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View Full Version : Rock Force Setup and Testing


dkingston
12-19-2008, 08:23 PM
I did some initial testing this evening as to motor, battery, pinion and gearing.

Here is the setup:
HS Gearset/23T Pinion = 56.09:1 Gear Ratio
55T Integy Motor
3S 1500 Cheap Generic Lipo
Mamba Max with Castle BEC
Hobbico CS170 for Steering
Hobbico CS170 for Dig
Ambient Temp: 39 Degrees

What I was intending to discover was a baseline setup that would provide decent wheel speed and reasonable temps for the motor speedo and batts.

Here is what I found:
All temps measured with an Exergen DX501 (http://www.amainhobbies.com/product_info.php/products_id/2246) temp gun.
I ran the pack until the voltage cutoff kicked in (the only thing I didn't do was watch the time DOH)
The highest the motor temped was 82 degrees
The highest the heat sink on the speedo measured was 42 degrees
The highest the axles measured was 85 degrees

I have believed that the temp issues that some had encountered were more to do with over-gearing the motor attempting to regain wheelspeed. The setup used was a more conventional one that I would expect to give great results from an efficiency standpoint. I was not disappointed.

Trying to establish a runtime in hindsight would be silly. It seemed like a reasonable amount of time to run but more testing will be done to get accurate timings.

Dig Testing:
I was constantly going in and out with the dig, trying to get it to respond as it would in a normal comp situation.

Using the CS170 was seemingly overkill initially. After using it I was satisfied that the additional torque is handy to have.

There were a couple of times that disengaging the dig it didn't just come out. A little blip of the throttle would bring it right out. This happend a few times initially and after going back and adjusting the spring tension on the lever it seemed to get considerably better.

The dig worked pretty well on power. I tried using it like I did with the berg: on power, in and out. It performed very well, actually better in engaging and disengaging on power than not.

I believe that replacing the springs with about 3/16" of fuel tubing with small washers at each end, will provide much more consistent functionality. I will try to get to this later in the weekend.

___________________________


I will be comping with the Rock Force on Saturday. Since it has been a while since I have been on the rocks, my finish may or may not reflect well on the rig ;) . There will be several drivers there who will get the chance to try it out. Hopefully, they will give some feedback on here as well.


- David

EeePee
12-19-2008, 08:56 PM
Right on. "thumbsup"

killjoyken
12-20-2008, 08:33 AM
Perfect! This is exactly the kind of test we need. Good luck at the comp.

I've been planning the same thing for the dig setup. I've got a 200oz Airtronics 94361 for my dig. After reading John's issues with releasing the dig from lock I was also planning on either using fuel tubing or even a direct linkage like my DNA dig. Did you use any grease on the pins and metal lock plate? The instructions don't call for it, but it may help with a smoother disengagement.

The high speed gears are nice, aren't they? ;-)

dkingston
12-20-2008, 04:31 PM
Whew, just returned from the comp and have several things swimming around in my head.

I think my assessment from last evening about the gearing/motor/temp issues were correct. The motor never temped over 92 degrees which was nearly identical to every Berg and Bully rig I temped today. (I think they must believe I was crazy, wanting to temp their motors!)

There was no real opportunity to time my runs today to see how the battery life was. I truly believe that the lack of runtime was a function of the gearing.

The Dig
I experienced some hesitation disengaging the dig on a few occasions in my fist run. Between courses, I decided to take about 3/16" of fuel tubing and put it in place of the springs. PRESTO, things were immediately better. Not quite perfect yet but from what others were saying at the comp it was as good if not better than any other mechanical dig currently available.

My satisfaction with the performance at this point is pretty high. Individual tweaking and adjusting will be necessary on your rigs but I highly recommend fuel tubing in place of the springs.

The only real bad news on the dig was something that happened that was totally my fault. Since putting it in last night, I didn't take the time to trim the excess servo arm that was left after the point where the linkage mounts. While goofing around, jumping through a gate, I landed and clipped the end of the servo arm. The arm broke right above the linkage mount. :-( That ended the testing for the day.

