Micro Class 3 Truggy Build

[89redranger]

Well, I've got a new itch that I've just gotta scratch...

I've been attending a bunch of local comps, meets, and my buddy Brian and I have been hosting our own get-togethers on our course lately. Normally I'm not that interested in the larger Axial type rigs, but these guys are pushing it to a whole new level. Tires over 5" tall, 2.2" wheels, dig units, 4WS, narrowed hard bodies, doved tails, pinched noses, and tubing aplenty. These are what my buddy Brian and I call "Super Class Scalers."

This build hasn't even started and it's already putting my other stuff on hold...

Here are a few examples that I've found right here on rccrawler.

"The Half Ton Druggy"

http://www.rccrawler.com/forum/2-2-scale-rigs/417371-half-ton-druggy-jack-tundra-build.html

Mattzilla/Bulldog built Tundra Truggy

http://www.rccrawler.com/forum/1-9-scale-rigs/406341-mattzillas-tundra-truggy-bulldog.html

The "Beast" Tundra Truggy

http://www.rccrawler.com/forum/2-2-scale-rigs/315912-beast-build-tundra-truggy.html

Justin's "F-350 Truggy"

http://www.rccrawler.com/forum/2-2-scale-rigs/274858-justins-f-350-truggy-rear-steer-axr10-axles.html

Using these larger rigs as an example I've come up with a combo I hope will live up to the beating I plan to give this little guy. Before I get excited about beating it up, I gotta build it though.

For power I plan on picking up another Stroker from DANALLY. This time in a 110+ turn. My 80T is just a little too quick. I'll run this motor through a stock Losi Micro trans with a billet HR case, Redcat Sumo Micro drive shafts, and into a set of Redcat Sumo Micro axles.

Electronics will most likely include a 1s battery on either side of the chassis, a Castle Micro or Tekin B1R for the adjustability and drag brake, all controlled by a cheesy Redcat 4WS RX/TX. Expect the ESC and RX to be shrink-wrapped and water-proofed.

Plans include 4WS, a brass tube chassis loosely based around the stock Trekker body (it's low slim profile is perfect...), including a new brass bed cage and stinger up front, brass plate boatsides tied into the cage with integrated body mounts, and at least one winch.

Tires and wheels will hopefully include DANALLY's new Delrin wheels, wrapped in MiClaws.

In the next day or so I'll get pics of my mock up on here, as well as an idea of what I'm in for as far as tube work. This rig will have no interior, but I will still try to include a few scale accessories on the exterior. Expect this to be a SLOW build.

Till then, lets hear YOUR ideas, comments, and suggestions.

 

[DANALLY]

Looks like a great project to do! Can I come over and play when mine is done? :ror: ROAD TRIP!

The only thing I would do is get away from the Redcat radio. I think you will be much happier with a simple 3 channel 2.4ghz radio and receiver. I use the Traxxas TQ3 and TQ4 set-up. I change the 3rd channel switch to a momentary 3 way switch for independent 4ws. They are so nice and the last one I bought on ebay I got for $30 for the Tx and Rx both! I even have some spares around.

Other than that...GIDDY UP!

 

[89redranger]

Looks like a great project to do! Can I come over and play when mine is done? :ror: ROAD TRIP!

The only thing I would do is get away from the Redcat radio. I think you will be much happier with a simple 3 channel 2.4ghz radio and receiver. I use the Traxxas TQ3 and TQ4 set-up. I change the 3rd channel switch to a momentary 3 way switch for independent 4ws. They are so nice and the last one I bought on ebay I got for $30 for the Tx and Rx both! I even have some spares around.

Other than that...GIDDY UP!

That's a good idea with the Traxxas radio! Those things are always on sale around here for dirt cheap. I had only planned on using the Redcat TX because I can bind it to the stand alone RX Redcat sells for their larger rigs. It too is cheap.

I think I can get the Redcat unit for around $15. BTW, I've found that playing with the steering channel D/R settings on the Redcat TX smooths the steering out quite a bit. I think mine is at 70% right now with EPA up around 95%. Sadly, I get the feeling the TX is a rather nice unit, and the Sumo board is just junk...

