Txmustangflyer

I would love...love to put the filler dot in the scale fuselage tank fill cap location just aft and below the radio shelf..no access. A 2 yr old couldn't wiggle a hand down there.
Options: Surgery (done enough of that already, thank you.)
Or...the chin hatch just behind the firewall. I had thought on putting the vent fitting there anyway with enough line so removing the hatch to get access to ignition and battery wouldn't be an issue. Putting the fuel dot there, again, with enough line to fill..not an issue.
I could also do underside of center wing on both..out of sight, but accessible...
Then theres the ignition switch...
Manual wants me to string a foot of wire from ignition battery, alllll the way back to the cockpit wall just in front of the panel, to a wood piece they prebuilt..then allll the way back to the ignition...

ermmm...no..but, I don't want it staring you in the face, eye to eye at ten feet either.....I have a remote kill, but the instructions were in German...I may have to go shopping lol.

Txmustangflyer

Oh yeah..forgot to post this. First time on all her shoes!



Still a punchlist of stuff to do. Servo extensions to the tail, center wing extensions, hole for the gear door servos is cut, but tray not mounted yet..slots for that linkage needs cut in wheel wells planning easiest and best way to do that) paint the gear wells same as firewall. Touch up the firewall (one small adjustment needed near carb. Needles hitting firewall..it will be alleviated some when spaced properly with spinner back plate but virbration is a b%$#@ so no chances)
And, of course the back ordered parts. May end up being all finished but the canopy which would suck...royally.)
I should be able to, at least get an idea of cg and final weight..with changes, modifications, etc, I think I'm going to be close to 32 lbs..Be really surprised if I'm not. The zenoah, despite the diet it was put on, is still a heavy engine, especially with the plate steel mount. Believe it or not, moving the fuselage, it feels a touch nose heavy..

Phil at fighteraces was kind enough to shoot me a picture of the spinner, in progress.

The cone, awaiting its machined back plate, notching and mounting..Perty

Txmustangflyer

Finally got an answer from E-flite that makes sense.

If you are using e-flite retracts and need this info because you are using a different controller. Heres the numbers for setting it up.

From E-flite: Both of those (EFLG700 & EFLG75190) can only operate between 6-8.4V and Current draw Idle: 10mA | Operating: 500–700mA | Full Stall: 0.8–1.0A

meaning max amp cut off in a Xicoy LG15, or other controller needs set at 800 miliamps to 1000 mili-amps
Normal operating load 700 mili-amps.

those settings will prevent burning out the actuator motors.

When I get back on the plane near end of April, I'll show, by screen, the LG15 setup for them. Pretty straight forward.

Txmustangflyer

So, I changed out all the servo arms ..most are same length as normal, for aluminum ones. A little less sloppy.

The only ones I did differently were the flaps. With the intended arms, the linkage hit the servo cov

er. I had 2 options. Cut the slot a little bigger or use a longer arm. I chose longer arm.

This is the Long arm. I have some that are shorter and not quite as long. Not liking the geometry on this one so will either have to shorten the flap horn, or try the other aluminum arms. Shorter would give more servo throw, while still keeping the lingage just off the skin. Yes, flap horn is in backwards, it has been corrected since this picture.

Txmustangflyer

The issue with the tank...well..its kind of a non issue if I slip it aft about an inch..

The notch for the carb. I could offset the tank to one side, but that would mess with the lateral balance, so its going to have to shift aft. I was puzzling at that last time home. Still tossing it around in my head, but, I'll come up with something.

I did muck about on electronics install some.



Yet, it may change again lol.

Txmustangflyer

So as I am back on the road for work, and all thats left on the mustang is basically ironing out kinks, final setup of linkages, and the wiring. I think its time to do a bit of a review of the assembly side of this plane.

Yes, I ran into some self created issues, thats not what I'm looking to address here, but manufacturing issues. Key word: manufacturing

The design of this ARF, had they manufactured EVERYTHING to the design, would have been near flawless.
However, Tower/Horizob/H9 did their own design, then contracted a manufacturer (Seagull) to kit it. Seagull took it upon themselves, without aproval from H9 to alter certain aspects of the design, this becomes apparent in the stab structure where, instead of mounting blocks, you are supposed to drill a rib and set if doublers as the mounting "block" and the size of hole needed is as wide as the rib, efectively weakening the rib and structure of the stab. I firmly believe a solid hardwood block was to be made to fit over the wing tube liner next to that rib, instead.
Another area where just pure lack of QC and lack if care becomes apparent that I, luckily, didn't have to deal with too much was the main wing sections in the main tube fitment and alignment tabs. Many reported that the tabs would twist the right wing as much as a quarter inch out of alignment to the center wing. Mainly comes from the tab sitting cockeyed in the jig.
I did have to deal with the burrs from press cutting the ply main wing ribs as well as a tube liner that was extremely tight, Many resolved that by sanding the liner. I did that, and machine polished the tube as well, removing a number of tiny bits of aluminum on the surface almost like individual grains if sand. That helped a LOT.
Brittle wood: meaning wood so dry that any bit of handling just to fit the parts resulted in cracked parts. Mainly the canopy frame. Also unclear in the manual is that the slide rail for the rear of the frame has a step in it. Its not a straight channel.

