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Old 11-27-2008, 07:54 PM   #1111
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Can you please send me a copy of that pm, as at the Nationals each year, it is a handout stock motor event. and the only way to run them in quickly is to water dip them.

Thanks.
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Old 11-27-2008, 09:33 PM   #1112
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Awww, c'mon...share with us. Or more specifically, share with me.

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The cheapest way to get a fast legal silver can is to buy a Red Dot from Doc. I've blown up or ruined about 40 of them before I got a handle on how to build a fast one and they're still not quite as good as a Red Dot. Close, but no cigar. Besides, it took some additional equipt., some of which I bought and some that I had to desgn and build myself. Believe me, way too much work. It's a great intellectual exercise, but I don't know if I'd do it again if I knew before hand how much work it would be.
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Old 11-28-2008, 01:27 AM   #1113
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Hey rccardr,

Are your red dot motors legal to the rules below:
66 STOCK MOTOR SPECIFICATIONS
66.1 Only permitted motors are unopened, unmodified Johnson 540s or Mabuchi
540s closed can, sealed end bell, bushed, with non-replaceable brushes and
bushes.
Motors to be supplied from Trevor Brignans Ltd.:
A) Part No. Mabuchi RS540 standard motor or
B) Part No. 53689 Johnson RS540 motor.
C) Part No. Mabuchi RS540SH
Tamiya, Mabuchi "Sport Tuned" motors are not allowed, nor any 540 variants
such as 540ST etc.
A stock motor run at 8 volts unloaded must draw no more than 1.7 amps.
Motor testing procedures are those outlined in NZRCA rules amendment dated
1st November 1999.
Any motor which draws close to the maximum allowable current (1.7amps) be
subjected to a second test.
The second test is a current test run in the reverse direction.
There should not be a major difference in the result of both tests
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Old 11-28-2008, 01:58 AM   #1114
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hell,, Im well off the pace,,
I have 3 different motors two johnsons and one mabuchi,
I can only get 15k @ 7.2 volts and 1.2amps,, no load at best.
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Old 11-28-2008, 02:09 AM   #1115
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hell,, Im well off the pace,,
I have 3 different motors two johnsons and one mabuchi,
I can only get 15k @ 7.2 volts and 1.2amps,, no load at best.
I can get 33,000 on a much more motor master
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Old 11-28-2008, 03:17 AM   #1116
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am i missing I big step or is there just some really good 'freak' motors out there,,
And have johnson had a (how can I say it) a dud batch,, as most of the motors that were brought and used around the same time as mine dont have much pull,,
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Old 11-28-2008, 03:23 AM   #1117
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Well i get them from a local guy he supplies silver cans aus wide for about au$40.....you need to order about 3 months before he does them....they are just as good as the red dot i tried......and pull 18.5k minimum on a fly wheel dyno (robotronics)
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Old 11-28-2008, 04:48 AM   #1118
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I would guess the main areas to getting a silvercan faster are:

Having the strongest possible magnets, correctly seated bushings and a good brush face for plenty of current flow, so make sure the brushes have been run in well.

The rest is down to how you look after it. Although even small things such as wire guage and making sure there is only one piece of wire soldered between the motor and esc may make a tiny difference to remove any wasted resistance in the bullet connectors that are on most silver can motors, but make sure you are allowed to take these off first, some rules can be very strict on what you can or can't do to a motor- the Eurocup is very well scrutineered from what i've heard.

Ive heard of special instruments to clean or cut the comm through the vents too, as you're not supposed to take a silver can apart for pretty much any major sanctioned events.

Dont take my word for gospel though, its just things ive seen and heard through almost 15 years of racing.

As with looking after any motor, a clean brush face and good conductivity through the comm/brush are what you're aiming for. A good speed control with plenty of FETS and an adjustable drive frequency will also contribute to the feel of the motor, the more zip you can get through the corners, providing the car is set up well for the track will help no end getting the laptimes lower.

