Poll..Graupner 10x5 or Stock Solo Props?

[Jubalr]

Today I received a set of Graupner 10x5 props to try on the Solo. After a slight modification I mounted them up and flew them briefly in a hover. I thought it would be interesting to get the feedback of fellow pilots to see what their opinion is. I used the front camera on my cell phone to view the flights while also filming from the GP. For those that aren't familiar with them, Graupner props are made in Germany and are some of the finest props available. They are slightly stiffer and also have slightly more pitch to them. Obviously, there is no post stabilization done. So point out the vibes if/when you see them. Both flights were done in manual mode from takeoff to landing. Time between flights was roughly 3 minutes, so conditions should be the same.

So take a look at the video below and vote your opinion, I appreciate it.

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[Marich]

Interesting... I ordered myself a set yesterday!
Any special mods needed besides putting in the hubs?
I've used Graupner stuff for years - absolutely amazing quality and performance. Your vid looks fine to me!

 

[Jubalr]

Thanks Marich, Didn't use the hubs. The hole in the props is too small to fit over the base of the studs on the solo motors. I increased the size of the prop hole but only to about 1/2 way through. That way the prop is centered and bottomed on the stud. Leaves just enough thread to get a good lock with the spinners.

 

[RolandS888]

What is the current draw with those props?

 

[Jubalr]

What is the current draw with those props?

Great question, so I loaded the logs in to MP to have a look. They were virtually identical in current draw with both flights between 18.5-19a

 

[RolandS888]

The stock props are softer than the Graupners and will provide a little damping in flight which is probably desirable. This is usually at the expense of efficiency, but if the Graupners cant do any better than the stock props in current draw (ie lower current) then I see no reason to change them.
A more efficient prop (using less power to acheive the same thrust) will also be quieter as it isnt thrashing the air as much.
I have seen some good numbers using APC MR and Mejzlik MR props whilst testing motor/prop combos on a thrust tester, certainly better than Graupners.
Graupners E-props were really good years ago when there werent the options for multirotors that there are now, they are still a good electric prop, one of the best, but nothing special for MR use. Graupner have now come out with their C-Prop for MRs which is very close in style to the stock Solo (and Ph) prop, but the efficency numbers are nothing special.
For gains in efficiency (lower power use, longer flight times, quieter) I'd be looking at trying APC 10x4.5 MR as the most cost effective alternative, (Mejzs are too expensive) then probably a motor change.
Also, the current you are seeing (around 18-19 amps) is hover current, the Solo current draw will reduce when in flight. I read the sweet spot is 6m/s, and whilst playing around with this I have seen my current draw down around 14 amps in level flight.
I do beleive 3DRs claim of 20 min flight times on 5200mAH is possible, but it isnt in a hover which is how most people gauge flight time.
That is how we are going to acheive longer flights - keep it moving.

 

[Jubalr]

The stock props are softer than the Graupners and will provide a little damping in flight which is probably desirable. This is usually at the expense of efficiency, but if the Graupners cant do any better than the stock props in current draw (ie lower current) then I see no reason to change them.
A more efficient prop (using less power to acheive the same thrust) will also be quieter as it isnt thrashing the air as much.
I have seen some good numbers using APC MR and Mejzlik MR props whilst testing motor/prop combos on a thrust tester, certainly better than Graupners.
Graupners E-props were really good years ago when there werent the options for multirotors that there are now, they are still a good electric prop, one of the best, but nothing special for MR use. Graupner have now come out with their C-Prop for MRs which is very close in style to the stock Solo (and Ph) prop, but the efficency numbers are nothing special.
For gains in efficiency (lower power use, longer flight times, quieter) I'd be looking at trying APC 10x4.5 MR as the most cost effective alternative, (Mejzs are too expensive) then probably a motor change.
Also, the current you are seeing (around 18-10amps) is hover current, the Solo current draw will reduce when in flight. I read the sweet spot is 6m/s, and whilst playing around with this I have seen my current draw down around 14 amps in level flight. That is how we are going to acheive longer flights - keep it moving.

Thanks Roland. I have used APC in the past and like them as well. This test wasn't for efficiency as much as it was for sound level and micro vibrations. Looking at the bridge in the above video, It appears to me that the Graupners are slightly smoother. Sound was a little different, but sound level was about the same.

 

[RolandS888]

Vibes is purely balance. Balance everything that spins and that problem will go away.

 

[J R]

Sure would love to jump into this thread but I've got nothing! You guys are way over my head! I am lovin' the learnin' though. Maybe in a year or so I can jump in on this one! Thanks for all of the educatin'!

Jerry

 

[Earldgrayjr]

Tried several props including DJI and carbon. I just don't like the stiffer props for filming. The stock props almost always need balancing. but once balanced I like those best so far.

