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Old 12-10-2006, 06:27 PM   #676
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Originally Posted by John Stranahan
(Note all these IRS axle items were available as a kit together, but they were out of blue pieces About $70 IRS 2123BL complete kit. Stormer had the blue pieces.
ahh so it's 2133, not 2123 as your original post says...
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Old 12-12-2006, 04:00 PM   #677
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Servo Mount III

I was still not happy with the servo completely flat. The problem is that if you have your normal spacer stack on the steering arms under the ball studs you have huge bump steer. Bump toe in. That means the car adds steering to the loaded tire, as the car rolls, all by itself. I removed some of this bump steer by adding a tall spacer stack under the steering ball studs that are mounted on the steering arms. This worked OK but there was some evidence that the steering arm was osciallting, and the ball cup was difficult to put back on during a race if it popped off from a crash due to limited clearance.

The original Associated plastic servo mounts tilt the front of the servo up to correct bump steer. They squirm around a lot because they are made of a slippery plastic and are secured to the chassis with only one screw per side.
There are aluminum mounts which might correct this problem. I have not tried these.

Here is a pic of my third attemt to mount the servo. I have tilted it, but this time to the side instead of front to back. I am using Losi JRXS servo mounts which have a pin and a screw on each side so they will not move. I have only used one screw per side to mount the servo, same as on an Associated TC4. It looks plenty rigid. I have a very slight amount of bump toe out which I think is prefereable to a lot of bump toe in. Later, I was able to put in a third screw low and left in the photo. I'lll give it a test tomorrow. We have had rain for a few days.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-servo-mount-iii-resized.jpg  

Last edited by John Stranahan; 12-12-2006 at 10:21 PM.
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Old 12-13-2006, 09:45 AM   #678
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Why is your servo canted like that?

The aluminum servo mounts which are triangular work very very well.
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Old 12-13-2006, 11:19 AM   #679
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It is canted for the same reason the stock mounts angle the servo up in front, to lift the output shaft so that you can run the steering links off the bottom of the servo. This improves bumpsteer and ackerman. My setup keeps the steering motion all in the same vertical plane. Center of gravity is not quite as high. There is more clearance to mount a low LMP body. The servo is very rigidly mounted so it does not move around if you bump a flapper board. I still need to test it this way.

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Old 12-13-2006, 04:44 PM   #680
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Track dusty.

The steering setup is a go. The car feels better than with the servo flat and a tall shim stack to eliminate bump steer. The steering is more precise. There is better steering traction in the sweeper which I presume is from less tire scrub from elimination of all bump toe in. The car oversteered a bit late in the decreasing radius sweeper. The solution was more throttle. This is always good. I was making up good distance on the two Nitros here.

I ran 2.7 ounces of lead toward the rear of the chassis. Acceleration and speed was better than just a single battery but not as good as with dual batteries on the dusty track. I will try this again in one of my qualifiers Sunday and get some lap times with and without the ballast. It should work better with a high bite track. If I run the main it will be with dual batteries. Jaco pinks worked well again with this 3.5 R motor. They actually warm up about 12 degrees after a run with this motor.

Throttle exit spins reared their ugly head again early in the session. I am convinced this happens when the front tires almost completely unload. This was aided by more weight in the back. It was quickly solved with better throttle control out of the corners.

I am using an 8# white MurdockRC spring now. Stability on the straight is excellent with this spring, this body, and front minitruck shocks.
John

Last edited by John Stranahan; 12-13-2006 at 05:02 PM.
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Old 12-13-2006, 10:34 PM   #681
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Here are some pan car video's:
http://home.zonnet.nl/ronskever/film.htm
I particularly like the one with Rene Fisher and me training on my hometrack.
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Old 12-14-2006, 04:00 AM   #682
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How about mounting a front shock like on this 1/12 scale?
http://www.rctech.net/forum/attachme...hmentid=188037
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Old 12-14-2006, 09:30 AM   #683
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I don't think that shock is connected to the suspension - I can't see any linkage.
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Old 12-14-2006, 05:15 PM   #684
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New Spektrum Micro Receiver - Sweet. Pic below. That is the entire antenna.




After using all of my photographic tricks on that single shock setup, I still can't make it out clearly. It looks like it might be the setup similar to what Tally RC drew up. Lower A-arm moves. It has an inner upright that acts directly on the shock. I don't like the non independent nature much. It would tend to increase roll by transfering motion to the other arm. A double shock setup like this would be better.

Mathijs-Thanks for the videos. You guys have a nice track.

New Stock TRC wheels at Sormer
I received some new stock TRC 1/10 oval/onroad tires from Stormer. They come in a nice plastic sealed round container. They are Jaco's. I have broken two Jaco wheels. No GRP wheels have broken.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-spektrum-mini-receiver-007-resized.jpg  

Last edited by John Stranahan; 12-14-2006 at 05:36 PM.
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Old 12-14-2006, 10:39 PM   #685
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Quote:
Originally Posted by John Stranahan
New Spektrum Micro Receiver - Sweet. Pic below. That is the entire antenna.




After using all of my photographic tricks on that single shock setup, I still can't make it out clearly. It looks like it might be the setup similar to what Tally RC drew up. Lower A-arm moves. It has an inner upright that acts directly on the shock. I don't like the non independent nature much. It would tend to increase roll by transfering motion to the other arm. A double shock setup like this would be better.

Mathijs-Thanks for the videos. You guys have a nice track.

New Stock TRC wheels at Sormer
I received some new stock TRC 1/10 oval/onroad tires from Stormer. They come in a nice plastic sealed round container. They are Jaco's. I have broken two Jaco wheels. No GRP wheels have broken.
Wow those receivers are getting smaller and smaller! It's time they start making smaller connectors for the servo and ESC!