The Shocks
The shocks do an incredible job of dampening the suspension. Maybe too good in fact! Running 30wt oil is too heavy, especially in the winter due to the temps affecting the effective viscosity. EeePee is running (I believe) 15 to 20 wt in his. I think for now that is probably the way to go.

The Suspension in General
Overall, the suspension cycles pretty well. There is some axle swing that I think can be adjusted out, to a certain point. I will be playing with some setups for this. Like I think I mentioned earlier, I am not running my righ cinched down. I like the 3" skid clearance. There are a couple of us that are working on Panhard tweaks for running the Rock Force fully extended. I think this will help the overall handling.

Where do I go from here?
I know I am a tad biased about the Rock Force but I have tried to be as honest in these posts as possible. To say that I am really happy with this rig would be an understatement. Now it is time for me to just spend some time with the Rock Force on the rocks, getting more familiar with the rig. Work on setups will be a pretty high priority as well.

As I find more things I will post them here. If any of you come up with any setup tips, please post them here as well!


- David

dkingston
12-20-2008, 04:35 PM
Perfect! This is exactly the kind of test we need. Good luck at the comp.

I've been planning the same thing for the dig setup. I've got a 200oz Airtronics 94361 for my dig. After reading John's issues with releasing the dig from lock I was also planning on either using fuel tubing or even a direct linkage like my DNA dig. Did you use any grease on the pins and metal lock plate? The instructions don't call for it, but it may help with a smoother disengagement.

The high speed gears are nice, aren't they? ;-)

Ken

The fuel tubing is DIALED, go for it. Grease won't help in my opinion. Give that a try and I think you will be happy. The dig is a pretty slick setup.

The Highspeed gearset are very nice. The "dewalt" noise appears to be gone and there seems to be less heat in the axles as well.

Let us know how yours goes!


- David

EeePee
12-20-2008, 05:20 PM
EeePee is running (I believe) 15 to 20 wt in his. I think for now that is probably the way to go.

Yep, you're correct. 15 in front, 20 in back. I put the 20 in back just because the shocks are laid down a little compared to the front. If I had 17.5, I'd go that route probably. And I'm using Losi oil.

And I didn't modify the stock piston as the instruction say to.

Racer4Life
12-20-2008, 05:40 PM
DK....very honest write-up!!

Reflection
12-20-2008, 06:05 PM
The Dig
I experienced some hesitation disengaging the dig on a few occasions in my fist run. Between courses, I decided to take about 3/16" of fuel tubing and put it in place of the springs. PRESTO, things were immediately better. Not quite perfect yet but from what others were saying at the comp it was as good if not better than any other mechanical dig currently available.

Be nice to somehow have the freewheel option. I'm glad to see your getting the dig working better though.

The Shocks
The shocks do an incredible job of dampening the suspension. Maybe too good in fact! Running 30wt oil is too heavy, especially in the winter due to the temps affecting the effective viscosity. EeePee is running (I believe) 15 to 20 wt in his. I think for now that is probably the way to go.

I've always liked my Kyosho shocks. Even the plastic bodied shocks I have still work like a champ after years of abuse. Are the pistons in these shocks the same as the Twin/Mad pistons? Or do they have holes in place of the flats?

The Suspension in General
Overall, the suspension cycles pretty well. There is some axle swing that I think can be adjusted out, to a certain point. I will be playing with some setups for this. Like I think I mentioned earlier, I am not running my righ cinched down. I like the 3" skid clearance. There are a couple of us that are working on Panhard tweaks for running the Rock Force fully extended. I think this will help the overall handling.

Be hard to get axle swing out without magical adjusto links.:lol: I'm interested to see what you come up with. Double triangulated is best for that though. If a guy is used to having a certain amount of axle swing or steer,you can use it to your benefit at times.....just have to know your rig.

EeePee
12-20-2008, 06:07 PM
Or do they have holes in place of the flats?

No holes, flats on a side. The instructions tell you to file another flat on the other side.

roborg5000
12-20-2008, 06:12 PM
Defiantly an improvement from the last time you brought it "thumbsup"

dkingston
12-20-2008, 06:16 PM
Raptorman, the freewheel option is there. I just didn't have enough time last night to program the radio to play with it.

