FlyingMonkey Posted October 19, 2022 Report Share Posted October 19, 2022 15 hours ago, 207WF said: I think the "constant speed" effect is not the blades flexing (they are much stiffer than the Neuform) but rather the washout in the blades near the hub. I think that during climb the center portion of the prop is stalled, and less of it is stalled in cruise. I agree, they didn't go into details but this is how the factory described it to me. I think it's a variable rate twist & thickness on the blade that changes along the length so that depending on RPM different parts of the blade become more or less efficient. Quote Link to comment Share on other sites More sharing options...
Jacques Posted October 19, 2022 Report Share Posted October 19, 2022 a bit of this,a bit of that, add some french accent..and magic happen Quote Link to comment Share on other sites More sharing options...
GlennM Posted October 30, 2022 Report Share Posted October 30, 2022 I finally got my CTSW back from annual new engine, new e-prop. I think I need to take 100rpm off the top end by adding some pitch. I think the e-prop instructions lists the angle change per 100rpm. Now, I get 5630rpm at WOT,which gives me 129kts at 2500 feet. At 5500rpm, it is 122 kts, which is slower than the Neuform. I hope the pitch change at the first oil change will make the difference. It certainly climbs better! Quote Link to comment Share on other sites More sharing options...
Jim Meade Posted October 31, 2022 Report Share Posted October 31, 2022 For the Rotax 912 engines, E-PROPS says 0.6° change is 100 rpm. 1° is 167 rpm. I've been tweaking my 2007 CTSW with E-PROPS. Lately, I have it set to be 5500 rpm WOT level flight (auto pilot) 3,000' MSL quiet air. Speed is around 113-114 KIAS. Before, I had pitch set so RPM WOT same conditions was over 5600 rpm. My speed then was often in the yellow, like 120-123 KIAS. I'm going to take some pitch out and see what happens to speed at 5500 when I get WOT 5600. I have a Rans S-7S with new E-PROPS and am trying to get it set optimally. On that plane, I will set it a touch fast, like 5550. Still tweaking it. Quote Link to comment Share on other sites More sharing options...
GlennM Posted November 2, 2022 Report Share Posted November 2, 2022 Sorry. I should have mentioned my speeds are true airspeed from the Dynon calculation. I have been using them to compare the two. Thanks for the pitch setting info. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted November 2, 2022 Report Share Posted November 2, 2022 On 10/30/2022 at 12:13 AM, GlennM said: I finally got my CTSW back from annual new engine, new e-prop. I think I need to take 100rpm off the top end by adding some pitch. I think the e-prop instructions lists the angle change per 100rpm. Now, I get 5630rpm at WOT,which gives me 129kts at 2500 feet. At 5500rpm, it is 122 kts, which is slower than the Neuform. I hope the pitch change at the first oil change will make the difference. It certainly climbs better! I would re-pitch to the factory-recommended 5500rpm @ WOT and see what you get. My CTSW went from 127kt TAS @ 5500ft to 131kt TAS @ 5500ft with the E-Props. I also noticed that my speeds are higher at partial throttle...I now get about 100kt indicated at 4600rpm at -6° flaps! And the climb is definitely better. Quote Link to comment Share on other sites More sharing options...
207WF Posted November 21, 2022 Report Share Posted November 21, 2022 On a recent 22 hour trip I learned that if I climb at flaps 0 and 80 knots the eprop climbs me at greater than 650'/" to 8000 (at slightly above standard temps). Climb to 6,000 is 800 '/" or better. This bird now climbs like a homesick angel! I am set to get 5500 WOT at 9500', and about 5600 WOT at lower altitudes. Also, the fuel burn was 0.2 ghp less at my usual cruise settings. WF Quote Link to comment Share on other sites More sharing options...
