PT-17 from eFlite

[F22trainer]

Ive read the cg in the manual is complete off. GG is supposed to be measured 86mm (3.38”) from leading edge of UPPER wing. What exactly is everyone using as their cg then? I bought this plane second hand, haven’t flown it yet, but according to the manual my cg is perfect.

The manual is not incorrect. You may need some adjustment on the elevator to provide enough control to get the nose down. 4S battery is better, and you should go for the forward limit of the CG. (I think it said 83 to 86mm) I checked mine both inverted first then upright. It required 2.5 oz in order to balance on the stand and tip forward slightly.

[FreightShaker69]

Ive read the cg in the manual is complete off. GG is supposed to be measured 86mm (3.38”) from leading edge of UPPER wing. What exactly is everyone using as their cg then? I bought this plane second hand, haven’t flown it yet, but according to the manual my cg is perfect.

[F22trainer]

Ouch, sorry to hear that. Don’t misinterpret not enough down elevator for tail heavy condition. I needed about 10 turns of down elevator adjustments to get it leveled in flight, but on the balance stand - it was just a shade nose heavy. Don’t just use your fingers - put it on a stand.

[Whizzer]

I put in a platform to move battery forward PLUS added two ozs. of weight to the dummy cylinders and it is still too tail heavy. Crashed it and just lucky it didn't bust up more than it did. Next time out will have club instructor check it out and perform the first post-repair flight.

[bob_stan]

There is also a suggestion to add a platform to the battery tray to raise the battery so your battery can slide further forward into the nose. On mine that is sufficient with a little down trim to fly perfectly.

[F22trainer]

Go to Wal-Mart or somewhere you can get B-B`s. Start with one cylinder adding B-B's until your CG is good. It will take some time and don't try to short cut it. After you fill a cylinder slip it back on a the the prop adapter and prop. You can use whatever glue you want just test what ever you are using on the plastic.

Steel shot from Sporting goods store - mix with epoxy or fill fingertips cut from latex gloves and tie. Fill Ziplock bags with remainder to use like weighted bean bags for holding wings or fuselage when working on them instead of clamps.
see post #1 and #33.

[Saltydawg]

Go to Wal-Mart or somewhere you can get B-B`s. Start with one cylinder adding B-B's until your CG is good. It will take some time and don't try to short cut it. After you fill a cylinder slip it back on a the the prop adapter and prop. You can use whatever glue you want just test what ever you are using on the plastic.

[ICM]

Like most, I've had trouble with cg (tail heavy) on my PT-17. Biggest battery I can fit on the slide-in tray is a 3s 2600 30c 210g as far forward as possible. Added an ounce of sick-on lead weights on the interior foam shelves bordering the opening to the motor mount and manually adjusted clevis for some down elevator which helped, but not enough. Next step is weight in the cylinder cavities of the dummy radial, take out sliding tray and velcro in a 3s 3300 30 c 256g or 3s 3700 40c 282g battery etc although I dislike adding more weight. However I noticed in the parts listing for this plane on Horizon a Prop Adapter Hex 32mm (EFL8204) which appears to be heavier than stock set up since it has a metal spacer with screws as opposed to the stock plastic. Anybody familiar with this? If so, how much heavier is it and is it drop-in with stock shaft and prop or if not, what has to be done to install? If its only 15g heavier that might be enough since its so far forward.

[ICM]

One last question (hopefully). I removed the prop nut, prop and white spacer when binding the PT-17 to my DX9. Stupidly, I didn't take note of which way the white spacer was facing. One side has ribbing from the edge down to the shaft hole. The other only has ribbing on the edge and around the shaft hole with cavaties in between. Which side goes back on toward the motor and which toward the prop? The manual is useless

[F22trainer]

I unscrewed the metal pins, screwed down the plastic pins a bit, tightened everything up and its now flush. Thanks much.

May you get even more flights on yours, than I have on mine - she’s on her 2nd set of tires.

[ICM]

I unscrewed the metal pins, screwed down the plastic pins a bit, tightened everything up and its now flush. Thanks much.

[F22trainer]

I just finished my assembly. Despite assuring that all wires were tucked away and clear and compressing the foam a bit, I could not get the trailing edge of the lower wing flush with the bottom of the fuselage, albeit its only off by less than 1/16th". OK, I'm anal. Can I assume this will have little to no effect in flight. I'd hate to pull the wings off and start again since it was a PITA to get them on.

As long as the pins lock, all good. The manual does not mention it, but the plastic pins actually unscrew to adjust in order for the metal screw lock pins to seat properly. That may help take care of the slack.
In my case I could not get the metal pins to line up with the holes despite my best attempts to get everything tucked away and snug the wing down, until I caught wind on a video that the posts would unscrew to make them a bit longer or shorter to snug the wing in the proper seat.

[boomer108]

That won't have any effect in flight ICM but if it bothers you that much you can take the wing off and see what's preventing it from fully seating and sand or trim that spot until it does.

[ICM]

I just finished my assembly. Despite assuring that all wires were tucked away and clear and compressing the foam a bit, I could not get the trailing edge of the lower wing flush with the bottom of the fuselage, albeit its only off by less than 1/16th". OK, I'm anal. Can I assume this will have little to no effect in flight. I'd hate to pull the wings off and start again since it was a PITA to get them on.

[F22trainer]

To those who have added weight in the dummy engine cylinders, what did you use and how did you secure it?

I think I may have mentioned earlier in this thread, that a latex glove is handy. Cut off the fingers, fill with bird shot, tie a knot and they will stuff very easily into the dummy cylinders - use a pencil eraser or similar so as not to rupture the glove. I pre-measured the shot I needed then two fingers was all it took!;)

[Hardway]

To those who have added weight in the dummy engine cylinders, what did you use and how did you secure it?

I used the Great Planes lead weights, but others have used shot from shotgun shells or reloading.... I poured 5 minute epoxy over mine to lock them in. I used about 2.5 ounces of lead plus the epoxy weight. Worked great!!! ;)

[ICM]

To those who have added weight in the dummy engine cylinders, what did you use and how did you secure it?

[rifleman_btx]

Ah cool i just picked up a drift ghost HD. Should be here this evening :)

[F22trainer]

What camera is that? I wanna put one on my PT17. :)

RunCam 2 - Amazon is your friend.

[rifleman_btx]

What camera is that? I wanna put one on my PT17. :)