Help in improving tank suspension

[general molotof]

Hi all,

So recently I have been building a T-90A at 1:25 scale. I solved a lot of problems but i am stack with an under performing suspension system. The problem lies at the road wheels, the way they are attached to the suspension, and the traction between them and the tracks, not the mechanism itself (which is fairly responsive).

Let me explain:     (sorry for the picture quality, it won't let me upload better ones)

There are two sets of 4185 wheels, attached to a 30374 light saber blade (which acts as the spinning axle). The light saber blade is itself attached to a 6632 1x3 thin lift arm, which is then attached to a 15462 5L axle with stop that acts as the pivoting axle of the suspension. The suspension is made of orthodontic rubber bands, but the smaller Lego rubber bands should work as well (i tried to explain the poor quality pictures as best as i can).

The problem: The light saber blade creates a lot of friction with both the wheels and the axle socket of the liftarm, so when the tank moves, the wheels won't spin (which is a problem). I am asking here for help, does anyone more experienced than me has a better solution (note that the overall dimensions of the suspension, must not change in order to keep up with the scale).

Thanks in advance!

[Tommy Styrvoky]

You may want to try this solution, it better fits the scale, as the distance between road wheels should be around half of a stud. If it is larger than this, it will make the model too long for its scale. I think this solution is better than the rubber bands, as it's more compact, and it doesn't utilize more of the space along the sides of the hull, instead it uses up the space at the bottom of the hull. Also using tires with rubber on them will make the model look more realistic. I don't know if you have plans to motorize this model, though it will be a challenge to fit everything inside of the rather narrow hull of the T-90.

You may need to double up the rubber parts if the model gets too heavy for the suspension.

LDD file

 

 

 

[general molotof]

On 9/18/2017 at 5:49 PM, Tommy Styrvoky said:

You may want to try this solution, it better fits the scale, as the distance between road wheels should be around half of a stud. If it is larger than this, it will make the model too long for its scale. I think this solution is better than the rubber bands, as it's more compact, and it doesn't utilize more of the space along the sides of the hull, instead it uses up the space at the bottom of the hull. Also using tires with rubber on them will make the model look more realistic. I don't know if you have plans to motorize this model, though it will be a challenge to fit everything inside of the rather narrow hull of the T-90.

You may need to double up the rubber parts if the model gets too heavy for the suspension.

LDD file

Thank you very much for the informative answer! The model has been actually finished: http://www.moc-pages.com/moc.php/442104 . And yes it has some problems that i am trying to fix! Your solution seems very good indeed, i also wanted to add rubberized wheels but didn't have the space, now it seems possible! I have some concerns though, the model weight is roughly 0.95Kg and will propably rise to 1Kg when it is done, as you will see from the pictures at mocpages, there is simply no more space than one stud for the suspension at each side of the hull. Will this solution be able to hold this kind of weight? i won't be able to sacrifice more space inside! Thank you very much for the answer and if you have any comments on my model, i would be glad to hear them! 

Edited September 20, 2017 by Milan
Removed quoted pictures.

[TeenLegoBuilder]

On 9/18/2017 at 5:49 PM, Tommy Styrvoky said:

You may want to try this solution, it better fits the scale, as the distance between road wheels should be around half of a stud. If it is larger than this, it will make the model too long for its scale. I think this solution is better than the rubber bands, as it's more compact, and it doesn't utilize more of the space along the sides of the hull, instead it uses up the space at the bottom of the hull. Also using tires with rubber on them will make the model look more realistic. I don't know if you have plans to motorize this model, though it will be a challenge to fit everything inside of the rather narrow hull of the T-90.

You may need to double up the rubber parts if the model gets too heavy for the suspension.

LDD file

Thank you so much for these pictures. I was stuck for so long on how I could integrate more clearance while also having a reliable suspension. Your post made my day and I will always be grateful for you making this post.

Edited December 21, 2020 by Milan
Removed the quoted pics from the same page.