|Nov 19, 2011, 06:07 PM|
Dynamic Foamie Micro F117 (Modded to 3S) VIDEO ADDED!!
On behalf of Dynamicfoamy.com, I have been given the privilege to conduct a review of the Micro F117. I decided to use a 3 cell set up on this model, as I wanted increased power and speed. For thrust readings and my prop choice see post #2. I apologize for not completing this earlier, but the weather has been horrible lately and very recently finally let up allowing me to finish this review.
My build is modified and NOT using required equipment suggested by Dynamic Foamy. The findings therein, are per my experience and YOUR results may vary.
Kit Maker: http://www.dynamicfoamy.com/
• Laser cut white 3mm Depron foam parts
• Push rods
• Laser cut plywood motor mount
• Instruction CD for use in PC
• Length= 18''
• Wingspan= 12''
• Channel= 4
• RTF weight= 1.9 oz
• Skill= Novice+
Equipment as Suggested by Dynamicfoamy.com
• Rx/Tx= 4ch+ with elevon mix
• (1) 5 gram brushless motor
• (1) 10amp brushless control
• (2) 4.3g servos (max)
• (1) 3030 prop
Equipment I Used:
• Hobbyking 10 gram BL
• Specktrum AR6100E – casing removed for weight savings.
• 2 micro 6 gram servos (no name)
• Plush 6 ESC
• Lipos used
• (3 x Nanotech 160 MAH 25C 1S lipo’s in series)
• Nanotech 370 MAH 25C 3S
• GWS 4540 prop cut down to 3.25 inches (for Thrust readings see post #2)
• Specktrum Dx6i radio.
This kit is very easy to assemble, thanks for the laser cut depron, very helpful instructions, videos and plenty of pictures included on a handy CD. The interlocking construction is easy, and there are mot many pieces so the frame build is fairly quick. I used Beacon Foam-Tac for construction of airframe, and hot glue to affix the motor mount to airframe.
I painted my model prior to assembly using Krylon Fusion for plastics flat black which comes in a rattle can. I used many more light coats, as heavy coats may melt the foam.
I bevelled the hinge area and control surfaces using a hobby knife on a 45 degree angle (see pics) and used Beacon Foam-Tac to make light weight strong hinges. I later added packing tape as I found the Beacon Foam Tac came loose in the colder weather. As suggested in instructions, I installed the control rods using the included piece of fabic, CA and CA Activator. As you can see from my pics, I didn’t do a very neat job, as I used thicker CA when I should’ve used thin. Still, this proved to be very effective and held up well. I constructed the hinge system to allow for as much travel as possible. On high rates the control surfaces have more than a 45 degree deflection; this is very much needed for elevator.
The included rudder gauge was a handy tool in assembly, and made construction of the tail much easier than without; see pics below. It is very important to get the vertical stabs as straight and true as possible; I added a generous amount of glue to the base of the rudders to support them as much as possible.
You can see from the attached pictures, that the electronics placement has been moved from its original position. This was to correct for CG from using different lipo configurations. Naturally, for the lighter 3 1S lipo’s in series, the CG had to be more forward, and for use of a single 3S lipo the electronics had to be moved more aft; see pics below. I ended up using the 3S 370 nanotech as it provided a better rate of discharge and longer flight times. The electronics have been secured using Beacon Foam-Tac, and Velcro where necessary. Lipo is also secured via hook and loop Velcro.
The only frame pieces I did not install were the flat top panel sections which hide the electronics. I did this at first as I knew I would be moving around the electronics for accommodate lipo scenarios. However, as explained later on I left them off.
Regrettably I did not use the included decals, as they would’ve looked very nice and are of high quality. I would use them now, but the model is all beat up from testing.
I added 2mm CF tubes, to the leading edge of the wing for durability and found this to be a very effective in crash ability, and is highly recommended.
Ready to Fly Weights:
• 3 1S Nanotech 160 MAH 25C lipo’s is 74 grams RTF produces 104 grams of thrust.
• 3S Nanotech 370 MAH 25C is 102 grams RTF and produces 115 grams of thrust.
FLYING (Outdoors only):
While this model will fly on 3 1S lipo’s in series, I found that the discharge rate was less than desirable and flight times were shorter than expected. Now, this could’ve been very well because of the colder temperatures, it is fall after all, and during the summer months this would likely be a very different story. However, due to circumstances, I opted for the heavier 3 cell lipo BUT was not disappointed in this decision.
This is a hand launch only model, and requires throwing the model into the wind, at a 45 degree angle at 80-90% throttle. This at times was sometimes tricky, and can be dangerous if your hand were to get caught in the prop. I did this safely by holding onto the center section of fuselage, would throw underhand at 45 degree angle and follow through with arm movement. Like all hand launch models using a prop, one must be careful not to injure themselves.
Once I had the electronic placement figured out to accommodate the larger 3S lipo, I then attached the flat top panel sections; HOWEVER, for what ever reason the model would not fly and crashed many times on hand launch. The F117, would quickly become airborne, and torque roll to the left side, time after time. I tried to make this work, but could not. I’m not sure if my electronics were causing airflow issues, or some other negative aerodynamic event was occurring. In the end I choose to leave them off; this is not to say that there is a problem with the airframe. As stated before, this is based on my findings and YOUR results may vary.
