RCMotion L-19

[Franco2fly]

Tried unsuccessfully to get the bird dog off the ground. I purchased the bundle containing motor prop and ESC. Have others had similar results? You can send me an email at Franco2fly@aol.com. There’s no way this gets off a grass runway. The battery I’m using is a new spectrum 5 cell and the charge was at 100% . When I put a tach on the prop found it turned 6500 RPM at full throttle which seems slow but it is what came in the bundle. I’m open to all suggestions at this point cuz i usually fly 20-30cc gas need help when it comes to electric. Thanks

[xviper]

Send a picture of the plane from the front showing the prop.
1. Aren't you supposed to be using a 4S battery? Why are you using 5S? On 5s, it should be turning 8400rpm.
2. On 4s, that prop should be going ~6700 rpm on fully charged battery.
3. With a picture, we can see if you have your propeller on backwards. If it's backwards, it won't produce the adequate thrust. Also, is the prop tight? It could be slipping.

[Franco2fly]

I m using 4 cell and it is turning 6500 rpm
but the plane never goes fast enough
m

[Franco2fly]

It is a grass field, maybe off a 5000 foot concrete runway it could stagger off the ground. I have GPS speed as it’s not getting to 25 mph prop is tight and I do see 6500 rpm but that not enough and so I’m thinking I might have to go to 5 cells. What do you think?

[Franco2fly]

Xviper can we chat via messenger or emails
I answer quickly to Franco2fly@aol.com

[Franco2fly]

I mucked up the model provider it should be MotionRC. Is there anyone that has done a review on the model? I’m new to this board so I am struggling with the search function

[Franco2fly]

Our field is one of the best on the East Coast. FARCC. (Fredericksburg area radio control club). Here’s a picture from this morning

[xviper]

Sorry, I don't do "chat". I prefer posting on this forum. You should get notification of a new reply by email instantly.
Here is what I got from your original post:

The battery I’m using is a new spectrum 5 cell and the charge was at 100% .

Using a 5s battery when a 4s battery is recommended is questionable. It might just burn up the motor or ESC or both.
Your pictures are not directed enough at the prop to tell but it appears as though your prop is on backwards. Which side are the numbers on? This KV of motor and at those RPM should be more than enough to get that plane off grass. I think your prop is on backwards. A backwards prop just won't cut it. If it's on correctly, then check that the pitch and diameter is as per recommended.

[Franco2fly]

No it is on correctly
and it never gets to flying speed grass is freshly mowed and not wet. I do not believe 6500 (which is what prop tach’s at) is enough for grass. Maybe concrete!

[Franco2fly]

Just re-ran tach on bench

[Franco2fly]

This was 30 seconds after coming off charger it does fluctuate hitting 6500 but mostly 6400. Prop is correct and also checked prop not is torqued down. There’s no way it’s coming out of grass. I think at least 8500 is required and simple level flight is gonna be around 7000.
if you have one let me see what you are flying off. And i would like to see RPM’s. Thanks. I’m also having problems logging into Hobby Squawk.com but that’s a separate issue.

[xviper]

It looks like your prop is on properly and is the correct pitch/length. 6700 rpm max for that motor and 4s fully charged battery is also in the right ball park. I'm at a loss for why it won't get off the ground. You can try a 5s BUT that's at your own risk. You may luck out or you may see blue smoke.
I've had a couple of Nexa planes and they seemed a bit under-spec'd. I only had success when I went from their recommended 4s to 6s.
No, I don't have one. Just trying to make some suggestions on what to check as I doubt anyone else here has one or will respond. I had a friend who had his prop on backwards and it couldn't get off the ground. Changed it around an it took off like a bullet. That's why I brought it up.
Try doing a search on YouTube to see if there are examples of this plane actually flying and what they are flying off of.

[Franco2fly]

Thanks, suggestions always appreciated. I ordered a 5 cell comes today. Also dusted off my gadget that measures amps/watts/ voltage etc. will first measure the 4 cell then keep close with the 5. My guess is that off hard pack or concrete runway one could get up enough speed to have rudder authority. Will post results

[Franco2fly]

So spoke with motionRC tech support and their feedback was 4 cells not nearly enough suggest going to 6 cells. Now that is way way more than what is called for in the manual. Also recommended changing prop from 13x8.5 to 13x10 also bizarre and more pitch than I like. I’ll look fo a 14x8

[xviper]

The ESC "might" hold up, but will the motor hold up on 6s? See if you can find specs on the motor to tell you if it will run safely on 6s.

[Lowshow]

I think that your problem is that you are spinning a SloFly Prop and the blades are cavitating ??

[tab28682]

I think that your problem is that you are spinning a SloFly Prop and the blades are cavitating ??

Definitely not a slow fly prop. Normal APC style Thin E prop.

[tab28682]

The ESC "might" hold up, but will the motor hold up on 6s? See if you can find specs on the motor to tell you if it will run safely on 6s.

I looked at the motor in the bundle. It is a 46-60 equivalent motor with 400 Kv rating and it will do fine on the prop he has, on 6s. The motor is rated for 4s to 8s, obviously dependent on the prop chosen. I run the same size and Kv motor on 6s with a 15/10 prop.

The original poster needs to strongly consider going to a 10 pitch prop, even if he is reluctant to use it. This is very commonly done on this size electric motor.

I have to say MRC did not get this suggested setup right.