It wasn't me, it was bad cote...

Recall I could not get the cote to shrink. It would just melt and wrinkle up. After several attempts I gave up. I asked John Hayes to help me figure out what was wrong.

I spent a couple of hours with John Hayes at his shop this afternoon. I had so much trouble with the cote work on the cubby, and now on the PT-19, that I asked him to teach me his technique. Turns out it was the cote, and not my technique. He had the same problems with it melting instead of adhering and shrinking properly. He brought out some of his stock and it went perfectly, and quickly. Good as new This is the large patch on the top  He uses a heat gun with a flat focus diffuser instead of an iron on the compound curve. Made short work of it. Incidentally, John gifted me a Top Flite mini-iron for the smaller areas of cote work.

The smaller repair on the underside.

 

I repaired the rondel!

All up and ready to fly!

It's like golf....

 I loved golf. But I hated sucking so bad at it and not getting better that I gave it up.

There was a deceptive break in the weather.

I decided to try Joppa Hill Field, infamous in my flying history for ripping the landing gear off my planes. Per usual, while cut, the grass was still too high. I tried a few times. I finally walked around and found a closer cut section, and took off. 

The Alpha Sport felt a bit under powered, an the gusts were once again a bit more than it could handle. 

In a turn it got pushed stalled and I recovered by so close to the ground it was a hard forced landing 

And the gear dot torn off 

One flight. 

Hated every moment of it.

And hated the hobby as I carried it off, for  no other reason than it sucked today, my decisions sucked, the consequences of my decisions sucked, and I sucked.

Well.... Enough of that. I drove home mad and went straight to the garage workshop to repair the landing gear.

The front gear just stripped out the screws. A bit of epoxy, screwed back on, front gear done in 10 minutes. I started the main gear repair just using weight but decided to remove the wing and use clamps.

Main gear simple, clean break by design. Epoxy the edges to allow breakaway.

Clamped.

Done, good as newish. Checked everything and the motor is sound, no bent parts. I e decided I am only going to fly at the field, as inconvenient as it is to get there. It's just not worth the stress of wondering if the fields are going to break a plane. And I need to wait for the weather with more patience for the lighter planes. 

Continuing my struggle to get cote skills. It's curious that I have done cote all these years for patches without issue, but this cote on the PT-19 and the Cubby is soft.

I spent the better part of the afternoon applying, removing, applying, removing, several times, cotte over this wing. I expected the compound curve to be difficult, but I could not get this cote to stretch and adhere. I could get a clean sheet attached to the straight parts, but the moment I went to shrink it with the iron or heat gun, it wouldn't shrink properly and the edges melted into wrinkles. I tried a long sheet including the compound curve, and two 

Separate sections, one clean rectangle and one to stretch around the curve. It was made more difficult in that I can't get the landing gear off.

After multiple attempts over several hours I have quit, and wrote my friend John Hayes who repaired the Alpha Sport wing. I asked him to help me repair this by teaching me how. I asked him if he's free this weekend as I have three days off.

I stopped, left the garage. I wanted to try the HK500, but no suitable place for a hover test, and I had had enough humiliation and failure.

I REALLLLY need a successful day of flying, or this will go the way golf went. Hopefully this weekend, weather permitting.

The Good and The Ugly

 8 hrs in the garage like it didn't even happen ... Memorial Day weekend, weather is for shit with much needed rain.

I replaced the motor in the Alpha Sport 450, proving that it is a bent shaft, though not visibly discernable. There is no wobble at all now, everything is clean and straight. My OCD is happy.

I will change the shaft on those other two 450 motors when they get here in a couple of weeks. 

I replaced the Viton tubing in the tank of the Ultrastick with Sullivan Proflex fluorosilicone, and it had the desired effect. It's short so the Viton didn't flex enough to reach the floor of the tank, but the Proflex is soft and works wonderfully. Ran the engine up to make sure the plumbing works, and it runs just fine. Looking forward to the maiden.

