Oh, well, that's it! I knew it is worth to throw the problems here.  I will test it for sure. Meanwhile I had to investigate the electric system and replace the battery of my ZRX, but now I am back to LEGO.

The modules come nicely together, till now I only had to change very little, and add some parts for sake of easier buildability. To be tested: gear ratios, locked diff, or open ones, body color.

EDIT: it is alive, on low batteries... and clicking in the front... I have no clue, everything is bracketed.

EDIT 2: I think the U-joints are not up to the forces. So, I need to test the open diff version, just for sake of saving parts... Or should I keep it as it is, and just replace broken parts? Which hand to bite? I think I will release both, and everyone can pick.

 

Edited December 15, 20177 yr by agrof

1 hour ago, agrof said:

I think the U-joints are not up to the forces.

But U-joints don't click or do they? Are you sure it's not the CV-joints that click? Did you fill the axle between the U-joint and CV-joint with (half) bushings?

I disassembled, and changed to differential. I learnt the next:

• U-joints were not harmed at all  (they can crack at axle joints, and in extreme conditions they jump on axle)
• With differential it is even worse, the 20 teeth gears slip on differential housing, unfortunately there is still enough space for part deformation.
• According above experiences, I guess the locked version slips as well within the bracket, as I saw the gears rotating.

I have no idea, what official solution could help, for now I settle with the locked one - as below:

I'm afraid the best way is to enclose the diff and 20t gear in a single frame. If you PM me the LXF I could look into it better.

EDIT: I think the problem has to do with the bracing to the left and right side of the diff. Even the toggle joint needs to be somehow confined to its left and right sides.

Edited December 15, 20177 yr by Didumos69

Here is the WIP lxf file, including both versions.

Thanks for the help! I am now confused, built it back, and it still looks like the U-joints make the slip. I need to disassemble to check them properly. I might change the concept to gear it up for bashing, but crawling would be better.

EDIT: deleted LXF as it was temporarly file.

Edited December 16, 20177 yr by agrof

11 hours ago, agrof said:

Here is the WIP lxf file, including both versions.

Thanks for the help! I am now confused, built it back, and it still looks like the U-joints make the slip. I need to disassemble to check them properly. I might change the concept to gear it up for bashing, but crawling would be better.

Going by the LXF I fear the diff and the toggle joint are not braced good enough sideways. I don't see any obvious ways to improve that. Only for the locked-diff version I see a few small twists that might help a little: 1) add a bush inbetween the U-joint and the CV-joint, so the U-joint won't be able to move towards the CV-joint, thus confining the toggle-joint better, and 2) add some parts to the sides of the toggle joint to make it better locked-in between surounding parts. I think the shocks leave some space for a cross-block. Its pinhole takes a full stud in width. Adding a 1L beam inbetween the toggle-joint and the cross-block should secure the toggle-joint better.

But it remains to be symptom treatment. The main issue is the lack of widthwise cohesion in the front section. I think it would be better to use the H-frames horizontally.

Edited December 16, 20177 yr by Didumos69

I tried it, added the solution like that (though there is still a tiny gap inbetween the parts). The U-joints are still in perfect conditions, no cracks, nothing.

Also I reduced the gear ratio, not with clutch gear, as it did not work at all. It is replaced to the normal 24 teeth gear.

Now it can crawl at least, don't judge the rear axle and suspension, it is just temporarly.

 

Edited December 17, 20177 yr by agrof

This is shaping up to be amazing! Very powerful!

Best of luck with it  I assume you will work out a solution to make sure the rear shocks won't fall out like they did?

2 hours ago, agrof said:

though there is still a tiny gap inbetween the parts

If you would use a crossblock there should be no gap.

Edited December 16, 20177 yr by Didumos69

I don't see why would it be different as in the pictures, the width of all components are the same as the crossblock.

I figured out, how to reinforce the lower pivot point of the front swingarms, now it works fine. Unfortunately I can not adjust properly the springs, I tried all possible configurations (soft-compressed; hard - compressed/not compressed; extra hard - non compressed), it is not bad, just a tad harder than I would prefer.

