While making up some new motors for this puppy, I "discovered" that the prop plug was not fitting tight enough (actually, it falls out under its own weight!) most likely due to the shims added reducing the depth of the plug. This most likely caused the thrust trim of the recorded flights to change.
I've swapped out the shims with a full surface wedge plus a bit more, anticipating the reaction of more torque, and more depth to the plug.
Dumb boo-boo...
SAAB Fighter
Re: SAAB Fighter
Comparing Spammers to a pile of organic waste is an insult to the organic waste!
Re: SAAB Fighter
Well... the prop plug doesn't fall out from its own weight, but the added down thrust was still insufficient 
.
Last Sunday turned out to be hot, and practically breezeless, so out I went for another try. I was even able to draft my confuser guru and FB to video the "fright". 700 turns on the two-strand 1/8th x 12.5" motor produced the following:
https://youtu.be/IFcOZBf9x0k
John (OFPAF) suggested that I take out a bit of incidence and/or add a bit more nose weight. I don't care to add more down-thrust as it already looks funny, and changing the decalage will be a PITA. The glide is as near perfect as one could hope for, so it seems my best bet would be to use a Gurney strip on the bottom of the stab/elevator.
High winds forecast for the next 5 days, so I've got time to spare.
.Last Sunday turned out to be hot, and practically breezeless, so out I went for another try. I was even able to draft my confuser guru and FB to video the "fright". 700 turns on the two-strand 1/8th x 12.5" motor produced the following:
https://youtu.be/IFcOZBf9x0k
John (OFPAF) suggested that I take out a bit of incidence and/or add a bit more nose weight. I don't care to add more down-thrust as it already looks funny, and changing the decalage will be a PITA. The glide is as near perfect as one could hope for, so it seems my best bet would be to use a Gurney strip on the bottom of the stab/elevator.
High winds forecast for the next 5 days, so I've got time to spare.
Comparing Spammers to a pile of organic waste is an insult to the organic waste!
Re: SAAB Fighter
Warm, rather stiff breeze from the wrong direction and a crowded field (rc giant-scale glider guiders were taking advantage of the conditions) forced me to wait all afternoon til things quieted down. I was able to get two comfortable flights.
I followed OZPAF's suggestion about less incidence (a change is nearly impossible on this model) with a 1/32nd sq x 4" Gurney strip on the bottom of the stab TE. With 700 turns, I was rewarded with what can only be called a "perfect" flight of about 30 seconds. The left climbout was quite shallow, with NO hint of a stall and three circuits. Glide was also very nice - shallow and flat, turning left.
About 40 minutes later, 750 turns went in. Left climb, a bit steeper than the last flight to about 50' - again with no hint of a stall - transitioning smooth as silk to a left glide and a greased landing (this one was flown directly on our main flying field). Flight was about 40-45 seconds. About the only niggle is that the power turn could be a bit wider (~ 60 feet). Glide circle is about 80'.
Next is a light finish and canopy, then a flight with the present motor on full winds and then a bit more motor x-section (4 strands of 3/32nd).
I followed OZPAF's suggestion about less incidence (a change is nearly impossible on this model) with a 1/32nd sq x 4" Gurney strip on the bottom of the stab TE. With 700 turns, I was rewarded with what can only be called a "perfect" flight of about 30 seconds. The left climbout was quite shallow, with NO hint of a stall and three circuits. Glide was also very nice - shallow and flat, turning left.
About 40 minutes later, 750 turns went in. Left climb, a bit steeper than the last flight to about 50' - again with no hint of a stall - transitioning smooth as silk to a left glide and a greased landing (this one was flown directly on our main flying field). Flight was about 40-45 seconds. About the only niggle is that the power turn could be a bit wider (~ 60 feet). Glide circle is about 80'.
Next is a light finish and canopy, then a flight with the present motor on full winds and then a bit more motor x-section (4 strands of 3/32nd).
Comparing Spammers to a pile of organic waste is an insult to the organic waste!