I spent a couple of hours reprogramming the BeastX Microbeast on the HK500cmt (forgot to take pics). The other day I spun it up and something was clearly wrong with the setup (I haven't flown it in years).  I lost the manual a while ago, and the only one online is for the PLUS, but the programming was the same. I only did the main setup and not the parameters, as I am not familiar with that second menu but will be reading up on it. The swash was off a tish, and the control rods needed a lot of levelling. Not sure what was up with that. It seems all set to go, but with the rain I didn't try a hover.

I decided to finish the repair to the left leading edge my wife had crushed by accident a long time ago. Once again my lamentable understanding of applying cote plagued me as I tried to get a simple patch on the upper and lower wing done properly. I could get it in place easily enough, but I could not get it to shrink properly. The edges melt before the center shrinks at all. Redid it several times and finally settled. Had the same problem with the cote on the Cubby. Tried lower temps, higher temps, none of the advertised temps of different cotes worked. On the Cubby the cote shrank but the edges melt-wrinkled. Here the shrink just would not happen completely with either the iron or the heat gun. I need to figure this out... I think it's the next favor I need to ask of John Hayes, who repaired the wing on the Alpha Sport 450; teach elme how to do the repairs.

Interesting thing on the electronics in the PT-19, another plane I haven't flown in a while. It has an intact ESC lead to the throttle, but it also has an IBEC or a UBEC (can't tell). I don't know why... Why doesn't the ESC leads power line just provide the power. I decided to remove the IBEC when I changed out the EC5 connector for the EC3 I have been using in my 3S batteries. Plugged in the battery and the motor chimed in, but the receiver didn't do anything. Nada. Huh... So I wired a UBEC in off the battery leads, plugged it into the AR650 battery slot, and voila! Checked the installed gyro stabilization system, and it's fine. All up. So, ugly wing repair, but the PT-19 is ready to fly.

I really want to fly. Its supposed to stop raining tomorrow afternoon. Everything is going to be soaked, but its worth a try. I want to check out Joppa Hill Field, where I used to fly when I lived nearby in Bedford, but the grass is usually too tall and clumpy. Depending on the sitch I may drive all the way out to the field in Derry.

All set for the crying! I mean, flying!

Nailed the CG with no adjustments! Came in a 7.7 lbs dry, much better than the 10 lbs of versions 1 and 2 that had the tail servos in the tail, requiring a lb of lead up front, and weighing in at 10lbs. I am optimistic this one is a keeper.

I kept referring to the Evo 10cc as a "single needle carb, but I had forgotten that there is the obvious HI sped needle on the port side, and the low speed needle is tucked into the center of the carb vent barrel on the starboard side. I rediscovered this last night as I kept wondering why the manual refers to both needle settings. I saw the engine diagram and slapped my forehead (not really, I was in bed and I sat up). I had forgotten all about it.

Today I set the HI at 2.5 turns, ended up tweaking it once to about 2-1/4. It screams with the 11x6 Master Airscrew Scimitar prop. Keeping the throttle at about 1.5 mm open at idle, I tweaked the low speed needle leaner, no idea where it ended up, and I found this to be the best I can get. Clean initial slam with a small stumble just before peak rpm, quite acceptable. Reliable and no thrust generating idle, and a screaming full throttle.

I am pretty sure that the recent crash of the Alpha Sport 450 bent the engine shaft almost imperceptibly, enough you can see a wobble, not enough to affect performance. I decided this needs perfecting. And therein lies my latest frustration with this hobby: finding parts. Why is this so fucking hard?

It has an aluminum nose cone that can with a 4mm to 8mm prop adapter with a threaded center hole for the M3 screw that secures the nose cone. China doesn't even sell these. I have to buy a whole new nose cone, about $20 on Amazon, with its own adapter. I could use a 4mm to 6mm adapter and a spinner nut that has the same M3 hole, but none of the 4/6 adapters tell you how long they are. I need 30mm. I bought 6 4/6 adapters on Amazon, the same ones that you see everywhere, and they are 25mm long, so they can't accommodate a base plate for the nose cone. I hate the bullet ends these come with, suitable for drones and tiny planes, but not on a 450 size. Doesn't matter for now, the current nose cone adapter is not bent, but it annoys me I can't have spares.

