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Old 12-10-2009, 09:11 AM   #1336
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I quoted a gear of 6.2 overall by mistake it should have been 3.2. The car comes with a 64 pitch 100 tooth pinion, that gives a 100\3.2 = 31 tooth pinion. Outside I prefer to use 48 pitch spur and pinion would be 72/22.
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Old 12-10-2009, 10:26 AM   #1337
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Quote:
Originally Posted by audriusv View Post
Ups... just looked again and they seems to have imperial as well...
you did a quick glance at first i take it?? lol

i gave you that link for a reference but im sure theres something closer to where you are at

good luck
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Old 12-10-2009, 10:39 AM   #1338
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CRC Gen X10 1s LiPo chassis

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Old 12-10-2009, 10:48 AM   #1339
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awesome chasis!
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CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-mckunechasis.jpg  
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Old 12-10-2009, 04:15 PM   #1340
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Of course, you can also get ANY screw you could ever need at www.mcmaster.com - McMaster-Carr is a black-hole of awesomeness when it comes to screws, bits, bodges, and any other doo-daddle. . .
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Old 12-11-2009, 02:10 AM   #1341
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Thank you for links about screws.

Now would like to get some suggestions about pinions sizes. It is time to order some. But what number to start from? CRC Gen X 10, 64P 100T Spur Gear, 58mm size Jaco 2100 and 2110 tires, 2S LiPo 5000 30C, carpet high grip track with ~30m straight, Tekin RS Pro with Speed Passion V3 17.5 motor, Protoform Sophia #1502 body, total ~1200g weight. Added some weight for left to right balance. Second machine all same only with ESC Speed Passion GT LPF Brushless ESC Version 2.0.
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Old 12-17-2009, 05:11 AM   #1342
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Hey John

I plan to build a new 200mm pancar for next year. The rear suspension will be something bewtween "standard" link cars and the 4-Link suspension (You can see it a bit in the attached picture).
How much antisquat is needed for pancars? How much should antisquat and rollcenter change during suspensiontravel?
If my sketch is too ugly, google for Axial AX10. THis crawler uses the same suspension type, just with the centerpivot-link on top, insead of the bottom.




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Old 12-17-2009, 11:25 AM   #1343
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Dave- I had a fourlink rigged up on the Pantoura thread with pictures. A general placement of links where you like them will result in serious binding making the roll stiffness too high. Big cars get away with this by having more flex in the rear axle tube. This flex acts a little like a sway bar but it lets the suspension work smoothly.

A measure of antisquat is found by putting a vertical line at center of gravity. Now draw the instant center for the rear links. The line from the tire joins that instant center. If that line hits the center of gravity you have 100 % antisquat. If half as high then 50%. I have found near 100% is useful on the pan car. Adding this with the front of the lower links elevated also adds some roll steer out to the rear end. This makes the car nimble.

You will find you have no control of rear roll center. It is at the center of the rear solid axle as if unsprung.

Front roll center is important. You are lucky just to get that right without worrying that it moves out and down with roll.

I have seen working pan cars with a similar front end to the one you have sketched. One thing that makes a front end really work with foams is accurately controlling the camber of the tire as it goes up in bump or as the car rolls. I don't see any here unless that lower pic shows dual a-arms. If so make them unequal length so you control tire scrub across the pavement on bump, and have some negative camber gain with roll. Anyway here is my attempt at the same thing.

CRC based JS Pro 10
Well I have had parts including the speed control just waiting for my graphite parts to arrive. I finally gave up and hand cut the parts from the CAD's I had produced. I miss driving this car as it is wicked fast.

One of the goals of this setup is to produce slightly better cornering on a medium grip track. You can see from the electronics shot that I have moved speed control and receiver forward. I probably will need a piece of lead on the right side. I am using the Tekin R8 because no one offers a speed control over here that will hold up to this 3.5 wide pan duty. The "Black Diamond" speed control from CRC may, but it did not ship. The new Novak may work as well.

