Da-50 2 or three blade sizes!!

[red_noir]

Hi guys

I was wondering what sort of difference would I find between a two blade 22x8 and a three bladed 20x10 prop?

as a side note the two blade is a NX prop
and the three is a carbon mejlick prop

thanks

Chuck

[Shawn Berkheimer]

You would find that the 3 blade will give you about 20% less pull on the vertical and will feel sluggish on throttle response. The plus is that they are quieter and look cool. I use them on my 150 to quiet it down and for me the flatter power band is helpful. I however would not consider a 3 blade on a 50 unless my club had harsh noise issues.

Shawn

[FlyguyXII]

im am currently running a 20x10 mej 3blade on my da50. I have a few flights on it now and like it the pullout from a hover is slower but my throttle respnse didnt change much it is also 3-4db quieter on the same plane going from a 23x8 MX prop overall impression of the three blade is good i will try to get thrust figures in the near future when time allows

[red_noir]

Does the motor have to rev up higher to create the same thrust as the two bladed, or is that a non issue due to the fact there is an extra blade?

I'm not doing any crazy 3d just more sport flying and Imac if anythin. My main atraction to the three blade is the cool factor.

[enephel]

Hello.
I know this is an older thread. I thought I might ask here instead of starting a new one. I just ran my DA 50 today with a 20x10 3 blade Mej. The engine would not take any throttle at all so I set both needles 1 1/2 turns out after running it a few times I am now out 1 3/4 turns on low and I am still at 1 1/2 on high. I got 6700 rpms.

Is 6700 decent? I didn't have time to tune it any more as it was getting dark and it is cold enough to snow. How much more can I expect to get? 6900 maybe? 7000?

Thanks,
Jerry

[digger44]

Just wondering, has anyone tried the 21 x 11.5 Mejzlik three blade. TBM specs this prop for the DA-50. Seems like it might be a little much. My DA is on a can if it makes any differance.
Thanks

[digger44]

	Quote: Originally Posted by digger44
	Just wondering, has anyone tried the 21 x 11.5 Mejzlik three blade. TBM specs this prop for the DA-50. Seems like it might be a little much. My DA is on a can if it makes any difference. Thanks

I was hoping someone had tried this prop combo, but if not, which 3-blade would you guys recommend.

Thanks
Bob

[Boulder]

	Quote: Originally Posted by digger44
	Just wondering, has anyone tried the 21 x 11.5 Mejzlik three blade. TBM specs this prop for the DA-50. Seems like it might be a little much. My DA is on a can if it makes any differance. Thanks

That prop sounds like it's way too much pitch for the diameter. According to my 2 to 3 or 4 blade conversion chart, you would take the 2 blade prop and drop the diameter and keep the pitch. So being that we know the 23 x 8 is a great 2 blade selection, the best 3 blade would be a 21 x 8.

Another good prop is a 22 x 10, so a 20 x 10 3 blade would also be a good selection, but keep in mine raising the pitch would decrease your pull out from 3D maneuvers a little slower, like flyguy stated above.

[digger44]

Thanks Boulder, thats kind of what I thought. I'm not really big into 3D just yet more IMAC type flying for now. I'll probably try the 21x8.

Bob

[ULTIMATE1]

This can be found on TBM website 50cc Propeller TestingTarget Date: 11/2007
We are testing many props for 50cc engines to determine the best. Below is the info we have so far. We are waiting for some props to come in. We will retest all the props on one day and one engine for the most reliability.

PropRPMThrust Ranking#1 PT 23x8 6700RPM 27.5lbs thrust #2 JXF 23x8 6600RPM 26.52 lbs thrust #3 NX 23x8 6200RPM 26.53lbs thrust #4 Mejzlik 23x8 6500RPM 26.54lbs thrust #5 PT 22x8 7300RPM 24.55lbs thrust #6 TBM 22x8 7100RPM 25.256lbs thrust

To be tested:
TBM 23x8
Xoar 22x8, 23x8
Vess 22B, 23B
MSC 22x8
Ranking is the overall flying performance, not static test values. Both 3D and normal flying were considered.
Test conditions: DA-50 with standard exhaust on an engine well broken in. We used a digital scale tied to the tail of an airplane to obtain the static thrust. This is the thrust available to pull out of a hover. After static testing we flew the plane to determine the overall flying performance. Test plane was an Aeroworks 50cc Extra 260.
We found that the MTW TD75K canister muffler hurts performance. A DA-50 will lose a few hundred rpm and several pounds of static thrust. Since the canister muffler is heavy and expensive, it's only benefit is less noise (but you knew that already I'll bet).
http://www.troybuiltmodels.com/R&D.htm

[Flatlandman]

One more thing to consider on these 2 particular props is that the NX is one of the higher load 2bl props and the mejzlick 3bl is not so I wouldn't be surprised if their performance was a lot closer than some think.

[ULTIMATE1]

	Quote: Originally Posted by Boulder
	That prop sounds like it's way too much pitch for the diameter. According to my 2 to 3 or 4 blade conversion chart, you would take the 2 blade prop and drop the diameter and keep the pitch. So being that we know the 23 x 8 is a great 2 blade selection, the best 3 blade would be a 21 x 8. Another good prop is a 22 x 10, so a 20 x 10 3 blade would also be a good selection, but keep in mine raising the pitch would decrease your pull out from 3D maneuvers a little slower, like flyguy stated above.

What you guys missed is the Mezlick 21x11.5 is a narrow blade and works awesome on the DA50