Jakezilla’s Junkyard fakeCX10 build. Injora / Austar 313mm Frame

[Jakezilla]

Hi everyone! I was in to crawling almost 10 years ago (man, that makes me feel old). I had a couple SCX10’s and dabbled with competition crawling with an XR10. Comp crawling wasn’t for me, I enjoyed just going out to a trail or overpass with a couple buddies and just scale crawl. Right as I got into straying from the RTR path and doing more building, my friends lost interest and it was getting harder to get everyone together to go crawl. I was still into racing, flying, and bashing; but the crawler parts either were sold or started to gather dust.

Fast forward to now. In addition to a pretty nice carpet offroad race track, my local hobby shop has a nice indoor crawling area. My dad was really impressed with the action and fun they were having so he picked up a Wraith a couple weeks ago. When I was racing the other day, he stopped by with it. Well, about 5 minutes into crawling around, I knew I had the bug again…

Problem: I’ve got a family now, and most dads out there know that means I have a fun budget. I recently built a new 2WD Stock Buggy race car, so the budget is pretty much nothing for a while.

Solution: CHINA! Normally I hate supporting the clone market, but these Injora / Austar chassis actually seem like a decently clean sheet design that I don’t feel as bad using it. I wish this would have happened a couple weeks ago because it looks like the Element chassis was on sale for $170ish. I think that would have been a much better start. But hey, we’ll see how this goes!

Goals: use as much of the stuff I have from my previous crawler life and anything else I can find. Any of that stuff I won’t count towards my build total.

If you are looking for more info on this chassis, I’ve been following marcod13’s build: http://www.rccrawler.com/forum/axia...injora-2000-jeep-cherokee-xj-scale-build.html
And mv1985's: http://www.rccrawler.com/forum/1-9-scale-rigs/613973-another-injora-chassis-build.html

 

[Jakezilla]

I actually started building this rig a week or so ago, but I wasn't planning on doing a thread though. I'll do a couple recap posts to get caught up to now.

First step in the build is waiting... I didn't want to wait too long, so instead of ordering straight from China, I ordered from a US based reseller.

While I waited, it was time to scrounge.

First thing I found was my old wheels and tires. I believe these were Montana Scale Design rims, and the fella I bought them from drilled holes and added scale studs and lugnuts. These were the very first crawler things I ever bought! Mounted up are some well loved TSL SX Super Swampers. Here they are next to a set of 2.2's that I found that I'm going to give to my dad.

The next thing was a body. I got this body for free and it was just (poorly) spray bombed with this safety yellow/lime green -ish color. Time to break out the Sharpe! After some quick artwork, I think it looks a lot better. Can't beat free! I also added some tape to the bed to make it kinda look like a tonneau cover, and some detail stickers.

Running build total* $0.00
*(again, I'm not counting the costs of anything that has been sitting in a box for more than 5 years)

 

[Jakezilla]

While I waited for the chassis, I watched a lot of crawler videos. I came across Harley Designs and in a video he went over doing an interior from an RR10 and I thought it turned out really nice. I'm going to add the voltmeter that he does too.

https://youtu.be/8MwFLdAnpVE?t=375

https://youtu.be/ndKwOnpeXNY?t=414

Time to break out the model paints!! I only have a little bit of time here and there to work on this stuff, so I didn't do a super nice job, but that is kind of the theme with this build. Get it decent, get it done, get to the fun!

Now I need to go find some of the kid's old PEZ dispensers for some heads...

Running build total: $19.99

 

[Jakezilla]

Found some PEZ heads and figured out a nice sturdy way to add a M3 stud.

First liberate the head from the body. Drill a small hole. Then I took a little nylon standoff I have a million of from quadcopter building, and superglued it in there!

Works like a charm!!

Now Santa and his favorite reindeer will have something to do in the off season. I like this setup a lot, because I can swap them out pretty easy if I see other PEZ heads I like!

Build cost in this post $0.00
Running build cost $19.99

 

[Jakezilla]

Chassis has arrived!!!

Just like other pictures I’ve seen, the box has taken a bit of a beating.

