yak549618

Hi, Everybody
can anyone tell me witch wing to use for the CG top or bottom. they say 120 witch has to be mm.
I think it would be the center point of the top wing as most I have seen but a few I have seen are inverted on the lower wing tips. Goldburg is one or upper wing tips on
Aero Works the manual just has a foil with the CG and states 120?
I would like to know before the planes turn to tooth picks. where should I measure for the CG? They are BEAUTIFUL the manual sucks but the plane is very nice.

Thanks guy's
Fly Safe
Dan

Lil Hoss

My Feedback: (58)

Hi
I just finished my Nitro 40 biplane today. I been emailing with opjose today and he told me the CG should be around 100mm from the leading edge. He sure has been a lot of help to me.
I balanced it on the top wing and lucked out with the CG being right on. Tomorrow I maiden it.(Weather permitting) here in Wisconsin

Good luck with yours
Hoss

Jetdesign

My Feedback: (8)

Opjose is a really great resource to have.

opjose

Lil-Hoss

Remember to set about 40-50% expo on the elevator and ailerons.

You'll have to adjust the value to your radio ( e.g. JR uses Positive expo, while Futaba uses Negative Expo ) to deaden the response around stick center.

Here are a few things to watch out for if you've not flown small biplanes like this before.

- At run up the plane will tend to yaw left. Do a ground test and make the plane steer slightly to the right to help compensate.
- The plane will tend to roll left immediately after take off due to the shorter overall wings. Be ready to trim it out.
- When landing keep it under low power until you are just over the runway threshold. Keep the plane shallower and lower than normal on approach.
- Once you have it over the threshold bring it down to about 8" and chop the power to let it settle in while holding back pressure.
- Once it starts to slow down, gradually apply up elevator again to give the tail wheel authority.
- Keep applying up elevator whenever you move the plane around on the ground but especially if you attempt to transition to grass.
- If you fly onto or off of grass, remove the wheel pants and install 2.75" wheels. Foam wheels work fine.
- You'll need to power through turns more than you may be used to.
- The plane slows down quickly when you chop throttle.
- If you bounce it on your first attempt and are clear, gun the throttle and go around again. You came in too high and fast.
- If the plane loops out of round when you pull back hard on the stick either fly a bit more slowly or lessen the throws a bit more.

You can help the left yaw condition by slightly toeing in the main gear and raising the tail, by bending the rear wire out... to make the tail stand a bit higher.

yak549618

Thanks Hoss I'll keep that in mind 100mm on your engine what did you end up with from fire wall to washer 4.5 inches sound right? my son is very happy with the plane and so i'm I.

I hope all go's well for you with a minumum of OH S!$T's
Dan

opjose

One minor problem with this plane is that the adhesive on the trim tends to let go when exposed to glow fuel.

I've covered mine with Top Flight Clear coat to prevent this from happening, and this works great... ( just never put it on any clear plastic pieces ).

My covering looks new after hundreds of flights because of this.

All you need do is clean and lightly buff the existing covering with a plastic dish pad/cleaner.
Apply light coats of the clear coat, waiting 15 minutes between coats. ( I usually put down at least 4-5 ).
Let the plane dry for at least 24 hours or more, then again buff with the plastic dish pad to restore either a shine ( for the shiny clear coat ) or a dull shiny coat ( which I prefer and IMHO looks more realistic, using the "dull" clear coat ).

Fuel cannot then seep under the edges of the trim, so the trim stays on well. The covering is also slightly strengthened by all of this.

yak549618

I'll get some this is the first for us with Nitro planes how is this stuff for iorning? it's not the shlve paper covering like on H9 little stick 40. also where did you end up with your engine from the fire wall to the washer? what I can see 4.5 inches is gonna be about right

Thank You for your help
Dan

opjose

Re: Ironing

Bring your iron temperature up gradually and try.

Use a cooler temp around the seams.

The covering shrinks well, and if you heat the seams the underlying adhesive can let go a bit quicker than with other coverings resulting in the covering pulling away...