For the 12th scale car: the lower arms must move. Look at the stabilizer rod mounted up front.

For the films: yeah we are really lucjy to have such a super track!
On the film with Rene and me you can see the way we train: running 2 or three car freight train and attacking eachothers position, but go back when you have almost passed the front car. It really helps in developing better lines around the track.
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Old 12-15-2006, 02:37 AM   #686
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Here is another single shock 1/12 scale (this is an Associated 12 IS):

http://www.rc-car-museum.de/1_12_Mod..._rc_12_is.html

The front suspension is made out of RC10 parts and was available as a kit from Associated.

Also a single shock front suspension on the 1/12th Delta Spyder:

http://www.rc-car-museum.de/1_12_Mod...ta_spyder.html

The article is in German, but http://bablefish.altavista.com should be able to translate.

Enjoy........
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Old 12-17-2006, 02:57 PM   #687
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Three- Thanks for the links. Those are interesting cars. All three cars have similar suspension in that the main front shock and spring adds 0 to the roll stiffness. Hence the need for a fat swaybar. If there were two little shocks in the center like that. One for each side, I think the suspension would be better. I am not able to test those cars but I think a more independent front suspesion with some damping would have to be better for outdoor asphalt.

Interesting gear diff on one of those cars.


Race Report
Nature was against me today. We had light fog and a cool morning but expected a warm sunny day later on so we sugar watered the track like normal. It dried very slowly. For some reason the sugar recrystalized to a powder. Normally it dries to tacky film. I think some dust which blew over the track may have caused the crystalization of the slow drying goo. Traction was poor. Temperatures reached 82 F. The LRP Comp speed control was erratic and then had a thermal shutdown. It is probably dead. I will need another track test before I know for sure and can send it in. Maybe a novak 3.5 is too much for it. I had a fan on it with no improvement. Interestingly 80 F was the temperature at which the novak GTB 6.5 R started to give me trouble in a touring car.

Pinion Gear Wear
12 tooth pinion gear wear. I have four good practice sessions with the 3.5 R motor. Mostly in very cool weather. In that time it completely knife edged a hardened steel Robinson Racing Pinion. Photo below. Normally the teeth have small flats on the tips. This is worn down almost to an edge.

I replaced this pinion with a Robinson racing Hardened steel pinion, but this time a Titanium Nitride Coated pinion. This hard surface coating will make it last a little longer. Mesh is not really that good with this small a pinion, but the 3.5 really needs these low gears to perform at its best. I don't have a lot of selection on pinion brands. This TiN coated pinion is also a bit wider than the regular pinion which fits our spur much better, all the way across with room to spare. (RRPB1212 Pinion Gear-Titanium Gold)

Note that I install two 1/2 inch ID x .0025 inch thick shims from an Associated TC3 diff along side of the spur (ASC3911). This reduces spur gear woble and gave me very even wear. I get very good wear with a Novak 4.5R and a 14 tooth pinion.

Amp-Max Batteries
I have a couple of 7.4 V, 6.5 oz, 4000 mA-h Amp-Max 2S1P Batteries on the way. I can run them both as a saddle pack. The total weight will be about the same as a six cell NiMH pack, but 3.4 ounces lighter than my current saddle pack setup. This is the brand they ran and won with in the 24 hour Enduro, with a Pantoura which is described earlier in this thread. I have lightened my car a little as well so the saddle pack car will only be about 45 ounces. I should be able to run a 20 minute main on a high grip surface with the new setup.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-robinson-racing-knife-edged-pinion-007-resized.jpg  

Last edited by John Stranahan; 12-17-2006 at 03:47 PM.
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Old 12-17-2006, 07:58 PM   #688
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Good to see you John at the track today. That car you have is just sick. I will get my pan car together and come out and play next month. Man that li-po, brushless pan var is the bomb.

I will run a Hyperdrive 1oth scale with a Novak 5.5, 4800 Orion li-po, The small futaba 9550 servo, micro spektrum rx. I will start the gearing around 6.00 and go from there. I found Purple and pink tires. Anything I am forgeting?

Thank,
Joe Maxey
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Old 12-17-2006, 08:43 PM   #689
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Joe-Good to meet you as well. Welcome to the thread. Here is a quote from Mathijs from another thread who also runs a 5.5 in a pan car.

"The Novak 5.5 runs best with rollout between 32 and 34 mm. I put on an extra fan blowing onto the motor to keep it from shutting down thermally however."

That would be about a 5.8 gear with a new tire. I run my 4.5 with a 6.2 gear.
I have been running a Novak 4.5R since August with no thermal shutdowns. This one today is the first, but with a 3.5R and no fan.

I am having the best luck on our track with a tallish ride height. 6.5 -7.0 mm to clear the bumps on the straight. Use Corally Jack the Gripper (TC2) traction compound for 20 minutes front and rear. Stormer or CorallyUSA.com

You should be setup very well. I will enjoy the company.
John
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Old 12-17-2006, 08:46 PM   #690
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Quote:
Originally Posted by John Stranahan
Joe-Good to meet you as well. Welcome to the thread. Here is a quote from Mathijs from another thread who also runs a 5.5 in a pan car.

"The Novak 5.5 runs best with rollout between 32 and 34 mm. I put on an extra fan blowing onto the motor to keep it from shutting down thermally however."

That would be about a 5.8 gear with a new tire. I run my 4.5 with a 6.2 gear.
I have been running a Novak 4.5R since August with no thermal shutdowns. This one today is the first, but with a 3.5R and no fan.

I am having the best luck on our track with a tallish ride height. 6.5 -7.0 mm to clear the bumps on the straight.

You should be setup very well. I will enjoy the company.
John
what roll out are you using with the 3.5?
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