Motor for lightweight build

[Mr_Stripes]

I haven’t flown a plane in quite a while. Why? Cuz I haven’t gotten around to fixing my ultrix (why they went with 1mm shaft I will never know) and I haven’t got anything else small and light enough to fly at the park close by. And so I’m browsing parts for quads and I see some nice motors and new t mount 5 inch props. And so I think what if I slapped those on a mini scout?

I’m thinking ~1404 size motor on a 5 inch bi or tri blade prop. But what Kv?

I have 3s 450mah and 1s 450mah on hand.
I don’t want to buy new batteries. I would like to go 1s because I have more of those batteries and they weigh less. Is that possible? What weight would the airframe need to be to be able to run 1s? And I saw that @FoamyDM has some experience in this area.

Any input is appreciated

Mr_Stripes

 

[FoamyDM]

That size of every thing (Motor, (prop is usually 3-5") works really great for the Mini Scout. but make it a Bipe and you will be happy. slower, with more lift to give you a larger speed window to fly with.

The EZ packs need about 50g-76g depending. The micro setups that MinimumRC seems To have about the same weight range.
lightest is best.

 

[Jade_Monkey07]

Im not familiar with the exact model what's the wingspan and How heavy is the plane without batteries?

 

[Monte.C]

I haven’t flown a plane in quite a while. Why? Cuz I haven’t gotten around to fixing my ultrix (why they went with 1mm shaft I will never know) and I haven’t got anything else small and light enough to fly at the park close by. And so I’m browsing parts for quads and I see some nice motors and new t mount 5 inch props. And so I think what if I slapped those on a mini scout?

I’m thinking ~1404 size motor on a 5 inch bi or tri blade prop. But what Kv?

I have 3s 450mah and 1s 450mah on hand.
I don’t want to buy new batteries. I would like to go 1s because I have more of those batteries and they weigh less. Is that possible? What weight would the airframe need to be to be able to run 1s? And I saw that @FoamyDM has some experience in this area.

Any input is appreciated

Mr_Stripes

Wow @Mr_Stripes I'm facing very similar questions right now. I'm getting ready to start a Grumman Widgeon scratchbuild and I'm trying to decide motor options. This will be a 32" WS. Close to 300g AUW.

I have a pair of Emax 140X motors, and also 110X. I keep thinking to be safe I should build to the 1400s, but I have a nagging suspicion two 1100s will give me all I need or want. Frustrating to be dealing with just guesswork.
I'll sure be watching this thread.

Isn't 1s a very different thing? different connectors, ESC, BEC... ?

 

[Monte.C]

I asked a lot of questions a while back, and after many answers the general idea I came away with is that lower kv is more torque and less RPM.
So for Emax 1106 ii I chose the 4500kv option. I'm not building a racing plane. I think the lower kv option will drive a larger prop.

I keep reading here 5" prop, but Emax recommends for this motor 2-3". I bet it could go up to 4" but that's a guess. Some sources say 2-3s battery, this chart shows info for 12v. (That's 3s, right?)

 

[Monte.C]

I just found this from FT: "Like our last release, with the FT Dart, the new Twin Sparrow uses our Power Pack H. This pack includes two Emax 1106 4500kv Motors along with two Emax 12a Bullet ESC's. This gives you plenty of power on either a 2s, 3s or 4s setup."

If you'll be running a single motor, I think you're still in the 1106-140X range, and I suspect you might wind up with more than 1S.
This also tells me they ran the 1106-4500kv motors on 4S without any horrible meltdowns.
I guess I'll build for twin 1106 and start on 3S.

 

[Hondo76251]

I got really into the smaller stuff a while back, I'll throw my $0.02 in:

1s is tricky. Foamboard is a hard medium to build a light enough plane that is still fun to fly. The EZ pack stuff is the way to go for 1s IMHO.

2s-3s is where i found a great sweet spot. I spent most of my time converting little chuck gliders but ive done a few foamboard ones of this size and had great luck.

These are about 24" wings and the twin has 1103's and the pusher is an 1108. Both seem to like 3" props best.

I think I have a build video that might include more details on the electronics if i can find it...

 

[Monte.C]

I got really into the smaller stuff a while back, I'll throw my $0.02 in:

1s is tricky. Foamboard is a hard medium to build a light enough plane that is still fun to fly. The EZ pack stuff is the way to go for 1s IMHO.

2s-3s is where i found a great sweet spot. I spent most of my time converting little chuck gliders but ive done a few foamboard ones of this size and had great luck.