Also the rear axle must be stabilized against torque twist. Other than that, not too bad. Thanks for poor light: lost and found footage is below. 

 

1 hour ago, agrof said:

the width of all components are the same as the crossblock

The pinhole of the crossblock is exactly 1L. The lever is slightly narrower. A normal liftarm also has exactly 1L width and slighly less height (when width is measured along the pinhole). This may seem negligible, but when it comes precise, it can make a lot of difference.

 

Didn't notice that yet, thanks for the information! 

I think I finished the BEAST. Couple reinforcement was needed IRL, but the majority of the LDD model worked. Some might not like the chopped back, but it is part of the concept.

I must say, the weight distribution is nice, let's say it is in centered. It ended up with 530 pieces, and 890 gramms (including batteries). I am not overly happy about the suspension responsiveness, but not bad given the constraints of LEGO. I will release the LXF file soon, just need to group it a bit, to give better understanding for the build sequences. Also, I plan to release the differential version too, geared up for speed - but no guarrantee for proper working, honestly: I have no mood to test it.

LDD file can be found here. Pneumatic tube used: https://brickset.com/parts/6150237/pneumatic-tube-384mm TO DO: flip the lime green marked parts, and connect the springs in place. Pink marked part should be this: 

Though due to drained batteries +cold +hard tires I could not make a real test, but I took it to hike, and placed into some imaginary situations. HERE you can find bunch more pictures, enjoy!

Frankly, I am winking now towards RC crawling, with real play fun...

Edited December 18, 20177 yr by agrof

It looks so good in it's "natural environment" and those 24 x 43 tires are just made for BEAST 

Wow, that looks so good! Looking forward to instructions!

Good news: I got fresh batteries! It can crawl!

Bad news: now I see, that the gear bracketing is not good enough, the low batteries fed me with false confidence.  Every help is welcome here, LDD file is available above for further analisys. What I figured out, that the 24t gear can move sideways, the brackets of it must be just beside. I will have to think about my life in a dark hidden cold and wet corner. I am sad.

EDIT:

I will test next this solution, but only tomorrow or later. There mst be a way to solve this. There is always a way. 

Edited December 18, 20177 yr by agrof

Coming along nicely! Are you going to put something over the back wheels to hold a spare wheel like on the real life model? I wanted to see what I could do so I started a mock-up. It needs the red piece at the bottom to attach. It does work IRL with a bit of stress. Maybe you can use this for inspiration? Or not, its your model.  

 

Hi, of course You can implement whatever You want, and also it is welcome to share here!

I would recommend to use the 2M rubber piece for that connection instead, it is more legal solution, but I don't think it will be long-term solution, looks bit flimsy. I made a wheel holder actually with very simple MOD in LDD, but I don't like the overall look, the huge wheel eats up the rear end visually, also the center of gravity is OK now without it, and I like the chopped look. 

But first things first: I must fix the drive train problem, it is embarrassing... 

EDIT: at least the disassembly is easier than I thought:

Edited December 20, 20177 yr by agrof

I think the redesign was successfull.

Still bugs me, that the steering still can slip. Not really annoying, but come on! Soon it will be back on Rebrickable, I need to update the LDD model.

 

The music is a perfect fit for the car :D Looks great, can't wait to see it.

Overall, very impressive! Especially the disassembly. Near modularity is hard to achieve 

Just noticed I haven't posted on this... 

Wow, great execution! I think it almost a HoF worthy.

Thanks for the kind comments!

I made extensive testing, I couldn't reproduce the steering slip with the new bracket solution, so now I am confident to release the BEAST. I am quite proud (after solving the embarrassing issues...) for this build, I achieved all the points I had in my mind: legal connections, modular, sturdy, compact, 4x4, heart-warmingly ugly. 

It is now back on Rebrickable, enjoy it as my christmas gift!

Edited December 23, 20177 yr by agrof

This turned out amazing! Beautiful in an ugly way! I'm glad you got all the issues fixed.

Though I must ask: what happened to the Tigercat Skidder?

The Tigercat project is not stopped, and winter holiday is there! 

I just got quick Buggy-infection, and had to build this. 

Edited December 23, 20177 yr by agrof