Ys 91 Prop?
 

OK I putting the finishing touces on my Yellow .60 SU-31 I have installed a YS 91 now I want to know what the best prop is. I have never had one of the 91 but I have had several 1.20s. I would like the largest/flattest disc possible as it seems to help the plane fly slowly as well as pull from the 3d stuff.


Chris Puckett

YS91 prop
 

Off the shelf an apc15x7 works well. My favorite funfly prop for my 60SuDoKhoi w. a YS91AC is a Zinger16x6 that I heavily modified. I pointed the tips, a straight line from tip TE to 2" in on LE, then reshape airfoil. Basically the whole prop is worked over, but with a little $60.00 disc and belt sander from Harbor Freight and with frequent balancing of the prop during the procedure, it only takes about 15 min. I would also like to try a PowerPoint16x6. I read that a Zinger16x6 develops the must thrust on a YS120, sounds good for my YS120NS and Jerry's Spoiler.
DKjens

Ys 91 Prop?
 

I'm not into prop reshaping. A Zinger 16x6 on my YS91AC will only turn about 7600 RMP's whereas a Zinger 15x6 will turn at 9200 RPM's. I have a Zinger 16x5 that I haven't put on it yet, but would guess it will be in the upper 8000's.

Ys 91 Prop?
 

I took alot of drag off the 16x6. After the reshaping, it is really soft on the hover with good induced tr by blipping the trottle, and when pulling out vertical, it accelerates slow at first, but then as the engine unloads it accelerates faster, really a trip to watch.
Where do you get Zinger 16x5 from?
DKjens

Ys 91 Prop?
 

I too am guilty of re-shaping a lot of wooden props;) I consider the Zinger to be a rough blank and I carve what I want into it. If you look at some of the Zinger tips, you'll actually see a backwards airfoil: that is a sharp LE and a blunt TE. Not good!
On my YS .91s I have always used a 15X6. I think for 3-D a 16X5 would be even better. My .91 on a 15X6 hauls booty around the sky and still gives unlimited vertical on a 9lb Ultimate but I think it lacks the insta-thrust at low speeds. I didn't like the performance of the APC 15X6 because the airfoil is too thick and won't let the motor unload. A while back I built a mold for my own props after carving up a sweet Zinger "blank". I built a bunch of carbon props to play and had a lot of fun tinkering with getting the perfect prop! The power point prop airfoils look to be machined a lot better than the Zingers but I can not attest to their performance. The pros I use to fly around flew Bolly CFs. Heafty price but great performance. There's a lot to be said about airfoil integrity on a machined prop mold.

Ys 91 Prop?
 

Has anyone used APC 16x4W with Ys 91?

YS91 prop
 

Now that I know the sizes that I want. I have to find a good manufacturer. I know I don't really want a Zinger but the Bolly's are so hefty that they take forever to spin up. Does Menz or Bambula make props in these sizes?

Chris Puckett

Ys 91 Prop?
 

I'm running a YS91FZ with a 16x6 pro zinger and a getting
9500 static slightly rich , I'd like to try a 17x6 pro zinger but
they no gots.......
BTW I'm using a Slimline muffler, prop is super light at about 30grams and provides good vertical out of hover, hover is about 3/4 stick.........

Ys 91 Prop?
 

I use a apc 13x11 on my pattern plane as there is not enough ground clearence to go up in diameter. As a result I get tremendous speed as I am for maximum speed.

On a scale model using another 91 I installed a apc 14x10; all pretty conventional stuff.

The pattern plane weighs 7lb-3oz and the scale model weighs about the same as well.

I am impressed with the effort folks put into carving out special props. Well done. I do not have the patience to carve props, I however do blance them.

Ys 91 Prop?
 

6 pitch is the best i see with the mezn:

http://www.desertaircraft.com/menz.html