Overall doesn’t look that terrible. Not that great either though…

Unlike others I’ve seen, mine has plastic balls in the links and bottom of the shocks, and some of the screws look super sketchy.

This is the first CMS rig I’ve had, and I thought I’d be fine with the 4 link bump steer, but I was wrong. Holy cow it is bad! Dang near goes to full lock when compressed. So, panhard bar was a must. Looking at images of other crawlers with panhard bars, it seems like the mounting point on this axle is very far out, close to the wheel. So while others have the bar extend up and connect on the outside of the chassis, to make the panhard bar a similar length and angle as the steering link, the mounting spot is quite a bit inside the chassis. Looking around for a piece of scrap to make it, my eyes met a servo mount. It is perfect! I just drilled out the holes in the chassis, found some extra long screws, and started mocking up a panhard bar. It turned out really nice, no bump steer at all that I can see. The only issue with it is that under full equal compression on each side, the bar hits the pumpkin with about 1.5-2mm of compression left. A. I don’t think it is that big of a deal, and B. I might be putting different slightly longer shocks on later that would be able to go to full compression.

I’m also using one of these cheap 20KG servos from Amazon and I’m actually pretty impressed for $15 (ordered a 2 pack, one for my dad). Just make sure you read the description! I almost ordered the 270degree rotation version….

Build cost in this post $129.25
Running build cost $149.24

 

[JatoTheRipper]

Holy shit that screw holding on the bottom of the shock!!! :shock:

The flat head screw driven into the axle cap isn't any better.

 

[Jakezilla]

Holy shit that screw holding on the bottom of the shock!!! :shock:

The flat head screw driven into the axle cap isn't any better.

Yeah... To call this thing rough around the edges would be generous.

 

[Jakezilla]

I do plan on getting wet at some point, so waterproofing is up next. I’ve had this Tekin FXR for ages, and I never used it because I didn’t want to be afraid of the water. I was also nervous to do the plasti-dip dip. Well, not anymore, it got dipped! If it isn’t fully waterproof and I smoke it, well I’ll just buy a 1060 or 1080 then. I’m also using a Traxxas TQ radio that I had left over from one of my Spec Slash builds, so I mounted up the waterproof box. Not pictured, but I put a Castle Creations BEC in there as well, cranked up to 6.5V. The Traxxas RX seems to run fine on it, we’ll see if it lasts!

I don’t have any 32P pinions laying around, but I do have some old 48P spurs from my Kyosho cars I don’t run anymore. So I put an 82T spur on and a 24T pinion, which is roughly the same ratio as what they ship it with (17/56). This also gives me the ability to use the slipper as a slipper, which will be good for the kids. While testing this out though, I realized that this is a reverse rotation gear train, but a forward rotation motor! What the heck!?! So I swapped motor leads, and adjusted the timing. I’m not super clear on the way they have their can marked, so I’m at either 6 or 12 degrees of timing. Either way, should be fine. I also fixed the arrow on the side of the can with some Sharpe, haha!

I found the next issue when mounting up the wheels. There was this weird click in the rear, and a ton of axial play. I opened them up and it looked like there was supposed to be a second bearing on the shaft, so I tried to put one on. TRIED is the operative word there… The square where the shaft goes into the locker measured 5.15mm in some spots, which is hard to slide a 5mm ID bearing over. So I filed down the edges a little bit to get the bearing on. Now there is no play, but that weird click is still there. I checked and shimmed the locker, click still there. I think it is the locker itself, maybe where it connects to the ring gear. I’ll check it out later.

Also, this chassis doesn’t come with body posts. What is the deal with that? I ordered the Axial SCX10 II set, and it is annoying because the suspension hoops on the chassis have a D profile, but the posts are round. Kinda funny that just body posts are 10% of the cost of the chassis… Anyway, looks like my wheel base is too long!

So I started hacking and slashing and making links, now it is too short! I’m going to be a link making pro after this!

Dremel and electric screwdriver batteries are dead. My battery is pretty flat too. I'll get to making the medium sized rear links this weekend.

Build cost in this post $11.51
Running build cost $160.75

 

[Jakezilla]

Well, I got the links made and did some basement crawling. The stock springs on this thing are super stiff! I measured them and they were stiffer than any recommended spring for a 1.9 rig, even with a heavy body. I still had some shocks in my bin, possibly from an old Losi crawler. I put those in and it is much nicer.

