w1nd6urfa

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Thanks Brad, Glazier808.

Now the bad news: I crashed it on the 4th flight when it snapped during a dive and wouldn't recover ...

In fact I did notice a strange behaviour earlier when at the end of a large loop (in the dive part again) it didn't exit the loop in the original direction but 90* to the left, I guess my brain didn't register this as potentially dangerous, went on to a cuban-8 which was fine and at the other end I started a reverse cuban-8. Everything ok to start with, 45* climb to good altitude, half-roll, then reduce throttle to let the nose drop to initiate the half loop, slight up-elev and ... WOW - ***!

Its repairable with a new cowl and some engine parts, but I am trying to figure out the cause so any help is welcome.

Some data & questions:
- Dry weight was 7.3 kg (16.2 lbs) with 300g nose weight, so with 3/4 full tank it would be around 7.7 kg, I will try to get rid of 0,5 kg in the rebuild
- CG at 95 mm (the previous owner insisted on this)
- Elevator travel was 20mm as per manual, is that too much?
- I flew it without strut covers, I guess that has an adverse effect on the wing lift - I will make a couple from 0.8mm alum before next re-maiden
- I also noticed that it is the old version with the 1-piece stab (no alum stab joiner). Is it possible that the stab was warping in-flight?

And a pic after the maiden:

Dave Bugz

To me 16.2lb seems heavy, mine comes in at 14lb. I changed the wooden dale pushrod for a carbon one, far less Flex. What servos are you using? If the problem occured exiting a dive it could be that either the servo was not "strong" enough to hold the elevator, the dale Flexed not allowing enough elevator.
Just a thought
Dave

w1nd6urfa

My Feedback: (4)

Hi Dave, thanks for your reply

14 lbs is my goal for the re-build, I will use lighter wheels and will move the batteries to balance without nose weight

Elevator pushrod: the previous owner is a very respected scratch builder, as you can see in the pics there was a piece of wood used as a guide at the front end, there could ofcourse be some flex at the other end?
I will also use carbon pushrod in the re-build

Servos are JR DS 589 digital, strong stuff

Still puzzled ...

Brad330l

My Feedback: (1)

hi w1nd6urfa, did you have to use full up elevator to complete your loop and cuban? It could be high speed snapping/stalling.
The lack of gear door would not effect the wing too much to the point of what you describe I think, but get them on ,,, they look great
I still love flying mine but am now waiting on new RX batteries before more of it.

Good luck with the repairs,

Brad

w1nd6urfa

My Feedback: (4)

Hey Brad
I can't be 100% sure of course, but I don't believe I used full up as it was only the 4th flight and I was still being gentle on the controls. What I do remember is that when it snapped I instictively let go of the controls to let it stabilise on its own as it still had altitude ... it proved to be not enough!

I've been inspecting the crash damage and it revealed some structural issues that I will be tackling in the re-build. I will post pics for your comments.

Cheers
Nick

Dave Bugz

hi w1nd6urfa, sorry to go on but with the wooden dales if you hold the rod and push the elevator there will definately be movement, i have a wooden one on the rudder and carbon on the elevator and there is definately a big difference.
The JR DS 589 digital on the elevator for a plane weighing 16lb is OKish ? but with the flex in the rod, there will be a lot of force on the elevator exiting a dive. All other surfaces will be OK as they wont be loaded as much as the elevator.
Good luck with the rebuild.
Dave

w1nd6urfa

My Feedback: (4)

Since I will be repairing the horiz stabs what I could do is install 2 mini servos in the stabs, 1 for each elevator. I have done similar mod in the ESM B-25 and has worked fine - been flying it hard over 1 year.

Brad330l

My Feedback: (1)

I don't recommend this surfa. Keep the weight up the front and just change that dowel out for a carbon arrow shaft and all should be good. This model needs to be kept light and there is no way I see you will be able to put it on a diet if you put servos in the tail.
I use an arrow shaft and it works fine.

Cheers,

Brad

kahloq

Sorry, but I cleary will disagree with Brad330l. I have two of these ME-109's and they can fly quite well with weight. One of them is glow(saito 180) and the other is electric power 110. On the electric one, I put a scale tail wheel assembly at the rear plus the AUW is higher simply due to the battery weight then the saito 180 glow one. Both fly just fine. The glow one is around 13.5 pounds and the electric one is closer to 15.5. It lands just fine, no issues and in fact is easier to fly.

So...windsurfa...your idea to use two small servos in the horiz stab is just fine. Might require you to move more stuff forward, but quite doable. This airframe can take a lot of weight up front without detriment.

