Hanger 9 1/5th scale Mustang.

[Txmustangflyer]

The wife only gets a breakfast stand to build her airplane?

On the Stang flaps, I have some concerns. Is the hook up per the plans? Do the plans go into linkage detail? I see what looks like a linkage geometry that limits the downward motion of the flap (3 pivots in a line). I also see that it looks like you are only using about 30% of the servo travel.

If the manual doesn’t go into linkage details I might be able to draw up a cartoon that covers some of areas of concern.

It' about 76 degrees of travel on yhe flap. Full motion, hitting the flap's limit. Its limited in travel be the wing/hinge area.
Its installed per the manual, but defection isn't set yet. Max is 72 degrees per manual. I may end up flipping the horns to face the other direction, haven't gotton that far yet, and I need to clean up the area between flap LE to wing TE..lots of loose/wrinkled covering there.

The issue I was running in to was the servo arms that were simply not long enough. Konrad, if you look at the pic with the plastic servo arm..yeah..huge issue..the aluminum arms I got from Wayne go a long way towards rectifying that. No, the servo won't be using much of its travel with the new arms, but, there also won't be interference between bottom of wing and the control rod. I had to stop work there as Bisson needs final measurements for exhaust so today has been a bit of a thrash on the firewall. Luckily, the mounting bolt's for the G-62's steel plate mount came in, I was able to get it drilled, now working on the recesses into firewall for the bolts from mounting plate, standoffs, to the engine. I have to have it mounted by tomorrow evening to be ready for that phone call.
After that, I'll move just aft of firewall and figure out which tank will be used, and start planning battery placement.
Then back to center wings, retracts and gear doors, then rx placement, direct underneath, wire tidying. Plumbing, slowly working aft till the last thing will be the tail wheel doors, springs, and tail wheel steering.
Don't worry, by the time I call it ready to fly, all linkages will be set up, at the right length, and moving properly.
My main concern for the moment, is getting the right servo arms for the job, and keep the surfaces from flopping around, possibly getting damaged.

Heres the to-do list:
1. Finish engine mounting, get throttle and choke linkages planed, cut, and temporarily in place.
2 Tank selection and plumbing in place. Drilled for, etc. Then Klass Kote.
3. Telemetry sensor mounting and and trial placement
4. Battery locations planned, battery trays planned. (Retracts will have a seperate 2s battery.
5. Rx location planned, tray mounted.
6. Retract door servos, doors, retract controller placement planned, tray made and mounted
7. Forward wire tidy, routing, and in place,
8. Final rudder pull pull set up and adjustment (has to be done here as once center wing is mounted, it has to be dismounted to access. Tail wheel, itself will also be mounted to set up tail wheel steering, then disconnected for tail wheel door install.
9. Horizontal stabilizer surgery to fix bad design. (See above)
10. Final assembly, loctite all.
11. Set throws using xicoy sensors. Finalize linkage lengths.
12, Balance with xicoy.
Lots left to do. Plodding along at the moment.

I need two more of the small, aluminum servo arms from aloft. (Retract door servos) the arms included, flex badly, and could cause the servos to jam agains the frame. The doors are a heavy composite layup...need rock solid servo arms.

 

[Txmustangflyer]

Work progression on engine bay. Touch ups will be required but first pass of Klass Kote completed. I'll have to recover the battery hatch..low tack pulled to ultrakote right off.

 

[Txmustangflyer]

Anyway, I'll figure out if that was paint or ultrakote. Someone on another forum said paint, so it may have to ba sanded down and some tamiya put on to bring it back.

Was able to shoe horn the engine in, get a nut on the one bolt I could reach with engine mounted to the steel mounting plate to get final exhaust measurements. That took some more adjusting to the carburetor notch to get everything to line up. The factory put as much as 4 degrees of left thrust in the firewall. Everything I've done to firewall was based on crank center as marked from the factory..mounted, that much angle on the firewall has hub off a half mm in cowl opening so some shimming is going to be needed to get the hub centered up in the cowl opening.
Thats the next job.

 

[Konrad]

It' about 76 degrees of travel on yhe flap. Full motion, hitting the flap's limit. Its limited in travel be the wing/hinge area.
Its installed per the manual, but defection isn't set yet. Max is 72 degrees per manual. I may end up flipping the horns to face the other direction, haven't gotton that far yet, and I need to clean up the area between flap LE to wing TE..lots of loose/wrinkled covering there.

The issue I was running in to was the servo arms that were simply not long enough. Konrad, if you look at the pic with the plastic servo arm..yeah..huge issue..the aluminum arms I got from Wayne go a long way towards rectifying that. No, the servo won't be using much of its travel with the new arms, but, there also won't be interference between bottom of wing and the control rod. …

From here, that white servo arm has much better mechanics! I don’t see any interference with the flap and control horn or push rod. (Are you concerned that the push rod may not go into the the slot )? With a smaller arm (the white plastic) the three point line (Locked linkage) will be pointing more towards the servo, allowing much more flap motion. Also a smaller servo arm will allow for much more servo rotation. If the clevis won’t go down the slot widen the slot. If the push rod hits the end of the slot lengthen the slot. Or try to flip the servo so the output is towards the LE, you may need to make a longer push rod. I see no reason that you can’t be using close to 100% servo motion. Can you move the servo closer to the bottom wing skin?

