majortom-RCU

My Feedback: (40)

That's a comforting analysis. If your concern is precision flying, most of that is going to be done with modest elevator throws, where the differential between the two halves seems to be negligible. When you use high throws for 3D stuff, I would think no one, probably including the pilot, would be able to notice the effect around maximum differential.

Scott Dilley

My Feedback: (3)

I have flown another guy's edge, and it flies really well in it's stock configuration. I will get down and dirty with mine tomorrow and give a flight report.

RysiuM

My Feedback: (1)

Exactly. 0.5 degree is much less then gear slope. I'm glad I calculated it. I didn't have such clear picture before. And adding new servo mounts would add the weight that I'm trying to reduce as much as possible.

Sorry Powerline for accusation

RysiuM

Scott Dilley

My Feedback: (3)

On another note... I am not sure if you have an engine yet, but both of the ones that I have built have been way tail heavy. One was with a Saito 150 and mine with a Supertigre 2300 with a pitts muffler. You might take that into consideration that if you have to add weight, it might as well be usable engine weight instead of dead weight. By the way, have you started on yours yet?

RysiuM

My Feedback: (1)

MVVS 1.6 with inverted pits (BCS) muffler. Got it from justengines from UK delivered in 2 business days


Not the engine part. I'm waiting for radial mount for MVVS. And now for the next couple days I'm stuck in Chicago area for customer support. I will be back to my plane next Wednesday.

I have both wings done and tail (glued and hinged). Now I need to make pushrods for tail and mount all tail servos. When I have all moounted in place I will start looking at the engine position for balancing.
Instead of moving the engine box forward I might use custom stand-offs and cut most of the engine box out. The engine box is 6 oz that may be reduced to 3oz.

RysiuM

IowaSilvia

My Feedback: (97)

When I built mine it was nose heavy and had a ST2300 in it. He's using a gasser so he will mount it on the moveable engine box and get the plane dead nuts CG. I personally think that the framing on the front of these are overkill. Just look at all the 1/8" ply they use. wow. But will guarantee it won't shake apart. ha.

The stock location for the elevator servos is awesome. No need for a servo Y reverser or anything like that. I watched mine and had them deflect 45deg. There wasn't any diference that I could see. And I watched them close.

RysiuM

My Feedback: (1)

For more real life scenario if I set the servos that they line-up at 30 degree the difference is even smaller. See for yourselt. Life is getting better

RysiuM

majortom-RCU

My Feedback: (40)

RysiuM, you da man! This analysis impresses the heck out of me. How come we don't see this kind of thing in the modeling magazines?

Scott Dilley

My Feedback: (3)

A lot of people aren't as meticulous as you are when figuring out things like this. I know that I am not. I just set throws up using the TLAR method and then adjust from there. I commend you for your work. By the way...what do you do for a living?

RysiuM

My Feedback: (1)

I was just curious. I new the surface deflection depends on the servo location. Especially at high angles. So I wanted to see how much these elevators are affected by tail servo arrangement.
I also did calculation what would happen if you move servo more than 30 degree - the difference is increasing rapidly. A couple degrees difference at 50 degree deflection. However I don't expect my elevator to move more than 30 degrees so I'm very cool.


Working for software company implementing our systems for wholesale distributors. Mostly designing and programming stuff on IBM i-series. Lot of fun too

RysiuM

RysiuM

My Feedback: (1)

I'm finally back home.

I mounted tail servos without any mods. I'm going to use my own pushrods - twice lighter than stock.

I found, that tail servo wires with 24" extensions are bouncing around the fuselage so I made simple paper tube glued in the tail part. It added 3 grams but wires stay in one place. Se the picture below.

I also got CF tube from CST. it is 3 ft long 21 mm OD and it cost me 52 bucks. I wrapped it in blue paper masking tape - couple layers to get nice fit. Then I painted all with gloss clear dope. After it dries I will sand it with 600 - 2000 paper to get smooth glossy finish. It will fit even better than original one. Now tube weights 108 grams (paper added 18 grams to 90 grams CF) but as I will cut off about 10 inches (wing tube is only 26 inches) My new wing tube will weight less then 2.8 oz (it is about 3 oz less then original one).

Below there is a picture of the new wing tube (not sanded yet) next to the stock one.

Stay tuned
RysiuM

RysiuM

My Feedback: (1)

One more question. CST recommended to put a wooden inserts into the tube (short piece of dowels) where wings meet the fuselage to protect the tube from crushing. I can easy make such pieces on my lathe but is it necessery? I have never seen CF tube with inserts. Or maybe I looked in the wrong place.

