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Old 04-28-2007, 10:28 AM   #1186
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Ok, may ask some more, it seems that ya can this (hope you accept some offtopic, i know this is a Pantura thread)

I bought some 64p Spurs for my I-Force 90-105 and 20-27 piniongs, am i waaay out of gearing with this? Is 48p gears to prefer? ofcourse the diameter on the tires is importent here.Motor will be Mamba7700 What, if you can annwser litttle lose, what rollout is a good range to be in, my frineds run 1:12 on that and was around 48-50 on Brushed motors, i was on 64 BL

This is the track , I think the 1:8 track runs around 17+ or o mabe little higher
1:12 Low 21 secs

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Old 04-28-2007, 10:50 AM   #1187
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Any Pantoura or 1/10 Pan Car or brushless or Lipo question is on topic. And of course we don't have to follow those rules.

I assume you are going to run 6 cell in the I-force.

"Here is a quote from one of Mathijs post. That 7700 kv motor has slightly more RPM than a Novak 5.5 R. I used the thread search tool for "gearing 5.5"

"On the 5.5 motor I noticed the following:
Top speed was highest with rollout between 32 and 33 mm, but runtime was reduced dramatically compared to a slightly lower rollout.
Furthermore, the motor runs dramatically hotter with a too tall gearing.
The car ran best with rollout between 29 and 32mm.
In that range it didn't really care where you are exactly, it will be about equally fast.""

I prefer the 48 pitch gears as they are more rugged and can handle more torque. If you are never on the brakes the 64 pitch gears will work fine. I'll assume you can convert to gear ratio from rollout. The GRP tires are 2.4 inches to start with. Little change in gears are neccesary with these brushless motors as the tire wears. Maybe once.
Really Nice Track and Pic Thanks.
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Old 04-28-2007, 11:09 AM   #1188
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Thank you so much John, this was a big help for me..Hmmm 48P spurgears, since im running BJ4WE car, i have a lot of 48p Spurs Kimbrough 69-81T, and 11T-32T i just realiced . Klick o the link,and just tell if they fit

http://i123.photobucket.com/albums/o...4/S5032109.jpg

Thanks again John, for the info

/Thomas
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Old 04-28-2007, 12:42 PM   #1189
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Kimbrough 48 pitch gears like the ones in the picture are excellent. I always use them.
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Old 04-28-2007, 12:59 PM   #1190
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Thx Mr Holand, real nice to hear
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Old 04-28-2007, 02:34 PM   #1191
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Track Test, Air Temp 89F Track Temp 125F! (52C) Traction poor but improved each pack. Starting to get hot.

I had a good hot weather test today. On the last run with a new pack, I had fair traction. Motor temp was 167F (75C, get the picture on that high temperature loctite, you guys that use heat or freezing to put on the bearing) on the Novak 3.5R. You have to check it in several spots. This was the hottest spot. So there is good hope for this system to run in August when track temps will go up to 140F.

New vs Old LIPO
When you run a brand new LiPo (MaxAmps LIPO) against your old LiPo with 60-70 cycles on it there is just no comparison. The new one is much faster. 300 cycles is a gross exageration of what you will be happy with. Anyway, it's going to cost you a buck a run for any type of battery to have them in condition to race. It's been that way a long time. Straight away speeds and punch are both much better on the new battery. I'll have to order up a second new LiPo as a brand new one fried right along with the GTB when that bearing seized.

The second prototype was hooked up well in the last run except for the sweeper. I suspect the ackerman is off a little. I will tinker with that next. I can by moving the inside of the steering arms forward or back like this adjustment is made on the Kysho Evolva 1/8 scale cars. On the first Prototype Ackerman is perfect so I will compare the two.

Last edited by John Stranahan; 04-30-2007 at 01:00 PM. Reason: Added Brand MaxAmps
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Old 04-28-2007, 06:31 PM   #1192
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Ackerman

Ackerman lets the inside wheel in a corner take a sharper angle than the outside wheel in order to match the wheels paths on the road in a corner.

I investigated the difference in Ackerman between the new and the old prototype by drawing some sketches and measuring the steering angles.

Old prototype: when the inside wheel turns 20 degrees the outside wheel turns 15 degrees. I drew a 20 degree line to set the inside wheel parallel to it. I drew a line for the outside wheel and measured its angle.

New prototype: when the inside wheel turns 20 degrees the outside wheel turns 13.5 degrees. I am going to call this " it had more Ackerman". There is more difference in the two angles.

Previously in this thread when I was moving the servo around (flat, then angled to the side, then in the standard pan car position) I found that the car was sensitive to Ackerman on the sweeper and less so every where else. Now whether it is sensitive to 1.5 degrees or not I'll find out the next session.
Since the steering arms on both cars had a similar angle I looked for the difference at the servo. The old car had a spacing on the inner steering link balls of .5 inch (black large Kimbrough Servo Saver). The new car had only 3/8 inch here (Large White kimbrough Narrow End servo saver). This was the big difference. I swapped servo savers. This gave me the old cars Ackerman Exactly and maybe its good performance on the sweeper. I also may need to lower my front roll center back down now that I am used to this prototype.
Note that Ackerman can also be changed by moving the servo forward and back a little.
John

Last edited by John Stranahan; 04-28-2007 at 07:03 PM.
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Old 04-30-2007, 12:58 PM   #1193
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I thought I would post my response to a private message as I may not have qualified a LIPO message clearly enough. I look forward to actually finding a supplier of a LIPO battery that performs as well as the original Scorpion Pack that I tried over a year ago.

"I have reported on that (this) thread that the Lithium Cobalt Dioxide cells are superior and do not loose runtime and Voltage as Fast. These Scorpion packs were made by Kokam.

