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Old 06-05-2007, 06:25 AM   #1411
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John, I used 10 of the $1 boca rubber sealed bearings in my Xray, and I found that the black seal had too big of a gap and let it in a lot of dirt, they did not last long at all. I now have the "no lube required" ultra seals in the car now, but haven't driven on them yet.
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Old 06-05-2007, 10:42 AM   #1412
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Mike
Thanks for the report.

There are a couple of types of bearing failures in a touring car. One is the type you describe. The bearing gets grit inside. You put it on a pencil point and spin the inner race with the pencil, you feel the grit at random points in the revolution. Eventually and rapidly the grit will cause wear and degrade all the bearings precision surfaces. Can you see the gap or have you inspected the inside of the failed bearing and seen the dirt? I just thought I would check before we write off these black rubber sealed bearings. I do notice that some of Bocas bearings describe a noncontact seal.

The other is brinneling. If the car takes a hit from the side on the boards and the boards are 2x4 inch wood or 2 inch PVC then the bearing will brinnel. Little indents are created in the race by the balls in the bearing by the impact. When you spin it on the pencil the bearing will ratchet a little. You will feel the indents, but they will be very evenly spaced and regular when you spin the bearing. This can happen on the very first run. This was the most common failure for me when I used sealed bearings. The first type was more common with shields.

Last edited by John Stranahan; 06-05-2007 at 03:37 PM.
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Old 06-05-2007, 03:35 PM   #1413
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Failure: Mamba Max or Novak 3.5 R
I changed the Mamba firmware to the previous version because it was one possible source of my prolems. The Mamba with the new capacitors pictured in a previous post ran about 10 laps. The car stuttered some on the start. The laps were fairly smooth but slow on the straight (like the LRP IPC V6 with a supplemental cap). I tapped the boards a couple of times due to bad traction. The Mamba would not pull away from the second board. It sat there and stuttered. I replaced the battery. The same. I cut the power cap off. The same. I removed the spektrum cap, the same. Seems like an internal failure of the Mamba which was probably also responsible for the self desoldering of the motor leads after it reached a certain internal temperature. Another possible explanation would be a failure of the 3.5R windings. A couple of more test of the radio at home and a test with another motor and then I will send it in for replacement.
John

Last edited by John Stranahan; 06-13-2007 at 10:23 PM. Reason: The Mamba actually survived to run another test.
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Old 06-06-2007, 01:57 PM   #1414
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RC4LESS Foams
I received and order from RC4LESS.com. I had asked to include their suggested 1/10 pan foams to substitute for GRP purple Fronts and Pink Rears. I am very happy with the GRP tires, but they are out of stock on occasion, so I need a substitute. They shipped Purple front and Pink Rear natural rubber foams on a nice looking Orange wheel. Here is a pic. Test to come.

Teflon Coated Pivot Balls
I also got some Teflon coated Aluminum pivot balls which I hope are also hardcoated. They look the same color as the IRS hardcoated pivot balls but are not in IRS packaging. I had ordered a set of these previously from stormer that came with a .114 inch inner hole diameter instead of the required .125 inch inner diameter. This is why I changed sources. I got the IRS installation tool to prevent small damage from occuring on installation and to reduce the effort involved. These slick pivot balls seem essential to get the best grip out of my front ends. They will probably help the stock front end as well.

.075 inch plastic spacers
RC4LESS also sells some nice narrow OD .075 inch thick plastic spacers for general use on the pan car kingpins and on my adjustable front end. The small diameter will be nice. Sometimes the little parts like these are hard to find.

My GTB controller is in. I'm in hog heaven.
John
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-rcforless-foams-resized.jpg  

Last edited by John Stranahan; 06-06-2007 at 06:50 PM.
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Old 06-06-2007, 02:48 PM   #1415
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Quote:
Originally Posted by John Stranahan View Post
The editor is messed up.RCFORLESS FoamsI received and order from RCFORLESS.com. I had asked to include their suggested 1/10 pan foams to substitute for GRP purple Fronts and Pink Rears. I am very happy with the GRP tires, but they are out of stock on occasion, so I need a substitute. They shipped Purple front and Pink Rear natural rubber foams on a nice looking Orange wheel. Here is a pic. Test to come.Teflon Coated Pivot BallsI also got some Teflon coated Aluminum pivot balls which I hope are also hardcoated. They look the same color as the IRS hardcoated pivot balls but are not in IRS packaging. I had ordered a set of these previously from stormer that came with a .114 inch inner hole diameter instead of the required .125 inch inner diameter. This is why I changed sources. I got the IRS installation tool to prevent small damage from occuring on installation and to reduce the effort involved. These slick pivot balls seem essential to get the best grip out of my front ends. They will probably help the stock front end as well..075 inch plastic spacersRCFORLESS also sells some nice narrow OD .075 inch thick plastic spacers for general use on the pan car kingpins and on my adjustable front end. The small diameter will be nice. Sometimes the little parts like these are hard to find.</p>
That web address is actually www.rc4less.com, not what's listed above. The tires that they sell are nearly identical to the GRP ones (Made by the same people from what I understand).

