CKRC OTA kit and a new Tekin 21.5 motor.

[rcjackson0926]

Today I purchased a CKRC OTA kit because the one I had left the servo arm still sitting in front of the steering arm, and I smashed it on the rocks and bent it, so I wanted to try something different.

So, a couple of comments on the kit:

If you have wheels that where the screws for the bead locks are not flush, they will catch on the arm since it is sitting up right where the screws are on the wheel. The CKRC aluminum wheels do not have flush screws. I am having to modify my wheels to work with this kit.

You will need to drill out either the arm or the steering knuckles to fit in the bushings so that the kit can steer freely. If you just screw it together the way it looks in the picture, it will not move freely.

After doing all of that, the arm works great, and in my opinion, is better than the arms that leave the servo arm in front because it is still sitting out there to get smashed on the rocks. This kit moves the servo and arm back so that it is better protected.

The other change I made was a new Tekin 21.5t motor with the 14mm crawler rotor. This was a change from the Xcelorin 21.5 motor. The Tekin is noticeably stronger, and in my opinion, is a better motor. It will cost you a little more since you have to buy the rotor separately, but you can actually feel how much stronger the motor is just spinning the shaft by hand. I am running it with a Mamba Max Pro, but the RX8 is roughly the same size as the MMP, so you could use that as well and get basically the same features as the MMP if you wanted to. I mention the RX8 instead of the RS1 because the RX8 supports up to 6s lipo. I contacted Tekin about using the RS1 with more than 3s, and they said some people have done it, but it wasn't designed for it, or warranted for it. They recommended the RX8.

[raf2379]

cool, I just ordered rx8 for my 8T, I was also looking at the RS1 and the 17,5T motor instead of the 21.5 for my LCC, but its too much $ to spend all at once. what size lipo are you using with your setup and hows the wheel speed? i was only planning on using a 3s.

[stubs179]

Could you post some pics?

[rcjackson0926]

Originally Posted by raf2379

cool, I just ordered rx8 for my 8T, I was also looking at the RS1 and the 17,5T motor instead of the 21.5 for my LCC, but its too much $ to spend all at once. what size lipo are you using with your setup and hows the wheel speed? i was only planning on using a 3s.

I have run both a 3s and a 4s. The 3s feels a little slow to me, but the 4s seems perfect. The 4s with a 15t pinion was running the car just slightly faster than a stock AX-10 with a 55t brushed motor on 3s.

[rcjackson0926]

Originally Posted by stubs179

Could you post some pics?

I haven't got it put back together yet, or finished modifying the wheels. I actually stripped the worm gear and spool when I locked up the wheel while crawling it yesterday. That is how I found out the wheel was catching, but it was too late! I'll try to post some after I get things back together.

Okay, I took some pictures of it in the broken state for the moment:

Beadlock mods in progress:


CKRC OTA kit:


What happens to your gears when you don't realize a wheel is stuck:


You may be wondering how I did that. I upgraded everything else in the truck to steel: gears, drive shaft, etc. I honestly would have thought the pins on the axles would have broken before this, but they were just bent a little.

Rusty

[Lineman A]

Had a set looking like that. The 10 year old thought it was neat to try to ride wheelies with it and then it was all down hill from there. So nice build and keep it up.

[TroyKrum]

Nice write up on the OTA kit... I've been wanting that kit and haven't seen anyone running it. Bummer on the worm gears... that's gnarly!

[rcjackson0926]

Originally Posted by TroyKrum

Nice write up on the OTA kit... I've been wanting that kit and haven't seen anyone running it. Bummer on the worm gears... that's gnarly!

Yes, it has been a little frustrating so far with the build. Turns out I received a bad Xcelorin motor. The sensors aren't working right, but I am happier with the Tekin anyway. It seems like a better motor to me.

The OTA kit is actually a really nice kit, and if you are using the stock wheels, or another wheel with flush screws, it won't be a problem.

[mascman]

I have the OTA kt and really wish I could use it, but I went MOA and it won't fit. I looked at even modifying pieces of it to make it work, but with e MOA, there is just no room.

I was impressed with the quality of the parts, and looks like you get your money's worth with it, but I need to sale it. ;)

[rcjackson0926]

A few shots of the car back together:




OTA kit and modified rim with flush screws:


Battery plate I made for the rear axle:

[rcjackson0926]

Okay, after some playing around, I went back to the RCBros OTA arm because I didn't like the slop in the CKRC arm that came from having to move the arm up higher to clear the spindles. However, I left the servo back like it was in the CKRC kit and mounted the connecting rod on the back side of the link. This gives me everything I wanted.

While I was at it, I did a little grinding to allow for more steering angle. You can see where I ground the front of the hub carriers. I also ground the back side of the spindle arms a little as well. I don't know if the ones from LOSI would need this grinding or not, but the ones from CKRC definitely had room for improvement by grinding them down.

[mrG]

what settings do you rum on your mmp, ive got the same setup and my motor click and squeals at times, mostly at the beginning of a climb then ive got to mash on the throttle or stop and try again. ive played with the setting and its gotten better but not butter like some people say. i run a 3s and a 14 tooth.

[RcBro]

Lookin good! I tried the OTA link in your first post and had similiar issues. During a good tire bind, the link would push down and twist the knuckles. This resulted in no steering on the rocks and I'm sure over time the knuckle would snap to, unless upgraded to aluminum.

I created my link because I wanted the rig to turn when I turned it, instead of flexing the link instead. I also don't particularily care for running standoffs on the knuckles either due to strain and another possible weak link.

[rcjackson0926]

Originally Posted by RcBro

Lookin good! I tried the OTA link in your first post and had similiar issues. During a good tire bind, the link would push down and twist the knuckles. This resulted in no steering on the rocks and I'm sure over time the knuckle would snap to, unless upgraded to aluminum.

I created my link because I wanted the rig to turn when I turned it, instead of flexing the link instead. I also don't particularily care for running standoffs on the knuckles either due to strain and another possible weak link.

Yep, that was exactly what mine was doing as well. i really like your link, I just needed to figure out how to move the servo back, and the CKRC kit gave me the idea on getting that done, so everything worked out great.

[rcjackson0926]

Originally Posted by mrG

what settings do you rum on your mmp, ive got the same setup and my motor click and squeals at times, mostly at the beginning of a climb then ive got to mash on the throttle or stop and try again. ive played with the setting and its gotten better but not butter like some people say. i run a 3s and a 14 tooth.

I had that issue, and it turned out to be the Xcelorin motor. I called Castle and let them hear the squeal that mine was making, and they said it was either the sensor port on the MMP or the sensor on the motor, and for me, it was the motor. That is how I ended up with the Tekin. I was testing parts. I actually like the Tekin better now anyway.

[stubs179]

Don't mean to thread jack..........but..........,

Thanks for the CKRC OTA! Modded it a little and put it on. Looks like it will work good.

[rcjackson0926]

Originally Posted by stubs179

Don't mean to thread jack..........but..........,

Thanks for the CKRC OTA! Modded it a little and put it on. Looks like it will work good.

No problem man, it was good to meet you today. Looks like that is going to work out good not having the servo back as far.