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| SteveM, Image # 8137 | 01 May 08 15:41 |
After several passes, few of which were anywhere near the runway, the ESC cut out on low voltage while attempting to pull out at full throttle. I reset the ESC and lined up the best I could, 4-5 large bounces later I managed to get stopped on the runway. |
| SteveM, Image # 8136 | 01 May 08 15:36 |
I did a little flying to and fro and managed to snap a few pictures of the Tyro. Then I settled into the business of attempting to line up with the runway and make passes down its length about 3'-6' in the air, I need a lot more practice. |
| SteveM, Image # 8135 | 01 May 08 15:34 |
My second morning out at the field with the Tyro. Winds were 0-1 MPH to start with and it was just warm enough to have clouds and dew but still rather chilly. |
| SteveM, Image # 8076 | 28 Apr 08 21:17 |
Cobri 20 gearbox with 5.67:1 gear ratio and an APC 9x7.5 prop. I got 6.1 amps at 6.6 volts for 41 watts. Despite the lower wattage, I feel like it had more thrust. No sense in further adjustments till I get the correct A123 batteries in a few days. |
| Creosotewind, Comment for image # 8008 | 25 Apr 08 18:41 |
| Steve, this weekend is the indoor electric flight expo at the University of Phoenix stadium here in Phoenix. Looks pretty cool. I may try to go, if I take any photos I will share them here. |
| SteveM, Comment for image # 8008 | 25 Apr 08 14:29 |
| Yes, I used the 3 bladed 8060 as that was about all I had left. I had an EP9070 with me but that is too much prop for now and last weekend I broke the 9043. New props are in the mail though.
I didn't time the flights and when your scared/excited time seems to crawl, but maybe 3-4 minutes. My new 1100 mAh A123 3S packs arrived just after I posted this, too bad they accidentally sent me 2300 mAh packs that weigh 8.65 oz. |
| jgood, Comment for image # 8008 | 25 Apr 08 14:20 |
| How long did these batteries last? Glad to hear the flights were a success! You used the 3 blader, 8060? |
| jgood, Comment for image # 8003 | 25 Apr 08 14:18 |
| Ah, what a lovely view! I'd have my whole fleet out for a morning like that! |
| SteveM, Image # 8008 | 25 Apr 08 13:42 |
I'm still working on landing on the runway, but these grass landing are soft and no damage is done. On my last flight I recorded 61 watts max, 8.44 amps max, 6.57 volts minimum, and 317 mAh used from the battery. Larger batteries are a must. |
| SteveM, Image # 8007 | 25 Apr 08 13:39 |
Performance is moderate with my current setup, but I am still able to get some altitude and stear clear of the treeline. |
| SteveM, Image # 8005 | 25 Apr 08 13:38 |
Minutes later the Tyro is airborne and after a few clicks of trim it settles into a slow and stable flight. |
| SteveM, Image # 8003 | 25 Apr 08 13:36 |
7am, 45 minutes after sunrise, 34F and calm. Gas planes are not allowed to fly till 9am so I get the field and the view to myself. The new flight box is a lifesaver, two Pb-acid batteries are hidden inside to provide recharging power. |
| jgood, Comment for image # 7984 | 24 Apr 08 22:59 |
| The repair job looks very good, BTW. |
| jgood, Comment for image # 7984 | 24 Apr 08 22:58 |
| Looks like a good place. |
| SteveM, Comment for image # 7984 | 24 Apr 08 22:56 |
| The field is about 300' wide and 700' long with the runway near the middle. |
| SteveM, Comment for image # 7984 | 24 Apr 08 22:54 |
| Update: The EP9070 prop provides 10.48 Amps at 6.89 volts and 72 watts. Looks like I was tripping the current and not the voltage! The bigger batteries will cure the voltage droop and a higher gear ratio will bring the current down below 10 Amps. Good thing I got the meter, it was all guess work (and wrong guesses) prior to now. |
| jgood, Comment for image # 7984 | 24 Apr 08 22:51 |
| I wish my weather chart looked like yours. My ESC (a GWS ICS300E) is rated to 8A, with 15A burst. I know I'm pushing the motor and ESC with the 3 cell - I usually hang the ESC in the air flow, to help it cool, otherwise I sometimes get cutouts. My gearbox is a 5.33:1 (C gearing). Good luck tomorrow! Get her up high nice and fast, to give yourself some time if you get into trouble. Does your field have plenty of room? |
| SteveM, Comment for image # 7984 | 24 Apr 08 22:32 |
| 6A and 40W?! That seems like so little. I did try the EP9070 but the ESC was tripping on low voltage at WOT (I assume so as I had no meter at the time). I have a 4.5:1 gearbox and the 15C battery means 9.6A max. But even at 7.8A the voltage on a fresh battery drooped to 7.2 volts.
My motor and ESC are rated at 10A so the only way I'll get close to 100W is through max current and 10 volts or more. The 1100 mAh A123 packs are nominally 9.9 volts and can source 30C, so I should have no trouble swinging a 9070. I also ordered a Cobri gearbox with two pinion and three spur gears so I can play with prop speed too.
Tomorrow bright and early I am going to try to fly again as the forecast is 0-1 MPH winds in the morning. |
| jgood, Comment for image # 7984 | 24 Apr 08 22:27 |
| 40W really flies it OK - I can still loft the camera with that. I think many r/c flyers like their aircraft to be VERY overpowered. I kinda like having to actually use a runway, rather than a rocket launch pad. :) BTW, my batteries are Thunder Power packs, some of them are 4 years old, and still working acceptably. |
| jgood, Comment for image # 7984 | 24 Apr 08 22:23 |
| OK, found my meter. 6A / 40W with the 2 cell 1320mAh battery. About the same with the 870mAh. The 3 cell 1320mAh was crazy though - no wonder it takes off like a rocket with it! 10.5A / 100W! This is all with the 9070 GWS prop. |
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