[TC22] Mini RC Tracked Loader

[SaperPL]

I've redesigned the internal structure and it is rigid now. I've also replaced black liftarm with alternating pin holes with standard one to move the attachment point of the linear actuator by one stud for increased lift. I'm waiting for white liftarms and white 3x7 panels to replace those two elements.

The black connector on the liftarm is moved forward from the middle of the arm to lock against the wheel arch panel sockets on the side and prevent pushing arms into the tracks.

I worked a bit on the look of the running gear. I'm in a weird situation where tracks are a bit too tight but if I add another link or replace one of the gears with 8 tooth gear, I end up with loose tracks again.

I'm considering a rear like this as those loaders usually have the back slightly wider than the main body. I had to move the tilt levers to the outside and it's not perfect, but the added value of this move is that they won't interfere with linear actuators this way.

The hub is placed asymmetrically to fix the issues with everything being attached with half stud step. It also allowed me to make a 1 stud wide gap for cables next to it which works really well.

[TechnicMOCer]

On 5/2/2022 at 2:13 PM, SaperPL said:

I've redesigned the internal structure and it is rigid now. I've also replaced black liftarm with alternating pin holes with standard one to move the attachment point of the linear actuator by one stud for increased lift. I'm waiting for white liftarms and white 3x7 panels to replace those two elements.

The black connector on the liftarm is moved forward from the middle of the arm to lock against the wheel arch panel sockets on the side and prevent pushing arms into the tracks.

I worked a bit on the look of the running gear. I'm in a weird situation where tracks are a bit too tight but if I add another link or replace one of the gears with 8 tooth gear, I end up with loose tracks again.

I'm considering a rear like this as those loaders usually have the back slightly wider than the main body. I had to move the tilt levers to the outside and it's not perfect, but the added value of this move is that they won't interfere with linear actuators this way.

The hub is placed asymmetrically to fix the issues with everything being attached with half stud step. It also allowed me to make a 1 stud wide gap for cables next to it which works really well.

Nice! Did you sloved problem with sudden start of driving?

[SaperPL]

1 hour ago, TechnicMOCer said:

Did you sloved problem with sudden start of driving?

Not really, the issue is that hub from CADA doesn't have proportional control and if I geared down the movement speed, it'd mean the loader is moving really slow. What I would need to do is to buy buwizz 2.0 or mould king hub and controller, and I don't think I'm going to do that just for this model. I already have a lot of RC hubs :P

[SaperPL]

Made a video on the final version:

 

Will have to make some cool photos for the entry, and maybe update the title :D

[1980SomethingSpaceGuy]

I love this little machine! It has a nice WALL-E touch to it and going full RC at this scale is just amazing.
Ok, it's not pure Lego, but the more time passes, the more often Lego confirm they can't do well with electronics and the more I get why third party solutions for that aspect really make sense.

[SaperPL]

32 minutes ago, 1980SomethingSpaceGuy said:

I love this little machine! It has a nice WALL-E touch to it and going full RC at this scale is just amazing.

Thanks! As for the scale - I was too lazy so far to even check the scale xD

32 minutes ago, 1980SomethingSpaceGuy said:

 Ok, it's not pure Lego, but the more time passes, the more often Lego confirm they can't do well with electronics and the more I get why third party solutions for that aspect really make sense.

Yeah, that's exactly the issue - what annoys me with Lego is that they should have already done a proper physical controller that doesn't require using a phone. CADA's hub is plug and play and it blows my mind how long the battery lasts. It beats all the shenanigans with control+ hub, but enforces different build style where I cannot set a specific servo angles etc.

[SaperPL]

The model is in progress - still need to split it into steps before I can make instruction:

I've also made the bounding box:

Counting on the outside its 15 x 25 x 15 which is 5625 cubic studs.

If I didn't had the lights on the edges of the arms, counting on the inside/close to the surfaces it would be 13 x 23 x 15 which is 4485 cubic studs.

Right now, if I posed it precisely for measurements, it can fit within 14 x 23 x 14,5 which is 4669 cubic studs

[Appie]

I really like how this turned out! It's very cute in how small it is and fully functional.

 

Personally not a fan of the usage of Cada motors, but that's just a personal thing. I draw the line at 3rd party battery boxes like Buwizz or recievers like Sbrick (and even those I tend to use rarely), but this model is a great demonstration as to why Lego should make a new micro motor already.

[SaperPL]

Thanks!

And yes, this is something that we've seen with Sariel's MOCs based on circuit cubes as well. We need small motors and small servos, we have small motors with CADA and circuit cubes and I believe circuit cubes is investigating possibility of making servo (I asked them about it like half a year ago), but I don't know if that's going to be small or a big cube part.

I also prefer use of Lego original parts in context of purity, but at the same time the plug and play aspect of this CADA hub is amazing. I've got two powered up hubs that I don't really use anymore because setting up profiles is annoying. I wish that someone made a physical controller for those already because I really prefer the liftarm based building over system.

[SaperPL]

Finally got time to make some outside photos for the contest entry:

I'm also going to rename the topic to Mini RC Tracked Loader since I've ended up slightly off from the original concept of bobcat's straight lift arms geometry.

[SaperPL]

Instructions are available on Rebrickable: https://rebrickable.com/mocs/MOC-130581 although note that I made them long after the original model was disassembled for other projects (the full studio model survived though).

Sneak peek on the instructions in this short video as well:

 

Edited December 3, 2022 by SaperPL