Hip Pocket Builders' Forum

Outdoor Free Flight Forum => Proven Techniques in building, trimming and flying models => Topic started by: lowrpm on May 02, 2014, 11:44:36 PM



Title: acts like a duck,walks like a duck
Post by: lowrpm on May 02, 2014, 11:44:36 PM
Must be a Canard. what is the trim adjustment for adding turn on these guys? Does Foreplane tilt add more turn ?would left tip up on canard=left turn.
Thanks again,
John


Title: Re: acts like a duck,walks like a duck
Post by: Dave Andreski on May 03, 2014, 03:55:41 PM
lowrpm,
Yes, foreplane tilt will effect the turn but it's the opposite of what you stated in your question.
Tilt the front wing/foreplane DOWN on the side you want to turn towards.
It worked on the one I built.
Dave


Title: Re: acts like a duck,walks like a duck
Post by: lowrpm on May 05, 2014, 01:28:00 AM
nice zephyr you got there Dave!. I built one as well. I spent about 2 hours trying to trim this model at the indoor fling today.  I could not get it to climb let alone turn :-[ this is my first canard and I had high hopes when it just crawled along in a test glide but under power of the suggested rubber...1/8 and the prop as per plan it just wouldn't get on step. Did you increase the front wing incidence for a better climb?
Thanks for the response,
John


Title: Re: acts like a duck,walks like a duck
Post by: Dave Andreski on May 05, 2014, 12:36:25 PM
Thanks John.
It was a fun build that was only flown outdoors on several occasions. I remember flying with 1/8" rubber at night and it would only get about 15 feet off the ground but that was OK with me.
Later flights with .155" rubber and some breeze were interesting because it would go up and backwards with the prop slowly churning away as the prop tried to 'grab air'. I ended up trying .170" and 3/16" rubbber to get some decent flights outdoors.

I don't remember increasing the canard incidence but in fact had to add clay ballast to the nose. See attached pics.

My prop ended up bigger than shown on the plan, then cut back to about 8". I formed the blades on a can/cylinder but don't know if I still have my notes on exactly what I did.

Mine weighs 5.4 grams w/o rubber.

Dave

Edit-
Cancel that bit about the 3/16" rubber. .170 was probably the most I ever used.


Title: Re: acts like a duck,walks like a duck
Post by: lowrpm on May 05, 2014, 04:04:40 PM
mine ended up under 5 grams. I think I may have built the leading edge of the wing a bit too light as once she stalls it can't recover. I may add a spar on my second build to make it more rigid for outdoor flying. the design certainly has potential and this weekend many people stopped to watch as I was trimming..


Title: Re: acts like a duck,walks like a duck
Post by: Dave Andreski on May 05, 2014, 06:32:06 PM
I think the extra weight on mine was due to the aluminum tubing hub and bamboo prop spars and of course the nose clay to offset that weight.

Did you try adding a small amount of weight aft of the CG?

Did you know that it was designed to be flown outdoors?

The plan and one page article was published in Model Builder, March, 1979.

Dave


Title: Re: acts like a duck,walks like a duck
Post by: lowrpm on May 05, 2014, 10:39:39 PM
I did not no it was designed for outdoor,but the weight of mine looked like nice indoor job. I did add weight aft of the cg and it did help, but I think my construction made it a bit flimsy when trying to use light wood


Title: Re: acts like a duck,walks like a duck
Post by: Dave Andreski on May 06, 2014, 11:02:29 AM
Here's the top part of the page I posted earlier. That's all that was published.
Dave


Title: Re: acts like a duck,walks like a duck
Post by: Bredehoft on May 06, 2014, 11:07:16 AM
John,  You're challenging me, again!  Grrr....so many projects!

--george


Title: Re: acts like a duck,walks like a duck
Post by: Dave Andreski on May 06, 2014, 12:02:30 PM
George,
It's good to hear that you have another 'challenge'.

Dave



Title: Re: acts like a duck,walks like a duck
Post by: lowrpm on May 11, 2014, 10:21:23 AM
your welcome George! the zephyr is a snap to build. I did add 1/16x1/32 basswood spars to the wing. Seems to be a better outdoor flyer now,but I can't really tell with all this wind lately.  Dave, thanks for the images


Title: Re: acts like a duck,walks like a duck
Post by: RandyW on July 05, 2019, 07:01:39 PM
Couldn't say exactly why but some of the Zephyrs I have built also show a reluctance to climb. The problem went away when I added a 1/64" shim under the trailing edge of the rear wing.

There is a good video of a zephyr flying indoors on Youtube. Type "canard monoplane" into the search engine