Due to a high wing loading, the F117 needs a good amount of speed on landing, and lots of elevator to flair the landings. Flying over grass is recommended and easy on the airframe. This model was strictly flown outdoors, and is much to fast to fly at my indoor venue.
This model flies very well and I was genuinely impressed. Once airborne, I would fly at 100% throttle nearly 90% of the time, and the F117 was quite at home. She tracks straight and true and doesn’t mind the wind at all, which is good for flying in my neck of the woods. I did find that she likes lots of elevator travel for altitude changes, yet aileron travel was quite different and required far less travel for basic flight.
I thoroughly enjoyed flying this model, yanking and banking her through tight circuits. I would estimate that the F117 can reach speeds of 45 MPH or perhaps more which in my opinion is impressive for a flat foamy model. It is small in size, and looks faster in the video than it actually is. Perhaps someone can do a doppler reading from the video.
Once again, this model has a high wing loading and slow flight, below 60% throttle is not going to happen for this model, especially with my set up. When dropping below 50% throttle, the model rapidly stalls, and goes into a flat spin type action and quickly seems Terra Firma. This is not a slow flying model though, and is not the F117’s intended purpose.
If you’ve ever heard of a flying lawn dart, well then, this model when it goes down fits the description very well. Most of the time on crashing, the nose of the model would be stuck in the ground, giving the appearance of an arrow head. During my testing, she was crashed many times, leaving many battle scars, but I was surprised at how well she held up to crashes. I credit this to using Beacon Foam Tac, which makes flexible joints and the use of 2mm CF rod to the leading edge of the wing.
• 3S 370 MAH 25C lipo, flight times averaged around 5 minutes at 100% throttle nearly 90% of the time.
• 3 1S 160 MAH 25C lipo’s in series averaged around 3.5 minutes at100% throttle nearly 90% of the time.
Aerobatics/Special Flight Performance:
Loops tracked very well, and with lots of elevator were performed with ease. Time after time, the F117 would navigate loops holding its heading very well and would not alter course and or topple at top of loop.
Rolls are very scale on low rates, yet still quite quick. On high rates it rolls like a drill bit and is quite fun. The Aileron function of this models Elevon Control surfaces is much more sensitive that that of Elevator. Rolls I found were very axial and tracked straight and true even in higher than desired wind conditions.
Unfortunately, for whatever reason I could not get my F117 to fly inverted, it would always pitch over, and transfer into a roll and my many attempts were fruitless. I will continue to attempt inverted flight, and seek a calm, or a no wind day which should help.
Is this model for a beginner?
I do not feel this model would be good for beginner due to its high wing loading, and need to fly fast; not to mention its quick agility. However, it would likely be a great 3 or 4th model once the pilot has some experience under his or her belt.
What I did different\recommendations:
• 3S BL set up
• Did not use flat top panel sections as explained prior.
• I HIGHLY RECOMMEND Adding cf to leading edge of wing for durability
• Allow for as much as control surface travel as possible; epecially for elevator function of Elevons.
In conclusion, I would like to send a special thanks to Bert at Dynamic Foamy for supplying the model and my brave camera man Glenn. This model flies great, and is highly recommended as a fast flying, yank and bank smaller park jet, which surprisingly handles wind very well. If I have forgotten anything, or if you have any questions, please don’t hesitate to ask.
ImagesView all Images in thread
|Nov 19, 2011, 06:10 PM|
I tested various GWS props with a hobby king 10 gram brushless motor, using a plush 6 esc, on 2 and 3 cell. The cells I used were 1S nano tech 160 25C. I tested these props in the pusher configuration
Here are my thrust findings in grams, I didn't get amp readings (sorry)
3S = 82 2S = 50
3S = 91 2S = 53
3S = 135 2S = 86
3S = 155 2S = 104
3S = 140 2S = 100
The GWS, 5030 prop is clearly the winner in thrust generated
this F117 can only accommodate a prop that is 3 1/4" long, which means the 3020 and 3030 would work,. but I also decided to try some cut down props.
The results are as follows.
I cut the following props down to 3 and 1/8 inches long.
3S = 104 2S = 60
3S = 94 2S = 54
3S = 93 2S = 57
Concluding these tests, I'll be using a 4540 prop, cut own to 3.25 inches
|Nov 21, 2011, 11:24 PM|
Forgot to mention, that I also flew this model on 2S Nanotech 370 25C lipos, and would fly, but didn't have nearly the authority the 3S did.
|Nov 27, 2011, 06:33 PM|
Canada, ON, Muskoka
Joined Jul 2011
Very well done Ryan,
I can attest to the accuracy of the opinions given in this review, I was the guy on the camera. This aircraft is fast and nimble, yet in the hands of a very competent flyer such as Ryan, it was a joy to watch it dart around the sky.
|Nov 28, 2011, 12:16 AM|
Thanks for the kind words Glenn; hopefully I can get her up again soon.
|Nov 28, 2011, 08:18 PM|
Joined Oct 2009
Hmmm, lot's of wind noise, and not close enough for me.
If you make another video, get some straight flights, closer, and write down the temperature while flying
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