Installing E-Prop tomorrow

[Bill3558]

You guys that have switched from Neuform, any tricks or suggestions?  An A&P is doing it. I’ll assist. But he’s not accustomed to working on LSA aircraft. 
I’m excited to see how it performs.

[Tom Baker]

The biggest issue is setting the pitch. The cheap pitch gauge that E-Props sells is worthless.

[Mike Koerner]

Yeah, the gauge is a hassle. You have to zero it on the hub and then make the blade angle measurements relative to that zero. But after a few minutes it assumes your done and deletes the zero reference. But you’re probably going to need more time because you have to tighten the blades enough so they don’t rotate accidentally when you’re making the measurement, but still have them loose enough so you can make tiny angle adjustments as needed.

Also, after you get the angle just right and start tightening down the bolts, that process changes the angle slightly. So, once you see which way its moving and how much, you have to readjust the angle factoring in the expected change.

Finally, in my case, the initial recommended pitch was too flat, so after a flight test I had to reset it. Fortunately, I was able to converge on a good setting the second try.

All in all, it’s not unusually difficult... as aircraft maintenance goes.

[Jim Meade]

I haven't installed the E-Props on my CTSW yet, but I have installed in on my Rans S-7S which I've just started flying.

I got along OK with the E-Props pitch gauge. 

The instructions tell you how to calibrate the gauge, where to place it on the blade, and which order to tighten the bolts in and it seems to work.  Interestingly, when you get really close to the right angle with the blades loose enough to twist them by hand, you snug the bolts down a bit and then you use a rubber mallet or the equivalent to tap the blade near the hub to nudge the pitch angle to where you want it.  Then you finish tightening in the recommended order and double check the angle didn't move.  Sounds crazy but works.  In other words, I simply followed the instructions just as given.

FWIW, I have only 4.3 hours on my Rans so far, but the recommended pitch from E-Props seems to be spot on.  My initial WOT RPM is 5680, which will do until I get the airplane wrung out a little more and can take another look at the prop pitch.

[FlyingMonkey]

10 hours ago, Tom Baker said:

The biggest issue is setting the pitch. The cheap pitch gauge that E-Props sells is worthless.

100% agree.  I tossed it and used my Warp Drive protractor.

[FlyingMonkey]

Be sure to carefully check the clearance between the spinner and the cowl.  It's a pretty tight fit and mine only has a few mm clearance on one side.

[Madhatter]

The digital protractor they send has poor repeatability  and so do others. After initial flight tests I use the digital protractor to make an adjustment on one blade and then use a machinist"s bubble protractor to  match the other blades. Bubble protractors are far more accurate for repeatability. 

[FlyingMonkey]

8 minutes ago, Madhatter said:

The digital protractor they send has poor repeatability  and so do others. After initial flight tests I use the digital protractor to make an adjustment on one blade and then use a machinist"s bubble protractor to  match the other blades. Bubble protractors are far more accurate for repeatability. 

That matches my experience.

[FlyingMonkey]

Just as an FYI, here's the kind of performance I'm getting with my e-Props propeller.  I took this the other day so ya'll can see the entire panel and all instrumentation. As you can see altitude was ~3000ft MSL (~2100ft AGL here), OAT 67°F.  The autopilot is on and tracking, this was a steady state with no acceleration/deceleration and vertical speed was zero.  RPM was right at 5000 (looks a hair higher in the pic due to parallax).

Speed is 113 KIAS, 119 KTAS, 118kts GS.  As you can see I had about a 5kt tailwind, but 113 KIAS is pretty darn good for 5000rpm @ 3000ft.  This airplane has the smaller wheels & tires so Tundra-equipped airplanes will probably be a bit slower.  This prop is pitched pretty much exactly as e-Props recommends:  5500rpm at WOT at cruise altitude.  Mine might get 5550rpm or so, but it's not enough difference to re-pitch.  WOT I get 125+ KIAS, climb is 1100-1200fpm solo.

 

 

 

[Towner]

Just curious what kind of speeds you were seeing at similar settings prior to the prop change. Also, what kind of fuel/passenger weight were you carrying?

Mine has always seemed slow compared to what everyone else gets! I’d love to gain some speed, but I’m not sure I’m willing to spend that much money for just a few knots.

Jeff

[Anticept]

Fairings make a difference. If you don't have those on, they will cost a few knots.

