[MOC] Mark 6 LEGO Autoloader Tank

[Kelkschiz]

maybe base the tank off of a real vehicle for added challenge ?

modern vehicles have very wide turrets. and what are you working on at the moment ?

Yes well, building a replica would certainly be a challenge for me, since i've never really done that. On the other hand, if there is anything that excites me and gives me enjoyment, it's building functionality. And i'd like to let form follow functionality. I don't want to restrict myself to a certain form. I also like to see the new forms that emerge by this creative process. Maybe i'll reach a point where i'd like to include all i learned into a replica, but that wont be for a long time, i think. That doesn't mean i don't enjoy really nice LEGO replicas of tank, like you make.

Besides tanks i love sailing ships. At the moment i am making a LEGO sailing boat. It will be my first attempt, so it's nothing fancy, just some basic functions and ugly as hell.

Very curious how your Sturmtiger will turn out, i imagine it will be quite a beast :).

[Tommy Styrvoky]

what about a Challenger 2 tank, it's similar to some of your previous designs.

and heres the finished firing mechanism

Lego SturmTiger firing mechanism by Tommy Styrvoky, on Flickr

and some progress on the tank

Lego SturmTiger 1/15 (RC) by Tommy Styrvoky, on Flickr

[Kelkschiz]

That Challenger 2 looks really nice, i can see the similarities. I'll think about making a replica of that some day. You are quite persistent .

[Sariel]

I just noticed the gyro JM1971 was tanking about is a sensor, which could also be useful as it would be able to detect the elevation of the hull and compensate for it.

Or you could use a counterweight for the barrel (see 2:28):

[Kelkschiz]

Or you could use a counterweight for the barrel (see 2:28):

Yes, i had a similar balancing barrel on my Mark 3. However what i really want is not a barrel that self-levels with the ground, but that levels with the aiming point. If you'd aim perfectly horizontally that would be the same thing. But if you'd aim with a 10-degree elevation and the hull is elevated by 5 degrees, then the resulting elevation of the barrel should be 5 degrees not minus 5 degrees as your Leopard 2A4 would do, unless i am missing something.

I think it can be done by adjusting the balance in the system, for instance by shifting the pivot-point or by shifting some weight. It could also be done by using the EV3 gyro and some programming, but i'd rather do it purely mechanically. In any case it will be some time before i will build a new tank.

Edited June 26, 2014 by Kelkschiz

[Tommy Styrvoky]

I might have found a solution for a self leveling gun. It uses a servo attached to a gun carriage with some gearing to allow the gun carriage to "float" freely when the ground angle is changed. A counterweight attached to some gearing on the rechargeable battery box allows for 15 positions of the counterweight, The servo mimics those positions and compensates the barrel by moving the gun up how many positions the counterweight has moved. The elevation mechanism for the gun is attached to the gun carriage.

Here's a image of what I mean, I don't have the parts to test it, but if someone is willing to try it would be helpful.

lego vertical stabilizer concept by Tommy Styrvoky, on Flickr

[Kelkschiz]

I like how you used the battery box in combination with a counterweight as a sort of attitude sensor. But if i follow you correctly it would mean you'd just get a 'balanced' barrel. Meaning it would act more of less the same as a well balanced barrel, like Sariel has done. The problem with such a system is that it only works with the barrel at one level of elevation. For instance if the barrel is horizontal it will keep the barrel horizontal. However it would stop working when you wanted to elevate the barrel. Or am i making a mistake? Your system could be used as an 'authentic' stabilizer if you would also be able to rotate the counterweight. But i hate to think how much space such a system would take up...

[Tommy Styrvoky]

I like how you used the battery box in combination with a counterweight as a sort of attitude sensor. But if i follow you correctly it would mean you'd just get a 'balanced' barrel. Meaning it would act more of less the same as a well balanced barrel, like Sariel has done. The problem with such a system is that it only works with the barrel at one level of elevation. For instance if the barrel is horizontal it will keep the barrel horizontal. However it would stop working when you wanted to elevate the barrel. Or am i making a mistake? Your system could be used as an 'authentic' stabilizer if you would also be able to rotate the counterweight. But i hate to think how much space such a system would take up...

The 2 systems are separate. The gun carriage has a m motor and linear actuator attached to the gun barrel for elevation. this allows for the gun to elevate/depress, while the servo keeps the carriage level with the ground. Though it will tilt the carriage if the hull of the tank changes position . I suggest mounting the battery box in the hull and the servo in the turret. it seems like there's enough room for this mechanism in the front or rear portion of the hull, the drawback is that if the tank is facing backwards... well there could be a switch that changes the polarity of it once it reaches past 180 degrees.

Another problem that I thought of when designing it is that if the tank speeds forwards or falls the gun will move up or down (though most real vehicles do this) a solution to this is that there's the same gear ratio on the servo as the battery box. the servo normally rotates 90 deg. in 7 increments but if it's geared down to 30 deg. with 7 increments, this allows for a total of 60 deg. of stabilization. allowing the gun to tilt roughly 4 degree's per increment or 3-4 studs of vertical movement per increment

Edited November 7, 2014 by Tommy Styrvoky

[Kelkschiz]

The 2 systems are separate. The gun carriage has a m motor and linear actuator attached to the gun barrel for elevation. this allows for the gun to elevate/depress, while the servo keeps the carriage in position though it will tilt the carriage if the hull of the tank changes position . I suggest mounting the battery box in the hull and the servo in the turret. it seems like there's enough room for this mechanism in the front or rear portion of the hull, the drawback is that if the tank is facing backwards... well there could be a switch that changes the polarity of it once it reaches past 180 degrees.

Another problem that I thought of when designing it is that if the tank speeds forwards or falls the gun will move up or down (though most real vehicles do this) a solution to this is that there's the same gear ratio on the servo as the battery box. the servo normally rotates 90 deg. in 7 increments but if it's geared down to 30 deg. with 7 increments, this allows for a total of 60 deg. of stabilization. allowing the gun to tilt roughly 4 degree's per increment or 3-4 studs of vertical movement per increment

Ah yes I understand now, interesting. Except for the drawback you mentioned, it seems like it should work, unfortunately i don't have a servo or that kind of battery box either.

Edited November 7, 2014 by Kelkschiz

[Tommy Styrvoky]

Ah yes I understand now, interesting. Except for the drawback you mentioned, it seems like it should work, unfortunately i don't have a servo or that kind of battery box either.

it's cheaper than a NXT though and smaller, I don't have the parts either but it's around $70-$80, unless you use bricklink. Edited November 7, 2014 by Tommy Styrvoky