I have tried a Orion Avionics Pack that is made by Kokam. It had poor voltage and runtime when brand new. Not that good in the car either. I sold it. It was as if it had aged 50- cycles from storage in the supply chain. It is probably one after the chemistry was tweaked by Kokam for safety. I had a similar problem with an Apogee Magnum Pack which had deteriorated in the supply chain.

I probably should qualify my statement better to MaxAmps which are the cells I currently am testing. The chemistry is not divulged, but they sell a 300 cycle warantee. This is specifically what I was reffering to. 300 cycles on a MaxAmp cell. I have stated the brand of cell with each performance report and the Chemistry when it is stated.

thank you for your message.
John

Last edited by John Stranahan; 04-30-2007 at 05:11 PM.
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Old 04-30-2007, 05:17 PM   #1194
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Track Report- Traction poor, but improved some with use. Air Temp 85F track Temp 109F.

Mamba Max, Novak 3.5R, geared 90/12, MaxAmps.com 4000 mA-h 2S-1P LiPo

I timed my last pack which is a new pack. It went 9 minutes and 20 seconds in the car before slowing. Maximum motor temp was 161F. Controller temp was 140F. Things are looking good for the next race. I have a new matching battery pack on the way. The car is steering better today. The problem on the sweeper is still there, but I can see the dust on that part of the track. Sweeping it helped a little.

John

Last edited by John Stranahan; 04-30-2007 at 10:27 PM.
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Old 04-30-2007, 11:58 PM   #1195
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Default IS this right :)

John, if you ask me, something is wrong here MambaMAX ESC sensorless ESC combined with a Novak 3.5r Sensormotor ? . I can promise,im CURIUS

Do you using a spec firmware for the spedo?(the one CC says they will fix,but aint availble yet) or do you just run it? Do you recomend me to do it? since our track is kind of huge

/Thomas P
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Old 05-01-2007, 10:36 AM   #1196
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Thomas-Yes the two work fine together. I cut off my sensor wires as the plug was melted anyway. Any sensorless speed control will operate a sensored motor. You just don't use the sensored part or small wire harness. I recommend this motor on a large track. The only problem or glitch is starting from a dead stop. Somtimes the car will back up a couple of inches before it goes forward. I am sure that this is just an unstated property of the sensorless speed control.

I am using the firmware that was updated from the Web. Nothing special here.


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Old 05-01-2007, 12:41 PM   #1197
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Quote:
Originally Posted by John Stranahan
The only problem or glitch is starting from a dead stop. Somtimes the car will back up a couple of inches before it goes forward. I am sure that this is just an unstated property of the sensorless speed control.
John: check out the Mamba max forum on this. Castle techs have reported that they're working on an update to their ESC sw that can work well with sensored motors like the Novak. They also discuss the issue of using a Novak motor and the Mamba ESC...maybe you should ask them about this just to see if there is an issue w/ running Novak or sensored motors in general with their system or if there is tweak you do to ge them to work 100% perfect...
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Old 05-01-2007, 01:03 PM   #1198
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Here are some pictures of last weekend's first race of the 2007 RC Le-mans racing series on the beatiful Oberhausen track in germany.
23 drivers, all modified 1/10th pancar.
http://www.mijnalbum.nl/Album=B7XVWUE3

I had some problems during qualifying.
Heat 1: my 3700's put out only 2900 mA's, so the pack dumped after 4 minutes.
Heat 2: I was on TQ pace with one of my 3 my 4200 packs when I made a driver error and broke a front suspension arm.
Heat 3: I was on TQ pace again when my motor thermalled after 4 minutes.
So I ended up TQ'ing and winning the B-main.
Before the last final I found the problem: my motor's front bearing was filled with dirt and had transformed into a bushing

Overall a fun weekend.
I was only 1/10th of a second off of the fastest lap of the race on my german colleagues' home track. Not bad!
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Old 05-01-2007, 02:09 PM   #1199
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YYhayim-I did check for motor running backwards on that thread as well as several other search titles. Did not find anything. I may ask over there eventually. The controller did the same thing with the Trinity motor. I notice that Tekin is working fevershly on the Same problem (stuttering from a stop) with the R1. I think the solution is probably going to be found by using Sensors.. I don't think it is a serios enough problem to delay the purchase. It is unsettling when it goes backwards as my finger instantly gets off throttle. You should not of course. I need more training with it.


Mathijs-What a great set of pics. Nice track and race. Good finish. Now here are some questions.
What motor thermalled on you? You were doing some experiments with the 5.5 last post.

I have had good luck with the $1.00 bearing from Avid RC. At least it has not exploded over three sessions. I think I will just change it before every race like I do my right rear axle bearings now. These two bearings just take a high load from the gears.

I noticed two bodies were common. One has a rib going to the top of the spoiler in the middle. What body is that? Are most guys not using spoilers or are they just painted. They seem to be as high as mine, to the top of the side dams.

I noticed the pic with the broken wheels and stripped gears. What wheels?

What motor were most guys using?

That's a pretty serious looking bunch on the A-main podium.

Nice Budweiser Paint!
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Old 05-01-2007, 10:32 PM   #1200
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The 5.5 with sintered rotor runs OK, just slower than the 3.5.
I haven't found the optimum rollout on the sintered 5.5 yet.
The 3.5 thermalled.

The bodies used were Hot bodies Nissan (with the fin) and Serpent Porsche.
Both are really high downforce bodies.
You don't need additional wings on those bodies.

The broken wheels are corally. They are made from a firm plastic that sometimes breaks in a crash.

Motors were divided between Novak 4.5 and 3.5's all with sintered rotors, GM's and Hackers and some brushed motors.
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