damage when inspected. I've just swapped them around from left to right, so that they are now being twisted in the opposite direction. I've also added 2 further sets of road wheels, reducing the weight/strain per axle and it now sits much better with significantly less twisting. I'm looking at potentially adding a spring on the rear end road wheels to further reduce axle twist. I'd love to use a mini LA to change the ride height, but I think I've enough headaches for the moment :-)

The gun is cool....I've just increased it's power again by moving the springs 1 stud forward so that compression starts earlier and is held longer before release. I'll see if it works and whether the motor can turn it.

I hate the top mounted reloader, but it does the job at the moment. I'm going to find a way somehow to find a mechanism to load from underneath to keep the model looking relatively sleek. I'd love it if I can get that to work.

Back to the bricks now ;-)

Edited May 19, 2013 by SteveNesta