Please don't crucify me over this, but searching for 4 * on this board doesn't work too well because the words need to be at least 2 chars....

I'm looking to get a second plane for my son after he solos with his PT-40. Read a lot of the posts here and many agree that the Sig 4*s are great planes both to build and fly. Now, here's the question - I have an OS 70 4 stroke. Would it be better to get the 40 or 60 size star? We're not looking for 3D type performance - just something he can do basic aerobatics with and fly around lazily when he wants to. I have a GP Ultimate to put together whe he gets ready for more advanced stuff.

Try searching for "Four Star" instead.

I would go with the 40 size.

joebob,

Maybe a long answer to a short question.

We had a 4*40 that we flew with three different engines during the time we had it. We started with a 40LA, if flew ok but seemed like it needed more. Put a 46FX on it, and it was nearly too much for it. Covering was pulling loose after some of my sons' flying. Then we ended up with a 46LA, it seemed like a perfect match. All of that said, I would guess that the 46FX would be closest to the 70FS.

I'm presently flying a 4*60. I started out with a 70FS on it. It flew very well and a lot like what you are describing
that you would like to end up with. After seeing my plane fly, one of the other local flyers set his up the same way.

I have a 91FS that came from another plane, and I thought I wanted to try it on the 4*60. The only performance gain is in a better climb, and to get that it added weight and is harder to get it to settle down and land where you want it to.

So, if it were me, based on our 4 stars, I would put the 70 on a 4*60.

You mileage may vary...

Good Luck,

Larry

I like the 4* WITH 70fs best of the two choices.

I have 2 4*s 40 size with 4 strokes one has a Mag 61 the other has a OS 52 . The 61 is almost able to go vertical it might with another prop combination .I am using a master air screw 13x8 on it. That planes weight is 4lbs 12oz. The one with the OS is slightly heaver because of wheel pants and a full length wing the other is cut one bayeach side.It is not quite as spirited. These engines are not as powerful as that 70 will be but they weight 5 0z less you will probably have to add some weight to the tail . I have a 60 size ready to cover with the engine size undecided . In my opinion the 70 a little much for the 40 but a little small for the 60 .

ment to say,I like the 4*60 with the 70 best of the two choices

It looks like it's a toss-up on this. I was afraid that the 40 size would be a little small for the OS 70, and the 60 size would be a little big. However, for the style of flying we'd be planning to do with this plane, it looks like the 60 size would be a closer match.

As I said earlier, I'm not looking for unlimited vertical performance. Heck, my son asked for a GWS Slow Flyer for Christmas! He likes the slower flying planes instead of the rockets. Hopefully, the 60 will give me a happy medium.

Thanks for all the input.

I like the slow flyer's too and have the GWS pico cub and Beaver. I like the Cub best I use it for indoor flying it is lighter and slower than the Beaver. I did make some floats for the Beaver . It lands fine on the water but won't take off from the water maybe with smother floats it would break the surface tension.