FT Sportster scratch build

fliteadmin

Administrator
Staff member
Admin
Moderator
FT SPORTSTER!
We love this guy! If you didn't see the VLOG with the control line plane we used the mini version of this guy!
Good luck with the rest of this plane... it is an AWESOME flyer. Can't wait to see the finished product friend!

Blessings,
Stefan
 

nhk750

Aviation Enthusiast
Thanks! I am having one small issue with the build. I am test fitting the wing into the fuse and it seems the wing is slightly fatter than the cutout in the fuse. Maybe about 1/8" fatter. I'm afraid if I force it bad things will happen. Is it normal to trim the hole in the fuse larger to make the wing fit?
 

Swimjim

Member
Thanks! I am having one small issue with the build. I am test fitting the wing into the fuse and it seems the wing is slightly fatter than the cutout in the fuse. Maybe about 1/8" fatter. I'm afraid if I force it bad things will happen. Is it normal to trim the hole in the fuse larger to make the wing fit?

The wing should fit in fairly "snug" If it were me I would take a piece of sand paper and enlarge the hole a little. When I build my last Sportster the wing turned out to be lower on one side compared to the other. I took it back out and tweaked the hole with a 60 grit flooring disk and got everything nice and square. Looking at it, one would never know. The plane flys pretty well. Better in the hands of a pilot who's middle name wasn't crash. lol

Jim
 

Capt_Beavis

Posted a thousand or more times
the wings are usually a tight fit and I have had to trim before. Don't force it, I did that on my Duster and broke the underbelly.
 

nhk750

Aviation Enthusiast
Thanks for the advice everyone, I will do some sanding before I attempt to install. Right now there is no way to install without breaking. It's not far off, but just enough. So far everything is coming out really square though, just got the tail installed last night.
 

hbb3367

Member
I had the same problem fitting my wing into the fuse...I had painted both parts first and blamed it on that...stiffer and thicker I suspect.

Sportster_2016.JPG
 

Usafa93

Member
Hmmm, the clamp idea sounds like a pretty good one. I usually just poke a few pins through on each corner and that holds the plans pretty good, but I like the clamp idea!

Lol! I guess I've gone completely lazy. I tried each method listed previously and have gotten to the point where I print the plans, then peel the paper off the DTFB and glue the plans on the foam with Super 77. I usually rough cut the parts and arrange on the FB to be as materially efficient as possible. Then I just cut away and start building. I like the cutting and building the best so this works for me.
 

nhk750

Aviation Enthusiast
Tail servo mounting

I ran into another issue...according to Josh's build video, you are supposed to mount both the servos upside down. There is no way to do this with the elevator servo as it will cause the wire to bend and rub on the fuse to much. He actually wants you to mount it lower than the rudder servo bending the wire even more! So, I mounted the elevator servo right side up and it works perfectly. Is that a mistake in his build video?

Hopefully the servo never fails, I would just cut open the posterboard and then repair/replace it.

IMG_0114.JPG
 

Swimjim

Member
I ran into another issue...according to Josh's build video, you are supposed to mount both the servos upside down. There is no way to do this with the elevator servo as it will cause the wire to bend and rub on the fuse to much. He actually wants you to mount it lower than the rudder servo bending the wire even more! So, I mounted the elevator servo right side up and it works perfectly. Is that a mistake in his build video?

Hopefully the servo never fails, I would just cut open the posterboard and then repair/replace it.

View attachment 81081


As long as you have the control wires exposed..... The control wires to the tail are a tad long. This results in them flexing when used and that results in poor rudder/elevator response. To deal with this issue I put a zip tie on each control rod and I ran the "tail" of the zip tie through the fuselage about half way between the servo and tail to act as a guide. I put a drop of hot glue on it to help secure it and clipped off the excess out side the fuselage... This keeps that control rod where it's supposed to be.

Jim
 

nhk750

Aviation Enthusiast
I used heavier gauge control wire (I learned from the Storch flexing to much) and they have no flex now. I will take another look at the that before it gets sealed though, thanks for the heads up.
 

Capt_Beavis

Posted a thousand or more times
I don't like the internal mount technique. I did it once and had one that kept coming loose. I now mount all of the tail servos externally.


I ran into another issue...according to Josh's build video, you are supposed to mount both the servos upside down. There is no way to do this with the elevator servo as it will cause the wire to bend and rub on the fuse to much. He actually wants you to mount it lower than the rudder servo bending the wire even more! So, I mounted the elevator servo right side up and it works perfectly. Is that a mistake in his build video?

Hopefully the servo never fails, I would just cut open the posterboard and then repair/replace it.

View attachment 81081
 

msestephens

New member
When sanding wing openings in planes like this, I find a nail file works best. I get a big pack of them at the Dollar Tree and they work great! Work for other areas too.
 

nhk750

Aviation Enthusiast
I don't like the internal mount technique. I did it once and had one that kept coming loose. I now mount all of the tail servos externally.

Too late now, but it is just like the Storch empennage, I probably could have mounted the servos the same way and it would have worked great...next build...

When sanding wing openings in planes like this, I find a nail file works best. I get a big pack of them at the Dollar Tree and they work great! Work for other areas too.

I wonder if I used my wife's nail files she would mind?
 

nhk750

Aviation Enthusiast
Fuselage done!

Got the fuse done, now to install the wing. I like the hommade file idea Craig, I may try that.

IMG_0115.JPG
 

nhk750

Aviation Enthusiast
Got the wing jammed in...that was scary...I hot glued sandpaper to a paint stick and sanded away, worked great!

IMG_2476.JPG
 

nhk750

Aviation Enthusiast
Repair control horn

Well, I made another mistake...when I drilled out the control horns for the elevator and rudder, I made the holes one size to large. This caused the controll rods to have too much free play in the control horn and made the control surfaces sloppy. So, I thought "how do I repair this without digging out the control horns and possibly dammaging everything?".

I engineered a fix: Take some 18 gauge electrical wire, strip off the insulation and feed the strands through the control horn hole until its snug, then hot glue the ends down and fixed!

IMG_0119.JPG

IMG_0117.JPG

IMG_0118.JPG

I didnt want to risk any dammage, I had a good build with this one!

IMG_0116.JPG
 
Last edited:

Tench745

Master member
Well, I made another mistake...when I drilled out the control horns for the elevator and rudder, I made the holes one size to large. This caused the controll rods to have too much free play in the control horn and made the control surfaces sloppy. So, I thought "how do I repair this without digging out the control horns and possibly dammaging everything?".

I engineered a fix: Take some 18 gauge electrical wire, strip off the insulation and feed the strands through the control horn hole until its snug, then hot glue the ends down and fixed!

A little tip I picked up somewhere that works really well with the wood control horns. With the pushrod in place on the control horn, drip a little CA into the oversize holes, let it fully cure, then move the surface to release the hold on the pushrod. Now you've got a zero-slop connection as the CA has filled in everything that isn't pushrod.