Picked up a set of aluminum bumpers and rock sliders from the classifieds, and unfortunately the bumpers are much to wide for my body. But the sliders are sure nice to have! Also threw a $10 ebay light bar on there. I was thinking for the body, but it too was way to wide. I like it on the front bumper like this though.

This will probably be my last post on this build. I just wanted to share my experience with this kit and I was excited to get back into crawling.

Build cost in this post $37.55
Total build cost (again, I'm not counting anything I had laying around) $198.30

CONCLUSIONS:
Do I like my crawler? Yes, it is nice to make use of a lot of the crap I had acquired over the years and was just rotting away in a box.
Would I recommend the Injora / Austar chassis to someone who doesn't have a bin of parts and the drive to make it work? NO. Too much has to be 'fixed' and the questionable quality will linger even after you make it perform decently. If I didn't have the parts bin to use, I think starting with an Element RC kit or the Traxxas TRX4 Sport kit would have been a better investment.

 

[OGTrout]

This thread has been pretty useful for me, I'm totally stealing your panhard mounting point. And getting the extra bearing in the drive axles. And your note on the motor finally made me sort out the faster in reverse thing. I'm pretty new to RCing, so that was the first time I've ever messed about with motor timing.

I think I agree with your assessment about the kit. This was my first proper RC and it got me into the hobby and I've since upgraded to a Trail King.
My injora chassis is now for light bashing. It's holding up to abuse and I never had any real problems with it for normal trailing and crawling.

The bump steer and incredibly sloppy front axle mine developed are the only issues and out on the road they were never fun stoppers

 

[Jakezilla]

This thread has been pretty useful for me, I'm totally stealing your panhard mounting point. And getting the extra bearing in the drive axles. And your note on the motor finally made me sort out the faster in reverse thing. I'm pretty new to RCing, so that was the first time I've ever messed about with motor timing.

I think I agree with your assessment about the kit. This was my first proper RC and it got me into the hobby and I've since upgraded to a Trail King.
My injora chassis is now for light bashing. It's holding up to abuse and I never had any real problems with it for normal trailing and crawling.

The bump steer and incredibly sloppy front axle mine developed are the only issues and out on the road they were never fun stoppers

Thanks for the reply, I'm glad some of my info helped! Felt like I was kinda yelling into the void...

 

[Stollenritter]

Good work on this projekt, you seem to be a tech guy with a lot of experience. I take my hat off to you. Thanks for sharing!
And I like the PEZ heads :ror:

 

[Jakezilla]

Good work on this projekt, you seem to be a tech guy with a lot of experience. I take my hat off to you. Thanks for sharing!
And I like the PEZ heads :ror:

Thank you!

 

[chevy42083]

Thanks for the insight! I've been tempted to try one of these as a loaner truck or for the wife.

I know, I'm late to the party on this but....
I'm not sure about that trans, but if its like the OG AX10/SCX10 ones, people usually took it apart and rebuilt it "mirrored", which put the motor to the front passenger side... helping with weight to counter torque twist, and supposedly the twist action itself is better in that direction.... and i THINK it reverses the motor direction compared to how you have it now.

For the upper panhard mount, I used a servo mount too, but it hangs off the outside of the frame rail and points down. This lets the bar be longer and more horizontal so there is less axle swing (though if you don't bump your servo over, might end up with some bump-steer from the steering link being shorter and more vertical in comparison). It means the endlink screw is facing straight up, so less articulation than a ball that can rotate down like yours... but its no less than the servo horn mount has anyways, and its likely to be at a more level angle... so not the limiting factor. it also lets you use a spacer to drop the link lower. My goal was really to limit the axle swing as much as possible... mainly so I don't have to deal with the axle not being centered if I move the ride height around.

I'm still mocking up my links... , but this kind of shows how the panhard upper mount is. I've got a new lower mount that will raise the pivot up higher to level out the link more.

 

[mv1985]

Nice build Jakezilla! Love the panhard mod, gonna try it on one of my Injora chassis. Again, great job"thumbsup"