Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Mar 22, 2004, 04:11 PM
Registered User
United States, UT, Payson
Joined Mar 2003
564 Posts
I've got some little tiny problems.

As the title states, I've got a few little 'Tiny' problems. I have a scratchbuilt Tiny that is ailerons/elevator/throttle. It is powered by a Dual-IPS and a 7 cell 370 mah 2/3 AAA pack. It is pretty hefty at 7 3/8 oz AUW. 10 x 7 APC prop.

The first flight after I 'ressurected' it and put some landing gear on it was a struggle. The flight was short, but the main problem was pitch. I had to hold up so that it would fly level, and it flew with a 'nose up' attitude, but didn't climb well. The made it slow and 'tippy.'

Next flight, I moved the CG back from the spar to 1/4" behind it. It is better, but I can't effectively gain altitude. It will roll in heartbeat, so the ailerons work well, but pitch is a big problem. With the new CG it has less of a 'nose up' attitude, but still refuses to gain altitude. It also got faster with the new CG, but this was expected because of the high wingloading.

It seems as though I am kept on my toes trying to get it to fly well. I want to be able to let go of the stick, and let it fly where I pointed it, rather than it dropping like a rock if I don't hold the nose up. At this extreme I can't trim the 'up' because it'll slow too much and stall.

Any suggestions to get it flying well?

~Chris
Azygos is offline Find More Posts by Azygos
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 22, 2004, 04:49 PM
Lookin' Good. Real Good.
larsy87's Avatar
London, Canada
Joined Aug 2002
3,979 Posts
Sounds like your still nose heavy. Are the wheels ahead of the CG?

A remote possibility is that the wheels are adding drag, and pulling the nose down. That's extreme though.
larsy87 is offline Find More Posts by larsy87
Reply With Quote
Old Mar 22, 2004, 06:35 PM
BEC
Registered User
BEC's Avatar
Auburn, Washington USA
Joined Jan 2001
12,937 Posts
It also sounds like you're pulling more current than those little NiMhs can deliver. They're not much good above about 2-3A. You don't say what gear ratio your IPS-D is but I'll bet you're propped for rather more than 3A.......
BEC is offline Find More Posts by BEC
Reply With Quote
Old Mar 22, 2004, 06:47 PM
Registered User
Joined Feb 2004
29 Posts
It sounds very nose heavy to me. If you roll the airplane inverted and the nose drops really quick. That tells you if it is nose heavy.
delman is offline Find More Posts by delman
Reply With Quote
Old Mar 22, 2004, 07:26 PM
Been There! Done That!
boomerace's Avatar
Eugene, Oregon, United States
Joined Sep 2001
19,187 Posts
I think BEC is right. You are probably pulling 3 to 4A and there is no way those batteries will deliver.
boomer
www.boomerseflight.com
boomerace is offline Find More Posts by boomerace
Reply With Quote
Old Mar 23, 2004, 04:28 PM
Registered User
United States, UT, Payson
Joined Mar 2003
564 Posts
Hm, batteries eh? Thanks for all the suggestions everyone. I think it is still nose heavy. Also, the wheels are CAed in front of the wing, but they are slim foam ones.

I may be drawing too much for the batteries. I should take it down to a 9x7 or less. I probably shouldn't tell you this, but . . .

I used to fly by GWS BN-2 and GWS E-Starter with these batteries! If I could easily fly the E-Starter with the EPS-300, then I imagine it'll fly the Tiny. However, I do realize they are very different planes, and shouldn't count on that.

I'm going to try it with the CG further back.

~Chris

Once again- thanks everyone.
Azygos is offline Find More Posts by Azygos
Reply With Quote
Old Mar 23, 2004, 04:40 PM
Been There! Done That!
boomerace's Avatar
Eugene, Oregon, United States
Joined Sep 2001
19,187 Posts
Quote:
Originally posted by Chris Stevenson
Hm, batteries eh? Thanks for all the suggestions everyone. I think it is still nose heavy. Also, the wheels are CAed in front of the wing, but they are slim foam ones.

I may be drawing too much for the batteries. I should take it down to a 9x7 or less. I probably shouldn't tell you this, but . . .

I used to fly by GWS BN-2 and GWS E-Starter with these batteries! If I could easily fly the E-Starter with the EPS-300, then I imagine it'll fly the Tiny. However, I do realize they are very different planes, and shouldn't count on that.

I'm going to try it with the CG further back.

~Chris

Once again- thanks everyone.
Chris,
You will NEVER be happy trying to fly a 300 powered plane with those wimpy cells. Bite the bullet and get you some 7 cell KAN packs they are as cheap as $14 a pack from www.cheapbatterypacks.com
boomer
boomerace is offline Find More Posts by boomerace
Reply With Quote
Old Mar 23, 2004, 07:28 PM
Registered User
United States, UT, Payson
Joined Mar 2003
564 Posts
The thing was, I was getting as good duration as the 7 cell 720 mah pack I had, because it would just float forever. Also, I was happy with it because I was just getting started in R/C flight. It was quite a rush.

Now I borrow some of my dad's batteries. He has a ton of 8 cell 720's, and a bunch of other misc. packs.

cheapbatterypacks.com - - bookmarked.

~Chris
Azygos is offline Find More Posts by Azygos
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
I've got some "plane" in me...pics simo10 Micro Helis 11 Dec 21, 2005 05:29 AM
Sold I've got some planes and stuff for sale fly2bob Aircraft - Sailplanes (FS/W) 4 Nov 12, 2005 01:54 AM
I've got a nikon 3700! (and some questions:) Newberry Aerial Photography 28 Jan 27, 2005 08:39 AM
Question My first aircraft design and I've got some questions! cadconversions Modeling Science 12 Jan 26, 2004 02:22 PM