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Old Nov 24, 2012, 12:31 PM
Micro Jet Pilot
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Dan, you don't really have a star connection. Please shorten the leads from battery to the star point as much as possible. Maybe the inductance of these wires is the problem. Maybe plugging in a cap across power in one of the free sockets of the rx helps.

Chris
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Old Nov 24, 2012, 12:41 PM
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Oak Ridge, Tennessee
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No problem, I will find all this very educational. I'll try to make a vid later for sure, with both setups. (and try the above changes you suggest). I have some errands to do, so it will be a few hours before I can get back into it.

On the servo dropping out- no, with both rx'es. The motor stops dead (no sputtering) and sort of magnet locks, not spinning with a finger flip or blowing on prop. It restarts after a couple of seconds of throttle off setting. (no reboot) The HK orange rx is more sensitive to throttle change, and much harder to start. (not self starting like before). The coil also got pretty warm, but stayed cool on the first test.
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Old Nov 24, 2012, 12:50 PM
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ok, if I get it right the servo is still moving while the motor locks. There is probably current flowing through the coil but no commutation. This would mean that really the blc is dropping out only. Could you try a clipped prop to see if the motor load is too high? This is educational for me too, but not what I expected
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Old Nov 25, 2012, 12:58 AM
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Hi Chris,

I could not get the controller to work with any of my DT receivers. However, I decided to try a Cricket receiver from Micro Flier Radio, and the receiver works well with your new controller! http://microflierradio.com/ I ran several tests today with a few of the motors that I made, and one that Shagrug made for me.

The 4.5mm 2 magnet 4.5 ohm motor that I made to try in my 1/72 scale A10 would only produce 2 grams of thrust with the 1442 chip and the bimRC 20mm rotor. I tested the same motor with your controller and the Ares 30 mAh cell and was getting up to 3.9 grams of thrust! (see video) I can really see the potential with your controller.

The Ares 30 cell is the best performing 30 cell that I have tested so far. Besting the FR, and even the new E-flite 30 cell.

I also tested the controller with the bimRC 15mm rotor and a little motor that Dan made for me to try in my 4.4 inch wingspan MiG. The motor was putting out one gram of thrust with a 20mAh cell and around .67 with the 10mAh cell. The 10 LiPo only held the power for a short time, but the 20 kept going strong.

I think I will try and make a better performing single magnet 4.5mm motor to test in my 1/72 scale MiG. I know that when Dan gets his controller working he will nail down the best performing motors for your controller as he is a master at building these single phase brushless motors!

Joe.
MVI 8399 (0 min 28 sec)
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Old Nov 25, 2012, 01:56 AM
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Joe just to understand if the problems you had with your other rx's were the same as Dan had: Did the motors lock or restart? I am happy you got it to run and see a clear increase in power compared to the A1442. Now we have to understand what is going wrong with the dt and other rx's. It might simply be the blocking of the rx. Dave added additional blocking in his setup to get it to startup at all. He added it at the end of the power lines of the blc I believe, so that most likely improved the rx blocking as well.

On the first sight, my conclusion is that it would be an easier task to make a blc+rx product plus tx module plugging in into the trainer port.

While giving you support I sit down now and install the servos in the squall...

Chris
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Old Nov 25, 2012, 02:41 AM
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Chris,

Dan and I were having the same problem with the motor locking up after increasing power. However, my motor seemed to cut on and off up until that point.

I am wondering what might be different about Nicks Leichty's Cricket that allows the controller to work?

Joe.
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Old Nov 25, 2012, 03:16 AM
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I guess it's the rx blocking. Do you have capcitances at hand? Maybe such a yellow tantalum cap like on the blc? Maybe you have a broken device, where you can take one off? Plug it into a free socket of the rx across + and -. But watch out for polarity of the tantalum.

Restarting without locking is different. This is what the controller does when it looses signal. It goes into fail save and puts throttle back to 0. Then the rx recovers and the throttle ramps up again. Dan, said he had to put the throttle stick back to 0 and before the motor would lock (constant current flowing through the coil I believe). He also mentioned that the coil was getting warm in this state.

Chris
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Old Nov 25, 2012, 03:29 AM
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Chris,

I am fine with just using the Cricket receivers to test it out in my planes. I have to test it with the Rabbit as that receiver weighs only160mgs! It should work the same as the Cricket.

Joe.
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Old Nov 25, 2012, 02:58 PM
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Chris-

Right- when it "locks" the coil is energized and holding the magnet. (not pulsing anymore). After I reset the throttle to lowest position for a couple of seconds it will restart again. It locks up like this at higher throttle setting points, but runs smooth below. The coil warms up from the constant current. (when locked)

The prop size did not seem to matter, I tried it again with a smaller dummy prop and also no prop at all. It still wants to lock up at the same throttle point.

I've just tried it again with a cricket rx, with even poorer results. With it it locks up at 5,000 rpm or so. (and won't self-start) I have a photo again showing the connections- I'm not clear on what you mean by a "star" hookup. And this particular cricket rx may not be quite the same as what Joe is using, it is the very first one Nick made with brushless output. (on special request) I remember he had to ask Martin for advice on how to do it. I have never used it before now, so it may be at fault.

What about trying a lower ohm coil? I may have some caps that will help, I'll look thru my box and see. And I'll see what other rx'es I have free to try. (mabe a ar6400 next?)
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Old Nov 25, 2012, 04:40 PM
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Dan, with the star connection, I mean that you should connect the power leads of the blc to the battery, not to the rx. So from the battery you have two + and two - wires, one pair going to the blc, the other to the rx. I can't see a cap on the rx. If you have any, add it close to the rx across the rx power lines. That should help.

Chris
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Old Nov 25, 2012, 04:43 PM
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It will be interesting how a lower ohmic coil will do, but since the rpm when it fails depends on the rx, it's probably not related to the motor.

Chris
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Old Nov 25, 2012, 09:04 PM
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Dan,

I am using an actuator version of the Cricket with brushless output, and my Plantraco transmitter converted to Hip Hop. It may be your Cricket like you mentioned. Mine starts right up and runs great with every coil that I tried. I tested it with coils from around 4.5-8 ohms.

Joe.
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Old Nov 25, 2012, 09:32 PM
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Joe-

That's what I have, a actuator version but using a E-sky tx converted to hip hop by Nick. I'll keep at it until I get it going well.

Your success has me thinking it may be the rx too, but I'll try another motor later to be sure.

I would like to order one (or two) of the BIM fans to test- mabe a 22mm is best? I didn't see the fan rotor shaft hole size listed, can someone tell me please? Is it the same on all the smaller fans?
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Old Nov 27, 2012, 08:51 PM
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Dan,

I am not sure of the exact size, but my 18 and 20mm rotors fit perfectly on the Ares 6mm motor shaft. The 15mm rotor fit perfectly on the 2.5mm motors that you sent me to test in my 4.4 inch MiG. On the 4.5mm motors that I made, I just added a little CA to hold the 18, and 20mm rotors on the shaft.

Joe.
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Old Nov 28, 2012, 05:41 AM
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Joe- Thanks, that would make the smaller holes at about .5 mm and the larger .8 mm.

Chris- In the photo above the 160 mah lipo was just below (like shown), and connected this way I didn't think it would starve for power. But I understand some of what you mean with the star connection, and tried it again as in the next photo. I've shortened all of the wires, and the power wires going to the blc and rx are the exact same length. The motor now runs a couple thousand rpms faster, locking up at 7,500 or so. So it seems it helped it a bit. I've got some caps to try next, and I may try another rx as well.
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