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Old Aug 27, 2012, 02:32 PM
A-4 nut!!
skyhawk's Avatar
Vancouver B.C.
Joined Apr 2002
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Your numbers are off.

Do not rely on the ESC to give you good numbers - they are known to be off......sometimes by quite a bit.

A fully charged 6S pack is only going to give you 25.2 volts. Multiply that by the motors UNLOADED KV of 2950 gives you 74340 rpm. Now load that up and your probably running around the 70000 range. I bet your amps are more like 45 as well.
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Old Aug 28, 2012, 10:19 AM
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Canada, BC, Surrey
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The power output and amperage between my Wattmeter and the data logging were reading pretty similar. Maybe varied by +\- 4%
Im going to do a full ramp up with both fans on full charged batteries and get some real data. I got the thrust tubes and heat transfer paste installed now.
I would like to get an idea of expected flight times.
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Old Sep 15, 2012, 11:18 PM
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I had one of my speedcontrollers burst into flames just after the intial ramp up. I had my wattmeter hooked up and I looked at the data log from the other one and I didn't see the current go beyond 50 amps. Anyhow, I sent it in to be replaced.

Since then work has been slow on the raptor. I started working on the landing gear again. Here is what I have come up with so far.

whalleyb0y's Raptor (retracts) (1 min 29 sec)


Now I would like to dress it up a little either with trim and wheel wells or with gear doors.
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Old Sep 16, 2012, 11:27 AM
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This is the method I had used for the bench tests when one of two speed controllers burst into flames after I cut the throttle.
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Old Sep 19, 2012, 09:06 AM
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Finally got the retracts all assembled and operating. Now I wonder what kind of AoA I should be looking for. How does one calculate the AoA needed? I had an FMS Mirage with a very high nose stance and the takeoffs were very short as a result. On the other hand a friend's Rafale had very low nose stance and usually had a hard time getting off the ground. Is there a sure fire method to setting this up?
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Old Sep 19, 2012, 09:13 AM
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San Diego
Joined Jul 2009
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You want a slight nose high AOA, your pic looks to be nose down.

On your fan test, how long were your battery wires and how old are the packs?
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Old Sep 19, 2012, 03:58 PM
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The battery leads are 10Awg 2' long with two capacitor packs per esc. The batteries are brand new never been used.
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Old Sep 19, 2012, 04:02 PM
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I will post the data log from the other esc when I get in tonight.
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Old Sep 19, 2012, 04:34 PM
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There is a equation you need to check ripple, that could have toasted the esc.
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Old Sep 19, 2012, 05:01 PM
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United States, CA, San Jose
Joined Jan 2007
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Maybe I read something wrong in the graph (my eyes hurt after looking at those tiny lines), but it appears to me that the ESC temp is around 125F with zero throttle?, then went up to 175F within a minute (less then 60s) with the max current below 40A? Something seems very wrong here. Did you disconnect the BEC wire on the ESC?
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Old Sep 19, 2012, 05:42 PM
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Name: 2950kv 22.4V.png
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This is the actual data log from the bench test that cooked one of the two speed controllers. This test included the extended battery leads and two capacitor packs.
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Old Sep 19, 2012, 05:51 PM
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This is the very same data but with ripple included.

Now correct me if I am wrong but the ripple should be no higher than 2V? Please have a look at these results. I see nothing wrong here.
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Old Sep 19, 2012, 05:57 PM
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Yea, it looks fine, but this is from the working ESC right? How did you connect the 2 esc throttle wires together?
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Old Sep 19, 2012, 08:39 PM
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I have both throttle leads (red wires removed) going into a Y-harness that goes to a single channel on the rx. I use a CC Bec on one of the battery leads to feed the servos and rx power.

Name: ImageUploadedByTapatalk1348103759.435150.jpg
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I have a total of 4 capacitor packs, using 2 per side. For either fan I have one mounted on the controller battery lead and then another one on the 2' battery lead extension going to the batteries up front. Each fan is powered by their own 6s 45C 3000mAh lipo.

I remember now as I write this that I had both controllers connected to my pc so that I could clear previous data. I had to replace the red leads so that they can be powered by my computer's usb port AND I forgot to remove them again for the bench test! I had to abort because one of the controllers wasn't starting up right until I removed the red leads and rebooted them. But they did start up and I ran them together for the duration of the test. It wasn't until I cut the throttle and the fans stopped that the one esc lit up into flames inside my transparent TT.
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Old Sep 20, 2012, 11:51 PM
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I had been thinking about filling some of the cavities in the fuse with spray foam. Sounds like many had tried this with less than sub par results and others managed to make it work.
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