Reflection
12-20-2008, 06:21 PM
Raptorman, the freewheel option is there. I just didn't have enough time last night to program the radio to play with it.

How do you get worm gears to free wheel?

EeePee
12-20-2008, 06:25 PM
How do you get worm gears to free wheel?

Disconnect the axle, from the gears. ;-)

dkingston
12-20-2008, 06:36 PM
How do you get worm gears to free wheel?

The worm spur gear spins free on the shaft. When the shift fork leaves 4wd and before it locks there is a position that allows for freewheel.

This dig is pretty clever in its design!


- David

Dewmerz
12-20-2008, 06:36 PM
Sounds like you had great results today. Ken helped me out with the needed part numbers so I should have a set of axles/trans in the next week or so with HS worm gears and dig. We're just waiting for the order to show up at the LHS.

killjoyken
12-20-2008, 06:39 PM
Well, I also got a bit of testing in today and the RF performed great. In fact, the RF outperformed my GC-1 on a number of climbs and even made one my GC-1 couldn't. :oops: In the defense of the GC-1, I was running some well worn Panthers that weren't biting like they used to. But it wasn't just that it was making the lines, but how easily it was doing it. Switching back to Claws on 8-holes was a big improvement over the Badlands on Epics. The rig likes to stay planted and likes the lower height of the Claws. The only downside was that the axles were getting hung up a little more than before. I need to work on smoothing them out some more.

I lost some wheelspeed with the new gear ratio but the motor never stalled and worked well for finesse climbs. Right now I think I'm sticking with this link and shock setup. I've got 2 weeks off to get some more seat time before the next comp on the 4th so I'll have a full report then.

For now I'm still amazed that I made it through a full pack without once wanting to check the rig off the mountain. :lol:

David, thanks for the fuel tubing tip. I won't bother with the springs.

I forgot to add: for the guys using the stock shocks make sure you follow the instructions on filing the pistons. It seems that everyone who doesn't has the same problem with the shocks reacting too slow.

dkingston
12-20-2008, 06:55 PM
Sounds like you had great results today. Ken helped me out with the needed part numbers so I should have a set of axles/trans in the next week or so with HS worm gears and dig. We're just waiting for the order to show up at the LHS.

AWESOME! Ironically, I just got off the phone with Steve from Kyosho asking about the diagrams and manual. Looks like they will be available around Monday.


- David

EeePee
12-20-2008, 06:56 PM
It seems that everyone who doesn't has the same problem with the shocks reacting too slow.

Not with lightweight oil I don't. "thumbsup"

dkingston
12-20-2008, 06:57 PM
Well, I also got a bit of testing in today and the RF performed great. In fact, the RF outperformed my GC-1 on a number of climbs and even made one my GC-1 couldn't. :oops: In the defense of the GC-1, I was running some well worn Panthers that weren't biting like they used to. But it wasn't just that it was making the lines, but how easily it was doing it. Switching back to Claws on 8-holes was a big improvement over the Badlands on Epics. The rig likes to stay planted and likes the lower height of the Claws. The only downside was that the axles were getting hung up a little more than before. I need to work on smoothing them out some more.

I lost some wheelspeed with the new gear ratio but the motor never stalled and worked well for finesse climbs. Right now I think I'm sticking with this link and shock setup. I've got 2 weeks off to get some more seat time before the next comp on the 4th so I'll have a full report then.

For now I'm still amazed that I made it through a full pack without once wanting to check the rig off the mountain. :lol:

David, thanks for the fuel tubing tip. I won't bother with the springs.

I forgot to add: for the guys using the stock shocks make sure you follow the instructions on filing the pistons. It seems that everyone who doesn't has the same problem with the shocks reacting too slow.

Great to hear, Ken!


- David

killjoyken
12-20-2008, 07:24 PM
Not with lightweight oil I don't. "thumbsup"

But you said:


The suspension is very smooth. I have only 15 weight in the front shocks, and 20 weight in the back shocks. But with the piston being the way it is, the rebound and compression dampening is still pretty slow. And with the front shocks being vertically mounted, they'll have a more direct effect than a set of laid down shocks will.