RysiuM

RysiuM

My Feedback: (1)

"Think twice before you do something" - I had to move tube lower in the fuse because it interefered with pull-pull wires. No big deal.
I used stock wires but two things I noticed. Wires are a little (like 1/4 inch) to long. I replaced clevises for servo with the shorter one, and I turned servo around. I used original horns (they are only 2 grams heavier than mine) as all fit right out of the box. No need to change it. Slots in the fuse are already cut and everything is perfect - I admire Powerhobbies for excellent design.

One small thing tho: Pull-Pull setup would be easy to setup it the left servo block didn't interfere with the wire. The left elevator servo front block extends down blocking the wire. I had to cut it - a little difficult to do it reaching there with exacto knife throuh servo hole.

RysiuM

RysiuM

My Feedback: (1)

Now the tail part is done. I took me a while to install the tail wheel. I substituted tail wheel brace with Great Planes stuff. I think I found why the original bracket is so soft. The whole tail block is just balsa - not much "meat" for screws to hold on. I used much wider and longer screws so they grab more material and I also soaked holes in the tail block with thin CA. It should make it a little harder.

Today I started to do "electricity". First of all the original place for switch is designed for standard RC switch. This is good for small glow engines - not for gas. I'm using heavy duty MPI switch. I didn't like the location either: just under the center of the wing. Not easy to reach. I glued in some balsa-light ply lamination just under the trailing edge and I mounted the switch on it.

I also mounted a LED-bar On-Board battery checker (set for 7.2V) to monitor the voltage of my 2 Durlite Plus LiPo flight pack. Bright LEDs are visible through the yellow covering when they are on. Battery pack with voltage regulator weights less than 4.5 oz. Not bad for 2500mAh pack that can deliver 10A constant current (20A burst) holding steady 6V.

To finish all radio setup I'm waiting for 3" HD extensions (for ailrons). But I'm really ready to put all parts together to check the sweet spot for the engine (where the plane balances the best). I'm not going to use sliding engine box - I mean not to slide it forward. I will cut the box about two inches behind the front wall and for mounting my MVVS forward I will use light aliminum stand-offs. The whole box weights 6.6oz so I'm hoping to save about 2-3oz.

RysiuM

RysiuM

My Feedback: (1)

First balancing test.

Without the engine plane felt very tail heavy. To check that I needed to do the test. I mounted the engine in the most forward position with some wire. A added all parts that will be in the nose (cowling, ignition, spinner, prop). With wings and LG in place i tested the balance. Right on spot. I can make small adjustments moving the battery. But it looks like I will not need additional nose weight.

What it means? I have MVVS 1.6 that is very short 33 oz engine with 5oz muffler and 5 oz ignition just behind the spinner and it balances right at it should. If I use Saito 1.8 I may have a problem with not enough weight on the nose. With MVVS 1.6 I think I'm right on spot. I will need 2.5 in long stand-off mounts without extending the engine box. I will be able to cut off the box and have enough space for the ignition and battery between the motor and the firewall. Quite clean setup. I don't know what the total weight will be as many parts are not installed yet. I just wish to be below 11 lb.

Now waiting for engine mounting plate (it's coming from Europe) I'm turning motor stand-off's - quite a task to turn aluminum rod into pile of small chips on my mini lathe Engine plate weights 2 oz and 4 stand-off are about 2.5 oz. That makes quite light engine mount.

RysiuM

majortom-RCU

My Feedback: (40)

Ignition mounted just behind the spinner? Not on the firewall?

Glad to see this project shaping up so nicely. I have one in the box, appreciate your breaking ground for us.

RysiuM

My Feedback: (1)

ROTFLMAO

Of course on the firewall. I mean it will be between the firewall and the engine (above) on the top of stand-offs. It is a matter of what "just" means. In my case it means 5.5inch.

This plane goes like Lego. I'm really pleased with the quality of design. When I tried the LG I found the wholes in the fuse and in the LG a little off. Then I realized that when I swap LG left and right all holes lined up EXACTLY. There is no mark which LG half is left which is right. If it doesn't fit PERFECT don't fight it. It means you need to swap it and it will fit.

It is the first class quality ARF. Even canopy is already cut. No guessing. You need a canopy glue or just a canopy tape.
Having all cuts and holes done by manufacturer I'm surprised that the cockpit mounting holes are not drilled in the fuse.