As for gearing, obviously that varies a lot too dependant on the track and the motor, as does the charge rate on your cells.

hth
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Old 11-28-2008, 06:22 AM   #1119
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would think advancing the timing would increase speed over the usual routine of long break in at 2-3volts is the only other way to increase speed.

advance 540 timing by physically rotating the magnets in the can or unzap/zap with advance timing. or play with brush angle. but would also think these are illegal in the spirit of 540 racing.
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Old 11-28-2008, 09:05 AM   #1120
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Matt, we've sold a lot of Red Dots down there but I don't remember seeing this particular set of rules before. On the other hand, lots of guys buy our motors for club racing where the rules are more open.

Red Dots are produced using TCS legal Tamiya #53689 cores, and the motors are not opened or cranked. I checked a few of my personal full-race Red Dot motors and they run 1.9 amps -or higher- at 8 volts with a significant difference between running in the normal direction and reversed polarity. As a point of interest, those motors run just a tick under 25K RPM at 7.2 volts.

However, we also produce a series called "Red Dot 15K's", which are longer lasting but have somewhat lower performance. These are typically purchased by tracks or race series directors in bulk as handout, control or blind draw motors. Those motors ride right on the edge of the 1.7 amp rule, have no significant difference in amp draw between forward and reverse rotation, and run about 21.5 RPM at 7.2 volts. So if I understand those rules correctly, a 15K would be legal if properly cleaned and maintained.
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Old 11-28-2008, 02:58 PM   #1121
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would think to get higher rpm we need to advance timing. given we can advance timing without cranking or opening can (e.g. via magnetism) is this legal? i though in 540 class any enhancement to motor is deemed illegal.

would enhancing or modifying the magnetic field, done without opening can, be considered legal?
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Old 11-28-2008, 06:22 PM   #1122
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what is so special about those red dot silver cans?
Are those special build,
are just the best silver can motors chosen by testing and then marked with a red dot?

And where to get them?
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Old 11-28-2008, 07:01 PM   #1123
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Originally Posted by rccardr View Post
OK, if you are limited to 19K at 7.2 volts (which is not such a fast motor) then start with a new Johnson 540J, part #53689 (not a Mabuchi- you'll get much better results with the Johnson) and just run it at low voltage (3-4 volts) with a slave motor (hook up the slave at reverse polarity so the race motor rotates in the correct direction) continuously for 3 or 4 days. Use comm drops on the comm (any light-colored comm drop works fine) and oil the bushings twice a day. That will loosen it up real nice and make it as fast as it will ever be without...enhancements.
running in Tamiya-competition overhere in Belgium as a newbe and Silver cans are the only motor allowed in TT01-class.
about running the motor in continuously over serveral days ... won't it overheat?
Also, could you explain me what the comm-drops actually do?
I' ve read (Doc's post) that you clean them every three runs, and aplye commdrops before running in again.
Do you also aply comm drops before starting a heat (qualifier, fianel?)
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Old 11-28-2008, 08:17 PM   #1124
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if a motor has a significant difference between running in the normal direction and reversed polarity, this means motor timing was advanced in one direction, making this motor illegal for 540 class.

yes a motor can be non-cranked nor opened, but timing still advanced, and advancing timing (via magnetism) is illegal i would think. (cranking is done to advance timing).

i somehow believe "freak" motors is just a smokescreen to justify the performance enhancement of motors whose magnets have been tampered (zap, unzapped) to change timing.

ive seen this done in club level racing, and for some reason people fool themselves into believing a magnetically tampered 540 is still legal yet cranking is not.

please let me know if i am mistaken about the MAGNETISM form of cheating. maybe this is why rpm limits are now used to determine if your motor is legal or not.
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Old 11-28-2008, 08:38 PM   #1125
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...or it may mean that the brushes have seated in the correct direction but not in the opposite one. Run the motor in reverse at 8 volts for awhile and watch the amp draw drop like a stone. There are far easier -and more accurate- methods for checking the magnetic field of a motor.
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