Time to build a plank with a bit of "Wick" so this is a build of the 60" Zipper put with a PW51 airfoil . The Zipper was originally Birdworks way way back with an EH 2-10 airfoil but for more than a decade it has been available as a part kit from Off The Edge Sailplanes in Oz. Yes it is an old design but then not all new things are that good.
http://www.offtheedge.com.au/page.php?id=16
Mine will probably not be quite as pretty as that on the Edge page my first build being WBPU and a few layers of light glass cloth. I will add a thin strip of carbon plate as a spar to help out the somewhat thinner glass skin. Glenn aka "Zipper" offered to cut me a set of balsa elevons as well which I will sand to profile if required as I will see if the WBPU covered elevons prove stiff enough. I will most likely commit sacrilege and add a motor
. Sort of functioning ballast.
There are a number of build threads out there and the outline instructions are on the Edge pages:
http://www.offtheedge.com.au/page.php?id=29
http://home.earthlink.net/~jaffee/zipper.html
http://www.offtheedge.com.au/page.php?id=16
Mine will probably not be quite as pretty as that on the Edge page my first build being WBPU and a few layers of light glass cloth. I will add a thin strip of carbon plate as a spar to help out the somewhat thinner glass skin. Glenn aka "Zipper" offered to cut me a set of balsa elevons as well which I will sand to profile if required as I will see if the WBPU covered elevons prove stiff enough. I will most likely commit sacrilege and add a motor
. Sort of functioning ballast. There are a number of build threads out there and the outline instructions are on the Edge pages:
http://www.offtheedge.com.au/page.php?id=29
http://home.earthlink.net/~jaffee/zipper.html
Comments (23)
I have a Dream Flight Weasel which has not had much flying mainly because the slope winds are not always kind.
http://dream-flight.com/products/weasel-trek
This proved to be the case recently and Ray mused "I wonder what it would take to add a motor?". He has a Weasel as well but he knew I would immediately take the plunge
.
So I did a quick mod and added a BE1806-2300 with a plastic 5x3 prop borrowed from my 250 Racer spares along with a Turnigy 12A ESC and 1000mAH pack. The weight has increased by a shocking 15gm
. Others, of course, have also done similar conversions if you search them down.
The static thrust of the motor/prop combination is 390gm just slightly above the AUW of 380gm so vertical is possible. Pack is good for around 15 minutes at full throttle and an hour at cruise. Air to the ESC behind the battery could be improved by removing top hatch or putting a tunnel through to the launch finger hole?
The changes to the fuselage are straightforward with the removal of the rear wall of the original battery box and a ply firewall braced backwards with triangular ply doublers - the foam is too squishy.
I could have just cut the nose off and end glued the firewall but I wanted to preserve the lines reasonably well. I used WeldBond white glue which takes a while to dry but is slightly flexible and adheres to the foam quite well.
Test flight confirms performance and certainly easily vertical. Two longish flights and only 270mAH from the pack. A rather bleak damp day but caught some thermals as well - surprising
.
http://dream-flight.com/products/weasel-trek
This proved to be the case recently and Ray mused "I wonder what it would take to add a motor?". He has a Weasel as well but he knew I would immediately take the plunge
.So I did a quick mod and added a BE1806-2300 with a plastic 5x3 prop borrowed from my 250 Racer spares along with a Turnigy 12A ESC and 1000mAH pack. The weight has increased by a shocking 15gm
. Others, of course, have also done similar conversions if you search them down.The static thrust of the motor/prop combination is 390gm just slightly above the AUW of 380gm so vertical is possible. Pack is good for around 15 minutes at full throttle and an hour at cruise. Air to the ESC behind the battery could be improved by removing top hatch or putting a tunnel through to the launch finger hole?
The changes to the fuselage are straightforward with the removal of the rear wall of the original battery box and a ply firewall braced backwards with triangular ply doublers - the foam is too squishy.
I could have just cut the nose off and end glued the firewall but I wanted to preserve the lines reasonably well. I used WeldBond white glue which takes a while to dry but is slightly flexible and adheres to the foam quite well.
Test flight confirms performance and certainly easily vertical. Two longish flights and only 270mAH from the pack. A rather bleak damp day but caught some thermals as well - surprising
.
I could not find any plans but this NASA Delta Wing seems to be based on an idea from a NASA schools project to teach basic aerodynamics.
https://www.nasa.gov/pdf/205703main_...ing_Glider.pdf
From what I can see on the video it uses a KFm2 foil but so far I have not found any other details so my dimensions are all guess work.
The video shows twin fins to clear the prop slot. Mine also has twin fins (because it looks good) but with a tractor prop and no slot (because it will fly better - probably
).
Initial glide tests are promising. Foam is ColorBoard from Diaso as for the Arado build. Electronics are from a WLToys PoleCat (F939) for now.
CG position calculated using WingCGCalc. Latest wing plan used is HERE. Elevons are 30mm at the root tapering to 20mm. CG 108mm from cutoff LE for twin vertical stabiliser version flies OK.
Modified version has original vertical stabilisers simply moved out to form winglets which give some dihedral and the CG moves to 114mm. The winglets are set at 45 deg.
Summary: OK once I added a bit of washout to the winglets but not all that fun to fly as it requires continuous control input. Retired.
https://www.nasa.gov/pdf/205703main_...ing_Glider.pdf
From what I can see on the video it uses a KFm2 foil but so far I have not found any other details so my dimensions are all guess work.
| RC Depron Delta Nasa Glider Indoor Flight Faszination Modellbau 2014 *60fpsHD* (2 min 18 sec) |
The video shows twin fins to clear the prop slot. Mine also has twin fins (because it looks good) but with a tractor prop and no slot (because it will fly better - probably
). Initial glide tests are promising. Foam is ColorBoard from Diaso as for the Arado build. Electronics are from a WLToys PoleCat (F939) for now.
CG position calculated using WingCGCalc. Latest wing plan used is HERE. Elevons are 30mm at the root tapering to 20mm. CG 108mm from cutoff LE for twin vertical stabiliser version flies OK.
Modified version has original vertical stabilisers simply moved out to form winglets which give some dihedral and the CG moves to 114mm. The winglets are set at 45 deg.
Summary: OK once I added a bit of washout to the winglets but not all that fun to fly as it requires continuous control input
. Retired.
