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rs-cap
09-15-2005, 03:26 AM
I'm just starting on a Top Flight DC-3 kit, I plan to make it electric and would like to use brushless moters and LI-PO batt's. I would greatly appreciate any suggestions. This plane will have a 82" wing span and I hope to have it flying at app. 11- 12 pounds.

ragbag
09-16-2005, 10:27 AM
Looking forward to following your thread. Polk Hobbies has an arf and there is one other that I have been considering, just to break the ice on twin motor types.

Might even see it at SEFF.:D
BY George:

rcers
09-16-2005, 04:34 PM
What was the kit's glow recommendations? That will give us a starting point.

Your powerplant/batter budget would be helpful too!

MIke

Tweet
09-17-2005, 02:11 AM
What type of performance are you looking for and what size props can you clear (or do you want to clear if you are trying to keet the airplane scale)? I'm thinking the AXI 41xx series, but which one depends on the above.

rs-cap
09-17-2005, 03:22 PM
This model calls for 40-46 glow motors, I had someone sugest AXI 2826 brushless motors with a 40 amp speed control and thunder power 6000 3 cel LI-PO's. AS for props maybe 10-12 inch 3 blade, ?pitch, I know 3 blades are less eficient but it would be more scale looking. As for performance I want high thrust, I don't need a lot of speed. As to my budget I want to do this right, I'll spend what I need to ( with in reason ), I hope to have this plane flying for $1000.00 or so. :) Thanks for your suggestions and advise.:D

rcers
09-17-2005, 09:23 PM
The 2826/10 wind motors will put you at the bottom end of the power scale. I might jump up to the 4120. The issue is the 2826 are about 6.5oz and the 4120 is 11oz. Big difference.

The 2826/10 with 4s (at least) LiPoly will be needed. 3s Lipoly won't give you more than 250-300w and that isn't enought on a 10lb ship IMHO. I think you should shoot for 800-900w at 10 lbs. If you get to 11lbs AUW you might need to go to 1000w.

So $400 for motors ESC's and 4s3p LiPoly is going to set you back about $350-$400 as well.

That only leaves about $200 for the plane and equipment. You may have to bump the budget just a tad, but we are in the ballpark.

Another thought on the 3 blade - I agree you really need them (OK you don't but should) the 4120's will spin a 13-14" and the 2826 will only spin about a 11". Keep the pitch up, then you can throttle back.

Mike

rs-cap
09-18-2005, 02:44 PM
Mike when you say 1000w are you saying 1000w from each motor or a 1000w total? I know this plane will be over 11 pounds if I go with the 4120 motors and probably closer to 12-12.5. I have a friend that built this same kit and it came in at 10 pounds with monocoat and fixed gear and 2-46AX glow motors, I will do every thing I can to keep it light but with retracts, glass and paint I'm sure I'll add a couple of pounds. FYI I plan to build this plane as the AC-47D, the first Gun ship ( Puff ).

Tweet
09-18-2005, 04:27 PM
I believe Mike meant 1000W total. I agree with him on the 2826 versus the 4120.

rcers
09-18-2005, 07:54 PM
Yep 1,000 watts total. Those motors won't approach 1,000 each, without melting!

At 10 lbs they will be the right choice. with 800w and 10lbs you it will be very non-scale like (meaning more!) power....

Remember the real one was a dog! But what a cool dog it was.....

c-47 is the way to go! Keep us updated!

Remember you can wait on the power system till near the end of building, and they you may have a closer idea on weight. If it is going to be 12-13lbs it will fly with the smaller motors, but may not leave you much in reserve power.

AXI really needs a 8oz ish motor that does 600w or so. That is what you need!

Mike

rs-cap
09-19-2005, 07:33 PM
Mike what LI-PO bat. will give me at least a 10 min flight (with several min. reserve) and produce 500 w. Roger

rcers
09-19-2005, 08:19 PM
I like Tanic packs....the 7500mAh should be enough, but talk to Brian on the phone and he will set you up right. That should give about 11-12 minutes safely, so long as the throttles are not pegged all the time.

http://www.tanicpacks.com/catalog/product_info.php?cPath=26_25&products_id=106

smilin jack
09-20-2005, 11:18 PM
I'm planning to convert a small 3 lb B25 with a foam 48" wing to electric flight. I am very new to the basics of motors and esc's. I would like very much for someone to help with the wiring and size brushless motors,etc.
Thanks

rs-cap
09-22-2005, 12:15 AM
:eek: Was I shocked buy the price of thoes 7500mah 90A packs, if I understand it I would need a pack for each moter (app. $700.00 ) in bat.s for this plane or will one bat and speed control run both motors?:confused: Thanks for all your help Mike Roger

rcers
09-22-2005, 02:52 PM
No that 90amp pack will happily run both. Or you could get packs with 40-45amp capabilities and run separate packs....

LiPolys are not cheap, you could also look at NiMh....but they will weigh more, much more.

Mike