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Old 06-07-2007, 01:46 PM   #1416
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Could pinions for 1/18th scale vehicles like this one be of use to us?
http://www2.towerhobbies.com/cgi-bin...?&I=LXJHU0&P=7
drilling a larger hole should be little problem using a drill press?
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Old 06-07-2007, 02:09 PM   #1417
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Quote:
Originally Posted by Pro ten Holland View Post
Could pinions for 1/18th scale vehicles like this one be of use to us?
http://www2.towerhobbies.com/cgi-bin...?&I=LXJHU0&P=7
drilling a larger hole should be little problem using a drill press?
Is it the same pitch? If it is, it should work.
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Old 06-07-2007, 02:21 PM   #1418
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Just a thought I had about your BL issues...I'm not really familiar with the Mamba system but it seems to me your gearing it like a hot mod brushed motor. My Novak SS instructions had me gear my cars like a stock motor even when in the 10T equivalent mode. Possibly your undergearing the motor too much?
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Old 06-07-2007, 02:52 PM   #1419
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Quote:
Originally Posted by John Stranahan View Post
Mike
Thanks for the report.

There are a couple of types of bearing failures in a touring car. One is the type you describe. The bearing gets grit inside. You put it on a pencil point and spin the inner race with the pencil, you feel the grit at random points in the revolution. Eventually and rapidly the grit will cause wear and degrade all the bearings precision surfaces. Can you see the gap or have you inspected the inside of the failed bearing and seen the dirt? I just thought I would check before we write off these black rubber sealed bearings. I do notice that some of Bocas bearings describe a noncontact seal.

The other is brinneling. If the car takes a hit from the side on the boards and the boards are 2x4 inch wood or 2 inch PVC then the bearing will brinnel. Little indents are created in the race by the balls in the bearing by the impact. When you spin it on the pencil the bearing will ratchet a little. You will feel the indents, but they will be very evenly spaced and regular when you spin the bearing. This can happen on the very first run. This was the most common failure for me when I used sealed bearings. The first type was more common with shields.
I think I have victims of both, out of 5, 3 cleaned up nicely using the flame method, and 2 stayed very gritty. I didn't try and measure them, but in terms of getting the seals off, an xacto fits much easier between the race and the seal vs my xray bearings.
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Old 06-07-2007, 03:08 PM   #1420
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I can't seem to search within threads anymore after the forum upgrade. I was wanting to know if you experimented with any brass pinion gears? I would think brass would be too soft for most applications, but I noticed Venom just released a new line of small pinions using that material, so maybe there's something to it.

http://www.redrc.net/2007/06/venom-g...ses/#more-3527


Edit: Err, maybe "mini" means 1/18th scale? I can't tell. Sorry.
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Old 06-07-2007, 04:01 PM   #1421
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RC18T pinions-I would have to think that these pinions are a different pitch although it is never stated just by looking at the pictures and spacing of the teeth. Drilling and reaming a brass pinion would be an easy task. A drilled hole will always come out slightly oversize on the diameter. The procedure would be to drill undersize and then ream the last .002 inch or so. Drilling and reaming a hardened steel pinion is another matter. The pinion should be as hard as the drill bit. There are carbide drills available as well as Cobalt steel bits. I imagine a carbide reamer would be expensive and very fragile. I have looked at those pinions. The first step would be what is the pitch. Somebody with one of those cars could try and mesh a 48 pitch spur with their spur to tell or I might order a spur one day.

If a hardened steel nickel plated gear (nickel is quite hard) goes 2 runs then a brass gear might last 5 laps. The Titanium nitride coated gold pinions go 20 runs in 12 tooth. The higher teeth numbers last much longer as there is little rubbing of teeth with the proper involute gear form. This form must be unatainable in the 12 tooth.

When I raced slot cars, I think we used 48 pitch gears and as low as 9 tooth pinions on a 1/16 inch motor shaft. It looked like a little paddle wheel. If you drill one of these out to 1/8 inch the teeth would just fall off as there is not enough metal below the root of the pinion teeth. I could grind an armature shaft down to 1/16 inch. I can actually do this on my lathe, but I think there will be too much flex when I am finished. There is already too much flex to brake with 64 pitch gears with a 1/8 shaft. Thanks for the gear input. I have thought about these things. I do have 10 gold 12 tooth pinions in hand. These should go at least a year. Stormer shows 6 in stock so maybe they have a nice box of 100 there.

