Slash 4x4 Trophy Truck!

[Liighthead]

Wow nice!
Should be a Epic build subed

[Army RC Crawler]

I know I said I would have a new build update after the holiday weekend but something else happened instead... My son was born! And you won't believe it but he was born on the 4th of July here in Korea! He is a true patriotic American at heart! Haha!

Before he was born on Monday I did make some progress with the build. I'll post up pictures in a bit.

[Army RC Crawler]

Ok, so I assembled the rear chassis piece with all the cross braces and got it mocked into place. If you look close I tried placing the Wheely King battery box toward the front to center the weight, but now I'm going back to my original idea of putting toward the back. I think if it is further to the rear it will help offset the weight of the trans and big 550 brushless motor I plan to put in.




In case you just breezed over the previous pictures and didn't read the details (like I do) I'll tell you again what I used. The plate is 7075 Aluminum with cross braces made of 4-40 all-thread sleeved with Aluminum tube.
Also, I added another plate of Aluminum under the main chassis for added support and to spread the load from the rear end over a larger area. Sorry no pics of that loaded up yet.

[SOMD_BASHER]

i cant wait to see more so far she looks awesome

[Liighthead]

hahaha thats mental!

about the weight. only thing i can think of is moving the batt. to the back and extending those 2 arms on the batt pack, to the frame?

[Army RC Crawler]

Ok, I know it has been a month since my last post but in my defense a brand newborn baby is a ton of work! On the plus side, all this time has allowed me to pretty much completely finish the Slash 4x4 Trophy Truck. Here is an action shot for proof!


...more details to follow!

[Army RC Crawler]

So, now on to the details...
At first I had a little bit of trouble getting the rear drive shaft to hold up to all the stress and torque of the Novak 550 motor and of course the extreme operating angles. I originally tried to use a couple Traxxas Jato female shafts spliced together with one male section between them for length. Which you can see in this picture. Also note the Aluminum reinforcement plate to support transmission and rear chassis uprights.



The solution for the drive shaft was to use T/E-Maxx yokes which come in both 5mm output and 6mm output sizes. The T/E-Maxx yokes coupled with the matching drive shafts were a perfect fit. They are much bigger, much stronger, and much longer.

[Army RC Crawler]

Here is the completed truck. This is pretty close to how it sits now, I have only made a few minor tuning/durability upgrades since this pic.




As you can see the battery box has been moved to the rear for better weight distribution. This is a key aspect of the truck, with the battery in the rear the truck's weight is almost perfectly balanced front to rear 50/50.
Also, the chassis brace has been removed. It keeps bending and/or popping off. I need a stronger solution...

[Chili]

The jump picture... oh the jump pic.. Do it again with a dirt track, would you? I would wet myself even worse.
Great looking truck, if possible once it runs well color some parts so it wouldn't have such a contrast. The shiny aluminum just wouldn't fit for me.
Could you take some video someday?

[MRCCRAWLER1.9]

holy crap, that pic of it in air looks SICK!!

Got some vid???

[Army RC Crawler]

Thanks guys! My wife says thanks for the picture complements. She is my personal photographer, but now with a new born baby to take care of it's hard to get her to take pictures. But don't worry I've got a few more pictures from that day to show off. I'll try for some video soon, but I'm not making any promises.

[Szczerba]

Cool handmade built rig! Couple questions.
How are the rear WK axle and Slash 2WD axle holding up?
Do you have any upgrades in the 2WD slash trans or WK axle (axle shafts)?

I now have this and will be making it 4WD shortly.
Custom Built 4-Link Trophy Truck

[minnesotamudder]

man that thing is cool, do you have any better pics of how you set up the links?

[Army RC Crawler]

Originally Posted by Szczerba

Cool handmade built rig! Couple questions.
How are the rear WK axle and Slash 2WD axle holding up?
Do you have any upgrades in the 2WD slash trans or WK axle (axle shafts)?

I now have this and will be making it 4WD shortly.
Custom Built 4-Link Trophy Truck

Thanks for the complements! I found your thread and bookmarked it while I was building mine. That truck is awesome! I couldn't swipe many ideas from yours though being that its all so custom. I love the cage!

I'll post up with pics in a while about the WK axle and drive-train. Pics are loading on photobucket.com as we speak...

[Szczerba]

I didn't do any work on it but will shortly. The guy i bought it off of was the second owner. I have a slash 4x4 donor coming soon for the front clip. Going to see if I can work the 4x4 front end in there.

I haven't torn apart the rear axle or trans yet too see what's inside and I am not familiar with the WK rear axle just yet. Just curious of bulletproof upgrades.

Really digging your build. Subscribed.

[Army RC Crawler]

Originally Posted by minnesotamudder

man that thing is cool, do you have any better pics of how you set up the links?

I built the whole rear end using info from RCCrawler.com and from my previous Crawler build which used WK axles as well. I'll have more info and pics on the rear suspension in an upcoming post. Stay tuned...

Where in MN are you located? I'm moving to the Twin Cities in October.

[Army RC Crawler]

The rear axle turned out to be a bit of a headache. At first I decided to skimp and save a little money and see how the stock Wheely King axle parts would hold up. According to the Ideal-RC.com build the Wheely King plastic diff cup "melts down" with hard use. I never had that happen, but the heat build up I felt on the input pinion of the axle was almost enough to burn me! The extreme heat in the diff cooked the pinion bearings allowing the pinion gear to wobble, stripping the ring gear which ended my day in a hurry. Of course it was all my fault, I was doing three wheel donuts for minutes at a time!




This failure forced me to upgrade. So I went all out. I ordered Axial HD ring and pinion, Axial Aluminum Diff cup made by Golden Horizons and HPI HD spider gears. I also put some OFNA Diff Lock Lube in the diff for a "limited-slip" traction aid. These upgrades coupled with the Hot Racing straight axles/rear lock out kit have made for a cool running bullet proof axle so far. The rear axle also uses Hot Racing's widener kit which brings the rear track width out to match the front.

[Meatwad]

Those were the next couple of questions I was gonna ask about the rear axle. Thanks for clarification

[MRCCRAWLER1.9]

Wow, the motor bearing is now wobbling????? geez, what temp did you get up to?

im thinking 1 issue may be because your running the stock slash 4x4 diff in the front, and a different diff in the rear, causing "un even" gearing for the motor.

[Army RC Crawler]

Originally Posted by MRCCRAWLER1.9

Wow, the motor bearing is now wobbling????? geez, what temp did you get up to?

im thinking 1 issue may be because your running the stock slash 4x4 diff in the front, and a different diff in the rear, causing "un even" gearing for the motor.

No, the wobbling was at the rear axle pinion, right where the drive shaft connects to the rear axle. Those bearings supporting that pinion cooked, stripping the ring gear in the axle. The rear differential got extremely hot after those three wheeled donuts.

Now that I've upgraded the diff parts I've had no problems at all, the diff is totally cool even after tons of three wheel donuts.

...and the Slash 4x4 diff gearing is almost an exact match to the WK diff. The difference between the two is completely invisible and totally negligible.