Futaba Micro Spline 21T....Maybe

I  wrote about the issues trying to find the spline to fit the Tactic Mircro TSX-10 Servos. I had purchased Dubro Futaba Micro Spline compatible servo arms and they were too small. At the same time I bought some aluminum arms for the same spline. Since the Dubros did not fit I didn't  expect the aluminum ones to, so when they didn't fit easily I was dismayed. I am still waiting to hear from Hobbico about what the proper spline is...

Today waiting for another project to dry, I retried the aluminum arms. With a bit more effort they actually fit quite snug. I removed them, and nothing had crushed to give the illusion of fit. I had already replaced the rudder and elevator with the original plastic arms since they were bolted on to extensions so the lack of width at the end didn't matter. I installed the aileron arms, and had to replace the carbon fiber rods with steel, but they work fine. Any more range of motion and they would come right off.

Aileron. From China on Ebay.

Elevator. Original plastic on epoxy extender.

She is ready to fly!

UPDATE (11/23/16): Hobbico had no idea what the spline is, but they got one and now know its 20T. They are checking to see what splines will be compatible. I am not aware of any 20T micro spline...

Big Stick Wing Repair

Several days ago the wing came off the Big Stick after the left tip touched on landing. It cracked the mid-seam and tore off the front attachment knob thingy. The simple job got complex when a lack of attention on my part lead to further damage to the top of the wing.

I epoxied the underside seam and used my drill as a weight to flex it down.

I pulled back the cote from the center and laid down 3 layers of fine mesh fiberglass cloth with alcohol thinned epoxy as the resin.

Not sure how secure the top was, I laid down 2 layers of fiberglass.

Sanded it flat.

Same on the underside.

While that set for 24 hrs, I examined the broken forward wing attachment. There should be a section of plywood that juts out; that goes into the fuse to secure the wing's front edge, the back end being held by wing screws.

Cut it clean as a right angle. You don't want this too strong or instead of giving way as it did here, the energy will break up the wing or fuse.

Epoxied in a new block.

Epoxied in some side supports. I sanded down the aft parts so they were flush with the attachment hard point.

In trying to sand down the very thick epoxy on top I didn't take into account the slight V in the center. The sander ground down a bit of balsa on wither side of center. I had to peel back the cote and fill it with wood filler. It provides some strength over Hobby-lite, of which mine had dried out.

The bottom finished. I painted the forward attachment with black gloss enamel. I used black cote aft as I didn't want to waste the red.

Ran a piece of black tape across the front and back as a soft shim for better fit.

The top is nice and smooth, re-coted, and applied a new sticker.

I had checked the fit of the forward attachment several times as I rebuilt it. I wholly expect that when I go to put it on, it will not fit and snap clean off... we'll see. Waiting for that black paint to dry.

Toying with putting a stabilizer on it.

Looking forward to flying her again soon!

Life on the other side IS better...

I haven't flown the 30cc MXS-R for some time, and there was no reason not to today. Wow, was it beautiful.

Its late fall, and the sun is making it ever harder to see aircraft silhouettes to the south end of the fields at Joppa Hill. I had often toyed with the idea of flying from the far (west) side of the field, putting the afternoon sun behind me and the a/c. I had flown a couple of circuits from the usual side and decided to pack up and mosey on across to the other side. It actually is very much worth the trip!

The set up on the west side, looking south, the sun is off pic to the right. You can see the famously clumpy grass that rips landing gear  from planes (and I expect, ankles form kids). Used the post to hold the plane back on a rope.

Looking back across the field to the east side.

You can see how deep in the grass the big 30cc gets, so you can imagine how high the grass is on the smaller planes. Little electrics have a bit of trouble here. Those are 4" tires! I can imagine how sweet a geo-tex runway would be here.

The tarmac.

Flew several tanks. She of course flew very, very well.  Upped the aileron differential to 40%. I had been planning on putting a stabilization system on her, but I would lose my flaperons and things like differential, so meh. Decided not to. She is a very stable flyer, though she does have some elevator differential I need to tune out.