Unable to get replacement parts: I have pieces on back order.
Also, e-flite discontinuing the programmer for their retracts (part number eflg-1000) is a huge alert that the demise of the current H9 60 cc mustang may happen in the very near future unless E-flite is fielding a new programmer/controller setup. So, if you buy this aircraft and the matching eflite retracts, treat that programmer like its solid gold. You can't replace it, and I'm not sure e-flite would have whats needed to repair it either. My advice, buy the retracts without the controller, and get a compatable sequencer setup. The specs for the actuators are in this thread.

Remember, if it looks or feels questionable, resolve it until you are satisfied with your aircraft. You'll note that I did not do much on the outside of it. That will come after a flying season or two, and thats kinda by design..fly it and have fun. Its not an exact to scale mustang. Its a good copy, but not a carbon copy.
Will it look nice glassed, flite metaled and paneled. Sure, and to most, it will look scale..but not to a perfectionist....or a competition judge.
It will turn heads. A lot of them.
On a scale of 1-10..it gets around a 6.5 to a 7. There are problems that shouldn't exist. A builder's arf means yeah, some modification might be needed to a firewall to fit a particular engine, installing control horns, doing some hinges, etc. All that is part of building this plane. It does not mean having to cut open a perfect looking stab to put mounting blocks in that should have been there to start with. Or parts snapping because you picked it up off a table to test fit.

H9 needs more QC on the assembly line and hold Seagull accountable for every kit that does not meet spec. Every wing alignment issue, missing mounting block, or bad glue joint. Will that happen? Probably not.

Futterama

Hi, can you share some pictures that could explain better the assembly problems you have had? English is not my native language and I'm having trouble following our explanation regarding "stab structure". Is that the horizontal stabilizer you are talking about?

I have this model myself and the wing fit is very tight, partly due to a poor quality aluminium tube. I have not assembled the model yet. I'm playing with the idea of ripping the ARF apart and trace all the wood parts into a CAD program and then treat is as a kit with plans or whatever you would call it, cutting new wood parts on a CNC router with modifications to the "stupid" mistakes made by the manufacturer.

Txmustangflyer

Yes, the horizontal stabilizer

Txmustangflyer

You won't need to go that far. A dowel with some 400 grit wrapped around it fixes the fit. Polish the tubes with a good aluminum polish, get them as smooth as you can. Its not the tube that causes the problem, but the press cutting of the ribs, it leaves a burr. Just get the ribs flush and it will stay snug but slide home.
But, for sure, check your horizontal stabs.

Beyond smoothing the covering, the mounting blocks, and sanding the burr off the wing ribs, not much of an issue. Just remember there is a "step" in the canopy slide rail for the rear canopy frame tab. It will slide aboyt an inch, then you have to lift up, slightly, for it to slide the rest of the way forward. Don't force it.

Make sure your horns for the wings point towards the tail.
Overall, the structure is good, if the factory followed the design. Just make sure they didn't skip anything. I have yet to find a bad glue joint.
The rest of my "assembly" issues were because of engine modifications done and were somewhat planned for.

Txmustangflyer

Houston, we may have a problem...

Hot Rod Todd

My Feedback: (1)

There is a limit to how much pitch that engine will pull on a 4-blade prop with that diameter. I believe you have a G62. Most warbirds run a 22X10 two blade on those. It would be lucky to pull a 21X10 three blade. Even smaller with 4 blades. It may be difficult to pull enough pitch on 23.6" to get much speed. I know it wouldn't pull 23.6 X 8. There's also a lot of inefficiency in a 4 blade when you turn much RPM since you get cavitation between the blades. You loose a lot going from a 2 blade to a 3 blade, even worse with a 4 blade. Good luck with it. Many have tried, few have achieved the results they would like.
The last thing you have to worry about is going too fast.