Okay, moving on. Replacing the 4mm x 49mm c-clip end electric motor shaft on this DY2836 electric motor (same as I need to replace on the original motor). Not in America you don't. Took some looking and on Walmart, selling for a Chinese vendor, I found 4mmx50mm c-clip end shafts at a reasonable price, but they are still two weeks out from arriving. I ain't got time for that, but they are on there way, and I need two now 

So I did what every RC addicted boy does and just ordered another DY2836 880kv motor from Amazon and it will be here tomorrow. 

Look, I just want to get this thing flying right, get my thumbs retrained, get used to the field, improve my confidence, so I can maiden the Ultrastick. I am confident in that I wasn't the cause of the last crash, and I managed a lot of crazy attitudes in the bad winds before that crash. But I want some clean flights under my thumbs before then. Matching up weather and my days off hasn't been in the favor of flying, which is probably why I chose poorly to try to fly in those winds last Sunday, but I am sure that day will come, hopefully with no one else at the field (I hate an audience).

OH, BTW: THE engine has a bit of low end resolution, but once the throttle gets to 50% it's pretty much screaming at full throttle. I tried a Throttle curve and it worked nicely to smooth the power curve. I may lower it in the mids a bit more.

All done but the crashing....

The Hangar nine Ultrastick Number 3 is done. I just need to verify the all up dry weight, goal is 7lbs, and check the throws on the ailerons and flaps, and check CG. I want to get some real thumb time on other planes as I really haven't flown anything this season, before the maiden.

It went as well as expected

Two clues before I even brought out the planes. There was only one guy there at 11a on a beautiful Sunday.And he left right after I got there and saw him struggle to land a foamie Cessna. The wind was dead calm, except when it wasn't when a sudden gust would pop up. 

First flight: Did I get the CG wrong because it flew tail heavy as fuck. Trims were all off. Where is that sudden wind coming from?? Barely got it down. Made some adjustments and found that the elevator trim was elevator up, not where I had put it when I reset up the airplane... Put the battery where it used to go, making it a bit nose heavy. Third flight, much better balance, trimmed up nicely but here came the gust and it just threw it into the ditch in the middle of the field as I was trying to get it back to the runway.

Butchers bill: tore off the nose gear taking with it the balsa sheeting under the fuse between it and the battery compartment, broke the prop and lightly bent the prop shaft (dammit). Damaged the firewall. 

The field really needs to be levelled, the Geotex is bumpy and barely useable. The flyable space is too narrow for my comfort as I fought the sudden gusts. I won't be able to comfortably fly the 26 and 30cc planes there, I fear. But it will have to do for this year. My son is at the NH Renaissance Faire today, and I see that it's on the same road as the Fremont Flyers field. I looked at it on Google maps and it is a wide and clear space, they even fly turbine jets there ... Their club fee is $40 less for a better field. It's 45 min away though... I will need to consider it next year if SNHRCC still doesn't have a field.

Ultrastick 10cc Almost Ready

It's kinda tight In there. The LiFe 2100 mAh 2S receiver pack turned out to be a smidge too big to fit in the well behind the tank over the landing gear, but it fit below the wing and is clear of the throttle servo. I made a shelf of thick closed cell foam CAd to the bottom of the battery and snap-lock velcroed to half that shelf behind the landing gear well,  and used a glue gun along the edge of the fuselage. It's secure and accessible. The leads are clear, the two loose ones are the ailerons and flaps. Going to be delicate closing up with the wing I place and the long wing leads.

Just a quick video of the 10 cc running with the Master Airscrew Scimitar 11x6. I don't have a lot of experience tuning these small 10cc single needle engines. Not a fan as it's hard to find the sweet spot between a nice safe and consistent idle, and a max full throttle setting. 

All that's left is to set the wing up, find and adjust CG and get a final weight. Without the wing it's at about 5.8 lbs. Designed all up dry weight is 7lbs.

Hoping to finally get to the Flying Tigers field today. I don't enjoy flying with an audience, so hope it's not crowded.