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Old 12-31-2008, 10:31 PM   #16
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It worked great with my trusty Reedy 19 Turn Mod. I had just skimmed the comm and replaced the brushes and it was still running on the standard ESC configuration. I only re-wired to high-power mode to use the 12 turn.

When I rewired it, the 19 Turn didn't work properly, nor the 25 turn Tamiya RZ, or the spankin-new 12 turn Putnum.

I've been running GP 3700's, matched and unmatched packs. They are getting older, but still hold a good charge. They are side-by-sides with good battery bars.

I use Deans plugs for the batteries. I have the original Castle wires on the esc, never opened it, and deans 12g wet noodles for the other wires. It's all good gear.

I don't know what makes a motor spin off-load, but not under load. I can only assume it is the ESC, becuase i've tried everything else.
My next thing I would try if you have access is a 2S 7.4 lipo or a 4600 NIMH matched with high voltage. If I was testing that is what I would try. If it works with no load but don't under load that seems to me that it is pulling more voltage that what the pack wants to put out. This is what I would do for the next step.

It might seem like the packs should be good enough but a 3700GP is back a few models so they would not be at full strength and under load I'm sure they will be strained alot when compared to a lipo pack.

It is process of elimination is what it comes down to.
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Old 12-31-2008, 10:54 PM   #17
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Yeah, I can't get hold of a lipo. Hardly anyone uses them around here.

The key for me really, is that it's happening with ANY motor. Regardless of the age of the packs, they still pushed the Tamiya and Reedy no problem with the old mode. I may have to wire it back the original way it was and see what happens.
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Old 01-01-2009, 12:36 AM   #18
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Yeah, I can't get hold of a lipo. Hardly anyone uses them around here.

The key for me really, is that it's happening with ANY motor. Regardless of the age of the packs, they still pushed the Tamiya and Reedy no problem with the old mode. I may have to wire it back the original way it was and see what happens.
If that is the case then my guess is that in the high powered mode the speedo is asking for more voltage than can be supplied when under load vs the standard brushed motor setup. I always had big voltage matched packs when I ran the high powered setup so it is hard for me to how maybe some lower powered packs would run like.

Even if you can get a 4200 to 4600 NIMH pack I would try that but it should be a good highend matched pack just to see what happens for you.

My best guess is if your car works good with the stock wiring then to me its all about the voltage and how the speedo is trying to apply it to the motor.
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Old 01-01-2009, 01:13 AM   #19
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I think you are right. I just went out with a full charged pack and it ripped it up! It started playing up after 5 mins, and my guess is that's when the voltage began to drop off.

Looks like I need to save for some new packs. At least the boy can use the old packs on his car so it's not a total lost cause!

A 12 turn is a whole new world compared to a 19 turn! It's a BEAST!
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Old 01-01-2009, 01:48 AM   #20
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the lipo cut off is on.

don't be ashamed, your not the only one
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Old 01-01-2009, 01:59 AM   #21
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the lipo cut off is on.

don't be ashamed, your not the only one
I would check the voltage cutoff just to be sure. It could be on as whitzac mentioned. Normally that function is not on in brushed mode but it could of been changed sometime accidently.
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Old 01-01-2009, 02:16 AM   #22
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Nah, it's off. I reprogrammed it 3 times over the last day to make sure of that stuff. Each time I set:

Voltage cut-off "none"

Motor type "brushed high power"

I don't have a castle link, but can easily hear the beeps!

I could try and have a cut-off and set it for "5" volts. Just in case. I dunno, fresh out of ideas. I need to get my hands on a new battery to make sure.
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Old 01-01-2009, 03:42 AM   #23
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I would make sure the gears on the motor are pushed down all the way. The whole car is screaming before you set it down then nothing has happened to me before with diffrent cars just because the gear isnt pushed all the way down on the pinion on the motor. Worth a shot, good luck
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Old 01-01-2009, 06:04 AM   #24
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Nah, it's off. I reprogrammed it 3 times over the last day to make sure of that stuff. Each time I set:

Voltage cut-off "none"

Motor type "brushed high power"

I don't have a castle link, but can easily hear the beeps!

I could try and have a cut-off and set it for "5" volts. Just in case. I dunno, fresh out of ideas. I need to get my hands on a new battery to make sure.
Well since it ran for you with a fully charged pack for about 5 minutes my guess is like you said after that the pack drops enough in voltage to makeit not work correctly after that. It seems like when you get a better pack your problem will go away up until the voltage gets too low to make the car go.
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Old 01-01-2009, 02:23 PM   #25
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Yep. I think the batteries aren't able to push to load through that is being wanted.

I guess the way the high-power mode is wired alows a lot more current to flow.

Hopefully Joe reads this and can confirm it, as i'm sure I am not the only one trying this.
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Old 01-01-2009, 09:21 PM   #26
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OK, the plot thickens. Got the trusty volt meter out.

I had it running on the bench, and if I ease the throttle up, it's fine, and goes to about 6.6 volts at the motor full-tilt. Not bad.

When I just gun it, the voltage reads -0.53 volts. That's negative. The green light is solid on the ESC, but no go-go juice.

I took out one of the brushes, and put the meter on it again, don't know why. At rest it reads 5.1 volts. Full throttle 7.6 volts. Full brake 1.1 volts.

Don't know what all that means. Any electronics geniuses out there?
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Old 01-02-2009, 12:13 PM   #27
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Anyone have an idea?

Joe is saying send it back, but that is easier said than done from New Zealand. The cost of postage alone is near 1/2 the price of a 2nd hand GTX, let alone it will be gone for at least 3 weeks!

Not bitching at Castle, it's not their fault I live on an island in the middle of nowhere!
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Old 01-02-2009, 12:49 PM   #28
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Did you try changing the motor timing on the esc? Start power and timing have a huge effect on the brushless motors.
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Old 01-02-2009, 02:09 PM   #29
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Do you have any punch-control setup? Try disabling that option.

You may have the motor overgeared. How about this. Let us know the gearing you have - pinion and spur.

Also, drop your pinion 3T and start there. Since you can get the motor screaming "off the ground" it sounds like overgearing and the brushed motor is just drawing too much power. When you go from 19T to 12T motors - you will definitely have to drop the gearing more.

Also, it "sounds like" in this thread:

http://www.rcgroups.com/forums/showthread.php?t=928926

That High Power mode is for 18T to 8T brushed motors, give or take. I'm not sure if 19T should be setup with High Power mode.

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Old 01-02-2009, 07:00 PM   #30
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I have the 12 turn geared at 21 teeth. It doesn't get too hot after 5 mins.

The manual says NOT to change motor timing on brushed motors. I may try it anyway, done everything else.

Punch control is disabled.

I may have a GTX I can borrow to eliminate everything but the esc....
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