Rudy,

I wish the weather here in the north east would let me keep up with your development/fun/pratice on my Electric Bearcat.

28 degrees as I speak this morning,  April 6. 


Linheart

 

Hi Guys,

Linhart,

I am sorry to hear about your poor flying WX. 28 degrees is just plain cruel in April! :-(   I hope you get to fly soon. I moved (escaped?) out here when I was 17 and never went back! I do remember flying in the snow as a kid. We would tramp out a circle and fly. I still have the scars on my fingers from being cut by the sharp nylon props. We did not know that you were supposed to sand them 1st :-(  We did not even know how much we were cut until we got home and our fingers thawed out. The oil and Nitro in the cut did not help the healing! ;-)

I won't be rude and mention what our WX is here, but I have been able to fly a little more than you have. The good news is that the calendar is in your favor, you should be flying that beautiful Bearcat real soon. :-)

Alan,

Good point about the grass. I should have mentioned that. 90% of my flying is in the park, on grass, near my home. Your right, you have to get used to the sound of the power needed to start the TO roll safely before launching the plane. It only took a few flights before I got it right. I started on the "high" side and backed into the correct amount of power needed before pulling the stooge sting.

It helps that my planes are set up for grass. My P-40 and Vector-40  have the gear well forward, axles approx. >1" ahead of the wing, and 2.5" wheels. When I said in my prior post that the plane barely moves upon release, I should have mentioned that the power was already coming up so that there was a good airflow over the Stab/El to help prevent a nose over. I'm sure it will be even better next week when I fly it off our cement club field.

RE: Props. That is a subject that deserves it's own thread! ;-) ...... It is interesting that you and Linhart both have such good success with higher pitch props. I think he uses an APC 12 x 6 to fly his beautiful Bearcat. .......It goes against the current thinking of less pitch and more diameter, but it is hard to argue with success! :-) 

I use a Bolly CF 3B 11 x 4 prop from Randy Smith @ approx. 11,500 RPM.  It pulls my 56 oz. 560 sq. in wing area, Profile P-40 at 57 MPH and a 5.0 Lap time (62' eye to eye lines + 5' for; arm, LOs, handle, and 1/2 wing). This is a PERFECT set up, (Thanks for the advice Randy! ), giving excellent line tension throughout the entire flight and giving a good pace to the maneuvers. I use 3,000 mAh from my 4,200 mAh TP 14.8V battery for a 5 min. 10 sec. flight.

Linhart, Alan,

It looks like 2007 will be a very exciting year for Electric CL. As soon as you guys back East start flying this year we will see more and more great ideas coming from your "Eastern Flyers" braintrust! Sparky's excellent forum has made it possible to have our minds function like the "BORG". This should allow us to move ahead at an accelerated pace.  :-)

I hope the WX gods smile on you soon. 

Regards,
Rudy
Hermosa Beach, CA

Had my first flight in three months today.   The timer was set for only two minute because I have got to reset the motor speed back to where it was before I tried Heli mode. 

Dean,  I set the ESC to Heli Fixed point (to get the desired static RPM), How does this differ from Heli high and Heli Low?

Hello All,

This morning (4-21-07) dawned 60 degrees and 0-5 mph here in Boston Massachusetts.  My batteries were charged and so were the airplanes.  Off to the field I went at eight am. 

The JMP3 timer was set up for four minutes.  I enjoyed four flights with Electric Bearcat back in good Trim.
Guess what.  The ESC was set on Heli Fixed Points.  The motor spooled up for the rolling T.O.  It spooled down for that power on Two wheeled landing and it gave me a two Blip warning. 

I was alone as usual and really wished my fellow Electric Enthusiast were there to share the beauty of the moment.

Thanks to Robert Storick, I can at least share my experiances on this forum.

Linheart

   

I am using the JMP2 timer on my Super Clown with the stock motor (kV=1500). I have to run in the low governor mode to get the rpm in the range I want for higher pitched props 8k to 10krpm. Unfortunately the JMP-2 throttle increment (64 steps from off to full on) ends up being ~800rpm per step. It does make it tough to get the "just right" rpm I need for a given pitch. I tried the high governor mode, but then I was tweaking down at around 1/4 throttle onthe jmp2 timer to get ~12krpm. Since I wanted to go lower, I was stuck I thought. Maybe I should just give up Heli governor mode.

But it is a lot of fun to play around!

Rudy,

I am loving this "Heli Fixed point" mode.  With an APC 12-6 electric prop the Bearcat is flying insides and outsides, verticals and hour glass with proper line tension.  I can hear the prop sing differently on the verticals and overheads.

The 4000 amp hour polyquest are consistently recharging at 3.18 amps.  My JMP 3 timer is set for 34 secs
zero RPM.  Total time 5:15.  This is JUST enough time to complete the pattern.  The static RPM  starts out at about 9000 the settles quickly to 8600. 

Hi Rudy,
The HI or LOW governor mode decision is based on the number of electrical cycles per mechanical revolution.
It's actually the commutation RPM range. Though not an exact method, most motors "cog" once per phase. The AXI 2826/10 has 14 cogs per rev.
The lowest I can get it to run is maybe 6,000 in the HIGH range, then you fall off the low end of the ESC RPM versus pulse width curve. Everything from 1000 uS to maybe 1200 is dead stop. This happens at about 2000 RPM in the low range with the AXI.

The maximum RPM that can be commanded may be very high. I don't know what it is, because I have never put a high enough voltage battery on the motor to see where it will go. If your motor cogs fewer times per rev, you may need the low range.

Hi Linheart,
So how did you get the JMP to give you a warning blip? Did I miss the explanation?

later, Friends!
         Dean P.

Thanks Alan,
It's good to know that you didn't need to do anything extravagant.

Dean