:-P

EeePee
12-20-2008, 07:29 PM
I forgot to mention how cold it was. :ror:

With them warmer than freezing temps outside, they really, really loosen up.

I'm content with what I have. I won't change anything about the shocks now.

Tanis
12-20-2008, 07:33 PM
Weird, silicone shock oil isn't affected by temps.

EeePee
12-20-2008, 07:35 PM
Bull crap it ain't!

killjoyken
12-20-2008, 07:36 PM
Weird, silicone shock oil isn't affected by temps.

Ooooo, sick burn! :lol:

Tanis
12-20-2008, 07:36 PM
It's just your imagination:-P

EeePee
12-20-2008, 07:41 PM
Go stick a bottle or your truck in the freezer for an hour and get back to me.

But also, it's a very small through hole for the oil to go through, so it's probably pretty sensitive.

Tanis
12-20-2008, 07:44 PM
That makes sense with the tiny through hole"thumbsup". I should have said silicone oil is not affected much by temperature changes:ror:

Tanis
12-20-2008, 07:46 PM
Feel free to clean up this thread, I'm not adding any useful tech:ror:

EeePee
12-20-2008, 07:48 PM
Feel free to clean up this thread, I'm not adding any useful tech:ror:

It's just your imagination:-P

You're just my imagination! :flipoff:

Tanis
12-20-2008, 07:49 PM
:ror::ror:

Rckcrwlr
12-21-2008, 04:44 PM
I am running 20wt in mine without filing the other side down on the piston...I like the "hanging" affect that I get when crossing large holes or drops...

That was in the indoor course.

I cinched mine down to having the panhard horizontal. I was real happy with how planted it was...sidehilling, verticals and maneuvering were flawless. Couple things that I will be working on for the next event:

Delrin Skidplate
Loosen the cinch a little (too low, sub 2")
Panhard Modifications
Breather holes in the wheels
HS gears
Dig (Wish I had Dig ;) )

This is the first rig that I am really excited about the potential. The SW3 has seen the shelf since I got it.

"thumbsup""thumbsup"

http://i139.photobucket.com/albums/q307/rckcrwlr_bucket/RC%20Items/WPaC/12-21-08%20Comp/122108Comp003.jpg
http://i139.photobucket.com/albums/q307/rckcrwlr_bucket/RC%20Items/WPaC/12-21-08%20Comp/122108Comp004.jpg
http://i139.photobucket.com/albums/q307/rckcrwlr_bucket/RC%20Items/WPaC/12-21-08%20Comp/122108Comp005.jpg
http://i139.photobucket.com/albums/q307/rckcrwlr_bucket/RC%20Items/WPaC/12-21-08%20Comp/122108Comp006.jpg
http://i139.photobucket.com/albums/q307/rckcrwlr_bucket/RC%20Items/WPaC/12-21-08%20Comp/122108Comp007.jpg

Rc_Cam
12-21-2008, 08:27 PM
What kind of weight were you running in your wheels for the comp?

killjoyken
12-21-2008, 09:59 PM
rckcrwlr: looks good. From the pics it seemed like there were some tight turns. How'd you do without dig?

David: Any chance you could talk to the Kyosho team about getting us some CVDs? That's the only thing holding me beck from gaining some more steering.

Rckcrwlr
12-22-2008, 04:44 AM
What kind of weight were you running in your wheels for the comp?

Front: 10.20 oz
Rear: 8.25 oz

Not sure if any more is needed. The lack of torque twist keeps the front axle planted

rckcrwlr: looks good. From the pics it seemed like there were some tight turns. How'd you do without dig?

Dig is a must...The first course was real tight (the one in the pics)...I knew going into it that I wasn't going to be able to place due to the lack of dig...

Re: the CVD's, Modding the knuckles will be the only way to get more steering whether you have CVDs or not. I think the dig is going to open a lot of doors. Should have mine this week. Those in combo with the HS gears should give you the ability to "pivot" when needed.

saydee1800
12-22-2008, 07:55 AM
how do you put the weight in the tire BB's?