Bill3558 Posted November 21, 2022 Report Share Posted November 21, 2022 Ain’t they great! Love mine. Wife wanted to fly today, a rare event. Flew over the mountains from Hendersonville NC (0A7) to Greenville Tennessee (KGCY) and back. Climbing to 7500 feet at close to GW, no problem. 120 knots TAS at 2350 rpm. Beautiful day to fly. Coming off the mountains to the flat Tennessee valley is a sight to behold. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted November 23, 2022 Report Share Posted November 23, 2022 On 11/20/2022 at 8:26 PM, 207WF said: On a recent 22 hour trip I learned that if I climb at flaps 0 and 80 knots the eprop climbs me at greater than 650'/" to 8000 (at slightly above standard temps). Climb to 6,000 is 800 '/" or better. This bird now climbs like a homesick angel! I am set to get 5500 WOT at 9500', and about 5600 WOT at lower altitudes. Also, the fuel burn was 0.2 ghp less at my usual cruise settings. WF Hmm...if I understand aerodynamics properly, you should get the best climb at the lowest drag, which would be the -6° setting. The speed will be a little higher, but it should be more efficient for extended climbs. I'm happy to be corrected if I'm missing something. I find my best climb to be -6° and 78-82 knots. For sure using some flaps can help to get best angle of climb (Vx) to clear obstacles or approaching terrain. My usual profile is: 15° flaps until 500ft AGL or so...then go to 0°...once above 70kts then -6°. I have not seen less fuel burn for the same RPM, but there is definitely less fuel burned for the same speed, since you can run a lower RPM to get the same speed as the Neuform would produce. So same fuel at higher speed or less fuel at same speed. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted November 23, 2022 Report Share Posted November 23, 2022 2 hours ago, FlyingMonkey said: Hmm...if I understand aerodynamics properly, you should get the best climb at the lowest drag, which would be the -6° setting. The speed will be a little higher, but it should be more efficient for extended climbs. I'm happy to be corrected if I'm missing something. I find my best climb to be -6° and 78-82 knots. For sure using some flaps can help to get best angle of climb (Vx) to clear obstacles or approaching terrain. My usual profile is: 15° flaps until 500ft AGL or so...then go to 0°...once above 70kts then -6°. I have not seen less fuel burn for the same RPM, but there is definitely less fuel burned for the same speed, since you can run a lower RPM to get the same speed as the Neuform would produce. So same fuel at higher speed or less fuel at same speed. We do get our best climb rate with reflex flaps and best angle with max flaps. Quote Link to comment Share on other sites More sharing options...
Anticept Posted November 23, 2022 Report Share Posted November 23, 2022 Don't know about the SWs, but best rate of climb for the LSs is 0 degrees. it's in the flight manuals. -6 is lower drag but if you have to increase AoA by pitching up more for the loss of lift, then you're not coming out ahead. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted November 23, 2022 Report Share Posted November 23, 2022 1 hour ago, Anticept said: Don't know about the SWs, but best rate of climb for the LSs is 0 degrees. it's in the flight manuals. -6 is lower drag but if you have to increase AoA by pitching up more for the loss of lift, then you're not coming out ahead. The POH shows zero degrees for best climb and best glide but its wrong on both. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted November 24, 2022 Report Share Posted November 24, 2022 16 hours ago, Eddie Cesnalis said: The POH shows zero degrees for best climb and best glide but its wrong on both. After testing for best glide I use 78-80kt @ -6° and that appears to work best for my airplane. I would think best glide and best climb would be similar, though a find a little faster than 80kt in the climb seems to do better. I have a feeling FD used a 15° flap setting for best glide in the POH to minimize configuration changes in an emergency and KISS. Quote Link to comment Share on other sites More sharing options...
Jim Meade Posted November 24, 2022 Report Share Posted November 24, 2022 Are you using engine out and if so stopping the prop for your testing? My take is that is the most likely - or maybe most critical - scenario in which one needs best glide. Also, are you testing at gross weight, most common weight, or which weight? Quote Link to comment Share on other sites More sharing options...