 

[Projeffrey11]

Today I received a set of Graupner 10x5 props to try on the Solo. After a slight modification I mounted them up and flew them briefly in a hover. I thought it would be interesting to get the feedback of fellow pilots to see what their opinion is. I used the front camera on my cell phone to view the flights while also filming from the GP. For those that aren't familiar with them, Graupner props are made in Germany and are some of the finest props available. They are slightly stiffer and also have slightly more pitch to them. Obviously, there is no post stabilization done. So point out the vibes if/when you see them. Both flights were done in manual mode from takeoff to landing. Time between flights was roughly 3 minutes, so conditions should be the same.

So take a look at the video below and vote your opinion, I appreciate it.

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Sounds cool I can't see your video for some reason? what type of mortification did you have to do to get them to fit? I might be interested.

 

[Marich]

Sounds cool I can't see your video for some reason? what type of mortification did you have to do to get them to fit? I might be interested.

I'll jump in a sec... the only thing you really need to do is rebore the prop holes halfway through like Jublar said. The thread size is ok but the bore needs reaming to allow a flush fit.

 

[Projeffrey11]

I'll jump in a sec... the only thing you really need to do is rebore the prop holes halfway through like Jublar said. The thread size is ok but the bore needs reaming to allow a flush fit.

Do you take it to a machine shop for that or to like a RC store?

 

[Marich]

Doing them myself with a Dremel tool/drill press jig.

 

[Marich]

I'm trying to decide whether a set of T-Motor props would increase flight times enough to justify their price - fifty bucks apiece - and just don't know.
Going with a 3.3 pitch, current draw goes down a fair bit, the trade off being far less torque. In other words, slow take offs and reduced overall payloads. Heck, lowered performance all around.
Still, Solos aren't race drones. They take pitchers, moving and otherwise. We don't need to rocket into space like a Saturn V or be as maneuverable as Supergirl after five daiquiris.
I just dunno!

 

[Jubalr]

I'm trying to decide whether a set of T-Motor props would increase flight times enough to justify their price - fifty bucks apiece - and just don't know.
Going with a 3.3 pitch, current draw goes down a fair bit, the trade off being far less torque. In other words, slow take offs and reduced overall payloads. Heck, lowered performance all around.
Still, Solos aren't race drones. They take pitchers, moving and otherwise. We don't need to rocket into space like a Saturn V or be as maneuverable as Supergirl after five daiquiris.
I just dunno!

That would be an interesting test Marich, keep us up to date on that. I also have a set of APC MR 10x4.5 coming just to test as well.

 

[z-axis]

For gains in efficiency (lower power use, longer flight times, quieter) I'd be looking at trying APC 10x4.5 MR as the most cost effective alternative, (Mejzs are too expensive) then probably a motor change.

I will second the APC vote. I've been using the 10x4.5 MR on my other multirotors and they are awesome. After hearing all the hubbub about Graupner I got three complete sets of their E-props that everyone was talking about and, well, I was not impressed at all. They were all WAY more out of balance than my APCs ever were and much less powerful. I was disappointed in them but if anybody wants three sets of them, PM me and I'll be glad to sell them.

 

[J R]

I will second the APC vote.

Z or Jubalr,

I'd really like to try these APC props. I've got to start learning about the different possibilities. I found the APC site. Could one of you tell me exactly what I need to order? Will the props require modification?

Thanks,

Jerry

 

[z-axis]

Z or Jubalr,

I'd really like to try these APC props. I've got to start learning about the different possibilities. I found the APC site. Could one of you tell me exactly what I need to order? Will the props require modification?

Thanks,

Jerry

I would have already tried them but the hassle of doing the mod is not worth it to me. I will wait until more self-tightening props come to market, rather than trying to make my own. I would not be confident flying homemade self-tightening props.

That being said, you would need two each of:
10x4.5MR
10x4.5MRP

Oh wait, they now sell packages of two CW+2CCW
10x4.5MR-B4

Oh snap! I *just* saw that APC is making those in Self-tigtening. Very interesting development!
10x4.5MR(ST)
10x4.5MRP(ST)

Also, realize that this will change the thrust at the same RPM, and the 50% throttle position is based on the output of the regular solo props. I'm not sure if this will be compensated for by the flight controller + baro. Anybody know?

 

[RolandS888]

I'll tell you tomorrow.
Ive got a set of 11x4.5 on Solo at the moment, but its midnight here so I'll test it in the morning. Ive gone an inch bigger to see how they go.
Good to see APC are doing ST props.
You wont get the standard APC 10x4.5 MR props onto the stock solo motors, unless you tap an M6 thread into the hub, the hubs are too thick. Go for the STs instead.