Woody 51

Personally, I didn't bother mounting the controller switch. Just switch it on and shove it back into the battery compartment and slap the cover on. Not that I really recommend this. I'm just a little lazy sometimes.

Rocketman612

My Feedback: (85)

Well some more progress. I mounted the elevator servo and made a standoff to straighten out the elevator pushrod. Also went with the Hitec HS-81 servo for the ailerons. Had to do some carving to get it to fit. The mounting blocks are 1/4 balsa that have been hardened with thin CA and epoxied in place. Nice movement set at 6mm could go 11mm or so without any binding.

Woody 51,
The plans call for 1.5mm up deflection of both ailerons in effect having some Spoiler effect. Is this correct and necessary?

Thanks, Pete

Rocketman612

My Feedback: (85)

Almost done...

The 1500 Mah battery placed for balance. It seemed to be farther back than I expected. Balanced inverted at 41mm from leading edge(measured from the mark on the belly pan)

Finished plane. Came in at 15.5oz published range for weight is 14 to 15 oz so not bad. Hope to maiden her this weekend weather permitting.

Woody 51
Thanks for the tips and answering my questions. Set the washout per instructions.

Pete

doggscube

My Feedback: (1)

I picked up my Alfa Corsair last night. I'm going to get an Astroflight watt meter (or homebrew my own low-tech version), but in the meantime I was hoping to get some feedback on my setup:

AXI 2208/20 outrunner (rated to 16A)
E-Flite 20A control
TP 1320 and 1900 3-cell lipo packs (I think they're both 10C)
9x6 APC SF prop

I know the setup will provide more than enough power for me, I'm just concerned about the current to the motor.

-Jeff

Woody 51

Jeff,
The set up will be fine, though I think you may be better using a slightly smaller prop with 3 cells.

That 9 x 6 on 3 cells is going to drag a huge amount of current. Consider a 7 x 6 and turn some of that wasted energy into flight time and performance.

Or go to a 2 cell pack with the 9 x 6.

Remember its a balancing act with "sparkies" and on a small motor with a the big prop, not all the extra oomph from an additional cell finds its way to the end of those blades. In fact the amp draw difference between a 2 cell and a 3 cell pack on the same prop, will be quite a lot.

I use the same AXI motor you mention in a former 1/2A Pylon Racer that weighs in about the same as my 2 ALFA prop models (which are both motor/gearbox powered, so are really no comparison with your proposed set up.)

On a 6 x 4 prop I only use a 2 cell pack and an 18 amp ESC. I get great performance and flight times of over 30 minutes from a 2 cell , 2200 Ma/H pack.

When I go to a 3 cell pack, (same ESC) I drop to a 5.25 x 4.75 prop for even more sparkling performance and only a few minutes less flight time.

If I was to leave the 6 x 4 prop on with the 3 cell pack, my flight time would be cut by nearly 50% and the performance increase would be marginal. (I tried it and frankly, the result made the exercise just not worth repeating.)

The other factor to keep in mind with a Lipoly is the packs "C" rating. The more current dragged out by the motor, the more stress is placed on the pack. Exceed the packs "C" rating and you will kill it in 1 flight. As I said, it is a balancing act.

Just something to consider. Give it a try when the model is built and flying and see what the results are.

doggscube

My Feedback: (1)

Woody,

Thanks alot for your reply. Your advice is exactly what I was hoping to get. Motor/batt/prop spec charts online don't really seem to provide info for lipo's, and while I'll probably have a watt-meter by the time I'm ready to maiden my Corsair, I was curious anyway.

I will follow your advice regarding the prop. I have had the impression already that I'm going to be drawing alot of current with it, and your experience confirms it. I'll swap the two 9x6's for a 7x6 and maybe an 8x6. If I don't pick up a watt-meter by the time I fly it, I'll use the 1900 pack, the 7x6, and conservative throttle use to play it safe.

Thanks again,
Jeff

Woody 51

Jeff,
The best diagnostic tool on the market is the new EMETER, which serves as a watt meter, battery pack conditon checker and also a tacho.
Also, if you chose the HYPERION brand of ESC, you can use this same device to program it.
For more details go to http://www.aircraft-world.com/#

doggscube

My Feedback: (1)

Thanks for the tip. I have an Astroflight watt meter on order, and I already have a tach anyway. If I didn't, I'd probably cancel the order in favor of that nice-looking device.

-Jeff

Woody 51

Jeff,

You should be able to go to at least 16 amps current draw on those packs if they're 10C.

This should leave you with a small reserve margain for pack life safety.

Nitro Blast

My Feedback: (2)

I'd only add that when it is NEW, take the time to reinforce the hatch edges. Where the access hatch is gets real ragged over time.

Take a few minutes with some white glue to harden that exposed edge on both the hatch and the fuse. It will make it far tougher and last longer without the dings.

I have many, many flights on my MP Jet, Castle 25, 3c 1275 packs. LONG flight times and awesome vertical.

Woody 51

Good hint about the hatch edges Nitro. Thanks