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Old Aug 30, 2010, 12:59 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
I think the airflow helps keep the burn rate slower. It also keeps the heat around the plane to a minimum. They designed this stuff for rc planes. Anyway, it was interesting to test it out. The switch I used is around $8. RC Switch

The switch needs a common ground with the output battery and receiver signal. The problem is, they don't give you ground connections for the switch side. Some people try to rig y-connectors and stuff but they are not current carrying wires and this switch can handle 10A. I take the shrink off the switch and add two ground wires on the PC board. This gives me a source ground and a load ground. I then shrink wrap it then put the label back on. I can then add a battery connector for the source and gound and the lead to the receiver. The receiver wire only needs signal and ground.

I made one of these as a remote ignition cutoff but we have not tested it yet. It is NOT optically isolated. If it were, the common ground would not be necessary.
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Last edited by waynemia; Aug 30, 2010 at 01:08 PM.
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Old Aug 30, 2010, 01:07 PM
Cookies Good - Bacon Better
NoMatta's Avatar
Portland, Oregon
Joined Sep 2008
1,615 Posts
Quote:
Originally Posted by harttvboy View Post
Hi all!

I posted a few days ago with what I should put in my 60 Twist (electric motor wise). I decided to go the Turnigy 50-55 580 KV route swinging (for starters) a 14x7 prop.

I am having a weird issue trying to use a watt meter though. See the pic with two batteries in series to reference. For some reason, ( I have not tried another pack yet) when I attempt to get a reading from my Astro Watt meter, its stops at 12.45 amps and around 240 watts. It will read batter voltage, and the motor will get to full throttle, but I can't get a reading. Any help here would be great- I am sure by guessing that I am within my limits ( I have another setup with this motor and a 13x8 prop that pulls about 70 amps-I dropped a pitch and increased length each by an inch-the worst is a 5 amp ish increase I would think...).

Enjoy these photos of the completed build-she doesn't get any stickers until AFTER a successful maiden day, hopefully tommorow!

Do you guys thing that with the above noted issue that it would be safe to fly? Let me know. I also could not seem to get the plane to balance with the 3.3 aH pack- I could just barely get it to 6 inches with the Hyperion 6s 5000 pack pictured as well. The Thunder Power pack is just another that is a hair lighter and will be more fun to fly with once I am used to the airframe. Let me know guys!

Best,

Chris

Another thing to check out would be to put a smaller prop on that setup temporarily and check again. If you are close to 70 amps on a 13-8, the 14-7 may exceed the limits on your wattmeter if it is rated at 70 amps. On larger props, it does not take much increase in diameter to add a lot of load. Sometimes I have found the increase to be suprising.
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Old Aug 30, 2010, 01:12 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
Quote:
Originally Posted by NoMatta View Post
Another thing to check out would be to put a smaller prop on that setup temporarily and check again. If you are close to 70 amps on a 13-8, the 14-7 may exceed the limits on your wattmeter if it is rated at 70 amps. On larger props, it does not take much increase in diameter to add a lot of load. Sometimes I have found the increase to be suprising.
I agree. My thought was you would see the current increase as you added power and it would reach a limit point and maybe fall back to some value after it reached maximum. So mid throttle you would see some high amp reading like 30 to 40 and it would fall off as you continued to increase and passed 70A.

I would test the meter first. If it is OK, then the battery, connections, ESC, or motor is causing the problem. You could temoporarily plug in a different ESC to test that, I assume you tried more than one battery pack, the motor is hitting the RPMs? Anyway, that was my thinking.
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Old Aug 30, 2010, 01:22 PM
Do Da Dippidy
plowboy1966's Avatar
Joined Jun 2008
7,316 Posts
What's up fellas? What did I miss? I see a bunch of deleted posts.


Dave, nice flying. Sorry about the loss. What prop are you using?
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Old Aug 30, 2010, 01:26 PM
BANG IT!!!
DaOldGuy's Avatar
United States, PA, Bellefonte
Joined Dec 2007
12,458 Posts
Wayne, excellent info on the smokers! What would you say the % chances are of accidentally causing a "flaming ship"?