Is there any way to add a pot on the 3rd channel to do completely stand-alone rear steer on the Traxxas stuff? If so, I could put a switch between the new pot and the existing steering pot. This would allow me to link the 4WS together or run it by itself with another knob or slider. I've literally got a bucket of potentiometers to dig through and choose from.

 

[89redranger]

BTW, DANALLY, you're welcome at my place any time buddy! You ever get out to Oregon give me a ring.

 

[DANALLY]

No plans for trips to the area but thanks "thumbsup"

I did a TQ3 a while back with a 3rd channel 3 position switch and top mounted pots for end point adjustments. Super easy. I found it in the electronics section with a search on TQ3. I really like the TQ series. They feel better in your hand than many other radio's. The position on the 3rd channel switch is perfect. I hate 3rd channels that are hard to reach or require a change in grip to make it operate both directions.

 

[89redranger]

So maybe I'll just pick up a TQ3 and mod it for EPA and put in the momentary switches. I've also got a shorter servo horn that I will run on the rear. A short horn cuts the throw down. Then I can adjust it up or down with the EPA to keep the angles in check. Another thing worth mentioning, I'm swapping the Losi knuckles onto the front and rear axles. They have steering arms with a shorter length and are closer to, if not, zero ackerman. The outside tire being the one that turns the sharpest is getting old, causes a lot of understeer, and makes these rigs not want to climb with the wheel turned uphill. The front-end just wants to slide downhill because the inside tire is still not turned in all the way. Also, getting the tie-rod closer to the housing has obvious advantages. The only other option would be BTA steering (proper ackerman angles would allow the inside tire to turn sharper, helping turn-in). I know it all sounds like senseless rambling, but it all trickles down from what I've picked up from my 1.9 comp rigs. Hopefully some of these little tricks will work just as well on these smaller rigs.

 

[DANALLY]

Never tried it...does the Losi knuckles work on the Redcat axles without mods?

By the way, the white truggy is my favorite design.

 

[89redranger]

They do. I've been comparing them, and the only thing that's different is the actual arm where the tie rod and drag link connect. It's quite a bit longer, and gives the steering the opposite of ackerman. It's not a lot, but I think I can cure it. Between the caster, Losi Knuckles, and the wheelspeed, I ought to be able to get this one to turn. One of the things I really struggled with on the F150 TTC project I did last, was the steering. It's got decent angle, some caster, and still wants to slide downhill badly when climbing off camber. I hate it. I almost wish there were an under/overdrive mod for these axles. That mod alone would kill the understeer! Over driving the front or under driving the rear does wanders for torque twist as well. As opposed to the rear axle wanting to walk up under the chassis, the overdriven front pulls the rear around. Works beautifully on my 1.9s!

 

[89redranger]

This project has been put on hold due till I can get replacement parts. I found out the hard way that micro crawlers don't like two story falls...

Long story short, the fall broke 2 rear links, broke a rear wheel, ripped the shock mounts off the c hubs on the same axle, broke the ears off my rear driveshaft, and ripped the screws out of my Losi trans. Basically, when it fell, it stuffed the whole rear of the truck forward. Anything preventing the axle from moving froward was conveniently relocated to another place or broken.

My luck has been crap lately and literally every rig I own is down due to an accident. This one got dropped, my 1.9 rig got stepped on by a friend, and the remains of my Losi micro got knocked off the shelf by my brother, losing parts in the heater vent. Yay! Thankfully, my daughter's Exceed Maxstone remains unharmed and intact!

I promise this build has only just begun! The unfortunate thing is, it'll be Winter before I can afford to fix all this broken stuff.

 

[89redranger]

Leave it to Redcat to add insult to injury!

Got my new replacement ESC/RX for my Sumo under warranty today. They were replacing my original because the antenna wasn't even soldered to the board. This time around, the board doesn't even have an antenna! No, not that it's not soldered. It's a blank hole in the board, no little black wire to be found, and won't bind with the radio.

Redcat, get your sh!t together! What good are electronics that don't work? Aren't they purty though? The electronics and bushings are a shame. You build such a nice little base rig other than these items...

Luckily, I didn't really plan to run their junk for very long. I'll just have to pick up a nice micro 3 or 4 channel RX and ESC that much sooner...