Thread Tools
Dec 26, 2012, 01:38 PM
Never fly an A model anything!
jayb1rdz's Avatar
Quote:
Originally Posted by STEVEAIR2
Whats the point in having the two Battery inputs?
I use JR921 RX all the time bt have never connected 2 Batteries. So I would love to know the advantage.
Cheers
Steve.
Some models with latge powerful or multiple servos can draw big current. Using two battery ports reduces the chances of overloading the wiring in the RX which can happen if putting it all through a single port.
Sign up now
to remove ads between posts
Dec 26, 2012, 07:13 PM
Registered User
Servo current draw on the H32 is fine for a single input. I only brought this up because I was thinking of some free redundancy if I wanted to go to the trouble of isolating the BEC from the receiver battery. Probably not worth the effort though. I think the weakest link on a typical radio installtion is the switch, and I don't plan to use one on this plane.
Dec 27, 2012, 02:56 PM
Another one on the way...
ysolomon's Avatar
OK, today I did a static thrust test, holding the habu vertically leaning on a scale. First thing I learned is that my AUW is 6.94lb. Full throttle added 4.3lb, so my static thrust is 4.3lb (62% of the AUW weight). Reading off the CC100 shows that the maximum power was 1,550W on a current of 69A, with batt voltage dropping from 25.2V to 22V minimum.

Do these numbers make sense?

Also--any recommendations for the CC100 programming for the stock fan/motor setup? PWM? Timing?

Finally, I have the cutoff set up for soft-cutoff and 3.0V/cell. Does this make any sense?

And one more thing, I see a range of CG that people were using for it, but it seems that the majority were in the 110-115mm. What do you recommend?

Thanks!
Last edited by ysolomon; Dec 27, 2012 at 03:03 PM.
Dec 27, 2012, 03:03 PM
3DHOG
jcdfrd's Avatar
the numbers look good, especially the auw
timing should be med or 5-10deg with 12khz pwm
how does the balance of the fan feel?
Dec 27, 2012, 03:05 PM
Another one on the way...
ysolomon's Avatar
Great. Those were the numbers I had in there. Fan sounds pretty sweet. Unlike some others I used. Did you have to balance yours? I don't feel the need. Really sounds good. What about the CG? 115mm and the "nose wheel soft liftoff" test?
Dec 27, 2012, 05:14 PM
Registered User

Thrust Tube adhesive


Starting my build and the adhesive on the thrust tube is not holding (factory adhesive down the joint making it a tube). Is it ok to use clear packing tape to hold it together? Or should I get a replacement, use some CA, etc?

Thanks
Dec 27, 2012, 05:22 PM
It's like an addiction!
Downwind3Zero's Avatar
Don't worry, packing tape (or any other strong tape) is fine as long as you use it along the entire seam.
Dec 27, 2012, 05:28 PM
Flying Full Size & Fun Size :)
jgalexander's Avatar
Yep. Take a look here: https://www.rcgroups.com/forums/show...6#post23604959

Gary posted some pretty detailed pics for how to do it (love the spoon BTW).
-Josh
Dec 27, 2012, 06:12 PM
efflux RC's Avatar
Quote:
Originally Posted by jgalexander
Yep. Take a look here: https://www.rcgroups.com/forums/show...6#post23604959

Gary posted some pretty detailed pics for how to do it (love the spoon BTW).
-Josh
Thanks for the reference Josh.

The spoon serves two purposes

1...to act as extension of your hand, by sticking the tape to the end of it so you can pull a full length peice of tape through the inside of the tube, for taping the inside seam.

2... Use the spoon to "burnish the tape down on the inside of the thrust tube.
Here's the pics again.

.........................................


Spike5150,
After printing the template and teping the peices together, you nee to add 1/4" (with a pen on the template) to the large curved (EDF) end. And add 1/4" to one of the straight sides. This creates the additional material needed to overlap the the rolled seam, and to overlap the aft end of the fan by 1/4".
Use 1/4" or 1/2" wide "Scotch" brand, SHINEY cellophane tape.
You can also cut clear packing tape to the proper width as well.
Tape both the inside and the outside overlap seams of the tube. Reinforce the the opening you cut for the motor wires with a couple of layers of tape too.
Last edited by efflux RC; Dec 27, 2012 at 06:18 PM. Reason: added text
Dec 27, 2012, 06:23 PM
Another one on the way...
ysolomon's Avatar
Oh, shoot... I haven't done this. Is the seam problem consistent for everyone? Should I remove the thrust tube to do this?
Dec 27, 2012, 07:14 PM
3DHOG
jcdfrd's Avatar
I have seen a few thrust tubes fail inflight.......not pretty
Dec 27, 2012, 07:56 PM
Stay Thirsty My Friends
swarick's Avatar
Got a Habu 32 for Xmas and was reviewing this thread to find servos used. I noticed quite a few people have used the HITEC servos. I want to run a 2 cell LiFe pack rather than separate BEC. do the small HITECs handle the higher voltage OK?

Rick
Dec 27, 2012, 08:46 PM
Registered User
Yes I just maidened mine with Hitec 85MG servos all around and a 2-cell LiFe 1100 Mah pack, and they worked just fine

You're gonna LOVe this jet!

Kevin
Dec 27, 2012, 09:19 PM
Registered User
As I mentioned, the maiden went well overall - tks for all the useful suggestions! The only hiccup was that about one minute into the flight, the motor started giving out alternating high and low sounds whenever the throttle was high - say, 75% or higher. This alternating sound sequence disappeared as soon as I reduced the throttle. The batteries were 2X3S 4500 MAH Turnigy Nanotech, 35-70C. I used the same battery series, but brand new, on the second flight, and the same thing happened. None of the batteries was ridiculously hot after I landed - just warm like normal - and I had 3.8V-3.9V left on every cell so nothing went bad.

Is this just a matter of the batteries not having high enough C rating?

Kevin
Dec 27, 2012, 11:21 PM
Registered User
Jetnfast's Avatar
Quote:
Originally Posted by kchen95
As I mentioned, the maiden went well overall - tks for all the useful suggestions! The only hiccup was that about one minute into the flight, the motor started giving out alternating high and low sounds whenever the throttle was high - say, 75% or higher. This alternating sound sequence disappeared as soon as I reduced the throttle. The batteries were 2X3S 4500 MAH Turnigy Nanotech, 35-70C. I used the same battery series, but brand new, on the second flight, and the same thing happened. None of the batteries was ridiculously hot after I landed - just warm like normal - and I had 3.8V-3.9V left on every cell so nothing went bad.

Is this just a matter of the batteries not having high enough C rating?

Kevin
A 35-70C pack should be plenty for the stock setup if that is what you are running. Also you mentioned you tried a second set and that seems to rule out the batteries as the direct source of your problem. Is the fan balanced? Have you checked all your solder joints with your connectors. Based on the info you posted, it sounds like you have some resistance between your batteries and motor which the most likely cause is a bad or cold solder joint.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Fiberglass Habu Airframe Calvin_220 Electric Ducted Fan Jet Talk 92 Nov 10, 2012 03:53 AM
Sold New in box Habu EDF PNP flyboy1945 Aircraft - Electric - Jets (FS/W) 2 Aug 01, 2010 08:24 PM
Discussion ESC very HOT - Sorry the discussion is moved to the Habu thread SalamSyed Foamy EDFs 0 Mar 20, 2010 11:15 PM
Discussion Baja SS Speculation and hopup thread. DaveESPI Large Scale Cars 3 Feb 03, 2008 08:39 PM