Stearman PT 17 kit

[hawkeye30]

I am in the assembly phase and the horizontal stabilizer does not seem to fit without removing part of D1 . Any suggestions

[Mitch]

I think you need to check that you "opened up" B10.
Looks like the Stabilizer should slide though B10 and fit into A6.
Some sanding usually required, but you should not have to remove too much of D1.

I have not built the kit (yet) but am looking at the plans!

Mitch

[Bill Gaylord]

I'll have to note this also, as I have one of these kits here that needs to be built. Got a complete ply version kit for under $25 shipped, so I couldn't pass it up.
When it comes to the rear fuse stringer terminations, no two Guillows planes are built exactly alike. I give the draftsmen a lot of credit, as it's difficult to detail features such as converging stringers.

[Bill Gaylord]

Finally got started on this kit. I actually love the pilots, since they are extremely light and add little aft weight. This one seemed to go together well, after assembling about 5 of them in the past. Now onto 7 cylinders, as I may as well get these plastic parts out of the way. Only two done so far, where the notches between the fins have to be filed and then sanded, after gluing the case halves together. Had to come up here and take a break, and will probably be taking more after each completed cylinder.

[Bill Gaylord]

Starting to finally get somewhere with this build. I don't complain about die-cut accuracy, as it is amazing that the die makers have done as well as they have, given the difficulty of the task. I am interested in hearing if others found the fuse alignment to be a bit more difficult than some of the other die-cut kits however. Since I bought the kit to be a relaxing build after a number of scratch builds, I'm just building it without major adjustments and it should still go together well, albeit a bit of waves in the stringers. I had to shave a slight bit of D1 for the stab fit as mentioned previously in this thread, but nothing major. I may build a scale airfoiled stab anyway, so a bit of additional fitting will be required anyway. From videos I've seen, the plane appears to be a fine flyer as an rc conversion. With an outrunner mounted in the forward dummy radial and the battery behind the cowl, balancing should be no problem without additional ballast.

[davidchoate]

Any advice on your stearman RC conversion Bill? How'd It Fly?.

[Bill Gaylord]

There's a build thread a while back here with a video. The plane flew fine with a few clicks of aileron trim correction. Actually it's a good video to watch, since it shows how important dead straight wings are. I finished the build with a slight warp which favored left hand banking, if I remember correctly. I've done so many of these that I knew it would still be flight worthy but still maybe need a few clicks of corrective trim. I figured I might correct it after the flight if it was bad enough to really need correction. The point is this "warp" probably amounted to a tiny mismatch in the incidence of the outer panels, probably less than 1/2 degree, in other words barely detectable. The video shows how perfectly these models have to be constructed, in that if it was any greater, it would have not effectively been trimmable and would have flown horribly. You can see the left hand turn after launch, before corrective trimming.
https://www.youtube.com/watch?v=2wwF-hfTbtY

The other main reasons these models don't perform as well as they can are not setting the CG properly. This model like a number of bipes, has no tolerance for aft CG. The wing incidences must match, or have a slight amount more positive on the top wing. Precision counts. My next biplane was a Comet Albatros, where setting the wing panels straight was a real pain. I managed to set them dead straight, and it paid off in flight. I launched it in a harsh cross wind and had no problem controlling the model. It was dead on and required no corrective trim as far as I remember.
https://www.youtube.com/watch?v=AGqNdDvahmI

Precision counts. My goal is to have models that fly straight out of my hand and don't need any inputs for 100 yards or so. Doesn't always happen, but the closer the better. You don't want to be struggling to control the model from the onset. It's a lot easier to fly one that basically wants to fly itself, where you only need to give it minor inputs to keep it in the field.

[davidchoate]

Thanx Bill

[davidchoate]

engine looking good. looking for rocker arms while glue drys.Mitch would be proud.

[davidchoate]

Would you (bill) think it better to use the 1/2A (whatever that means) aileron linkage; which will take alot of wing saddle modification, or use Sullivan Gold Cable, or a 3g servo in each side of wing.The sullivan cable is the only method I have not tried. There is a new method that I think is the best ever; I will make a picture ,as it'll take pages to describe.

[davidchoate]

I did the best I could without a T-square and table, but I hope you get the idea.

[davidchoate]

The picture of aileron hookup.

[Bill Gaylord]

The simplest method is to just use single 3gm servos in each wing. I use to use single cable setups for minimum weight, but individual 3gm servos weigh little if any more. Until I have one fail which hasn't happened as of yet, the smaller the better. I still see people using 7-9gm servos in these models, but I haven't found the need for servos that large. I've seen the method that you described above for hidden linkage which does look nice, but it has to be done precisely for it to work well, which is a bit of work. The standard horn-pushrod setup takes minutes to setup and works well. Another good thing with the latter setup is that you can offset the servo arms and/or aileron control horns to set differential. That's a good thing, since it otherwise has to be done with separate channels and a mix, versus a simply y-harness for both aileron servos into a single channel.

Detailing the engine looks nice. I thought about it but didn't go to the added work. A person could go as far as they want with making scale pipes on those radial engines. Lots of work there!

[davidchoate]

Who Knows;Maybe I'll win "Model of the Month".LOL.Never gonna happen on a flying RC Model.

[Bill Gaylord]

That was a fun time fitting that motor. If you wrapped a piece of Scotch tape around the bell it would no longer have clearance and would be rubbing inside the dummy radial. It's that close!