PB...um...your back already? What deleted posts?
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Old Aug 30, 2010, 01:36 PM
Montana Transplant
mt_flyer's Avatar
United States, OR, Klamath Falls
Joined Aug 2005
1,941 Posts
Who is back....
Was someone gone??
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Old Aug 30, 2010, 01:42 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
Quote:
Originally Posted by DaOldGuy View Post
Wayne, excellent info on the smokers! What would you say the % chances are of accidentally causing a "flaming ship"?

PB...um...your back already? What deleted posts?
Probably 0% if you install it correctly. There was no evidence of heat on the EZ*.
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Old Aug 30, 2010, 01:43 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
Quote:
Originally Posted by plowboy1966 View Post
What's up fellas? What did I miss? I see a bunch of deleted posts.


Dave, nice flying. Sorry about the loss. What prop are you using?
What? I thought you moved?
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Old Aug 30, 2010, 01:46 PM
Registered User
Joined Jul 2010
172 Posts
Plow,
13-4 APC sport
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Old Aug 30, 2010, 01:48 PM
BANG IT!!!
DaOldGuy's Avatar
United States, PA, Bellefonte
Joined Dec 2007
12,458 Posts
Quote:
Originally Posted by waynemia View Post
Probably 0% if you install it correctly. There was no evidence of heat on the EZ*.
That is good to know. The price isn't too bad for the set up, Blenderm tape is the fix all for everything, it is the new DuckTape!

Thanks for putting this together, I shale provide video results. I am curious about the indoor ones, it really never said <that I noticed> if there was an required amount of indoor space, proper venting, and such...little nervous with that.
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Old Aug 30, 2010, 01:48 PM
BANG IT!!!
DaOldGuy's Avatar
United States, PA, Bellefonte
Joined Dec 2007
12,458 Posts
Quote:
Originally Posted by Dave_45 View Post
Plow,
13-4 APC sport
I have grown to respect the APC Sport, even on my E - Twisted.
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Old Aug 30, 2010, 03:28 PM
Cookies Good - Bacon Better
NoMatta's Avatar
Portland, Oregon
Joined Sep 2008
1,615 Posts
Plow - The cowl is baffled, I'm confused, got to do a shut down in the middle of the night tonight, but I can bring you Extra over later in the week, like Wed or Friday evening. Got a Buckaroo meeting Thurs night. Patching my Edge now.

Later on.
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Old Aug 30, 2010, 03:30 PM
Montana Transplant
mt_flyer's Avatar
United States, OR, Klamath Falls
Joined Aug 2005
1,941 Posts
ELECTRIC GURU'S QUESTION

I HAVE:

turngy 4240-900 rated 44amp
turngy 60amp ESC
4 cell 2200mAh 20C 44amp cont

with 12.25 x 3.75 prop, WOT is 36Amps

OK should work good

when i throttle up quickly from 1/4 to full I get a horrible squeal and no power, bogs down. When I go up slow it works fine.... any ideas??

i have tried changing timing no difference except for amp draw and rpm
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Old Aug 30, 2010, 03:37 PM
Do Da Dippidy
plowboy1966's Avatar
Joined Jun 2008
7,316 Posts
Oh you boys are a regular riot! That's okay, if you're messing with me then that means you're leaving others alone. Consider it a public service.


Dave, I like that one too, but I also like the MAS 12 x 7 S2. I wish someone else would try it and let me know what they think.
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Old Aug 30, 2010, 03:40 PM
BANG IT!!!
DaOldGuy's Avatar
United States, PA, Bellefonte
Joined Dec 2007
12,458 Posts
I upped my timing to high and got rid of most of the squeal but not all. Then I jerked the APC-E Style prop off and went to a wood one and it was GONE. Then I switched to the APC Sport, no Squealing there either. I was supprised how much better things got after the prop change.



Quote:
Originally Posted by mt_flyer View Post
ELECTRIC GURU'S QUESTION

I HAVE:

turngy 4240-900 rated 44amp
turngy 60amp ESC
4 cell 2200mAh 20C 44amp cont

with 12.25 x 3.75 prop, WOT is 36Amps

OK should work good

when i throttle up quickly from 1/4 to full I get a horrible squeal and no power, bogs down. When I go up slow it works fine.... any ideas??

i have tried changing timing no difference except for amp draw and rpm
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