Txmustangflyer

You would be correct on prop size and blades of it were a bone stock G62, Todd. .
mine spun a 23x8 xoar at 7800 because its not stock. The modifications have been posted previously in this thread.
The goal was a half hp gain. The modifications actually netted a 1 hp gain because we took almost a pound and a half of mass off the crank and we didn't account for it. The stock flywheel is just shy of a lb on its own. Shaving the spring starter tail shaft was another 7 oz. Its not losing as much power trying to get and keep the crank shaft turning.
We forgot to account for that when we set the timing.
That was changed from 9 degrees before tdc to 15 degrees before tdc in addition to reducing the squash with a slightly longer connecting rod and thinner cylinder gasket.
For simply the sake of demonstrating how much of the effective stroke is being used now. At tdc compression is 16:1
at point of spark its 15:1
a stock zenoah g62 at point of spark has a compression just over 9:1.
the timing and squash mods we figure netted what we wanted by themselves. The decisions I made to save nose weight and for reliability, and to be ablr to use frsky telemetry, actually netted the rest due to less parasitic power loss.
The less mass the piston shoves, the easier it rotates. Add in the better, smoother turning bearings...less drag. The stock bearings were..notchy is best I can describe it..the new bearings contain more ball bearings and run smoother. It doesn't fell like you are turning a ratchet wrench..and moves freely. Power-wise, that doesn't mean much.

Now, for the ending of this near heart attack...Christian also misunderstood which prop. He hasn't lessened the uh oh part. I still may have a 130 mph race P51 on my hands..

Hot Rod Todd

My Feedback: (1)

I know those modified G62's will rev up quite high, providing some impressive power (I didn't see all the mods you did). The problem is they typically make that power mostly due to the RPM they turn. When you get into props with more than two blades RPM becomes the enemy, since the blades are too close and interfere with each other at high RPM. I would imagine you could use all of the power with a two blade, but trying to get that RPM out of a 4 blade could result in issues as they blades cavitate off of each other. Not many go though the effort, so if you're willing to keep trying you may find a combination that works well enough. Since you're likely to end up with a fairly low pitch number it may be difficult to keep the RPM within the limit of the prop, especially as you unload in flight.
I have a three blade on my TopRC Corsair, but I know from experience that a 120 with a 26X12 is way more than I need. I'm sure it will fly great with a 3-blade 25X12 (just like I use on My 1/4 scale LA-7).
Looking forward to see how it goes. I'm hoping the DLE-65 and a 23x10 2-blade pulls my P-51 around with good authority.

Txmustangflyer

Again, you would be right...I figure at the varioprop (the one I have) max is 6400 rpm..that the power output is probably right around 6.5 to 6.6..Its not the horsepower, though, but the torque that matters when spinning a propeller. The horsepower is kind of a side effect and I'm not sure how to figure the torque. The one thing we've done to try to "target 6000 to 7000 rpm range was an intake with a longer intake runner..Typically, its something done on a car to improve torque...I'm not sure if, or how well, it will do that on the Zenoah.
I, also, had to still make it fit..


The intake is around twice the length of the stock intake, but it does bend 90 degrees so I'm not sure how much of an affect its having on the torque, midrange. I have to guess its doing what I hoped based on the xoar test.
Thing is..we kinda overdid it, I think. If we had simoly just converted to cdi, shaved the tail shaft, and added the intake, it probably would have been enough to turn the vario, respectably...not at the prop's 6400 max, probably, but close enough with 8 inches of pitch..
But, as I said, we didn't take the reduction of parasitic loss in to account at all, instead, relying on the internal modifications and timing to get us there...that was the oops.
As a perspectove, I've heard the older Kolm 65 cc put out 7 hp at around 7500 rpm...
My zenoah is hitting 7.2 at 8000. Didn't mean for it to, but, cost wise...I'm still in the zenoah around 500 less than kolm's price for an EZ77. (Advertised as same dimensions as the EZ65)

Heatwise: these telemetry readings were on an engine stand, not in the cowl. Warmed up, at half throttle-ish) 220 degrees at the plug (CHT)
and 180 degrees at the intake bolt. Not too shabby after running at around 3800 rpm for 4 minutes or so. After the WOT test it only climbed ten degrees.

Hot Rod Todd

My Feedback: (1)

Had a bit of nice weather over the weekend, so I was able to get a maiden flight on the P-51. Conditions were nice, maybe 55 degrees with little wind. It’s always nice when you can run a new engine on a cool day since they tend to get a bit hot until they get some time on them. I ran the DLE-65 three times before the first flight. It started up and ran perfect, transitioned well. Turned the Xoar 23X10 prop at about 6350 RPM.

The takeoff roll was uneventful. It seemed like it didn’t want to lift off, but that’s not so bad as I was building up more speed. Once I did take off I noticed I needed quite a bit of up trim which explained why it wanted to stay on the ground. Ailerons were perfect, not one click of trim needed. I started to get the feel of the plane flying around at about half throttle. It tracks nicely and felt good. Medium rate aileron felt slow to me and didn’t have the roll rate I like. I bumped it to high rate and did another roll and found it to be better, but I’ll likely bump it up a bit more than that. Elevator didn’t feel too bad on medium rate, maybe just a touch more throw would be to my liking. I didn’t do a stall test because the engine only had a few minutes time on it. The DLE-65 pulls it around fast even at half throttle, and really burns up the pattern wide open. I’m happy with the engine match as it has plenty of power and speed for this airframe. The sound going by on a high speed pass is quite rewarding. I burned off about 7 min. of fuel and decided to setup for the landing. I dropped the gear and went to full flaps. They don’t seem to have a lot of effect; I think I’d like to try to get more flap to help add some drag on landing. I came in a bit fast but didn’t bounce at all on the landing and was able to slow down without any problem. It will slow a bit better once I get the engine broke in and the idle lower I’m sure.

