Avro Vulcan in foam board from Model Aviation - Page 2 - RC Groups
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Nov 30, 2015, 03:07 PM
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Finished Flat Foam Vulcan


Here is a picture of the complete Vulcan. Details are in the last post. I installed the model settings in my Futaba 6EX-2.4 GHz transmitter. It has an Elevon mix choice in its menu. Need to remember to reverse Channel 3 to get the ESC to work, otherwise setup straightforward.
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Dec 02, 2015, 08:05 AM
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Thanks for the very informative and precise build thread. However, the most salient point is did the darn thing fly? If your final weight was under 14 oz., you should be pleased with the way it performs. I've had e-mails and videos sent to me with planes in excess of 20 oz. that required a larger battery than I specified, but still flew to the builder's satisfaction. I look forward to seeing a report of your rendition in the air.

Best regards,

Larry Kruse
Dec 02, 2015, 02:25 PM
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Larry
Thanks very much for your kind comment on this thread. I enjoyed putting the Vulcan together, and was glad I was able to keep the weight down. I used a few little triangles as keys to keep things square, and put a little two-way fiberglass tape along the bottom edges.

I'm not a very good pilot, so I'm waiting for the wind to settle down a bit before I try the Vulcan. I mostly fly free flight, so I know enough to get the plane trimmed on the ground, before I go out. I'm going to get the CG spot on by moving the battery.
Dec 06, 2015, 07:29 PM
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Vulcan Maiden Flight


My foam board Vulcan flies like a Vulcan! I took it to the field today to take advantage of low winds (5-10 mph) and a 6 degree over normal warm spell ( 45 degrees F - woo hoo). I installed a new 1000 mAh 3S battery I charged to about 12.4 V. I made a range check with the low power function of my transmitter and it was OK to about 200 feet at least. Neutral elevator was set to roughly 1/4 inch up, for a bit of reflex appropriate to a delta. I made a few "pancake" flights first. I launched at 45 degrees nose up with the throttle advanced to full. The plane pulled out of my hand. I let it go up about 6 feet and then my dumb left thumb pulled back the throttle too much and I let the Vulcan drop to the grass. I did find out that I wasn't getting roll with my neutral settings, so that was a good sign. After a couple more of these, and not much damage (see picture), I decided to go for it and kept my thumb off the throttle until the Vulcan got to altitude. Success! It took off at a 45 degree angle with the prop screaming. I was heading south west into the wind on launch, and I was able to make a left turn parallel to the east/west runway before I lost sight. I was glad I was three mistakes high, because I forgot to drop to low rates and roll was pretty strong when I pushed the stick over. I made a fast run along the runway direction with the sticks in neutral position, throttling back as I was going. The Vulcan held a steady course, slightly nose up and level side to side, during this run. I was able to turn at the east end of the field, but my turn into the up wind leg was too long and I crossed the fence. I dropped the Vulcan into the prairie weeds at that point without damage. I wasn't able to draft a photographer to come along, so no video. The Center of Gravity was 16 inches back of the nose, as shown on the plan, and there was no tendency to dive or stall.

I'm not having much luck with the motor. It seems to be binding now, and pulls too much current at full throttle. Looks like I'll need to find a new one before Spring. I'll be replacing the paper on the bottom panel with some silver Duck Tape for better grass resistance.

Took the bell off the motor and found the problem. There were three loose magnets. Needless to say the cogging was a lot worse than normal with three magnets sitting in one place. There is a thread dedicated to fixing this. You can fill the gaps between the magnets with epoxy and microballoons for one thing.
https://www.rcgroups.com/forums/show....php?t=2357100

Thanks Larry, for a great design!
Last edited by DuPageJoe; Dec 06, 2015 at 09:31 PM. Reason: Add note on motor problem
Dec 07, 2015, 08:39 AM
gpw
gpw
“There’s no place like Foam”
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JMHO, it might have been a LOT easier to make this a Pusher (motor on rear) and eliminate the draggy box and prop in slot structures ... Simpler airframe , Lighter , FASTER ... I believe the older MA articles had that ...
Dec 07, 2015, 10:32 AM
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gpw
Tastes differ. I like the launch with the prop forward of my fingers. The Vulcan was fairly easy to balance forward of the Aero Center when made this way too. I used the Dieffenbach slot, which is more open and might have less drag than the square ones. Motor was noisier than the prop. Got some JB Weld to fix that. (Iron filler shouldn't be a problem. The rotor the magnets are glued to is iron anyway.) I've got no problems with the airframe. I need to fly slower than I have already. So far plenty fast.

Nice thing about the DT foam is you can build any and all prop locations without breaking the bank. When will we see yours?
Dec 07, 2015, 09:03 PM
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gpw: Thanks for your interest and comments. The mid-fuselage motor location was consciously selected to make launching easy by simply releasing the plane by using the tail cone as a grip, and to keep the weight of the motor close to the CG. I suspect putting the motor clear at the aft end of the plane would make any anticipated weight savings problematic, and would certainly have made launching the plane an exercise in avoiding the Cuisinart prop!

Best regards,

Larry Kruse
Dec 08, 2015, 07:20 AM
gpw
gpw
“There’s no place like Foam”
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Gentlemen , Apologies , i was un aware of the danger, having perfected the launch technique (out of necessity) years ago .. It’s all in the follow through ...
That and I always take the easy way modeling Foamies .. and others prefer something different ... Which is all good eh !!!
Dec 08, 2015, 10:13 AM
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gpw
Thanks for appreciating my point of view. I've just now looked at your SkyRay thread. It's a fine looking airplane, much along the lines of the Vulcan, but with the rear prop. I've built an EZ Cruiser from Park Pilot with a similar CD-Rom motor and GWS prop with a prop saver but on the front. That's a high winger weighing 11 ounces and I have no trouble launching it. I assume you launch the SkyRay style plane with an underhand drop. Do you throttle up before or after you drop it?
Last edited by DuPageJoe; Dec 08, 2015 at 10:19 AM.
Dec 08, 2015, 10:23 AM
gpw
gpw
“There’s no place like Foam”
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~Half throttle . just a gentle push forward ....it just flies "out the hand” really ...

Our diversity is our strength .... if we all thought the same , we’d all be flying P-51s .... hahahahahahaha
Dec 09, 2015, 10:55 AM
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Thanks for the launch info. I might prefer a Van's RV-6 to a P-51, except in a dog fight.

Got my motor going again with two doses of JB Weld epoxy in the rotor. Secured the loose magnets with one dose, then put more in the gaps to keep the others from breaking loose. Reassembled OK, because the shaft and bearings were fine. After a day's cure, I ran the motor at 50% throttle and it was smooth, with 48 watts going in. That's close to what I got when I generated my test curves.

Waiting for another good day to test in the air.
Dec 13, 2015, 08:59 PM
Up! Up! And Away!
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Quick post to subscribe.

Looking forward to reading more flight reports down the road.
Jun 16, 2016, 10:34 PM
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My dad found the plans in the AMA magazine. He liked the design so he cut out the article, emailed me the plans file, gave me 2 motors, escs, and 4 servos and told me to build 2!

Well I got the first one done just in time for Father's Day.
Maiden this weekend! (Weather permitting)
I went with non traditional colors. My dad said to go wild with the color sceme when I asked what color he wanted it to be. LOL!

sent from my Note 4
Jun 17, 2016, 01:44 AM
Registered User
I like it!
Jun 18, 2016, 09:20 AM
Arizona Rim Country

can you post a plan


of your Father's Day Vulcan


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