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RcBros Berg Build

That was happening to me as well, next time it happens look at your tire and lower link, mine was grabbing the lower link and locking the front up. Try spacing your lower links in 1/8". That caused my tire to hit the shock a little more which the tire slides off of. It's worth a try, it worked for me. Hope you figure it out.

I've made sure its not hitting the shocks or links, it always comes back to the steering link flexing. I know how to solve it just don't have the time for the machine shop at the moment. Strep throat is a killer!

Great build and great feedback on the Pink rover's need to return mine and get some whites or sedonas :)

No problem, I've since switched to white rovers that I have siped slightly and won't ever go back. These things are insane!
 
Alright, I have two robotronics servo horns on the way, I noticed with the CKRC mount I need a longer servo horn and the racers edge ones simply aren't long enough to clear.

Below is how the currently have the RCI link setup

apfxpi.jpg


34obtk6.jpg


Now below are two videos I took showing the link flexing when at full turn when I manually do it. Keep in mind, it did this same thing with the RCI servo mount and many combonations of servo arms and links.

http://www.youtube.com/watch?v=MdsyhgjNUKA

http://www.youtube.com/watch?v=fL0xZEx97LI

Now, here is a video with the berg in front dig with power to the motors. Look at how much the link is moving back and fourth. This combined with high traction ultimately pulls the CVD's so far in the entire steering locks.

http://www.youtube.com/watch?v=KB9uMi--De0

Any guidance would be greatly appreciated.

While I'm stumped with what to do, I drilled out the CKRC link and added bushings.

b4bwa9.jpg


2zscfo8.jpg
 
Just as I thought, That bouncing at full steering lock has nothing to do with your steering. That is the cvd binding. You either need to do a little dremel work to the cvd to free that up, or let it break in more. You dont have axial 300's with berg knuckles, do you?

The RCI link wont work with you servo still mounted in the ckrc mount. The link will hit the servo and the servo mount at full lock. Your going to need to lay your servo down more for it to work. The robitronics horns are the way to go.

Also, Your beating up on the RCI steering saying the arm flexes...I'd be confident betting that I could bend any steering arm on the market using both hands and forcing the wheels in opposite directions. Thats hardly a real life scenario.
 
There are about 7 people on the boards using the CKRC mount and the RCI link so I'm sure it worked just fine as many say its the best combo, with the longer robotronics horn I believe I will have enough throw both left to right to get the steering I need without hitting the servo or mount at full lock. Wether the CVD's are binding or not, the link is still flexing under the power of the rig itself and no me aiding it, it may not be apparent in the grainy poor quality video but it is happening.

I'm more inclined to believe its the link as Dave/John the maker of the 300's did not see the CVD's being at fault with my issue, I have been at his place the last two saturdays and this past sunday both crawling and trying to figure out the issue. None the less, I will still take them back out and do some polishing and relube to see if I can eliminate the issue.

thank you for your reply
 
Is it the delrin tirod flexing?? From the videos it almost looks like the holes with the grub screws are loose or sloppy...or maybe loose screws..
 
We'll put it on the bench and figure it out. He has the newest cvds and they dont bind at all. the stub will run on the ball base. which is 51.5 degrees. past what i say they will turn. the issue i saw originally on his car was a non-zero ackerman. one tire was caming over and with the position of the link it had little to no control over the knuckle, and the tire once camed over would just bend the link. Its not to bash the link being derlin, i think its the position of the link with all of the steering angle coupled with the non-zero ackerman that is the issue either way well post up what is the solution. I know that Rockcrawler is having a similar issue with the same setup.
 
I'm curious to see what you guys come up with. I know I'm having success with the RCI kit...so I hope it works out for you as well. I've actually come to like the non-zero ackerman. The inner wheel turns less and stays out of the links/shocks at full lock. If the set-up were a true zero ackerman then the inner wheel would be all over the links/shock before the cvd's were even close to their potential.

It has it's advantages but each to their own I guess.

