How to measure the thrust line? That's not easy. Props often have runout. They often aren't square to the crank. Sometimes thrust washers aren't. It's usually more accurate to use a thin flat stick with a hole in it. Some incident meters can measure 90* things like props.

The best way to judge the thrust line is to simply fly the plane when you've got an operational plane as your subject.

BTW, the Hellcat in my post has visible elevator deflection showing when trimmed. It recently clocked 110 mph plus. It's flown with that trim for some time now. I think the plane is a couple of years old now.

I wouldn't sweat where your trim winds up.

Thanks for the info and pic da. To me in your pic it looks like a little down elevator instead of up.

There is a slot on one (or maybe both) Of the black mounting brackets on the meter. You can mount it to your engine here. You may have to take an old prop and cut the blades off and use it as a washer to fill out the space so you can tension the prop nut. The thrust is most likely not causing your trim issue. I am surprised your readings are zero on both stab and wing.
Make sure the elevater is in its nuetral position and measure the wing at the root. clamp a stick to the elevater to make sure it stays put.
Any trim you carry is no biggie really. Usually people are just embarrassed about how it looks in the pit area.

VG you are correct. I just re checked and with my wing at 0 my stab is at -1. I checked the wing again to make sure it was still at 0. I would rather not rip the stab out ,so what do I do to the wing to correct this? Or is it not possible?
I also see the slot on the meter thanks.

I think I understand now. Like you said VG in a earlier post, I need to shim the LE of the wing.
So if my stab is at -1 and wing at 0, I need to shim the LE of the wing to -1? Engine also? If I want to leave the stab as is..

Judging from your picture it was looking quite good. you have pos' stab and wing...<div>You just need down thrust!</div>

Before you start chopping the wing or stab, just remember the incidences you measured (0 wing -1 stab) are in real life saying that the stab is set at 1 deg less possitive incidence than the wing. For example, lets say in real life you wing is set at 3 deg poss, and the stab 2 deg poss.

I put your side pic against the profile (hardy rocket science but it gives a quick impression)... and they're quite similar.
Whats obvious is the engine thrust angle as mentioned earlier. I'd start there... it's the simplest.

How do you measure it? Best to fly it in. Meaning add some, add some more untill you find the best place.
You'll have to built a spacer to move the engine out some, then add a spacer at the top of the mount to angle the engine down.
Start with 5mm and add/adjust as necessary.
Be informed that you'll very likely need to add some elevator mix to high throttle as the design was never ment to fly at the speeds we fly are models.
Good luck.... and remember, what ever you do, have fun.

1/2" of down elevater trim is a ton. It does not seem to jive with your incidence readings. I think you need to fly the plane and go through trimming procedures based on that. Look up articles on how to flight trim and set it according to your liking. -1 degree is a very small amount really and does not equate to 1/2" of trim. I was expecting more like 7 degrees or something.

Thanks David, I'll start with the engine and go from there. Was hoping to fly it today but it's raining so it will give me time to work on it. I understand that my stab is 1 deg less positive than the wing but also thought they both needed to be at 0. I think i'm confused again.. ha ha

Thanks again VG, I'll fly it again and re trim and also take a pic of where my elevator is at for level flying.

Here's a pic of the Elevator set for level flight. It looks like a 1/2" to me but I may be wrong..

I always trim my models at 3/4 throttle setting. Anything above or below this throttle setting is you flying the plane. If down trim is required at this throttle setting I would check the CG location according to the manufacture placement. If your CG falls withing the reccommended range listed then I would do your own math and verify this location. Balance your plane at 27% CG as a reference point and enjoy. Unless your scratch bulding the designers of our model aircraft usually if not always have done the homework for you. Incidence angles and offsets of the powerplant have already been accomplished before they release the aircraft to the consumer. If your still having problems contact the vendor. H9 recently released an ARF Tiger Moth with the CG listed incorrectly.

Thanks fly, but as mentioned earlier I had to replace the firewall and was concerned that my engine had to much up thrust.

Sure looks like a CG problem to me. That much down elevator and the fact that it lands great point me in that direction. Do you have the instructions? Look on H9's website for how far back it needs to be. I have seen a few ARF's with incidence problems but very few. I normally do the math myself to get the CG in the ballpark. Then fly to adjust everything else... I even have an android app that will do it for you if you have the measurements.
Wally

Hi Excalibur, I have the CG set at 5 1/4" per manual. I will check that again today.

Ok guys, I think I found the problem. I guess when that tree reached out and grabbed me it did more damage than I realized.
Just before I was getting ready to check the CG I noticed while looking at the left side of the plane, the stab looked like it had very little down elevator. I then looked at the elevators from the rear and there it was... The right side was down a lot lower than the left. I know it wasn't like that before the tree and I didn't feel any play and both felt tight. So is it possible that the elavator joiner bar got bent without causing any damage to the elevators?
Now, How do I fix this problem?

Your incidence angles sound right on. But when measuring you should “0” out the tail first, this is how your plane will set in the air at its intended cursing speed. Two degrees of angle of attack on the main wing is “right on” for a nice relaxed cursing speed. It sounds to me you just like to fly faster. Aerobatic aircraft are usually set to 0-0-0, one reason for this is so they can fly upside down with no change in the trim and aerobatic planes more then likely have a more symmetrical airfoils.
Before changing the incidence of the main wing you should really check your balance first and maybe change it to see what happens, it maybe a little tail heavy. If it balances out ok then you can adjust the main wing incidence angle to soot your preferred speed range.
Remember that you control the plane’s altitude with the throttle “not the elevator”.

I say "if it ain,t broke, your not flying it hard enough".Seriously, I agree with the rest of the folks. I would look at eng. incidence. However, if it's a good, fun flyer, let er rip.

The pen is mighter that the sword.
Exept one on one
Ho no CHECKSIXCHECKSIX</p>

I do like how the plane fly's. I'll recheck the CG then shim down the engine a bit. I'll also fix the difference in elevator halves.
I fly at 3/4 to full with a st g90 with a 14x6 prop.

I knew one day that I would have to learn how to use a incidence meter but for some reason I was scared of it... Now I understand how important it is!

Thanks for all of your help, info and teaching guys! I learn something on here every time I come here!

A few people have suggested changing the thrust line to fix the elevator trim, but I'm going to caution you about that. The point of tuning the thrustline is to center the thrust on the plane's drag so that changes in throttle don't cause changes in pitch. A bit of confusion can come in the situation because speed can cause pitch changes too, which is not a thrustline problem. The way to check the thrustline is to get trimmed for level at full throttle then chop the throttle. If you get a pitch change in the first second or so, adjust the thrustline in that direction. So if it pitches up, you need to angle the thrustline up and obviously if it pitches down you need to angle it down more. The opposite test will verify your results, letting the plane get slow and then observing what happens when you suddenly gun it. Yes, a thrustline that is off will affect elevator trim a little, but tuning it is all about having the plane not change pitch with throttle. Once you get the thrustline right, you can then really know if you have a wing incidence issue.