Originally Posted by jbj620

Hello, I will be flying off of a grass runway with a AXI 2808/20 so the APC 8X8 "E" prop could be a good choice for this model. A 9" prop might not work well. Looks like larger wheels without wheel pants will be required at our flying field but my Lancair is far from complete (other major projects going on at this time ). Any other 2808/20 "short" prop suggestions? Thanks!

Assuming the APC "Sport" 8 X 7 Propller fits in the Propeller adapter....hub thickness?

http://www.apcprop.com/cgi-bin/store...1073&ppinc=apc

If so, then, this propeller would be an excellent alternative to the "E" 8X8 propeller as it will provide you with more a little more thrust but, yet will still provide you with speed once the model is in the air.

Here we go.......

Leave it to Tower having the APC "Sport" 8 X 7 propeller in stock and less expensive....looks good too!

Check their web site as it provides you with more details of hub thickness etc...

http://www2.towerhobbies.com/cgi-bin...?&I=LX1520&P=7

Originally Posted by guapoman2000

Here we go.......

Leave it to Tower having the APC "Sport" 8 X 7 propeller in stock and less expensive....looks good too!

Check their web site as it provides you with more details of hub thickness etc...

http://www2.towerhobbies.com/cgi-bin...?&I=LX1520&P=7

your were right the first time 8x8 e , 8x7 is a gasser prop

Originally Posted by mavdriver

your were right the first time 8x8 e , 8x7 is a gasser prop

No it is NOT! I use "Sport" propellers on my models and I don't see any Glow exhaust coming out of them.....

Spec's:
Computer-optimized design gives these props a thinner profile and
more "bite" with less noise.

Lightweight molded nylon construction reduces rotating mass
for higher output and longer life.

Reinforcing carbon fibers help maintain true, constant pitch at any rpm.
"C2" design.

Thickness at hub: 3/8" Hole diameter: 1/4"
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If your recall those Videos of my Great Planes Super Sportster "EP" was using nothing but, the APC "Sport" 9 X 8 propeller!!!!

Anything above 9 inch "Sport" the hub is too thick for most Electric Propeller Adapters and in this case I can agree, especially for this size model!

Originally Posted by jbj620

Hello, I will be flying off of a grass runway with a AXI 2808/20 so the APC 8X8 "E" prop could be a good choice for this model. A 9" prop might not work well. Looks like larger wheels without wheel pants will be required at our flying field but my Lancair is far from complete (other major projects going on at this time ). Any other 2808/20 "short" prop suggestions? Thanks!

Once again, I don't know if MotorCalc is using the APC "Sport" - "E" - or - "Pattern" Propellers????

However, here's the best I got....from MotorCalc...

Originally Posted by guapoman2000

Here we go.......

Leave it to Tower having the APC "Sport" 8 X 7 propeller in stock and less expensive....looks good too!

Check their web site as it provides you with more details of hub thickness etc...

http://www2.towerhobbies.com/cgi-bin...?&I=LX1520&P=7

A test and comparison between the APC "Sport" 8 X 7 and "E" 8 x 8 would be interesting considering the difference in the molded airfoil shape of these two prop designs. Hub thickness is not a problem with the AXI radial prop adaptor but the stock spinner could require some trimming or another spinner might be required. jbj

Originally Posted by jbj620

A test and comparison between the APC "Sport" 8 X 7 and "E" 8 x 8 would be interesting considering the difference in the molded airfoil shape of these two prop designs. Hub thickness is not a problem with the AXI radial prop adaptor but the stock spinner could require some trimming or another spinner might be required. jbj

I would bet on the APC "Sport" 8 X 7 as it is much stiffer than the "E" 8 X 8 and it retains it's airfoil shape the best....recall that it was stated that some Gassers use them on high reving Glow Engines that might reach 10K RPMs...

Originally Posted by guapoman2000

I would bet on the APC "Sport" 8 X 7 as it is much stiffer than the "E" 8 X 8 and it retains it's airfoil shape the best....recall that it was stated that some Gassers use them on high reving Glow Engines that might reach 10K RPMs...

I agree, no doubt that the "Sport" is a stiffer prop but the two props are molded in a different way. Of course, as you know, the difference is in how the pitch twist begins close to the hub and also in shape from this point to the prop tip (you would think that this design change is for a different RPM range... glow vs electric). Maybe we need a "Sport" and "E" prop of the same length and pitch for in flight comparison. Thanks for the 8 X 7 info., it would be nice to know which APC prop design MotorCalc was using. Regards, Boyd

Originally Posted by jbj620

I agree, no doubt that the "Sport" is a stiffer prop but the two props are molded in a different way. Of course, as you know, the difference is in how the pitch twist begins close to the hub and also in shape from this point to the prop tip (you would think that this design change is for a different RPM range... glow vs electric). Maybe we need a "Sport" and "E" prop of the same length and pitch for in flight comparison. Thanks for the 8 X 7 info., it would be nice to know which APC prop design MotorCalc was using. Regards, Boyd

Boyd,

I fly the APC "Sport" 9 X 8 Propeller in my 550 size Modified Brushed Motor/Gearbox combo and it propels my Great Planes Super Sportster EP like a Speed Demon I have tried the APC "E" 11 X 8.5 and of course this propeller was just too much AMPs but, it did provide significant air speed, the "Sport" 9 X 8 provides additional air speed as it is designed for Speed with it's robust airfoil yet slender to allow for good performance.