You want to use100% to 120% of the servo motion. This is particularly true of flaps as they have a high air load and for an extended time.

That looks like a paint failure rather than a film failure. Tamiya paints are great but very delicate. Please don’t use Tamiya paint near any fuel that contains alcohol. I do break the shine on my films when I paint. I like to use 400 grit.

 

[Txmustangflyer]

From here, that white servo arm has much better mechanics! I don’t see any interference with the flap and control horn or push rod. (Are you concerned that the push rod may not go into the the slot )? With a smaller arm (the white plastic) the three point line (Locked linkage) will be pointing more towards the servo, allowing much more flap motion. Also a smaller servo arm will allow for much more servo rotation. If the clevis won’t go down the slot widen the slot. If the push rod hits the end of the slot lengthen the slot. Or try to flip the servo so the output is towards the LE, you may need to make a longer push rod. I see no reason that you can’t be using close to 100% servo motion. Can you move the servo closer to the bottom wing skin?

You want to use100% to 120% of the servo motion. This is particularly true of flaps as they have a high air load and for an extended time.

That looks like a paint failure rather than a film failure. Tamiya paints are great but very delicate. Please don’t use Tamiya paint near any fuel that contains alcohol. I do break the shine on my films when I paint. I like to use 400 grit.

The arm on the white servo arm hits the skin of the wing at edge of slot. With the new arm, I'm going to change the mounting position on the horn. Haven't gotten there yet. But it will correct the linkage and no worry about interference.

This morning, back on the engine. Going to have to put two washers, one either side of stand offs and move engine a bit further from the firewall, but shes in.

 

[Txmustangflyer]

Surgery on the stabs went well.

Here is what I did. I opened the skins on bottom surface up arpund where the block is supposed to be.
The only thing coming close to resembling a block was the rib and doublers holding the fiberglass tube channel. You can see in one of the pictures I somehow managed to hit that when drilling earlier.

I put in two blocks per side, above and below the tube channel, the one above the channel stops any upward movement of the tube.
The bottom block was drilled and tube marked prior to closing up the stab and recovering.. I replaced the skin, not with balsa, but 1/16th ply as well for a bit more strength in the screw area.
End result..rock solid. No movement of the stab when pressure applied. Spar and formers would give first.
One last, easy issue to resolve with the port stab before I can move on. The stabs have 4 screws that mount the stab, the two I just fixed, and two that go through the antirotation tab.
The port tab's predrilled hole is off. To get a screw in there causes a good 1/8th inch gap between stab and fuselage at LE.
Not good enough so thats a quick project. The stab has blind nuts there, its a clamping force, so fixing it is a non issue, the screw will still get a good "bite" with an elongated hole.

The block is 3/4 inch by 1 and 1/4 inch top and bottom. All were epoxied in to place tying the stab skin, as well as the rib and spar to the blocks.

 

[Txmustangflyer]

Lots accomplished. Seems like I'm jumping around, but waiting on things that are back ordered, or ordered, to finish up things. Doing what I can, where I can.
Accomplished: Structural issues with horizontal stabilizers resolved, skin patched with 1/16th aircraft ply and recovered. Its not beautiful, but it will work until I get the energy to fully recover the plane this coming fall/winter.
I deep sixed H9's idea of rx and battery mounting. Too much weight forward. I've made a tray out of cf, installed mounting blocks into the fuselage and mounted the retract controller, reciever and reciever battery to it. Its removable with four screws for troubleshooting/servicing.
After trying three different fuel tanks, decided, in the end, to use the included fuel tank that came with the plane. Its around a 30 oz tank and will be plenty big enough. Waiting on straps to get it installed and plumbed. Figured out exact placement of ignition, battery, and telemetry box as well.
Need to find my "Y" harness for elevator servos. Run all the leads, install some wire control stuff in the fuselage, build an engine test stand to get the engine and prop tuned,
Finish up the gear doors and do final set up of the retracts.

Waiting for: Bisson exhaust, Spinner (back plate being made, cone finished)
Straps for tank and batteries (coming from Wayne and crew)

Nobody has either goldenrod or any double walled pushrods for throttle and choke linkage, not even the lhs, so the search goes on for those.

 

[Nigel]

Now that is what I call a radio battery. Bigger than what I use all-around on most of my planes. Electric start?

 

[Txmustangflyer]

Now that is what I call a radio battery. Bigger than what I use all-around on most of my planes. Electric start?

Nope, just all hv servos. 12 in total.
It was also, origionally, going to power retracts and retract controller (eflite) until that fried. The xicoy needs its own battery for retract power. Now, it just has to power the rx and the 12 servos.
Yup, its overkill but that battery should do 3-4 flights without charging easily.
30 oz of fuel means she'll be up for a minute.

All HV:
Throttle
Choke
Flaps x2
Ailerons x2
Elevators x2
Rudder
Main gear door servos still pull power from the rx battery x2
With the sr 10 gyro, possibly working them some at times as well..