I have received some feedback from a couple of testers which has improved the breed. The Panhard bar shown in the last pictures, now has Dubro 4-40 rod ends which are actually quite a bit stronger in tension compared to our normal rod ends. The ball is more captured by plastic that is more centered on the ball. I used to use them in a 1/10 scale Losi truck to keep the camber links from popping off the rear bulkhead. A larger Aluminum Standoff is used at the motor plate for one end. At the other end the new rod end are thin and don't require sanding for a large 90/13 set of gears. The center post does require a clearance cut for the best clearance on the gears. More Rear droop was attained by removing a piece of chass from the left rear area near the Panhard Bar rod end.

I have developed a lathe procedure to shorten the 1/2 inch Hourglass Red Aluminum standoffs which decorate the front end. It was not a trivial task. I achieved good results and will be shipping (hypothetically) the front end with this standoff on both wide and narrow cars.

I can't wait to test it. It is raining right now.
This pro ten should be as fast as this new electric 1/8 scale from serpent, I predict. If you have a report let us know.
Attached Thumbnails
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-js-pro-10-005.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-js-pro-10-006.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-js-pro-10-007.jpg   CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks-js-pro-10-002.jpg  
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Last edited by John Stranahan; 12-17-2009 at 05:25 PM.
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Old 12-17-2009, 11:51 AM   #1344
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Corner Exit Hooking

On outdoor asphalt, Every new pan car driver has trouble with this. Right at the corner exit point where you give a four-wheel drive good power, the pan car behaves poorly. It darts toward the inside board. I discovered and discussed this early in the Pantoura thread. There was even a video there of a readers wide pan car that exhibited the same problem.

People that have driven pan cars for a long time may not even notice and may have forgotten that at one time they experienced the problem.

I did not call this oversteer on purpose. Oversteer has clear meaning on the track. The front end has too much traction, the rear end slides out from the race line. The rear end hits the outside wall so to speak.

The pan car does something odd. It drives toward the inside wall in a J shaped track.

We have made some good progress in our Petit Lemans, World GT class, 10.5, 2s LiPO class in reducing this problem. Here are some items that help.

Making the front tires softer.
Making the car 1/4 inch longer or to the limit of you chassis.
Making the rear shock stiffer. I have gone to 40 weight in my single RC18T shock.

Now if you are blind you will look at all this stacked evidence and declare that the car is just oversteering. On the oval site they just skoff and say ghosts must be acting on my car. Make the rear soft, making the front stiff, make the front tire hard; this is just opposite of what the car needs.

On the oval this can be eliminated completely with left rear down tweak and left rear offset. I saw each of 20 oval drivers plagued with this same problem to one degree or another. I just tuned it out. This is another couple of pieces off evidence added to the pile.

So what is happening to the car. Based on all the above and some knowlege of Physics and Vehicle Dynamics. On corner exit the right side tires, and especially the right rear tire are highly loaded. When you squirt the throttle you get torque steer from that rear tire. So where else have I seen this. On some of the bigger trucks with low gears, one trick is to back the truck, start a turn, and then slam it in forward at high throttle. The truck will pivot on the loaded rear wheel and almost do a pirouhette. It can spin like this for a long time in one spot. Well our pan cars are doing the same thing. If we slam on the throttle too soon they almost stand on the outside rear tire, the front tires are scrubbed accross the pavement, the car darts to the inside board. that is not oversteer. We have briefly lost steering. Torque steer from the loaded outside rear is greater than availble (unloaded) front steering.

The experienced driver will delay this throttle roll on just a little at this corner exit point and wait for the car to straighten and unload that wheel before a strong throttle roll on can be started. You have to concentrate on watching the car more carefully here.

I invite alternate views.
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Last edited by John Stranahan; 12-17-2009 at 12:38 PM.
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Old 12-21-2009, 07:39 AM   #1345
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Tekin R8 and Novak HV 3.5R Unsuccessful

I have this combination pictured above in my wide pan. I thought I would report that it did not work. The motor would run at slow to medium speed but once it got into the sensor-less mode, no more power was delivered; thus the car would only reach a slow maximum speed.

