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JA 37 Viggen

OutcastZeroOne

Fly, yes... Land, no
#4
Very nice. I used the same hotwire technique on my very first scratch. Yours looks MUCH better then mine did :D great work. The real trick about this method is getting those parterns lined up strait on both sides of the foam. Once you got that you are good to go.
 

Liemavick

Member
Mentor
#7
Great work David! Fly's as good as she looks (nice work Chad). My son wants to know when Im setting up a hot wire cutting station, my wife wants to know where I'll be living if I do.:rolleyes:
 

Non Action Man

Nose Landing Specialist
#9
Have you guys seen or used this 4 axis cnc software for making models like this?

http://www.tjzoide.com/

If so, any feed back, as it looks like it could be a real good thing!

Awesome plane guys, I couldn't believe how stable it was!

NAM
 
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earthsciteach

Moderator
Moderator
#10
Non Action Man - thanks for the software link! That is very cool. Now to build a CNC hot wire cutter...

My Physical Science students have been "designing" high lift airfoils using a very basic airfoil simulator online from NASA called foilsim III. We export the geometry coordinates to Excel, plot them and with a bit of magic by me, end up with wing profile templates that they use to hot wire cut the shape from 8"x6"x1" foam blocks. Then, they mount them on a little wind tunnel rig I made up to test. We are wrapping this up tomorrow. Its been pretty cool.

Having a CNC cutter with this software would be AMAZING for school! Too bad our budget for the year has already been used up. I can't even get paper towels for my classroom!
 

OutcastZeroOne

Fly, yes... Land, no
#13
You can glue the templates to some good stiff cardboard (sometiems called ship board, even good art board will work). I use 1/16" art board for all my hotwire templates. I sometiems stiffen up the edges by putting a thin bead of supper glue on the edge, especially on thin parts.
 
#14
You can glue the templates to some good stiff cardboard (sometiems called ship board, even good art board will work). I use 1/16" art board for all my hotwire templates. I sometiems stiffen up the edges by putting a thin bead of supper glue on the edge, especially on thin parts.
I need to get the plans into a printable format...are they available in a printable format?
 

OutcastZeroOne

Fly, yes... Land, no
#15
There is a link right under the video on hte original post. Looks like they are only in a full sized PDF, so unless you have the ability ot make a tiled printing, Kinkos is your best bet.
 

OutcastZeroOne

Fly, yes... Land, no
#18
I found this image on the original build thread by Johan



If you watch the video carefully you can see them grabbing the plane by the forward wing area and having it balance there. Looks like CG should be somewhere between the tail and wing root.

I've got a plane that is also a canard style craft whos CG is a in a very similar area.
 

TxRider

Junior Member
#20
Inspired by David's project as well, saw the video and jumped in. Well on the way now with assembly and waiting for some components to arrive. When sourcing a motor/fan combo I had trouble with so many out of stock. This caused me to take a different path and experiment with a slightly higher powered (and heavier setup). I have a Cyclone Power SMT 7010 12 blade fan with 2200kv motor. Means I will end up running 6s (probably two 3s in parallel) and getting 2200g of thrust on a plane that weighs about 200g more than Davids. Anyone try anything like this yet? I am concerned about weight, slow speed handling impact and how hot it will have to land. Loved the flight characteristics in the video and would hate to lose that...2:1 thrust to weight might rip the foam board wings off!