SAL98

My Feedback: (6)

I purchased a 40b for my H9 quarter scale edge 540. Horrizon recommends a saito 180 with a 16x8 APC prop.
I know guys that use a 17x8 with that engine and plane combo. My question is this, I have the 40b on there which comes with a bambula 20x8 prop. If I wanted to go to a smaller prop like an 18 inch ( this is due to the fact that this plane sits very low and I keep breaking props on landings), what would my pitch need to be and also will this smaller size prop be a problem for this engine.

wdgreen

My Feedback: (1)

Rule of thumb is if you go down one size in length go up one size in pitch. So an 18X10 would work fine. I would hazzard to say the ZDZ40 would probubly turn a 18X12 with ease.

Red7fifty

My Feedback: (73)

Another route you can take, and this is what I would do, since the engine you have is rated at 4.1 HP, consider going to a 3 blade prop to gain ground clearance, and load the engine so it doesns't over-rev, and by going to a 3-blade, you don't have to use too much pitch either. On some planes, too much pitch causes over speeding of the airframe, leading to flutter. More pitch also means faster landing speed. Something like a Mejzlik 18-10 3 blade should do the trick. Although you will have to get a new spinner along with it.

BigBirdFlyer

My Feedback: (13)

A 2 blade prop on a motor that small will work better for aerobatic or 3D flying. Stay with a Mejhlik or Bolly 18 X 10.
You won't be sorry.

Red7fifty

My Feedback: (73)

I am sorry, sorry I replied that is.

BigBirdFlyer

My Feedback: (13)

Nevr be sorry for what you post. We all have our opinions.

SAL98

My Feedback: (6)

Thanks for the informative info, just what i wanted to know.
I actually tried a 20 x 8 cut down to a 18 x 8 which seems to let the engine overrev. So i think that 18 x 10 might work. One other problem is that the hubs of these 18 inch props are sort of small. My engine has a 6 bolt hub arrangement.

BigBirdFlyer

My Feedback: (13)

I am not sure about all of the props . The 3W , Bolly , Menz and Mejzlik all have large enough hubs and are good props. I use a Mejzlik on a ZDZ 50 with a 6 bolt hub.
Make sure you get a drilling Jig to help line up the holes . It's the only way to guaranty that it will line up. Set your motor at TDC and the hold your prop horizontal to tell where the holes should be drilled. That way it will be in the right place to start the engine.
Good luck.

CGAV8R

My Feedback: (2)

I have used an 18x10 on my zdz40b, it works great.