Newbs flying with 2200mah batteries

[Jaimie]

Hey everyone, my friends and I are head over heals excited about getting into flying RC planes, but we have a major impediment... We live in Iceland.

There are some problems with living in Iceland, mostly if you want something that you can't buy in the supermarket, it's very likely to be hard to find or it's going to be very expensive. This includes LiPo batteries as they cannot be shipped to Iceland. Fortunately I have a friend from the UK visiting me and he's managed to find us some 2200Mah 3S 30C batteries at short notice (there wasn't much choice) which is awesome but problematic.

Our plan is to make a shared hobbyking order and buy foamboard in Iceland but before we make an expensive mistake I wanted to ask some questions.

With the increased weight of the batteries (193 g) should I scale up the motor and print out size relative to the difference in battery weight? How large would that be?

What size motor and prop should I pair with this?

Is there anything else I haven't thought of?

 

[highflying]

You are supposed to fly them with 500mah 2s, and the weight difference, and the bulk is huge. As you know the 2200mah is around 200g, and a 500mah is around 30g.
The weight difference is going to wreck the performance. The standard motor is said to give (at maximum efficiency) around 400g. You won't get maximum efficiency, and chances are your foam is heavier than DTFB (Dollar Tree Foam Board). The electronics combined weigh around 70g, and the airframe around 120g, with DTFB (your will almost certainly be heavier).
All together you get to around your thrust limit, at 100%. This means at 100% throttle, you will get a 1:1 thrust ration, allowing it to hover. If you do this for too long, though, the motor will burn out.
Effectively, if you were going to make an FT Flyer, you would need to double the wingspan, at least, and get a bigger motor, and a big prop.You could deal with it, but it would be a beast to handle, the velcro would rip off, and the CG, would change quite a lot. Just get different batteries, otherwise you're in for a world of pain, and tedious changing.

 

[Tactical Ex]

HighFlying has some good points and each one should be considered before making the purchase.

My experience isn't nearly as gloomy as predicted, though. I typically run a very heavy plane (FT Flyer) but I did fine with a 2200mah battery on my FT Flyer and a 24g motor. You do notice it to be sluggish but it's not a game ender. I have since moved to a 58g motor and the 2200mah batteries are pretty much standard for me.

By the way the CG never changes unless the airframe changes, where you distribute the weight to balance the plane DOES change. I have also never had an issue with Velcro ripping off even with a 58g motor and full throttle high G maneuvers. The latter of which is partly due to my method if hot-gluing Velcro to the power pod, though.

 

[rcspaceflight]

I made a variation of the FT Flyer with a simple airfoil wing with polyhedral and I flew it with a 2200mah 3S battery without any issues.

http://forum.flitetest.com/showthread.php?6426-1-swappable-trainer

But I used Dollar Tree foam board and I'm not sure what foam board you're going to find. In my experience Dollar Tree weighs half of all the other foam boards I've been able to find locally in the USA.

You're not going to be able to fly an FT Flyer with a 2200mah 3S battery very well, but there certainly are easy to fly planes that will work with that heavy of a battery.

This is the motor I used with an 8x4 prop. If I remember correctly that motor comes with 3.5mm bullet connectors. Be sure to pick up some of those because most ESCs don't come with any connectors on it. But you could always get a bigger motor than that one. It's better to go too big than too small. You can always use less throttle but you can't magically add power. Plus you can prop down but you can never prop up.

Even if you can't build the plane I linked to light enough, you certainly can come up with a design that will work. The plane I linked is actually close to a noob tube and just making a bigger noob tube should work out.

 

[Jaimie]

I've done a little more reading and 'the internet' is saying that people typically fly 1200mm (47") to 1400mm (52") wingspans with this kind of battery.

Taking into account what space flight and HighFlying said do you think that I should scale up an old fogey 25% and use this motor and spread of props? What props would you try? Can you scale up by printing the plans 25% larger or would I be missing something?

 

[Montiey]

I fly my flyer with slightly heavy gear and a park zone 1000mAh, its definitely heavier, but its just sluggish, no real problems.

 

[Coleman]

I have an DTFB Old Fogey running on an Turnigy 2200 mah 3c 30c with a suppo 2208/14 8x4e prop and it floats like a baby. I have found that the extra weight does put more stress on the wing, I've folded three so far pulling out of stalls and fast dives in moderate winds (perhaps a spar is in order). I'll probably just make a wing with the center piece Elmer's Foamboard and the wing tips DTFB, or buy recommended batteries. Having never scaled up a build I can't tell you not to do it, but for my first build I would leave the plans at 100% as making the plane larger on account of the battery is unnecessary. I would be afraid the larger wing would only increase it's likelihood of folding under stress.