P.S. John...I hope you know I'm not trying to beat up on your cvd's "thumbsup"
 
Well the zero ackerman knuckles and extended mounting legs for the addition width did the trick.
The wheels did need larger spacers installed but I believe it was worth it.
 
Well the zero ackerman knuckles and extended mounting legs for the addition width did the trick.
The wheels did need larger spacers installed but I believe it was worth it.

Pics if you don't mind... I'm having the issue but not enough to bind the CVDs.

When rear digging in reverse with the wheel at full lock and hung up, it will sometimes over flex really badly.
 
Pics if you don't mind... I'm having the issue but not enough to bind the CVDs.

When rear digging in reverse with the wheel at full lock and hung up, it will sometimes over flex really badly.

I ended up installing steering stops to prevent this from happening as it happened all the time.:x There is a threaded hole in the axle by the shock mount, thread a 3mm with 1/8" axial spacer into that hole and it will stop the knuckle from over flexing. Ultimately I ditched this set-up and went with 86 jeep inspired set-up."thumbsup"
 
I will try to get pics tonight once I get back from working on my 1:1. After this weekends comp I will be ditching this setup and going with a 86jeep inspired setup as well.
 
Pics if you don't mind... I'm having the issue but not enough to bind the CVDs.

When rear digging in reverse with the wheel at full lock and hung up, it will sometimes over flex really badly.

Sorry it took so long

Luckily I live close to Dave owner of SDS customs and 300 CVD's and he was able to point me in the direction of temporarily fixing the issue until after this weekends comp.

I first installed a set of home brew 0 ackerman knuckles that Dave had made back before Vanquish made such a nice set (mine on order) this requires widening the front end to clear the knuckle but that was accomplished with some 585 hubs. Due to the width of the delrin arms that secure the link to the knuckle its still slightly rubbing the sidewall of the tire, but some taller foams should solve this issue.

B36_DSC_0009.JPG


Next up, I moved the passenger side mounting arm to the outermost hole, then I drilled a new second hole.

D64_DSC_0004.JPG


Then I created a new driver side arm, using the old piece as a template. I'll need to add a few spacers as mines alittle thinner but no biggy there.

6C4_DSC_0007.JPG


I'm using the CKRC servo mount and its a tight clearance for servo throw and the racers edge arm wasn't enough, so a robotronics horn is now in the place, it barely makes full turn left to right before hitting the 4 link mount or the servo itself, but it does fully clock each direction.

1D5_DSC_0002.JPG


I got some new 45T motors to install before this weekends AWCQ then after the comp I will be doing a 86Jeep inspired steering.
 
Well I was fortunate enough to attend the 4th Qualifier of the Axial West Coast Championship this past weekend.

Having only comped 3 times previously with my berg and battling issues with my steering since day one, I woke up at 3:30am in the morning half asleep and half excited to get the fun underway.

Around 8am I pulled into the sand and made my way to the Epic rocks where the show down was to begin.

The rocks looked amazing, the sun was up and a bonfire was a blazing!

Top Drivers were spotted such as Bender and Scott Hughes from Axial, John Ripplinger the Maker of the Killer 300 CVDs and Top Finisher and Super winner at Motorama and his number 1 G.I. (AKA stepbrother, inside joke
biggrin.gif
) Dustin Siegfried.

After an always fun, well spoken drivers meeting from Brian Parker the competition began on what was some of the most epic, fun and challenging courses I've ever ran on.

I myself started out on course #4, after waiting my turn inline I turned the beast on and went into the zone, I managed to complete the entire course without a single penalty earning a smooth -20 for the first run of the day. First perfect run I've ever done, and at a large comp at that! It was truly an amazing way to start the day.

I then jumped over to course number 5, closely watching how other drivers navigated the course taking notes on what I liked and didn't like. This course was challenging but there was only one gate I was worried about which was a challenging drop down with a challenging gate location.

