Hello All,
I recently purchased this P-51 and after getting her together I found she is real nose heavy. Should I add weights as far aft as possible or is one place better than another?

thanks,
bhomer

If you can move weight do that, this should always be your first option. It may mean cutting a little covering and putting you batteries back then replace the covering.

I hate to add weight, it will increase the wing loading and slightly decrease overall performence.

If you must add weight do it a far back as possible, this way you will add the least amount.

Is that a PTS Mustang? Did you get it new in the box?

CGr

Because it is a low wing plane make sure you balance the plane upside down. It is less sensitive that way.

If the picture you posted is how you are balancing it then you may not be getting a good reading as to where it's balancing at. You can make a very quick balancing machine with a piece of 2"x4" board and two pencils. Drill two hole in the board that are wide enough apart so the fuselage will fit between them, then insert the pencils in the holes with the erasers up. Now mark the position on the plane that the instructions indicate as the center of the CG range. Now place the plane on the balancing stand on those marks to see if it balances. As indicated above, since this is a low wing plane you will want to balance it upside down.

Since this is the Hangar 9 PTS Mustang, and it looks like you have the recommended engine on the plane, it should balance with little to no additional weight. I think the issues you may be having come from how you are trying to determine the CG balance point. GIve this advice a try and see if you come up with a better result.

You can also do the same thing with two finger tips to balance on. Just have somebody place the plane on your fingers for you and see where the plane balances. This will do in a pinch, but you'll be better off with a more fixed balance system like the one I described above or possibly a GP CG Machine from Tower Hobbies.

Hope this help

Ken

Does your engine have the black flywheel ring around the prop driver? That flywheel is Steel, and quite heavy...you can press the prop driver out of the flywheel ring with a couple of sockets and vise.

This will save you from having to ADD weight to the tail...
You will have a slightly lighter and a more responsive airplane...wait to do this until after you've flown the airplane some and are getting bored with it.

Yes, It is a PTS and yes it was NIB.

Bhomer

Thanks to all for your advice. I did balance her upside down (with my fingers) the first time according to the directions. I will try to make a balancing stand tomorrow and see if I can get atruer ideaof how out ofbalance she really is beforeI add any weights.

bhomer

Trainer type airplanes are typically set-up a little bit nose heavy. Your PTS Mustang is a fairly well proven design...it should be OK the way it is.

Save the removal of the flywheel tip for later, when you're ready for more responsive controls.

Proptop, are you serious? I've read many of your posts and know your smarter than this. Are you realy advising to blow off checking the CG before the first flight? That's terrible advise. The plane probably is OK, and RC Ken's diagnosis and advice are solid, but skipping the CG check would be a big mistake, especially if somthing is amiss.

rrragman

No...I most certainly am not suggesting that...what I mean is that he should not have to add any weight to the tail...and of course the procedure of checking for proper Center of Gravity is crucial!

"It should be OK the way it is"
What I meant by that is:

That airplane is assembled with virtually all the equipment already installed...it's a well proven airplane...many have been flown over the past few years (flown 2 of them myself ) and if one reads the manual then there should be no problems as far as getting the C.G. in the proper position.

We cool now?[8D]
(BTW I'm a Python fan too...)

Always were Just didn't want bhomer to get the wrong idea.

rrragman

bhomer; please follow kens advice, mine was also nose heavy out of the box, not by much but just enough to affect it

I'm goingto Ray, I'm going to see if I comeup withsomething using the pencil idea tomorrow. If not I'm going to buy the CG stand from tower.

bhomer

Here, this doesn't get much simpler. I used a 2x6, and 2 new pencils.

and if your up to some reading

http://www.rcuniverse.com/forum/m_31..._1/key_/tm.htm

Thanks for the link Ray, very interesting reading. I'm a newbie so all the info both good and bad was/is going to very heplful when I get her to the field.

bhomer

HI USE YOUR FINGERSif nose heavy move your battery as far back as it takes to be SLIGHTY NOSE HEAVY-on the CGupside down on a low wing-do not forget to balance the plane left to right -hange the plane by the engine thrust washerbe sure you are not on compression plane should want to come to center-fly level on its own when left right balance is correct
on the first flight - check the balance in the airwhen making your left and right turns (while holding some up elevator ) if the nose drops you need more tail weightadd tailweight at 1/2 oz amounts until she flys level around the cornerswhen inverted you should only need a little up elevator input to hold you levelthen your balance is correct and as it should be
a nose heavy plane will fly-a tail heavy plane WON 'T FLY FOR LONG !! ENJOY GOOD LUCK HAPPY NEW YEAR REGARDS TONY ( flying RC for 20 years )

hi put your lead under the fuse -as far back as is possiblebe supper sure it will not move or come off-or you will be in big troublebalance is EXTREMELY IMPORTANT to the plane handling as it shouldTONY

Another thing to think about balancing is the prop...most of those 3 blade paddle props I've seen are quite out of balance.
I would suggest you get a prop balancer...think of it as part of your required equipment...your engine bearings and radio equipment will thank you for it.

Another suggestion would be to think about getting a couple of 2 blade props...like a Master Airscrew 11x6 and or APC 11x5 because the airplane flys rather sluggishly with the supplied 10x4 3 blader...especially with those barn doors attached to the landing gear struts.

Here's something I found on one of the web sites, not sure which one. Very easy to make.

Love all the heads in the background. NICE!!

As suggested, try moving the battery pack back to adjust the C.G.

You may have to move it out of the provided space.

Now all of that said.

Because this plane has a nose flywheel, it does come out somewhat nose heavy.

If you've placed the battery packs and components where the instructions and the plane provides for, then

THERE IS NO PROBLEM WITH THE C.G.

That is, there is a purposely designed compartment for the pack and receiver.

Stick the battery pack in the battery compartment as shown and fly ( with an instructor! )

The plane does well this way and it is designed to fly like this.

Don't overthink the C.G. issue.

Later when you do remove the flywheel, you'll find that the plane will then balance out perfectly at the recommended C.G.... but save that until you are a more experienced and certified flyer.

ARFs are manufactured with the hope, just the hope no guarantees, that the woods and components used will all weigh the same. They usually don't. Because of that, the retailer includes the suggested CG in the instructions. He wouldn't have to do that if all wood weighed the same, and your installed components matched his.

It's always worthwhile to check the CG. How you adjust it when it's not where it should be can be done a number of ways. The absolute best way is to move your installed components.

I just did the deed to an AirWorks Yak. Now, AirWorks is one of the premier retailers of ARFs we have in the US. Yet my Yak was noseheavy. What did I do?

Since the YAK came out just under the advertised weight and I plan to fly the stuffings out of the sucker, I really didn't want to add dead weight. Sliding the battery along the underside of the sucker while it was upside down on the balancer showed the plane level with the batter just aft of the wing's trailing edge.

I built a balsa box that almost exactly fit the battery and braced it back in the aft part of the fuselage. Bracing went to the bulkheads and supported the box really well. Some scrap balsa was all it took. OK, I also used some tongue depressors to brace and position the box. I'm guessing there was an ounce in the materials I used. It's neat and trim. And moved the balance where I wanted it. I'm guessing it took about an hour of very pleasantly spent time. [8D] Truth is, I was quite happy to do it. That's what the hobby is for, isn't it.

This statement is bothering me more than your CG problems. You say you are a newbie.....Does that mean you haven't actually flown yet? If so, I suggest another airplane, (a trainer), and save that one for your second or third plane. My2 cents.

Lm