YXL Concept Monster Truck

[SeanKewley]

I'm looking forward to someone coming up with a nice center diff option for the Yeti XL (basher DIY or vendor). That would be the icing on the cake for me. Keep up the awesome innovation.

[tonyfalkon]

Printed differential case adapter came in yesterday but its not up to spec, disappointing as it may I had to adjust, shave and sand it down and tried to salvage what was sent. Assembled the parts together and here is what it came out to.








I had to shave down the bearing carrier it was supposed to be 10 mm but the bearing was wobbling it was printed 0.189 mm narrower which allowed me to put a bigger bearing 8 x 16 x 5 mm downside is now the bearing carrier is now only 1 mm thin.



here are the 2 bearings side by side



backside photo of the differential case adapter pre-assembled.




Here is the mock up with the motor

[tonyfalkon]

Just an update on suspension after breaking the shock loops I replaced the balls with hard silicone based rubber bushings.



I got these from old atomizers, for those who are not familiar with atomizers its used in vaping.





Immana add another shock for additional dampening to help on the landing.





Since the second position is longer I had to change to a longer rod end so the ones in the front won't be constantly compressed.





The longer rod ends were skinnier than the stock ones so I put bushings on spring catch as well so the rod will travel in a straight line, good thing its a snug fit too.

[tonyfalkon]

Changed out the aluminum upper links with the stock trailing arms got tired of changing out the broken M3 and M4 bent rod ends so I'll try this and see what happens, convenient to for the servo wires too.

[tonyfalkon]

In anticipation of some mudding on the weekend I designed an axle boot plate to keep the pinion bearings semi clean.











Then drilled the axle to anchor the plate.



Unfortunately the silicone rubber boots didn't make it on time so I had to make do with neoprene, had to make 2 for each axle, they'll have to do for now until the boots arrive, I just hope they can keep at least some of the mud out wishful thinking I know but better than no protection at all.









I think I will keep this setup for now it looks better to me than putting the truck body on it. When I upgrade the chassis to something sturdier and longer shock mount distance maybe then I'll consider mounting the truck body.

[84yoda]

Of course you make the most fancy dust boot out of everyone. Lol, but awesome work. Keep it up.

[tonyfalkon]

Also beefed up the steering links to M5, the printed 15 mm main link will have to do for now until I finish building a rod bender and turning wheel or if funds allow a mini lathe for more precise cutting, boring and milling. Of course with a mini lathe I can turn custom length shafts too, hmmmmmmmmmmmm...

[tonyfalkon]

Originally Posted by 84yoda

Of course you make the most fancy dust boot out of everyone. Lol, but awesome work. Keep it up.

Didn't mean to one up anyone yoda LOL Last year I wanted to convert the axle pinion to 8 mm shaft then use the RC4WD punisher shaft II for the tamiya clod buster which has the 8 mm hole. The cover seals the bearings and at same time houses an 8 x 22 x 7 mm bearing carrier, this was actually a last minute redesign of the shaft adapter to an axle boot plate for some weekend mudding.

Below is the original design I did last year, I'm gonna be stuck with it for a while since RC4WD stopped producing the punisher shaft II for the tamiya clod buster, I'll have to wait a little longer until they decide to bring those back or redesign it again to house a 6 mm shaft instead.

[BarHarborBasher]

When are we going to see some action video???

[tonyfalkon]

Originally Posted by BarHarborBasher

When are we going to see some action video???

When I work out all the kinks, test run after test run the truck has shown including but not limited to areas that needed to be addressed and/or areas that had been previously addressed but not enough and monster truck driving style which has its own unique learning curve. I have tons of videos of failed test runs that shows the truck isn't ready, I use it as reminder of what was and how it should be the next time around also to hire more experience driver. Sadly as of now the build budget will run out before any video comes out.

[tonyfalkon]

For those who don't know, I caught the RC bug in the last quarter of 2014, Yeti XL is my first rig(ordered in Marched delivered in April), complained incessantly about it until my brother (20 year RC basher, who crashed the speedster (note to self never ask a basher to drive the speedster)) dared me to build it better. I like to figure out how things work, taking them apart (if they are cheap) learning as I go along and figure out how to improve on them to suit my needs. To date I have done 2 builds 2 pending(all YXL sourced parts)this one being my first and only one being documented, I could use some stuff to speed this one along like more funds, lathe machine with accessories , machinist skills, engineering background, YXL parts that have been broken discarded and ready to be thrown out (for testing new ideas to design better parts), 3D printer and a manual for this particular build, that would really be helpful (but that will take most of the fun out if).

This build is taking longer than I anticipated, I don't mind it at all, during this build I finished the cardinal speedster as well and wrecked it in less than 10 seconds, finished the 4 wheel steering all wheel drive buggy racer(code name pending) too but the BIG T MT (YXL CMT code name)I enjoy building more than the other 2. Its the one that challenges me the most, it pushed me to do better, the speedster and the racer came naturally to me, building them were a way for me to decompress from building the BTMT. My stress reliever now is my YXL bouncer build(code name pending) all done just waiting on a roll cage I was quoted $800 for built one and funds not permitting I'm learning how to bend and braze rods and tubes. I'm hoping this is the last YXL sourced build too, it will serve a timer, by the time I finish the bouncer roll cage, I should including but not limited to have buttoned up and addressed all the kinks on the BTMT, improve driving skills in the time allotted and/or have more funds to hire a pro driver to make the BTMT look good in the video (note to self make room in the budget for a pro videographer) .

[tonyfalkon]

Dust boot are here of course after the mudding event and after I cleaned up the rig which took 2 mins with the power washer and 20 mins on the compressor

[tonyfalkon]

The rear axle wasn't so lucky though without any protection the back bearing locked up and fused with the plastic spacer.

[tonyfalkon]

Which is nothing compared to what the bearing did to the pinion slot, lets just say it may need a new axle housing.

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[tonyfalkon]

The ring gear and the pinion were unfortunately affected too.