I think I will make the trip across the field to fly every time I come out here. I liked having a better view of the plane, and the sight lines are better. I seemed to be able to see where she was in relation to the Ents at either end much better, and since she wasn't flying over the eastern forest, I didn't have them to worry about either. I do have to be careful not to overfly the road or the lot if there are people or vehicles there. I do still have to be aware of the goals... almost nailed one again today but for luck.

Ooooh... New Shiny!

The bullet spinner I bought for the Waco was ginormous... too big, but pretty. It is a 2: spinner across the broad base. I bought a Tru-Turn 1-1/4" (1-3/8" across the base) bullet spinner, and its perfect.

The larger 2" one and the Ttu-Turn 1-1/4" spinner.

Much nicer fit and look!

Tactic Servo Spline Mystery

Now its just annoying.

I built and flew the HK Sbach 1200 EPP with a hodgepodge of various micro servos from EXI and Solar, and they worked quite well together. My OCD wanted the servos to all be of the same make, so I bought a set of Tactic TSX-10 micro servos. High speed, metal gears. Nice servos.

The arms were just long enough, but they tapered at the end, so when I drilled holes big enough for the control arms there was so little plastic left I did not want to use them. I thought,"Meh... I can order some longer ones on line." So I went in search of the spline. Most of what I read was consistent. Tactic, seemingly a Futaba servo, used Futaba splines. Ok. So I ordered some Dubro Futaba Micro Control Arms, and they were too small. Maybe they meant the Standard 24T spline. Nope, don't fit, too big. Okay... Maybe they used the Mini Spline? Hmm... nope, they don't fit either.

Nobody lists the spline, not Tactic, Hobbico, Servo City, Servo Database... no one. I got the info from RC Groups and other forums, that they use the equivalent sized Futaba Spline, but that doesn't seem to be the case.

I have an email out to Hobbico. We'll see. So for now, I can't fly the Sbach.

Damn OCD.

Wing came off clean at least...

I am resisting putting a 3-axis stabilization system on the Big Stick, in part because there is really not a place for it, its a very stable flier, and I like having some planes without it. But today made me rethink that.

Took her up for a flight, and on the first landing a brisk wind, about a foot off the ground, the left wing dipped suddenly, struck softly and came right off. Clean. Off. No damage to the fuse, which humorously continued along on its way for about 30 more feet. The wing did split along the center seam on the underside, pulled the fuselage wing attachment block off cleanly, and broke off the leading edge tip that secures it to the fuse, but there is no other damage to the wing or the servos. It yanked the servo wires out of the receiver, and tossed the receiver* from the fuselage breaking off the side of the receiver next to the plugs. The wires all survived, nothing parted or pulled out from the servos, all the servos work and the receiver works. Basically, wing only. It is easily fixed, but I want to also make the seam stronger.

*I noticed the receiver was missing when I got home and was looking to plug the wires back in and it wasn't there. I drove back to the field and found it half way between where the wing had landed and where the fuse ended up.

That's the wing block attachment dangling from the back of the wing. The aileron servo wire extensions were pulled right from the receiver.

You can see the plastic end of the receiver is gone. It works fine.

Drill and battery pack is my favorite workshop weight. I gapped the crack and packed it with epoxy.

After laying down the fiberglass. Underside where the crack between the halves is. I epoxied the halves back together by opening the gap on the bottom, let that dry an hour or two with the weight on it, then laid three layers of fiberglass and epoxy thinned with alcohol out 1 inch out either side from center.

A little over 1 inch wide on the topside. I can't say how far down toward the top of the wing the split between the wing halves might have gone, so I decided to lay 2 layers of fiberglass on the top too. I have a couple of days at work, so I can let it completely dry. I will sand them down smooth and re-cote or paint them on Wednesday.

And with that I reset the Crash Clock.

And I am okay with that...