Honestly, considering the size and weight of this model that we are discussing here, I beleive either one will perform just about the same with the exception that the "Sport" 8 X 7 will provide you with some additional Static Thrust at low RPMs while you are trying to take-off from Grass field.

The rule of thumb that I was tought at the Club Field is you can try out a Propeller that was meant for Glow/Gas on a Electric Power System but, you never try out an "Electric" propeller on a Glow/Gas Engine!!! The reasons are quite simple, the Glow/Gas Engine will vibrate the "Electric Propeller" to pieces and the ramp up RPMs "or' combination of both.

Be nice that someone would try it out and you seem to be right on it.

This discussion is very interesting on the use of APC-E propellers, I have an UltraFly PC-9 which had a 8 x 6 APC-E propeller, I think that I had sy one stage shares in the LHS with the number of propellers that broke on landing. I fitted as it was the only thing available at the time a 8 x 6 Mastercrew propeller and too my surprise there was a major improvement in performance. Is there a rpm limit where the E propellers start to loose their bite..?

Originally Posted by Dennis L. Payne

Is there a rpm limit where the E propellers start to loose their bite..?

Had you ever heard those "ORANGE" GWS Slow Flyers make that noise while your little park flyer dived?

Yes, it loses bite because at the higher RPM's the airfoil flexes and deforms so, you no longer have the propeller that you thought you had .....especially propellers with low pitch speed !!

For those that are spinning above 8,500 RPMs on those Brushless Motors...I would think of investing on some "Sport" propellers, however, for the size of Brushless motors being used here and the size of this model (still on the small scale) you will not have anyone attempting to fly this little bugger too fast so, it really does not make that much difference here....

Hi guapoman2000, I heve never owned any Orange GWS propellers so never experienced the effect. However your explanaton is good I can see what could happen especially with those more flexible propellers, I shall get some Sport ones and check the difference. Thanks

Got my Lancair finished up. On the short bench test with the stock motor, APC 8X8E, and 1500 Mah 3 cell lipo, my whattmeter showed in the 8.5 amp range and around 85-90 watts. Does this sound correct? The testing was short lived because I have discovered now the factory did a nice job of stripping the holes in the motor the gearbox screws to. I now can't keep the pinion and spur gear meshing properly. I have since put loctite on the two screws, but I'm not gonna hold my breath on that working. I'm probably going to either have to change the motor in it, or maybe bite the bullet and do the brushless motor mod on it.
Another area that upset me was that when I screwed the front wheel assembly to the fuselage, the wood/fibreglass area that it screws to broke away. Very thin and poorly done area for that wheel to screw into. Also, the wheel pants??? Now that's some crappy thinking there on how all that goes together!!
Rest of the plane looks great, and went together nicely. Hope my motor woes aren't too much to sort out, and hope to maiden it monday or tuesday.
J

I have a buddy that just purchased this plane and he already burnt out the motor. So he is now upgrading to a brushless himax. Is 2815-3000kv too much for this plane. If not what is the best setup for him. Direct drives , gear box... What kind of prop ?

Thanks

Mark

I had two thoughts to add from yesterdays third flight report. Now that I have flown the plan with each of the three power configurations, I would say the stock battery and prop have to go bye bye. If you do nothing else, go 3s1p and the 8x8. the plane goes from barely flyable to a real nice flyer. I went with a 2100 mah so you can fly longer and enjoy it more. I'm not sure how long the stock motor and gb will last however. Putting in the AXI 2808 took the plane from really good to AWESOME! I will not have to worry about things coming apart, overheating or dying early. It's very quiet and no vibration. The other thing I forgot to mention is how easily the plane flys out of your hand since I didn't install wheels. I learned from the Hobby Lobby test pilot (see online warbird videos) to throw the plane with your left hand and hold the radio with your fingers on the right stick so you are ready for anything unexpected. You use your mouth to add the throttle when you're ready to launch. It works really well. Launching the Lancair has been VERY easy to do. All my landings have been very gentle as well. I noted that a lot of people say how much ground roll the plane needs.......even without the brushsless, the plane flew right out of my hand...no scary moments.

Enjoy flying this bird.