Stika (F5K)

[Konrad]

I found a great deal on this DLG based F5K electric assist 1.5 meter glider. (Thanks, Wayne and Aloft)!

As it is looking like my conversion of an F3-RES to a F5-RESt is going so well I thought I'd might as well own up to my demographic (Fat Belly) and electrify a smaller 1.5 meter glider.

DJ Aerotech Chrysalis F3-RES to F5-RESt

On the competition circuit the last two years haven't been kind to the DJ Aerotech Chrysalis lite F3-RES. Most of these problems can be traced to a nagging problem with the V tail flutter on the high start. In the USA it is getting difficult to get enough workers to man the lines for a classic...

forum.alofthobbies.com

Well the first thing I noticed is that the wing servo mount is odd. I couldn't get the larger normal sized DLG servos (X0-8) to work. So I'll be stepping down to the new X0-6 servos. This allows me to mount the servos on their side on the bottom of the wing center section and still fit down into the fuselage.

KST X06 - 1.8Kg (24.99 oz in), .07-sec - Wide Voltage

From Blue Bird Model comes the BMS-M57V Hall Effect wing servo, ready to effortlessly move your control surfaces. Inside is a powerful coreless motor and a beefy metal gear train, riding on not one or two, but three ball bearings. But the main feature of this servo is a contactless Hall Effect...

alofthobbies.com

To do this I sanded down the center ridge to allow a flat spot to glue the X0-6. This isn't much of a problem as the wing is two piece and there are no continuity of fiber concerns across the wing center line. (There is a carbon joiner rod, but that wasn't touched).

Now I'm old school and hate to mount electric motors to have a rear firewall mount. (this generally cause all sorts of resonance issue and often has the cooling fan (can slots) fighting the natural air flow into and around the motor. I was going to use a Hacker A10-7L with a front spinner ring mount. But I'm seeing a lot of great climbing shots with these new F5K DLG's using drone motors and way too small a prop!

Emax Red Bottom RS2205-2600KV CCW

The Emax Racing Spec. 2205 brushless motor. CCW

alofthobbies.com

No big deal you say just mount a drone motor and see which set up I like. The problem I have is that these drone motors are usually set up so that the prop is driven off the rotor not the motor shaft. This means an aft firewall mount. This is a configuration decision I have to make early, in the build, as it is rather difficult to change the bulkhead from a rear motor mount to a spinner motor mount.

So are there low cost drone motor that will allow a spinner ring mount to keep the airflow going the correct direction? Or should I just bite the bullet and follow what seems to be working and go with an aft bulkhead firewall motor mount? I'm liking the drone motors as the motor models are showing that these have about twice the power rating as that Hacker A10!

 

[Wayne]

This popped up recently, thought it might be handy for you.

 

[Wayne]

I have one of these on my build table too. Think we have one more in inventory.

 

[Konrad]

Thank you!
I see the ESC is a rebranded HobbyWing.

I have to say I've never liked "L" bend aileron push rods without some kind of feature to keep the rod from moving laterally. (There may be some blocks in the fuselage that controls this). Laterally moving pushrods give me poor centering and poor fine tuning response (large dead band).

My high school French in nonexistent. So I don't know if he mentioned the control horn axle supports.

Love the "inrunner like outrunner" ring mounted motor. But I think I'm going to budget for a drone outrunner.

 

[Wayne]

It think I have an Emax 1806 motor for mine? I'd have to double check at home.. Should be more than enough.

 

[Konrad]

Yikes!
What is it with the drone method of calling out the outrunner by prop rotation? Prop rotation is easy for the end user to change just by switching 2 wires from the ESC. The defining feature of the motor is the thread rotation (left vs right hand rotation). This is not so easy to change. A "clockwise" thread would be the standard righty tighty, right hand thread. But no with drones the CW motor is defined by which way the prop spins. So to help keep the props on the shat thread is cut to allow the motor torque to aid in keeping the nut tight. In the case of the "drone" motor the CW motor has a left handed thread!

So a clockwise drone motor has the left handed thread. Not a thread that tighten the nut as the nut is turned in a clockwise direction (right).

This is ridiculous! The motors should be called out by the defining feature, in this case the threaded shaft!

The draw nut for the CN 25mm spinner is a right hand thread (the classic righty tighty thread).

 

[Hank GB Z]

Yeah. I hear you on thread direction. I was at a hobby shop in Singapore and the guy sold lots of FPV quad stuff and he was saying that since it can be hard to find left hand nuts some guys stopped using the motors with left hand thread and just started to use loctite a long with a locking nut.
Hank

 

[Konrad]

So I may have a dinosaur with this motor? Whatever it won't fit the CN 25mm spinner.

 

[Hank GB Z]

“It’s not a winner if it doesn’t fit the spinner!”

—Me

 

[Wayne]

If that is the motor you got from Nigel, then he should have the other direction he can swap??

Here is the general rule for the hobby: If there is an industry standard, do the opposite. But sometimes follow the industry standard just to mess with people.

With this bit of information you will be ready to tackle anything in the hobby!

 

[Konrad]

Yes, I'll have to ask if he has one. For all I know the correct motor might have burned out and this is the left over mate. It's not a big deal. It is just holding me up for setting the firewall. But I have a lot of other work to do. Read; the whole build!

 

[Nigel]

I have a normal thread 1806 sitting on my desk for whenever you're here next...

 

[Konrad]

Nigel, THANK YOU!

I should be up north sometime afternoon on Friday.

Again thank you.

 

[Konrad]

Well they canceled the F3F race for lack of wind (lift). This gave me some time to build on Sunday. Thanks to the crew at Aloft I acquired an 1806 with right hand threads.
I have to admit I like the shape of the CN spinner with this Stika fuse. Some other brands of spinner look too flat.

The Stika firewall is really nicely thought out. I love that there is a bridge in the wire pass through area to allow these forces bending the motor wires off the fuselage. This allows the firewall to float and find its own center while installing the firewall with epoxying and Cab-O-Sil. It also has flat spots to take into account the side seams. Again a well thought out firewall.

I kept my motor thrust lines close to what the factory nose would dictate. I have a slight mismatch between the fuselage and that of the spinner size of about 0.7mm (fuse is a larger diameter). I biased this mismatch so the the upper left part of the nose ring shows this. I wanted to make sure I had down and right thrust. I also didn't want a scoop on the bottom which would dig into the dirt on landing.

 

[Wayne]

I sort of have my motor mount in.. Need to get a bit of good glue in there. I'll say it is a bit of a pain to get this in there. I'm not 100% happy with how mine ended up.. slightly out of alignment, but think it will be fine.

You are going to have a fun time getting that motor screwed in there.. I elected to mount my motor and spinner and install the ESC before glueing the firewall. Will see if it ends up stinging me or not.

 

[Konrad]

Pics?

Yep, I've had the motor in and out twice. I have a "special tool" for this.

 

[Wayne]

Yeah, mine was more of a build night after hours at the shop kind of process.. ughh, how am I going to do this.. We didn't have a custom tool, and having done something similar I was not excited about trying to get the motor mounted to the firewall after glueing.. I do think these quad motors are no at all attractive to me for the next one of these I build. I much prefer to use a smooth shafted motor and collet spinner. And we have those parts now.. Yay! But I bought my parts for this one a long while back.

The little Dualsky motors would make install and service much better!