RysiuM

RysiuM

My Feedback: (1)

Two things happened yesterday:
1. Radial engine mount came (thank you, Pe')
2. I finished my custom stand-offs. I weighted them and all 4 are exactly 2.5oz. They are 50 mm long, 12 mm thick with 25mm base. 4.8mm hole through for 10x3 screw. If I measured right the most forward position of the engine will be 7 - 7.5 inches in front of the firewall (the most forward position of the cowling). I need to fit all parts together. The sliding box will help a lot with fine adjustments. This is very clever idea.

The engine thrust line is built into the engine box - my measurements show about 2 degree right thrust. Center of the engine mount is already marked too (horizontal and vertical line). Vertical line is 5.5mm to the left of the fuselage center. I calculated that at 7 inches from the spinner's backplate to the firewall the offset should be about 6.5mm. I still need to verify the horizontal line if it lines up with the cowling. I might move it down about 5mm to accommodate motor better as I'm afraid that the bottom of the engine and the muffler is to close to the top of cowling (engine mounted inverted).


RysiuM

RysiuM

My Feedback: (1)

Unfortunately (for me) the horizontal thrust line is marked with less than 1mm accuracy. But I had to move my engine mount about 7mm below that line otherwise the stand-off would be to close to the top edge of the box. I'm sure I can make it up by tilting the cowling 2.5 degrees down (yes, only 2.5 degrees).

I'm still impressed with the idea of sliding box. I can move it out or if I need I can move it inside (behind the firewall). I don't want to shorten my stand-offs (50 mm) as this is exactly the space I need for ignition module. I will not glue the box until I have cowling cut out and mounted. So I can adjust the engine to the cowling not like it used to be cowling to the engine.

I didn't have much time today, so I only put a blind nuts and I laminated the entire front of the box with one layer of glass cloth and epoxy. This way my mount will have hard surface to stay on. Otherwise under vibration they would cut into the wood. I did the same on my H9 Edge and the mount is solid like new.

The good thing is, the weekend is coming - more time for building and flying (if the weather stays as good as it is now).

RysiuM

RysiuM

My Feedback: (1)

Picture time

I solved the choke problem today. I went "hard way". I drilled two spots on the choke shaft through the hole (do0n't let any chips to get into carb): Choke fully open and fully closed. Than I made a spring plate 0.35mm - thickness gage is made of very good steel. I drilled two holes: 6.25mm (for carb screw) and 3mm (for ball) 6.3mm apart. For locking I used 3.25mm steel ball (from some old ball bearing). It works very well. Even with the spring hooked the choke can be lock in the closed position.

It was not difficult at all.

So here are the pictures of my new Choke-lock.

RysiuM

RysiuM

My Feedback: (1)

I missed some pictures, so here they are:

1. Tail wheel - the brace is Great Planes the rest is Powerline
2. Heavy duty switch and On-board battery checker. I set it for 7.2V (6 cells) - if voltage drops to yellow it means the battery voltage dropped below 6.8V 3.4V per cell). It is under load so the battery will have enough juice to finish the flight.
3. You can't see the battery checker, but when it's on it lights through the covering.

RysiuM

RysiuM

My Feedback: (1)

Here is the engine mounted in the nose. MVVS backplate mount (Thanks Pe') and custom made stand-offs. The engine looks small

RysiuM

RysiuM

My Feedback: (1)

The last one for today. I designed throttle linkage. I might extend the arm of the bell-crank to increase resolution even more. Right now the full travel is 1/2 inch. As I have zero slope on the bell-crank (it has bushing taken out from CR-ROM motor ) I want the best resolution on the linkage as I can. I will have slope on the servo linkage because the cable needs to be quite long.

Pictures attached.

RysiuM

RysiuM

My Feedback: (1)

I was walking around it for whole day and finally made my mind. I redesign and rebuilt the whole throttle connection. This time I used glass-filled HD servo horn. The benefit of new designs are:
- This arm can withstand heat from the motor,
- It is longer so now full travel is 1 inch.
- because it works at different angle now I have some kind of mechanical expo near the idle. This will give me better precision at low rpm (because it is mechanical on the throttle arm it is not sensitive to the slope on the cable or servo).

I think this is final.

Pictures at idle and full throttle, and from the front.

RysiuM

Texastbird

Hi, RysiuM,
How about some more pictures to help convince me that this is the plane I really want. Like the color scheme top and bottom. I'm waiting to see how the MVVS runs.
Thanks,
Tim