Rckcrwlr
12-22-2008, 10:54 AM
how do you put the weight in the tire BB's?

You can do BB's, Airsoft Pellets, Wheel Weights, Memory Foam or any combo of them... "thumbsup"

saydee1800
12-22-2008, 11:42 AM
what speed control and motor are you running?

Rckcrwlr
12-22-2008, 12:32 PM
7T HH Cobalt Puller
4S 25C Holmes PolyRC LiPo
Mamba Max with Castle BEC
Hitec 7955tg

HiloDB1
12-22-2008, 05:26 PM
Here is what my current setup is

Mostly stock kit form.
15wt oil all around (didnt add the extra flat on the piston)
Axial Beadlocks with Hammer M2 and memory foam
Rear dig
Battery mounted on front lower links
Excess chassis braces removed
Tekin FXR ESC (push control set at 3)
40T motor with 35t/72t pinion/spur (62:1 ratio)
7955 steering
133oz futaba servo for dig
CC BEC
Futaba 3PM
Added link extensions wb at 12.375"

So far not bad in the limited testing that I have done. My dig is not as smooth as I had hoped when bound up. It still does a somewhat decent job most of the time. I am thinking of puting a 7955 for the dig but the plastic dig arm worries me. I will have more in a week or so as I will do some heavy testing over the winter break. Lucky for me it doesnt get cold in Hawaii :-P

saydee1800
12-22-2008, 05:40 PM
[QUOTE=HiloDB1


I read that if you put gas line on it instead of the spring it will fix your sticking dig

So far not bad in the limited testing that I have done. My dig is not as smooth as I had hoped when bound up. It still does a somewhat decent job most of the time. I am thinking of puting a 7955 for the dig but the plastic dig arm worries me. I will have more in a week or so as I will do some heavy testing over the winter break. Lucky for me it doesnt get cold in Hawaii :-P[/QUOTE]

I read that if you put gas line on it instead of the spring it will fix your sticking dig

HiloDB1
12-22-2008, 05:53 PM
Im not using the spings on my dig. I have my EPA's set so I eliminated the springs right off the bat. It only gets stuck when the truck is bound up. Most of the time its not a problem.

spinner
12-22-2008, 05:55 PM
This is my set-up:

Novak Goat.
cc bec
novak lipo 3 cell cut off
2x flight power 1345mah batterys
lrp 21.5 brushless crawler motor
Hpi mesh 2.2 wheels
panther cougars
dx3r
645 servos
rear steer(till my dig arrives)
stock spur with 23t pinion

So far I'm really happy with it. adjusted my links to get 12.5 wheel base. I have only had it on the rocks for one comp and took second.

dkingston
12-22-2008, 06:25 PM
Im not using the spings on my dig. I have my EPA's set so I eliminated the springs right off the bat. It only gets stuck when the truck is bound up. Most of the time its not a problem.

I would at least run fuel tubing. Running nothing could burn up your servo.


- David

killjoyken
12-22-2008, 09:58 PM
I would at least run fuel tubing. Running nothing could burn up your servo.


- David

Not if he's got his EPAs set correctly. AFAIK, every dig on the market runs a direct linkage with no fuel tubing or springs. My DNA works fine that way and I have no worries of burning up my servo. After taking the plastic dig arm off the tree it's fairly ridged and should hold up for a while. Eventually we will need a metal version though. One of these days I'll probably mill one out of stainless.

David: If you can, please talk to Kyosho about getting us some CVDs. I've trimmed the C's and gained steering, but anymore and the dogbones bind. Thanks.

Hilo: Lucky bastard. It's been raining here off and on and killing my testing!

Spinner: 2nd? Wow, good job!

Rckcrwlr: 4s huh? That motor must get nice and toasty!

spinner
12-23-2008, 11:00 AM
Thanks Killjoy.
I wish It would rain here. it's been -20c to -30c for two weeks here. that's 0 to -22 in fahrenheit.