Biggles2

Can anyone tell me what brand of paint KMP /YT use on the me109

Redback

Biggles

Doubt you will find the brand. I needed to match after ripping out a retract so I took a piece of covering to the local hardware store to paint match a water base paint. Even with a clear coat on top came out OK


Terry

Brad330l

My Feedback: (1)

I'll tell you one thing it is not and that is Warbird Colours!!!!!
My match was terrible!! But not to care, it was underneath so not noticeable on the ground and in the air,,, well I don't care. Close enough. (not really)

Brad

glazier808

My Feedback: (1)

I'm pretty sure ModelMasters RLM 66 matches the dark grey. That's the only one I found though.



Casey

kahloq

Ive had no problem getting colors match perfectly at my local Home Depot. I take a piece of the plane in that has the color on it and bam...put it under the scanner and 2 mins later ive got a sample size amount needed. If for some reason the color doesnt come out just right they will adjust it for you and/or run another scan twice more if required.

okie52

Started on a KMP 109 ARF 5 years ago and its been sitting ever since. I've got a lot of reading to do on this thread.

Asanders

I inadvertently snap rolled mine at high speed. Fortunately I had some altitude and was able to recover in time. Scared the crap out of me. I usually make graceful turns and climb outs but this one time I pulled back on the stick too much and too quickly and she did an awesome snap roll, would have been awesome had I planned it. But when that happens when you didnt mean to! Lesson learned.

okie52

Heh...Think you can duplicate it?

Asanders

I am sure I could not sure I want to, I like my 109 too much hehe.

loukos

My Feedback: (2)

Here is my YT/ESM/KMP BF 109. Powered by a laser 150, robart retracts

okie52

I don't blame you.

okie52

Really nice looking. Hope to have mine ready to go by this spring. I'm going with a Saito 180. How have you liked your laser's performance on the 109?

Redback

Hi Loukos,

Like Okie interested to hear how you are going with the Laser. Got one in mine, it hauls it OK but would like a bit more power up my sleeve. Motor is still quite new though and still experimenting with props.

Terry

loukos

My Feedback: (2)

Guys, thanks for the kind words. The laser is ok, not a power house, I think I over propped mine (16x8), had a bit of an accident on the maiden takeoff, ran off the runway and clipped some shrubs, which broke the rudder..so hasn't flown as yet...I will be using a 15x8 for subsequent flights as recommended by Neil Tidey

Brad330l

My Feedback: (1)

Hi loukos, is your engine well run in or a new one? Nice engine choice by the way. The smaller prop will defiantly be the go for initial run-in. My Saito 150 loves 16x8 props and I have even run a 17x8 with much lower revs but still acceptable power. It is however much happeir on a 16x8 and well run in.
Maybe after a bit of running your will be fine on 16/8.

With my '109' I got a couple of pretty eventful flights in last week end with two engine failures and subsequent dead stick landings. I think the engine was a bit lean on flight #1 although performing well with lots of smoke but after a sustained climb it cut out. Oh dear, Ok tracked straight to a down wind leg, gear down and don't go too far down wind, no flaps required, keep the nose down, bugger, going to drop short into the scruffy stuff, ease back on the elevator to slow it down,,,,, and it kept on gliding!!!!!! Right to my feet to a three pointer. FEWWW.
So I richened the needle a good couple of clicks and once again engine sounded great so off I go again and having a nice time of it when it was inverted time and ,,,Konck!! Another dead engine!!! Same thing as before except this time (after forgetting to recharge my tiny retracts air tank)
I only had the left main come out. This approach was better and it gave me time to think about keeping the dead leg up while on the touch down but even though I tried it sunk down pretty quickly and nosed up all within about 4 meters and then had the audacity to pop the other leg out and sit perfectly on it's nose. Oh man what have I done??? I quick check revealed no damage except for a bent gear cover. I didn't even break the prop.
Once home I pulled it all apart and did some 'deep maintenance', checking all out. I gave the gear legs a good work over and found that my short mounting screws had de-laminated a section of ply mount. Easy fixed with some resin and longer screws that go all the way through the mount.
One tiny little crack in the rear fuselage (I could have done with my thumb at another time) was 'ZAPPED' and wiped and that was it. Ready to go again after some serious engine tuning. Oh, with the wing off I was able to check that the tank clunk had free movement and it was OK.
All good fun, Cheers,

Brad

glazier808

My Feedback: (1)

Now that's just the reason I go electric[:@]

Glad she's still in good shape Brad, although a little bird told me you have another "Emil" in your life now.
LOL

Casey