Some issues I found. We noticed the wing had a slight amount of movement that I hadn’t seen before. It turns out the wing bolts are just a bit long and run out of threads. I added some washers for the quick fix and it pulled the wing in tighter. I did a second flight right away, but didn’t stay up long because I heard some noise. Turns out the engine mounting bolts had loosened up. The firewall is a bit soft, and as it compresses the wood the bolts come loose. I got some fender washers to help spread the load from the stand-offs, and I’ll put some lock nuts in the back of the blind nuts to lock them in better. Even so, I imagine I’ll have to re-tighten it every few flights until the wood compresses fully. Luckily the loose engine didn’t destroy the cowl or anything.
Everything considered I’m very happy with it. I didn’t think I’d be satisfied with the power of a 55, so I went a bit bigger using the new DLE-65. I’m very happy with the selection and the way the new engine runs. I’d say it is smoother than the DLE-61 I had, not much different than a 55 in that regard. The landing gear and doors worked perfectly (so far). I didn’t get any video, but my buddy took some photos.

BarracudaHockey

My Feedback: (11)

Looks great!

Txmustangflyer

Congrats todd!

Txmustangflyer

Todd, How well did yours flare on landing, Were you able to get a nose high attitude?

If so..did you cg per the instructs or set it rearward a touch?

BarracudaHockey

My Feedback: (11)

You don't flare it, you come in level, let the mains touch, let it slow down till the tail falls, try to do anything too soon and you will have a handful

Like every Hangar 9 manual, the CG is conservative, you can start there but you will be nose heavy, don't be afraid to start near or at their rear most recommendation

Hot Rod Todd

My Feedback: (1)

I didn't really need to flare it much. It seemed to like touching on the mains, then the tail would drop as soon as I pulled up the flaps. I think I'm right on the recommended CG and it felt OK (6 3/4" I believe). I landed with quite a bit of fuel and it wasn't too nose heavy on landing (I have a 32 oz. tank, so I'll usually land with some fuel). I came in a bit faster than normal though. Once I slow up a bit more I'll find out if I need to move the CG back a bit to get some elevator authority on landing. Most likely it will stay where it's at. I'll know more as I get the rates adjusted and get some more flight time.

DGrant

My Feedback: (4)

Very nice Mustang Todd! Congratulations on the maiden flight! Looks like you'll enjoy it for years to come!

Txmustangflyer

Keep me posted, I'll use yours as a guide line. I've tried placement of the included tank and a two tank setup (carb notch) the two tank is 36 oz total. I think the included tank is 32..ish?


When it comes to fitting, I could use either setup. But for space for throttle and choke linkages, I'm probably going to end up using the included tank. I don't think I'll miss the 4 oz of fuel. Ten minute flight times shouldn't be a problem, you've got bigger displacement and on the test stand the zenoah doesn't seem to be super thirsty. Not running the flying exhaust yet, though and the B&B is probably pretty restrictive. That hurts the fuel consumption some.

DGrant

My Feedback: (4)

A gas engine in the 50cc-60cc range can run more than 20 minutes on a 24oz tank. I have 32oz tanks in my 100cc twin cylinder giants and use barely half of it in 15 minutes of IMAC sequences. I have 24 oz tanks in my 50cc planes and same thing. My 170cc twin takes a bit more though(64oz tank).
Just sayin'. Carrying an extra 8oz's or more of fuel that will never be used is quite heavy.

Txmustangflyer

Todd can confirm, but the tank that came with the airframe is bigger than 24.

Hot Rod Todd

My Feedback: (1)

Fuel capacity depends a lot on what you're doing. Big difference between aerobatic planes and warbirds. I have an extra with a 55cc engine, and 16 oz. is plenty. Mostly due to the light weight of the plane and the low throttle that is needed to fly it. It seldom needs over half throttle, unless you put it into a hover. Most warbirds are much heavier, and get ran at higher throttle settings. My 55cc warbirds all have 24oz. tanks. That gives about 8 min. with a couple min. of backup. If you go to big flying events you usually like a bit more backup fuel on board. It often happens that you have to extend your flight because of some incident on the runway or a backup of landings and takeoffs. For my Warbirds (fighters) I run 24 oz. for the 55cc, 32 oz. for 65-70cc. and 40 oz. for my over 100cc engines.
I think the stock tank is about 30 oz., but I'm always afraid to use stock ARF tanks because the seams often split.