So yeah..a lot going on.

The retracts also pull 8v so the eflite controller would have pulled from that battery as well. Two main, plus tail wheel retract.

The field she'll usually fly at doesn't have a permanent power source to my knowledge, either. So...that should give me enough juice for a nice day of flying whether there's a generator on hand or not. I have a 3s 850 and a 3s 1500 for the ignition. If she balances light in the nose as most of the H9's have, I'll swap the 850 for the 1500 and see if that helps. But, for sure, shes not going to be lacking on power lol. Personally, after having manhandled the fuselage I think shes going to be a touch nose heavy. That big battery, even just aft of cg will help a touch.

And electric start...I wish..If there was room..oh heck yes I would. The modified engine is a damn stiff flip.

 

[Txmustangflyer]

Phew...found some 2-56 golden-rods. Hopefully those will do until Wayne gets some double walled pushrods back in.

 

[Txmustangflyer]

So, a good rc friend has told me that gilden-rod expands and contracts with temperature changes. Me, personally, never had an issue, but, the guy has done commission builds down under for years.
I eas considering a run to the bike ship for a brake cable off a bycicle long enough to make some linkages, then Chris, the Mustang savior, popped me a pm and said he had a few of the Aloft listed double walled, flexible push rods at the house and hed sebd me a 36 inch..more than enough to do both linkages. In return, if ever we meet up, he gets a beer and some mustang stick time. (Before the beer, Chris, no drinkin and flyin. Doc would pull you over in a sail plane)
Back to the LG15...this thing is a technological wonder, if sorts.
Eflite controller, I'd have to continuously manually adjust the linkage lengths on the doirs till I was happy with how they closed...LG 15: set to length in manual and adjust servo throw in the menu..that saves...hours.
Single channel servo set up bypasses the need to have a set of brakes hooked up...I think. Waiting on confirmation on that...manual isn't exactly clear on that at all. It has built in sbus compatability with jeti, jr, and futaba...no mention of frsky...be nice. But non issue with the Mustang. Down the road...maybe an issue on a later plane, but that's for then. Maybe, by then frsky will have an sr12pro and negate that problem again if having more need fir channels with servo connections...not sure what plane that would be..but ya never know.
Overall, its a very capable gear controller, with a learning curve, a short one, but one nonetheless.

 

[Txmustangflyer]

So, as I sit in wisconsin at the moment, Been thinking on the flap linkage. Getting the arm up out of the wing solved one problem (the linkage hitting the wing skin at about 60 degrees)
Turning the horn would make that worse if the origional servo arm is used, and not solve the over-center on the arm.

The horn, now, has to be shortened. I'm thinking, by about a third. This means even less servo travel, but solves the over center and keeps the linkage away from the wing skin...
Final flap throw goal is full flaps at 72 degrees deflection with half at 36 degrees-ish. I also need the pivot point on the flap behind the hinge axis, not in front of it. That would throw the flap in greater proportion to the servo and not overcenter the linkage...I think.....

Option 2. I have a second set of aluminum arms like I used on the ailerons..shorter than whats there now, and I think, still long enough to keep the linkage off the skin. I had forgotten about those and remembered I had them around in case I flubbed up the slight modification to make them vlevis compatable. They have thick tips and are threaded for ball joints. I ground them down to uniform thickness for the ailerons. Worked a treat and the slop is way less.

I'll kinda mock up before modifying them just to see whats what.

 

[Konrad]

The primary concern should be to use a 100% of the servo’s motion. Maybe 80% if really boxed into a corner! This means a shorter servo arm, period. A shorter servo arm will allow your flap to get closer to 80° before reaching the 3 point lock up.

If need be flip the servo so the output is closer to the LE. Move the servo up or down in the wing. Place the control horn pivot aft of the hinge line (with the flap in the profile setting [up]). And the simple fix is lengthen the slot to clear the push rod. But whatever you do, please follow good solid mechanics! Flaps do put a load on servos, so give them a fighting chance.

 

[Txmustangflyer]

The problem is not a whole lot if meat to modify the slot.

 

[Konrad]

Flipping the servo to move the output to the LE should allow for a more oblique angle. Do you know how to use the cosine error between radial and linear motion (AKA, Differential or Ackerman Effect) to your advantage?

 

[Txmustangflyer]

Nope, just installed per the book. This is top of the list though. And, as always, there's the book way, and the way it should be. At times...they are mutually exclusive.

 

[Txmustangflyer]

Some good news. The new canopy frame will ship this week!

 

[Txmustangflyer]

More news, I have a "stand in" muffler coming while I wait on the bisson. I will, at least, be able to dial the engine in.

 

[Txmustangflyer]

Then I get this bit of a "wake up" and its kind of funny. Lets just say there was a slight bit of language barrier miscommoonicashun (miscommunication) goin on.

For a moment I thought I was gonna have a heart atrack..150 plus mph...I don't think the airframe was built for that kinda speed...

Luckily..he misunderstood which prop was used. Needless to say, Christian and I both had a good laugh.

 

[Txmustangflyer]

Spinner ships today..just leaves the exhaust...