Dean
Right now I am flying on 62 ft lines so the lap times will relate to that length. I'll probably increase to 63 which is the length I normally fly .35 size planes on (keeps Big Art from coming after me!).
I have gotten an inline tap to measure static amps with props before I fly them. I did get a few suprises before I did that.
I have the speed control set up as you recommend with 10000 rpm on an 8X4 and it produces 9800 rpm on the full size flight props.
The first prop I flight tested was an 11.25 X 4 Bolly 2 blade carbon fiber prop. If I had had the inline tap I would never have flown the plane with it but it was interesting and confirmed later what I thought. Lap times were 7 sec. Nope, not a misprint. Obviously I could not do much with it. But it did stay out there on the horizontal maneuvers. I did not attempt a square 8 but all the other horizontal maneuvers were there with enough line tension to be fliable. Was kinda like flying a small helecopter it was going so slow. Charge of the battery showed the problem. It took only 1515 mah to charge. Obviously the prop was not drawing enough amps. Assumption number 1 dispelled, lower amps are better. Not in our case. The prop would become usable at higher rpm, but I'm not going to change that variable yet till I learn from other options as it is.
Next I flew a zinger 11X6. This yielded 4 second laps and required 3600mah to recharge. Combat Smoothie! Something was obviously wrong. As I was waiting on 2 more batteries that was my practice session. I got home and checked that zinger 11X6. Suprise! One side was indeed a 6 inch pitch, thr other side was 8 inch! Zooom!. Guess you can't trust anything you read anymore. Pitched that puppy (as opposed to repitched). I have a charger that balances as it charges so I was able to bring the battery back up without issue. All the cells were discharged the same so no problem there.
Next day 2 more batteries arrived along with the inline tap so now I could pretest before going to the field. I did the following props with these results with props with pitches measured pre testing, all at 9800 rpm:
Prop static draw flight lap time mah drawn notes
Revup 11 X 5.5 36 amps draw to hi not flown weather 48 degrees, wind 8 - 12 mph:
Zinger 11 X 4 19.4 amps draw to low not flown
Zinger Pro 11 X 5.5 32 amps usable not flown yet unloading in air should let it be usable
APC 11X5 26.5 amps 5.0 sec 2380 mah too fast; excellent line tension
APC 11X6 33.4 amps will be too fast not flown
APC 11.5 X 4 wide 27.2 amp 5.3 sec 2640 mah good line tension throughout
The apc 11.5 X 4 worked decently. It is the wide blade prop we have been using in 3D RC flying. I doubt it is a final prop but certainly usable and I can trim the plane with it. Battery temps were 104 degrees right after landing and at the cold outside temps I don't think this means alot at this point except that Frank Carlisle's internal air flow design works fine. At this point I need to trim the plane some as I am not used to flying planes of this era. Once I get my handle dialed in then i can start to work more on prop selection and refine the power setting. I did have one flight with some pretty good gusts, probably near 18 mph in the overhead 8. No line tension issues at all. The governor does a pretty fair job of maintaning power. My most noticable observation is that you need more than 4 batteries. You fly flights a fair number more flights in a given period of time with electric than glow power. After repositioning the plane, its only 10 or 15 seconds to refuel and turn the switch to go. You can do alot more practice in a given time period. Nice that power quest has decreased to price of their 4000mah 4 cell to under $100 at Hobby Lobby. I am doing a second electric smoothie, this one an ARC so I can fly it in classic and not take the appearance points hit.
Dean, what other 2 blade props would you suggest I try based on what info I have presented so far?
Bob Branch