Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Jul 11, 2003, 02:06 PM
Registered User
Randall's Avatar
Oliver BC Canada
Joined Nov 2002
189 Posts
Can't get it up!

My Hummingbird that is,,, and actually I can get it up, but just not for very long at a time.

I just got my Hummingbird put together with stock motors and separates and aluminium shaft collar.
Separate items are:
CSM HLG200 Gyro,,,, Pixie 7 ESC, GWS ICS-50, FMA M5 Receiver and 2 cell 1020 Li-poly battery pack. I had to install extensions and mount the battery pack well forward of the battery struts to get it to balance.
I'm a total novice to RC Helis of any kind, yet remarkably I got it trimmed and hovering (sort of) in a couple hours.
The problem is it seems to poop out rather fast and I am unable to keep it in the air for more then about 30 seconds at a time. Even with a fresh charge if I can hold it steady for long enough it will start to lose power and settle back into ground effect and gets tougher to control so I land right away. If I wait a while I'm able to get off the ground again and do the same sort of thing.
I'm guessing it's the batteries that aren't able to hold the current draw. I have yet to hook up my amp meter (will do that soon).
But I have heard there are people using the 1020 Li-poly batteries with good success, so I'm wondering if there might be some other problem????
Anybody with any ideas or suggestions???
Here are some pics of my Hummingbird set up. http://www.southokanagan.biz/hummingbird/

One comment about the CSM HLG200 Gyro I would like to make that in all my reading about these helis here and other places on the net I have never seen anybody mention this fact. That is that it would be easy to burn out the tail motor quickly with this type of Head lock or Head Hold gyro. If you crash or tip the heli you would or at least should cut the power right away so that the main motor doesn't get stalled and burn out itself or the ESC, but with a HL type gyro if the tail rotor gets stalled and the gyro senses that it is needs to turn to get back on track it could give the tail rotor full power trying to right itself and there is nothing you can do to stop it from the remote control, you'll have to run over and pick up the heli to free the stalled tail rotor and quickly. Maybe this could account for why some people are having very short lifespans on their tail motors???
Randall is offline Find More Posts by Randall
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 11, 2003, 02:19 PM
"Simplify, then add lightness"
Raleigh,NC
Joined Nov 2000
2,700 Posts
Randall,
The Kokam 1020's are very marginal with the stock HB motor. When I first got my HB I thought they were OK, because my flights rarely lasted more than 30 seconds. When I was able to keep it up as long as I wanted, the Kokams seemed to get worse and worse. I didn't know if it was the batteries or the main motor going bad. I replaced the motor with a rewound cdrom brushless motor, and the same Kokams are flying it great now.

As for the tail rotor with the HLG200 if you hold the rudder stick full left, no power will go to the tail rotor. I always move the stick full left after a crash.

Jeff
jeffs555 is offline Find More Posts by jeffs555
Reply With Quote
Old Jul 11, 2003, 02:47 PM
"Watch this!" SMACK!
jaggies's Avatar
Mountain View Moffett Fd, California, United States
Joined Apr 2001
1,048 Posts
I've seen the same thing on the Kokams. Lasted one flight on the stock motor and ballooned

He replaced the stock motor with the next size larger (370?) and it works much better now.

But the current is high, so you should use 2s2p Kokam 1020s or Etech 1200s

--jim
jaggies is offline Find More Posts by jaggies
Reply With Quote
Old Jul 11, 2003, 03:01 PM
Registered User
mlehman's Avatar
United States, FL, Cape Coral
Joined Jun 2002
1,181 Posts
yep..the kokams don`t deliver enough amps ..you will have to run a 2s2p pack or a 2s1p pack of etecs..I use the ectecs and they work great
mlehman is offline Find More Posts by mlehman
Reply With Quote
Old Jul 11, 2003, 07:02 PM
Registered User
Randall's Avatar
Oliver BC Canada
Joined Nov 2002
189 Posts
I have some 1200 E-tecs on order and I did try the hummer with a couple 1020 packs (2s2p Kokam 1020s), but it was unable to lift off with the extra weight on that stock motor. Guess I'm gona have to order one of those 370 motors too. Not ready to invest in the brushless yet, although I probably will down the road when I find I have an extra $200 that I don't know what to do with.

I thought I read that people were using the 1020 kokams on the Hummingbird and it was working for them, also some were suggesting that the Hummingbird draws only 3 amps in a hover. The 1020 are rated as Current capacity: 3.5-4 amps sustained, 5+ amps in short bursts. That should be more then enough to hold a hover??????
Either that rated current capacity for those batteries is wrong or the Hummingbird draws more the 3 amps in a hover.

By the way Jeff, thats for the bit of advice, it's obvious now,,,,hold rudder full left after a crash, makes perfect sense. Still I don't remember reading that good bit of advice anywhere?
Randall is offline Find More Posts by Randall
Reply With Quote
Old Jul 11, 2003, 10:37 PM
"Simplify, then add lightness"
Raleigh,NC
Joined Nov 2000
2,700 Posts
The stock motor probably pulls closer to 4 amps than 3, and when the motor starts going bad, it can pull more than that. I have seen lots of reports of motors going bad after only an hour or two.

As for the brushless, you can get a motor and controller for a lot less than $200. If you wanted to convert a motor from a broken cdrom drive, it would be a lot less than $100. I was going to get a couple of Etec packs to replace my Kokams, but then I saw all the threads about converting a broken cdrom drive. I had a broken cdrom laying around, so I spent the $60 I was going to spend on the Etec's, on a Phoenix 10 brushless controller instead. I am really pleased with the results.

Jeff
jeffs555 is offline Find More Posts by jeffs555
Reply With Quote
Old Jul 11, 2003, 11:15 PM
Registered User
Randall's Avatar
Oliver BC Canada
Joined Nov 2002
189 Posts
Actually I was thinking Canadian dollars, anything over a hundred dollars US plus shipping and duty usually ends up working out to about $200 Canadian.
You don't happen to have the link to that broken cdrom drive thread by any chance?
Randall is offline Find More Posts by Randall
Reply With Quote
Old Jul 12, 2003, 02:11 AM
"Simplify, then add lightness"
Raleigh,NC
Joined Nov 2000
2,700 Posts
Sorry Randall, I didn't even look to see where you were from before writing my last post. Anyway, here is the main thread where I got most of my info about the cdrom motors.

http://www.rcgroups.com/forums/showt...ighlight=cdrom
jeffs555 is offline Find More Posts by jeffs555
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Help – I Can’t Get it UP RC Man Castle Creations 24 May 21, 2004 12:36 AM
can't get my hummer up? jstevens Micro Helis 1 Oct 12, 2003 11:44 AM
Can't get loopy Mike C Beginner Training Area (Aircraft-Electric) 6 Aug 06, 2001 08:09 PM
Can't Get Zagi 400-X Motor to Start mpj220 Foamies (Kits) 8 Jul 31, 2001 10:26 PM