Help! Maiden Flight Issues

[JasonK]

There is certainly nothing wrong with tinkering with this one and is great fun, but I'd recommend something with a longer body that will just be inherently stable at the first throw. Anything that looks like a Cessna 172 would be fine. Like the Tiny Trainer for example.

I have a Tiny Trainer and have been flying it for a bit, this is just me working through trying to build a second plan (without making a whole second Tiny Trainer) and I am trying to get some experience building as I have a plane that I want to make (Just waiting for some electronics to come in) and need to get some experience as I go.

 

[Aireal Anarchist]

thats funny I was going to post why would you assume he doesnt have a Cessna and a tiny T?

have you decided how your going to approach your flexing push rods in your experimental? another approach that would WAY LESS WORK since your just experimenting, is to increase the pushrod size to a dia that wont flex at that length, it would be less weight to adjust your CG to aswell...

I know parts and buliding supplies in a lockdown is difficult at best but...have any larger pushrod wire?

 

[JasonK]

No, not yet. I am working (Monday)...

I don't think the tubes will work here, because I don't have anything good for them to ride in. (there is about a 1in gap between them and the BBQ stick that supports the tail), and I also noticed that the large Z-bend for the offset imparts some flex opertunity, even if I hold the rode directly before it. apparently the paper delamiated some on one of the rudders also, so I need to fix that also, as that makes the rudder side have almost 0 authority over it.

I definitely have some repairs and fixes to do here and some planning to do. Right now, I think moving the servos is probably the easiest fix (I have room to deal with fixing the CG).

 

[Aireal Anarchist]

my similar but larger box tail build the servos will be going on the tail feather too, ofcourse I dont have the weight/CG issues as big as it is and it will be caring a 5000mah 4s battery up front it weights just over a pound

maybe connect the rod from the servo to the same rudder horn that connects to the opposite rudder, maybe that will eliminate one servo horn?
I haven't got that far yet just finished covering the tail feathers but its what is in my mind

 

[dahacker]

thats funny I was going to post why would you assume he doesnt have a Cessna and a tiny T?

True. I was incorrectly pre-judging based on the wild video. Carry on...

 

[JasonK]

I ended up moving the servos and had to move the battery right to the nose to keep the same CG. The control surfaces have almost 0 play in them under reasonable force with my fingers.

It appears that the elevator is very impacted by the airflow from the prop but not the rudder. Which raises a question -> should I/Can I do some sort of mixing so that if I have a higher throttle input, my elevator gains go down? (I have a Spectrum DX6e)

 

[Merv]

Which raises a question -> should I/Can I do some sort of mixing so that if I have a higher throttle input, my elevator gains go down? (I have a Spectrum DX6e)

Yes, its possible & a good idea, I have done it with OpenTx, not sure about Spectrum. With OpenTx you can use a multiplier to a mix. If nothing else you can add in some expo to the elevator. This will soften the stick near neutral and still allow full deflection. I'd start with 20% expo, then add 5% at a time until you are satisfied with the performance.

 

[JasonK]

I have expo already there... the more I hear about OpenTx, the more I like it (seems to be the most 'user extendable' option and the least pay-walled for features TX systems)

 

[Merv]

I have expo already there...

You could try adding more expo. You could also just use a simple dual rate switch & change it manually.

 

[Aireal Anarchist]

yes on dual rates or if the elevator is just too much decrease the servo end points in your transmitter settings, this will ensure you tame it down even in high rates

 

[JasonK]

I found it... I can do Dual rates based on my throttle, only 3 'steps'.

 

[Aireal Anarchist]

like the guys in FT have fun with ....you can make most anything fly, its fun figuring out how and as you said earlier in the post you have learned a lot on this build

with the short tail its going to be pitchy so without further modifications, think of this like military fighters, they are built to be so maneuverable they almost cant fly, and require programing to compensate for the inadequacies we pilots have. and now there is more to learn with your radio setup to tune up the aircraft

 

[JasonK]

Yup... I do have a flight controller board on order, so I should be able to spin up some flight stabilization code here in the near future on builds. But, I do happen to have that planed for my VTOL project.