These are about 24" wings and the twin has 1103's and the pusher is an 1108. Both seem to like 3" props best.
View attachment 213871

I think I have a build video that might include more details on the electronics if i can find it...

Thanks @Hondo76251. Based on your experience with the 1106 twin, would you think that setup would comfortably pull a 32" 290g flying boat?

 

[Mr_Stripes]

Wow @Mr_Stripes I'm facing very similar questions right now. I'm getting ready to start a Grumman Widgeon scratchbuild and I'm trying to decide motor options. This will be a 32" WS. Close to 300g AUW.
View attachment 213869
I have a pair of Emax 140X motors, and also 110X. I keep thinking to be safe I should build to the 1400s, but I have a nagging suspicion two 1100s will give me all I need or want. Frustrating to be dealing with just guesswork.
I'll sure be watching this thread.

Isn't 1s a very different thing? different connectors, ESC, BEC... ?

I had a set of 1105 5000kv on a quad on 3s 3 inch biblades it was a rocket 120g auw. I say was cuz im building a cinewhoop with those motors now. 14xx starts to get powerful...

 

[Mr_Stripes]

I asked a lot of questions a while back, and after many answers the general idea I came away with is that lower kv is more torque and less RPM.
So for Emax 1106 ii I chose the 4500kv option. I'm not building a racing plane. I think the lower kv option will drive a larger prop.

I keep reading here 5" prop, but Emax recommends for this motor 2-3". I bet it could go up to 4" but that's a guess. Some sources say 2-3s battery, this chart shows info for 12v. (That's 3s, right?)
View attachment 213870

The recommendation is for a quad. On a quad if you put a 5 inch prop on a 1106 you would feel the under motoring. On a plane it doesnt matter as much unless you are going for speed. Just drop a cell or 2 on the battery. I would say 2s on a 5 inch prop ould probably be ok/ and 3 inch on 3s would also be good I think.

 

[Mr_Stripes]

Im not familiar with the exact model what's the wingspan and How heavy is the plane without batteries?

Idk,how much does a slightly lightened up ft mini scout weigh?

 

[Mr_Stripes]

That size of every thing (Motor, (prop is usually 3-5") works really great for the Mini Scout. but make it a Bipe and you will be happy. slower, with more lift to give you a larger speed window to fly with.

The EZ packs need about 50g-76g depending. The micro setups that MinimumRC seems To have about the same weight range.
lightest is best.

So about what kv on what battery?

 

[Hondo76251]

Thanks @Hondo76251. Based on your experience with the 1106 twin, would you think that setup would comfortably pull a 32" 290g flying boat?

The twin is actually some odball Chinese specials, 1103 or something i found cheap. Its not overpowered but flies well.

Ive run 1106 twins (ft mini cruiser IIRC) well into the 400gram territory playing with FPV and 18650s. I'd think you'd be safe with 290 gram plane. Might not be 3d capable or anything like that, but should be enjoyable.

 

[Monte.C]

The recommendation is for a quad. On a quad if you put a 5 inch prop on a 1106 you would feel the under motoring. On a plane it doesnt matter as much unless you are going for speed. Just drop a cell or 2 on the battery. I would say 2s on a 5 inch prop ould probably be ok/ and 3 inch on 3s would also be good I think.

Bingo. Invaluable information. I've got a bunch of 3-blade 3" props, and I'm good for 2s or 3s.
Sorry I can't really help with your question. Um, what exactly is your question? Build something and put a motor on it.

 

[Hondo76251]

 

[Monte.C]

The twin is actually some odball Chinese specials, 1103 or something i found cheap. Its not overpowered but flies well.

Ive run 1106 twins (ft mini cruiser IIRC) well into the 400gram territory playing with FPV and 18650s. I'd think you'd be safe with 290 gram plane. Might not be 3d capable or anything like that, but should be enjoyable.

Thx. Enjoyable is exactly what I'm after.
18650s? Dude you're a dinosaur!

 

[Hondo76251]

Build something and put a motor on it.

😂 that's usually how i roll!

 

[Monte.C]

Many thanks. Do I win a thread-hijacking prize?

 

[Hondo76251]

Many thanks. Do I win a thread-hijacking prize?

Yup!
Long as i get a 2nd place prize, I'm out feeding cows, wasn't really paying attention to whatever the topic at hand was 🤪

 

[Hondo76251]

Thx. Enjoyable is exactly what I'm after.
18650s? Dude you're a dinosaur!

Tell me about it! Lol
I ran that single engine one with 4 18490's (half size 18650) for over an hour and, had my hands not froze, it could've gone two! 😉