Anyone familiar with the multi pitch props?

[acerc]

This one is the 170 boxer, the 210 boxer will be going into the Bulldog if I ever get around to building it. I did speak with Toni and he simply relayed Valach's spec. There are some real world numbers on Toni's engine page from a builder/flyer but he does not venture into 3 blade's, only two. The prop Valach list is a 30x14, 3 blade, and after I tried it I doubt they ever put one on an engine. The 32x12x3 pulls so hard it is difficult to hold the aircraft back, the 30x14x3 I could hold with two finger's.

 

[Snoopy1]

This one is the 170 boxer, the 210 boxer will be going into the Bulldog if I ever get around to building it. I did speak with Toni and he simply relayed Valach's spec. There are some real world numbers on Toni's engine page from a builder/flyer but he does not venture into 3 blade's, only two. The prop Valach list is a 30x14, 3 blade, and after I tried it I doubt they ever put one on an engine. The 32x12x3 pulls so hard it is difficult to hold the aircraft back, the 30x14x3 I could hold with two finger's.

The only other advice I can give you is to go to JoeNall a have a look around there will be few motors there and the people are very helpful but then again it will most likely be on 2 blades and not 3 blade. .

 

[acerc]

I appreciate all of your advice and conversation. I think I have pretty much hit a dead end and will have to stay with where I am at. But I will try the 31.5 just to ensure I have exhausted all options. In the end, if Solo had the proper size for my app it would have been a far cheaper and a much easier route to have taken from the beginning. I looked at Solo back then but did not get past the cost, I am on my fifth prop and about to try another. At this rate I might not have to worry about taking it with me when I go. LOL!!

 

[acerc]

Today I had a revelation or the brain fart went away, don't know which. First I need to explain that when I went to a three blade I had the pulling power of the proper two blade to compare to. I get the thrust by hooking the fuse up to a digital scale and run the engine full throttle. The two blade was pulling around 62lbs and was superb in flight so I wanted to get nearest to that as I could. I went through three props before landing on the current 32x12x3 that works, thrust and flight performance wise, real well.
Today I got the Eagle out to do a good tune, I tweaked this way and that and just could not get the rpm's I was looking for. I finally settled on the idea that I would have to, for now, be satisfied with a well running engine. I was sitting on the patio taking a break from assembling the Eagle and thinking about whether I wanted to run and get the 31.5 prop next week. That is when it hit me, "Hey dumb ass, your not going to get the same rpm from a 3 blade as with a 2 at the same thrust as well as airspeed"!! Duhhhh...

 

[Snoopy1]

It is sometimes interesting when you are able to take a step back and look at it with different mind set. That is what is so good at work sometimes we would do drain storming session to get out of hole.

 

[natelivliv]

In my limited experience with these props, the effective pitch you should use is about halfway between the two advertised pitches, maybe closer to the smaller number (for example, a 14-6/10 would be closer to a 14-7 or 14-8). This was with glow stuff back in the day.

Also, APC is a better prop (more efficiency/thrust) in my experience and I'll bet that XOAR and Vess are better as well.

 

[natelivliv]

In my limited experience with these props, the effective pitch you should use is about halfway between the two advertised pitches, maybe closer to the smaller number (for example, a 14-6/10 would be closer to a 14-7 or 14-8). This was with glow stuff back in the day.

Also, APC is a better prop (more efficiency/thrust) in my experience and I'll bet that XOAR and Vess are better as well.

(for example, a 14-6/10 would be closer to a 14-7 or 14-8).





Bluestacks Kodi Lucky Patcher

 

[Snoopy1]

(for example, a 14-6/10 would be closer to a 14-7 or 14-8).





Bluestacks Kodi Lucky Patcher

I have tried those variable propellers and they never worked for me.

 

[natelivliv]

Also, APC is a better prop (more efficiency/thrust) in my experience and I'll bet that XOAR and Vess are better as well.




https://pasta-straw.com/

 

[TonyHallo]

Here's what you get when you run an APC on a giant scale engine, the prop broke in flight, 26" x 8", Zenoah GT 80. Only thing holding the engine on the plane was the throttle cable! Got it back to the runway and the plane stalled as the speed decreased as the engine had moved several inches back. The photo is from 2006, boy I loved station wagons.