My crawling buddy got this Axial JKU body from another enthusiast. They are now unobtanium, so I was tickled to find a narrow and short option for a WB4 crawler. And since I had a couple of the K5 Blazer bodies now I thought I might as well paint one up and run it from time to time. Got a set of wheels to match it, and another set of 4.75" crawler tires.
What I've learned here over the past few months, as well as driving them and getting through my first crawling competition, is that maxing out the limits of the class is the best way to compete on a level playing field. The long wheelbase climbs better, weighted axles/wheels, and max tire size with a comp compound being just a few of the upgrades to do to a crawler rig.
Rather than try to model after a 1:1 rig this one became what I would do if I had unlimited funds to build a competition rock crawler. Here are my notable build parts:
4.75 PitBull Rock Beast XL's with 'alien compound'
CI Lil' Nova foams
Alloy beadlock wheels (1 set for each body)
Codyboy axles
SSD Titanium suspension links (where I could get them)
Outboarded shocks
Arrma ADS-15M steering servo - 208oz/in high-volt
HobbyWing 1080 QuickRun ESC with 3S lipo power
Yeah Racing 35T brushed Hackmoto V2 motor
Spektrum 3 channel receiver (I have a 4ch in another rig I can swap)
Before I add more weight I thought I would run it and see how it does. The wheel and tire assemblies weigh 7.2oz, and with the weighted CodyBoy axles I may well be good on lowering the COG sufficiently already.
Just got it built and running this week - it is the quietest running of all three of my Ascenders, so gearbox, spur and pinion, and axles must have come together well - I paid particular attention to each assembly to make sure it was smooth. For example, the diff ring and pinion ended up with the shim washer on either side of the ring gear under the bearings. If I put both on one side to shim it closer to the pinion I would get a rough turning in the assembly. So I did a lot of trial assembly and turning it to make sure it was smooth.
In this pic if you look really close you can see the 2mm spacers I made for the upper rear links by cutting up an extra 12mm spacer. This corrected a down-pointing pinion/input shaft for the rear differential. The lower links are the SSD 90mm titanium links. They did match the stock links for length, but in setting the whole thing up the rear diff pointed down too much.
I also added a mm or so spacer to the tie-rod link as there was too much toe-in. You can really see it with the bigger tires mounted. So now everything lines up correctly.
I'm really pleased with how this one went together. I thought I would try the Hackmoto motor for $20. It gets good reviews and test running shows it has a LOT of speed and power on 3S. Replaceable brushes on these. Hopefully it will perform well.
I would have liked a little stronger steering servo than the ARRMA ADS-15M, but was in the LHS and they had them in stock for $40, and loathing to spend $100 on a servo I thought I would get another one. If it proves to be a weak link or fails I'll upgrade. I have one of these in my RTR and they come in the ARRMA Typhon and Kraton which both run 6s high power, so for a crawler it may well be good enough for my use. It's a high-volt, so setting the HW BEC for 7.2V makes it sing pretty well and attains the full rated power at the higher voltage. The Spektrum radio allows me to adjust steering travel to where the tires just barely clear the shocks on full lock. I'm getting all I can get here. "thumbsup"
The body came without screws for the heavy duty black plastic fender flares so I found those at a local industrial supply. The AXIAL screws for them are backordered. I played with drilling and mounting them somewhat higher on the body and trimmed out the wheel-wells for the bigger tires, while keeping the body as low as possible. A trick I learned here from you guys. "thumbsup"
Next is painting and details. I need figure heads for driver and passenger - Browneye driver and Mrs. Browneye co-driver. 8)