Anticept Posted November 24, 2022 Report Share Posted November 24, 2022 Technically, weight has no effect on best glide distance, it only affects glide speed. Regarding best climb: i checked the 2012 edition of the flight design poh. in that one, -6 and 0 appear to match. prior to 2012 editions, testing amounted to using a GPS and whatever read out on the instrumentation. for the 2012 models and later, testing methods were revised and many speeds were quoted a few knots too fast in older models. This is per Dave Armando. Anecdotally seems to be supported by my testing with my aircraft, 0 ends up being a tiny bit better. Haven't honestly checked that hard. Quote Link to comment Share on other sites More sharing options...
Tip Posted August 14, 2023 Report Share Posted August 14, 2023 My friend has a Zenith 750 with an O-200. Is there an e Prop for that setup? Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted August 14, 2023 Report Share Posted August 14, 2023 43 minutes ago, Tip said: My friend has a Zenith 750 with an O-200. Is there an e Prop for that setup? According to their FAQ they are working on them, and should be available when their expanded facility is completed. Quote Link to comment Share on other sites More sharing options...
CloudCatcher Posted February 6 Report Share Posted February 6 I installed a 3-bladed E-Props on my Tecnam and it has caused me to cruise uncoordinated and in a slip now. I'm getting notably better climb and cruise performance overall from the 3-bladed Sensenich prop I switched from, and the lower vibration on startup/shutdown is nice. But I went from flying coordinated to now half a ball out and right wing low in cruise. Increasing the bend of my rudder trim offset tab didn't help. Not sure what to do at this point and considering I may have to remove the E-Props. I guess it might not work for every airplane and could screw up the aerodynamics due to the increased thrust it makes and increased spiraling slipstream. Quote Link to comment Share on other sites More sharing options...
Jacques Posted February 6 Report Share Posted February 6 low wing or high wing Tecnam ? Quote Link to comment Share on other sites More sharing options...
CloudCatcher Posted February 6 Report Share Posted February 6 4 minutes ago, Jacques said: low wing or high wing Tecnam ? Low Quote Link to comment Share on other sites More sharing options...
Jacques Posted February 6 Report Share Posted February 6 I installed one on a friend's Tecnam Sierra ( low wing) and no bad behavior reported.. just better performance Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted February 6 Report Share Posted February 6 40 minutes ago, CloudCatcher said: I installed a 3-bladed E-Props on my Tecnam and it has caused me to cruise uncoordinated and in a slip now. I'm getting notably better climb and cruise performance overall from the 3-bladed Sensenich prop I switched from, and the lower vibration on startup/shutdown is nice. But I went from flying coordinated to now half a ball out and right wing low in cruise. Increasing the bend of my rudder trim offset tab didn't help. Not sure what to do at this point and considering I may have to remove the E-Props. I guess it might not work for every airplane and could screw up the aerodynamics due to the increased thrust it makes and increased spiraling slipstream. I did a switch on a CT from a Sensenich to a E-Prop, and the only thing I experienced was better performance and smoother operation. I expect you will find the issue to be something besides the propeller. Quote Link to comment Share on other sites More sharing options...
CloudCatcher Posted February 6 Report Share Posted February 6 30 minutes ago, Tom Baker said: I did a switch on a CT from a Sensenich to a E-Prop, and the only thing I experienced was better performance and smoother operation. I expect you will find the issue to be something besides the propeller. Like what? Before the E-Props propeller, I was flying coordinated. After, I was flying in a slip. See attached. Top is before, bottom is after. Quote Link to comment Share on other sites More sharing options...
Madhatter Posted February 7 Report Share Posted February 7 I don't see how a prop can cause an aerodynamic change. However if the engine is canted significantly or not enough maybe the more efficient thrust of the prop could cause the yaw. There is an answer but it will take some time and work to evaluate it. Quote Link to comment Share on other sites More sharing options...
CloudCatcher Posted February 7 Report Share Posted February 7 1 hour ago, Madhatter said: I don't see how a prop can cause an aerodynamic change. However if the engine is canted significantly or not enough maybe the more efficient thrust of the prop could cause the yaw. There is an answer but it will take some time and work to evaluate it. The plane is factory built so I can’t imagine the engine was mounted improperly. Quote Link to comment Share on other sites More sharing options...
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