I plugged in the car and did what Parker told me to do, and that was, do work! I was doing another clean line up until gate 10, what I thought would be plenty of traction was now slightly covered in sand and water which I under estimated. I simply lacked the momentum needed to make it up the obstacle to complete the last gate. I hung on my belly where I was forced to use a reverse, I then flopped it on my lid in a section of flat sand that forces me to turn the rig over, one more reverse and boom I was through with a -13

Course 3 was next and this thing had a valley of death that required a wide truck and the use of all 4 sidewalls, everything up to this point was a walk in the park for the most part, but the last 3 gates were challenging. Luckily both John and Dustin were the judges and my personal coaches and cheer staff
biggrin.gif
I managed to make it pass the gates in the valley of death, but once pass I was wedged, with two very smart reverses and one forward and some good coaching, I squeezed backward through the gates and took an alternate route to the last gate where alittle bit of vroom vroom and the right timing made the last gate a breeze and I finished with a -18

Course 2 was next, I watched a huge number of guys struggle with this course and it had me very worried, but once the remote was in hand everything just fell into place, after taking a gate which I think 90% of the drivers did that day on a very challenging obstacle and one reverse I managed to finish the rest of the course without mistakes finishing with a -9.

Course #1 was another course I watched drivers struggle with. I decided to try some of my own lines instead of watching what others did and it really paid off. I noticed that the 6 minute time limit was a major hangout for most, so I kept that in mind. I quickly dominated the first 9 gates with ease leaving me 2 minutes for one very tough gate. The gate was in a very strange spot with a nice drop off below and a boundary as well. I could have taken the gate and finished the course, but I knew there were drivers with alot better scores then me, so I had to take a chance. With some uses of the digs both front and rear, and a few reverses I flopped off the edge and hit the boundary, adding 10 points I didn't want to my score. With 30 seconds left I knew I had to book it, I made it to the top once more and almost had it, but it just simply wasn't working and I flopped off the cliff again, this time, missing the boundary but running out of time.

Later, I watched Dustin, the winner of the comp, finish this gate in reverse and kept smacking myself wishing I found that line. He landed backwards just as I did off gate 9, but instead of turning around, he kept it in reverse and mastered the gate. It was beautiful.

Overall I ended up placing 7th which is way better then I ever expected, I may have placed better if I didn't play rough on my last course, but you only get better by trying new stuff. It was the funnest I've had at a competition to date!

I will have some video up in the next coming days, but below you can see my score and the places for everyone else who attended.

76C_1.JPG
 
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Well heres the progress on the updates.

First I took the entire crawler apart.



Then I headed to the machine shop. We chucked the axle in the CNC, made a few measurements and went to town.



We cut it so my servo fits in snug as a rug.



On my lunch break yesterday I took a scrap piece of ABS plastic and cut out a make shift servo mount on the band saw, nothing special but looks as though it may work just fine.

 
Looks great Will"thumbsup" My axles came in yesterday so I would like to work on the steering while I'm waiting for other parts to come in. How much is your front clocked?
 
Mine was clocked 20*. When i machined the axle down I forgot to bring a pinion gear which looks like it bit me in the butt. I should have machined the axle so that the servo sat in at a slant which would give more room for the pinion to slide over. Because I didn't do this I cannot run this axle clocked unless I want to run a larger pinion. So I'm going to finish it unclocked and put some miles on it. If it bothers me unclocked it's just a matter of ordering another long shaft.
 
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Mine was clocked 20*. When i machined the axle down I forgot to bring a pinion gear which looks like it bit me in the butt. I should have machines the axle so that the servo sat in at a slant which would
give more room for the pinion to slide over. Because I didn't do this I cannot run this axle clocked unless I want to run a larger pinion. So I'm going to finish it unclocked and put some miles on it. If it bothers me unclocked it's just a matter of ordering another long shaft.

I'm sure it will work fine. I'm thinking about sending mine out to get done because I really don't have the knowledge, skill or tools to do it myself:oops: If I do that it will not be clocked because he does not offer the option.
 
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