First Post and a plea for help for a creative way to attach an M motor

[Dreadredbeard]

First off I'd like to thank you all for the amazing ideas. I have gone back dozens of pages in the forum to admire the many models and unique answers to some questions I've had about building.

That being said I'm in a quandary for my own creation :(

I started with a crawler chassis but I wanted to add forced articulation to increase it's performance.

Here was the original design that only had 2 points of forced articulation:

(Sorry for the picture quality, the rest are much better!)

This design worked very well but obviously wasn't ideal because only the "Front" of the crawler's suspension could be adjusted.

My next design incorporated all 4 points of forced suspension:

(Please pardon the aftermarket tyres)

This design worked okay, however, with the position of the Linear actuators there was no option for NEGATIVE travel, the axles could not move "up" from ride height.

The easy solution at this point would have just been to lengthen the frame to allow the linear actuators and M motors to be placed further down in the cradle to allow them to push up on the swing arm. but I didn't want to rebuild and redesign the entire suspension and I enjoy the current length of the crawler.

Which moves me to the most recent design for the actuators:

This design has filled my requirements for positive and negative forced travel of the suspension.

Here it is at normal ride height:

Here it is at full droop:

Here is full compression:

And finally here is the mixed stance at full extension and droop:

(Do be aware the back left tyre is NOT in contact with anything)

I am very happy with the performance, but I find myself unable to find a place to mount the M motors to run the actuators remotely...

My original plan was to run the M motors through the side, underneath each opposite actuator, in this area:

(Where the grey axle would be extended and connected to the motor)

While this partially worked, it limited the actuator above it from being able to retract completely, and the M motor stuck out a very large amount from the sides of the model.

I then thought of trying to mount the motors on TOP of each actuator, something like this:

But with the very limited clearances I don't know how to securely attach and gear the M motor to the actuator.

Another option I have thought of would be to mount the M motors higher in the chassis, and run U-Joints to the actuators:

With this solution I still cannot find a good mounting point for the motors, and I worry about the U-joints slipping off with constant movement of the actuators.

Finally I thought of mounting the M motors behind each actuator, but there simply is not enough room to accomplish this:

So I come to you for help!

I feel as though I am very close to finishing this drivetrain, but this one solution stops me from being able to continue... Any advice would be greatly appreciated!

Thank you for reading and sorry for the long post!

[Zerobricks]

If you really must complicate with LA's.... Put one M motor on the abck of each LA.

[cgg199]

The area on the last picture, put another 12 tooth gear meshing with the 20 tooth gear, directly out of an m motor.

[Alasdair Ryan]

Welcome to Eurobricks Dreadredbeard.

I agree with Zbij,that would be the easiest solution.

However this would require you needing to lengthen the chassis by about 3 stud on ether end.

The area on the last picture, put another 12 tooth gear meshing with the 20 tooth gear, directly out of an m motor.

I do not think that's going to work,I think it would limit the amount of movement in the suspension.

[vmln8r]

Failing a complete redesign, what about parallel with one of each pair of LAs?

[Lipko]

How about placing the motors vertically at the driven end of the LAs?

Or how about micro motors?

Edited March 14, 2013 by Lipko

[Lakop]

Hi,

Could you mount your M motors above the actuators? Desing a structure/frame for the motors to sit above the actuators.

Failing that have you considered pneumatics.

H

Just to clarify. When I say put the M motors above the actuators, I mean for them to be pointing down towards the actuator.

H

[cgg199]

I've made a design that MIGHT work, but I'm not sure. I'll post a picture when I can.

[Zerobricks]

One more idea, use smaller LA's?

[cgg199]

The range in suspension height would only be very small if the smaller LA's were used.

I don't know if this will fit, or if it would be useful, but give it a go if you want. If you want the LDD file, for instruction, I'll happily send it.

It's 4 studs wide, and 7.5 studs high, with the 24 tooth gears, but, with different gear ratios, could be lowered to 7 studs high.

EDIT : Nevermind, it's too wide. I'll get designing again.

EDIT 2 : Here is a narrower 3 stud wide version that will need a bit of modification for strength.

Edited March 22, 2013 by cgg199