I tried this previously with a Novak Ballistic 3.5. Same story.

I have a report that you can adjust this Tekin to an all sensored mode, but then the system runs hot. I may try this just to confirm the situation.

The R8 works fine with LRP motors (in my TC) and Te kins I am sure.
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Old 12-21-2009, 07:47 AM   #1346
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i just watched your website videos. (wide pan car)

i like the guy in the background

"Oh, good grief... fast little bugger"

lol


where's the video's of your tc5 and losi?
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Old 12-21-2009, 08:20 AM   #1347
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Quote:
Originally Posted by John Stranahan View Post
Tekin R8 and Novak HV 3.5R Unsuccessful

I have this combination pictured above in my wide pan. I thought I would report that it did not work. The motor would run at slow to medium speed but once it got into the sensor-less mode, no more power was delivered; thus the car would only reach a slow maximum speed.

I tried this previously with a Novak Ballistic 3.5. Same story.

I have a report that you can adjust this Tekin to an all sensored mode, but then the system runs hot. I may try this just to confirm the situation.

The R8 works fine with LRP motors (in my TC) and Te kins I am sure.
Running the 17.5 ballistic with a GM90 we have retarded the timing as we found that even on zero timing the 2nd part of the 2-speed was over timing the motor causing it to stall/stutter, and in some cases burn out.
I run my 17.5 ballistic at the first retarded mark and lowered the gear change point from 18,000 to 15,000.
Hope this helps?
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Old 12-21-2009, 08:47 AM   #1348
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Quote:
Originally Posted by John Stranahan View Post
Tekin R8 and Novak HV 3.5R Unsuccessful

I have this combination pictured above in my wide pan. I thought I would report that it did not work. The motor would run at slow to medium speed but once it got into the sensor-less mode, no more power was delivered; thus the car would only reach a slow maximum speed.

I tried this previously with a Novak Ballistic 3.5. Same story.

I have a report that you can adjust this Tekin to an all sensored mode, but then the system runs hot. I may try this just to confirm the situation.

The R8 works fine with LRP motors (in my TC) and Te kins I am sure.
I had the exact same thing with my rs pro and novak 4.5t on 2s in my pro10 driving in hybrid mode. First few meters were good cause of sensor driving and after that it was a slug. Once in full sensord mode it ripped to full speed in one go. With the boost higher then 9 the motor stutterd so 4 or 5 would be good enough i think. I tried this on the old software without the turbo function. On a relative big gas track

I haven't tried it with the new software where you also have to turbo after the boost. Probably boost of 2 or 3 with a turbo of 3 at the end would be enough (first test without the turbo and see where the speed flattens out and on that spot the turbo needs to kick in). Then First step you get motor timing and when accelerating further you get boost in the middle and after that the turbo does the rest once on full speed. Turbo should be 1 second delay or higher depending on the track ( on a big track i would start with 1.5 seconds just to be sure). Probably you have to use a lower rollout then normal and hold a temp gun to measure after every 2 minutes or so.

As you are using the R8 esc there shouldn't be a problem with heat of the esc as there is a fan on the R8. On my rs pro wich doesn't have a fan i glued a 25mm fan on my chassis to blow against the solder posts and that helped a lot against overheating. (only 3 -4 lamps on).

The 4.5t with sensor was really nice and easy to drive.
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Old 12-21-2009, 12:14 PM   #1349
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2-w drive- I like the guy in the background as well. Priceless audio. I don't have any touring car videos.

http://www.stranahan-rc.com/videoclips.html

Looks I have some more testing to do then. I will first retard initial timing and use a ballistic 3.5. The Novak HV in the car is my 820 W motor. Best ever tested. I shall save it for a "black diamond speed control" if it ever comes.
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Old 12-23-2009, 10:23 AM   #1350
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An LRP TC-spec or SXX should be able to handel your Novak 3.5.
Otherwise, you may want to check out a GM Genius 120.
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