What I do is I attack seems FIRST at a cooler temp, let them cool, then at a higher temp work in the inner portions so there is no chance of this.

Re: Engine

That sounds right, but it has been two years since I've built one of these ( 2 are still in their boxes however ).

I've had so many flights on them and I have not had to pull off the cowls for any reason.

I have one however that I need to do so to check on a filter so I'll let you know after I measure it again with the cowl off.

Lil Hoss

My Feedback: (58)

Opjose
Success............. The little ultimate flew like it was on rails. Very little trimming and with the 52 on it ,more than enough power. Only flew at 1/2 throttle.
Loops were smooth and no falling off. Rolls nice and tight. As far as I'm conserned, Nitro planes has a nice litte biplane. Only got a flight on it because of the long,unrolled grass on our field. But I see great flying with this in the future. I did put a next size wheels on it but I refuse to take off the wheel pants. Mabe I'll try again tomorrow.
35% expo on elev and Ail is perfect. Greased it in for a nice landing and than tipped on its nose. Not a big deal. Thanks for the advise Opjose

Hoss

yak549618

Thank you for your help I let you know how it turns out

Fly Safe
Dan

Lil Hoss

My Feedback: (58)

Dan
Set you CG at 100mm from the leading edge.......... It's perfect

Hoss

yak549618

I will thank you for the fyi. I miss WSCO lived in Stevens point 8 years get me A cream puff from the fair

Fly safe
Dan

Lil Hoss

My Feedback: (58)

Hey Dan
I put 3 more flights on the ulitmate today. There is no bad habits with this plane. For landing it slows down to a crawl without dropping a wing. It was very windy today and it handled it well......... Nice plane
Happy to hear that you spent some of your time in Wisconsin. It is a GREAT state

Hoss

yak549618

I'm getting excited to get it out there. Sounds great with everything your telling me, it sure is a nice plane and built well can't beat it for the price. Thanks Hoss



Fly safe
Dan

michael wood

My Feedback: (1)

Lil Hoss did you balance it slightyl nose low at 100mm? I have a pt 17 and balanced it at the recamended cg and flys nice. Did you mount the engine in verted or up right? any pictures? thanks michael

opjose

You do not balance a plane, "nose low" nor "nose high".

Rather the C.G. is the point at which the plane shows no preferance for which way it may tip, either forward or backward... or at which point it can level off.

"Nose low" indicates that your actual C.G. is further forward than the point you are trying to balance the plane.

Lil Hoss

My Feedback: (58)

Michael,
At 100mm the plane balanced perfect. I lucked out with centering the battery in front of the servo's. As you can see in the picture, I mounted the motor sideways and put on a Slimline pits muffler. I think I overpowered it by putting a 52 on it. I have not opened it up full throttle for the fear of ripping it apart. All I no is vertical is unlimited,,,,, I think a 46 would be perfect.

Hoss

Lil Hoss

My Feedback: (58)

Sorry, Forgot to click "OK"

Hoss

michael wood

My Feedback: (1)

sorry opjose iam old school and and was tought to balance a little nose low. Now my pt 17 is balanced slightly nose low and flys good i have to keep the speed up for landing. so if what you are saying is to balnace it level is that correct? thanks michael

opjose

Re: Level

Eh, in a manner of speaking, you could say that is true however...

The C.G. is revealed by balancing the plane at the point it shows no preference for either the nose or the tail.
The point at which this occurs is always the current C.G.

If the nose goes down, then you are not at the C.G. point, you are balancing the plane just behind it.

michael wood

My Feedback: (1)

guess i will try to balance it level and see how it flys the plane will be here on the 27tn of march i will let you know how it flys thanks michael

mountainroad

My Feedback: (18)

Lots of nice (and important) info here guys. I might be blind, stupid or all the above, I saw to balance the plane at 100 mm from leading edge, but I did not see what wing to balance from. which one is it? And because of the stagard wing how close or how far from the fuse do you measure?
Thanks

opjose

On BiPlanes the C.G. is normally given and measured at the TOP wing, from the Leading Edge Center.