Mike-Thanks for the extra detail on the bearings. Now tell me about this flame method. I'll tell you ahead of time if you get up to soldering temperatures which is well below red hot the part will anneal and go soft.

Syndrome-The search within threads is still there, you just have to scroll to the bottom of the new page that pops up for the input window. I had the same trouble.

I also had trouble with the editor. I had to go back into settings and change from Wysiwyg back to normal editing to fix the problem.

Inspgadgt- If you compare my present gearing to my former gearing with stock pan cars you will find I use lower ratios. This is mostly for performace but it has the benefit of lower temps. Temps are still high. I am running hot mods. 3.5 and 4.5 turn are hot mods. The car has more rear traction with the 3 link. Instead of spinning the back tire the lower gears now create weight transfer and more forward traction. I am satisfied that my Mamba problems are a sensorless problem that shows its ugly head under difficult driving conditions, Low traction, delicate cornering, starting from a stop. In some classes of racing these problems may not appear.
I have the GTB in the car now. It is so damn smooth on the bench. It is like a night and day difference. The brakes are also very smooth. The Novak rep is looking into trading my Mamba plus some cash for a GTB system.

Eric-Thanks for the note on the tires. I made the correction once my editor got fixed up.

I.R.S. Pivot Ball Installation Tool
I got this tool in and just tried it. Removing and installing the ball is now a low force operation. Now the good part. I had a couple of balls that were tight in the socket. If you take and insert the ball and then snug the tool and take another 1/3 turn tight, you very uniformly increase the socket size without leaving any burrs to create friction. If it is still tight you go just a fraction more on the tightening than you did before until it fits with no play. That part was super nice and hard to obtain with the method I used previously.
The RC4less pivot balls fit the kinpin and socket nicely.
Attached Thumbnails
Pantoura, 1/10 Pan Car, 2S LiPo, Brushless, Tips and Tricks.-i.r.s-pivot-ball-installation-tool-resized.jpg  

Last edited by John Stranahan; 06-08-2007 at 09:21 AM.
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Old 06-08-2007, 06:09 AM   #1422
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Motor spray and a match It doesn't get that hot, you can touch the bearing after the motor spray has worn off.
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Old 06-08-2007, 11:49 AM   #1423
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Inspgadgt- If you compare my present gearing to my former gearing with stock pan cars you will find I use lower ratios. This is mostly for performace but it has the benefit of lower temps. Temps are still high. I am running hot mods. 3.5 and 4.5 turn are hot mods. The car has more rear traction with the 3 link. Instead of spinning the back tire the lower gears now create weight transfer and more forward traction. I am satisfied that my Mamba problems are a sensorless problem that shows its ugly head under difficult driving conditions, Low traction, delicate cornering, starting from a stop. In some classes of racing these problems may not appear.
By hot mods I meant like a brushed hot mod....say a 9 or 10 turn motor...in a pan car you would gear those around 6:1 or lower depending on track conditions. But the Novak SS says to gear theirs like a stock motor which would be around a 4:1 on the same track even though it is the equivalent of a 10T motor. But the Novak SS is a very early BL system and things have changed a lot since then so I'm not sure if the way they geared still holds true with today's BL systems.
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Old 06-08-2007, 12:48 PM   #1424
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I donīt think drilling a pinion is a good idea. I think it wonīt run very true anymore. Maybe there also isnīt enough "meat" for the setscrew.

I still canīt believe you guys are running 3.5T in a pancar. Just saw last weekend how fast a pancar can go with a 5.5T and this was really fast. But maybe there are some difference between brand of motors.

Regarding the IRS tool I bought a similar one made by Racetech but that was some years ago. Works very well especially if you want removing the ball.
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Old 06-08-2007, 02:27 PM   #1425
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The fastest SS motor has a RPM per Volt rating of 5000 RPM/V

The Novak 3.5 R has an RPM per Volt rating of 10,500 RPM/V

They need to be geared accordingly. Things have changed some.

the current GTB manual suggest gearing a 3.5R 4-5 teeth lower than a 6 turn brushed. I imagine this would be in a touring car. Three of us are running this motor in a pan car and have reported gearing on this thread. It really is fast. All are using gears in the 7.5 range. Azmio a little higher numerically at 8.0 last report. Mathijs a little lower numerically.

I have run this motor geared 7.5 on a high grip track a couple of times. I have not seen any other RC car accelerate quite as fast.

Drilling a hole with a true pilot hole already in the pinion would not lead to very much wobble. If I were manufacturing the gear from a blank, I would drill it and then machine the teeth afterward to obtain the truest gear.

Last edited by John Stranahan; 06-13-2007 at 10:25 PM.
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