As for airspeed otherwise: Everyone's aircraft isn't just different on the outside, but the internals are a factor too. You might not be as slow as you think, but your pitot static system might have some quirks that cause it to read lower.

If you fly abeam to someone and you both set the same RPM, that will tell you a lot.

[FlyingMonkey]

35 minutes ago, Towner said:

Just curious what kind of speeds you were seeing at similar settings prior to the prop change. Also, what kind of fuel/passenger weight were you carrying?

Mine has always seemed slow compared to what everyone else gets! I’d love to gain some speed, but I’m not sure I’m willing to spend that much money for just a few knots.

Jeff

Speeds are so condition dependent, it's hard to say what the exact differences are.  At 5500ft I used to get 127kt TAS at 5400rpm.  I now get 131-132KTAS at the same altitude and rpm.  I do seem to be faster in mid-range...I don't think I'd get 113kt indicated before the change at 5000rpm.  Probably more like 108kt.  These speeds are all at my typical setup, which is solo (I weight 190lb), with ~20 gallons of fuel, and whatever junk is normally in the airplane, probably 25lb or so.

But even if you don't gain anything at all from an e-Props in performance, you still gain -- because it's 8lb lighter than a Neuform.

[Madhatter]

Less vibration over entire rpm range, much better climb rpm for very good rate of climb. Gets off the ground quickly due to increased initial acceleration. 

[Towner]

Thanks for the response. For me, it’s kinda like adding a new sky view or g3, I really want to, but can’t justify it (especially to my wife). Plus, I get to have my first hose replacement this year! Let’s see how that goes. I haven’t told her about the hose change expense yet. Wish me luck!

[Bill3558]

This is where we are after 5 hours. Suggested pitch was 24.8.  Engine went immediately to redline. Made 2 more adjustments to 27.5.  Engine now turns 5500 static. Seems excessive but I’ll see how it flies when weather permits. 
Are you guys turning 5500 full power static run up?  I expect we need another 2 or three degrees.

Appreciate any comments or suggestions. 

[Bill3558]

E-prop manual says go fly if static run up is between 5100 to 5800. That don’t sound right. 5100 maybe but 5800?

[FlyingMonkey]

1 hour ago, Bill3558 said:

E-prop manual says go fly if static run up is between 5100 to 5800. That don’t sound right. 5100 maybe but 5800?

It's correct.  My rpm on takeoff roll starts at 5700+ and then goes down as the airplane accelerates.  The e-Props are opposite of most other props, which start off at lower RPM then get faster as the airplane accelerates.  It's a little weird, but you really only notice it when you start the takeoff roll and see the RPM close to the redline...

[Bill3558]

Well okay then.  Thanks FM.  Can’t wait to fly it. 

[Bill3558]

Do you remember what your final pitch is?

[Tom Baker]

In my limited experience what you will see static will be close to what you see unloaded in cruise. I don't have a record of the final pitch of the one I set up, but I remember asking Coppercity about hi blade angle, and mine was close to the same. For the life of me I can't find the post anymore.

[FlyingMonkey]

Somewhere e-Props has a pitch recommendation for Rotax as a starting point, I think mine was very close to that.  Check their youtube channel.

[Bill3558]

On 5/12/2022 at 6:03 PM, FlyingMonkey said:

It's correct.  My rpm on takeoff roll starts at 5700+ and then goes down as the airplane accelerates.  The e-Props are opposite of most other props, which start off at lower RPM then get faster as the airplane accelerates.  It's a little weird, but you really only notice it when you start the takeoff roll and see the RPM close to the redline...

Are you turning 5500 in Level flight?  Thanks for your info. 

[Bill3558]

21 hours ago, FlyingMonkey said:

Somewhere e-Props has a pitch recommendation for Rotax as a starting point, I think mine was very close to that.  Check their youtube channel.

24.8 was their recommendation but the engine redlined at static run up. Currently at 27.5 degrees and turning 5300 in level flight. Will try to take out 1.2 tomorrow. 

[Anticept]

Did it go over redline or just right up against it?

[coppercity]

Both of mine are set to about 28.2 deg.  I see around 5670 static, 5200-5300 during climbs at Vy,  and 5500 at WOT 7500' Pressure altitude.  Our field elevation is 5000MSL with Density altitudes of 8000-9000' as a reference.