GYPSY MOTH DH 60 DUMAS KIT 336 RUBBER POWER PARK FLYER 30 INCH

[Lastwoodsman]

GIPSY MOTH DH 60   DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Fri July 10 2026       Reply #60        post  2  of  2

Completing the Fuse Side Frames

Pic #1     3898     Completed left side frame is now glued up and dry,  and final sanded to  220  grit.

Pic #2     3899     The left side frame further up,  was just carefully removed from the waxed paper with my sharpened butter knife.

Pic #3     3909     The two frames are stacked on the big board.   They turned out really well -  almost exact copies of each other.   So I am really glad about that.   Plus,  I saw yesterday that there was going to be no wind today,  so I went out with the Beaver for  180  finger winds,  expecting six second flights,  and got in 10 flights,  starting off with an nine second flight! after my first dud flight into the wind,  which went nowhere -  I was going to quit ...    The grass was still good even though they cut it.    We had a rain downpour yesterday.   I'll put up a flight report.

Pic #4      3911     Testing out how the two fuse side frames look on my Gipsy Moth Fuse Jig,  that I made a while back.    This jig is easy to disassemble -  made with round head pins -  and remove a couple of plates for assembly,  etc.  And it will be coming in handy.

    I will be going for ten second flights with the 30" Gipsy Moth Biplane in the Cricket Field.   

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60   DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Sat July 11 2026       Reply #61        post  1  of  2

Completing the Fuse Side Frames

Pic #1     3915     Frame on the big board.

Pic #2     3918     Close-up of the frame with  1/8"  dowels.

Pic #3     3924     Mandrake and Bloodroot check the dowel holes in both fuse sides together.

Pic #4     3926     Another view.   I really messed up the hole in the new forward peg planks.    We will try to get away with it.   At least it is not as bad as the very misaligned peg holes,  in the Beaver's forward peg plate.

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60   DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Sat July 11 2026       Reply #62        post  2  of  2

Completing the Fuse Side Frames

Pic #1     3928     The two fuse side frames were held together by the three laser cut holes (six total),  and long dowels,  and Mandrake used a  1/8" diameter  round file to line up the new peg plank holes (two total),  better,   with a final enlargement of both at the same time.

Pic #2     3931     Another view of the hole enlargement action.

Pic #3     3936     Bloodroot eyes the straight line matching edges of the two fuse frame sides,   with the three dowels in their laser cut hole places.   It is all square so far,  ready for the next steps.

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60  DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Sun July 12 2026      Reply #63        post  1  of  2

New  'finger-wind'  motors

    I played around making a few finger wind,  tight rubber  motors,  for the  30 inch Beaver,  and for the coming 30 inch Gypsy Moth bipe.    I added  more "forward"  rear motor peg plates up front,  with the motor tight,  from the prop shaft hook to this new motor peg,  with the Center of Gravity positioned equidistant,  C of G to the shaft hook,  is the same distance as the C of G to the rear peg.

    The Beaver has a  10 inch prop wire hook to rear peg distance,  and will get  9 inch motors that get stretched taut when installed.    The Gipsy Moth  has an  8 inch prop wire hook to rear peg distance,  and will get  7 inch  motors which will stretch taut when installed.    These motors have been,  and will be,  used for initial trimming,  using only finger winds.

    I made a couple of mistakes and ended up making a  more powerful finger-wind motors from what I intended,  so I might as well try them.  So forgive me if I made any mistakes on these two posts.  In the end I made three,  8-strand motors  -  two for the 30" Beaver, and one for the  30"  Gipsy Moth.    The Gipsy Moth 7 inch has the same  0.813" total cross section of rubber that I have been using.  But I made two stronger motors for the 9 inch Beaver motor  -  0.875"  and  0.938" .    The  0.938"  is in the Beaver now,  and I got maybe 6 practice seconds on 200 safe finger winds.  For some reason,  I had thought that I was not able to finger wind that high safely ...

One 7 inch motor for the Gipsy moth  0.813"  X-section

One 9 inch motor for the Beaver  0.875"  X-section
Stronger motor yet.

    One 9 inch motor for the Beaver  0.938"  X-section
This is the strongest motor yet,  and it is in the Beaver now.    Can't wait to try these out ....  I must go check the grass at the Cricket Field  -  it is  6:40  PM  now with winds from the East at 6 mph gusting to 11 mph,  41% humidity and  84 Deg F (88 deg F),  and there is great low wind all tomorrow morning ... 

Pic #1    3946    The  7"  motor needs  17"  of rubber to start.  The  9"  motor needs  21"  of rubber to start.  I leave  1 1/2"  of extra rubber to tie the knots with.

Pic #2    3949    I used  3/16"  rubber by mistake,  instead of  1/8"  rubber.  I salvaged a couple of more powerful motors out of it.

Pic #3    3952    This is how I tie the motors up.  I still have not made it to a Hardware store yet,  for some small plumbers elastic o rings.

Pic #4    3955    More confusion,  but you get the picture ...

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60  DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Sun July 12 2026      Reply #63        post  2  of  2

New  'finger-wind'  motors

Pic #1    3958    The most powerful motor yet  -  the  0.938"  total cross section of rubber yet.

Pic #2    3962    The regular  0.813"  motor.

Pic #3    3964    The  0.938"  motor is in the beaver now.    It takes 200 finger winds safely - maybe 6 seconds ...   The old broken strands  0.813"  motor sits on top of the Beaver.

Pic #4    3966    Here is the good summary.

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60  DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Sun July 12 2026      Reply #65 

      After making all those motors,  we did shoot out to see what the grass was like.    I'll just stick this short pictureless Beaver Flight Report #29 in here,  in the Gipsy Moth thread,  after that rubber motor preamble.

30 Inch Beaver Flight Report #29  of  Sunday July 12 2026

    Well,  we left the apt. at  8:00 PM.  By the time we got to the Cricket Field,  the players had just walked off after playing in the heat all day.  And the sun had set low enough to cover my half of the flying field in shade,  for both winding and flying.    Four flights of 7, 6, 5, and 4  seconds,  all on 180 finger winds with the biggest  0.938"  motor.  And the grass was still very good.   

    No pics as I brought the camera,  but I forgot the disc in the computer.      The humidity was bearable at only  41 %,  but the heat warning is real.    You can tell when you  get back in the apartment air conditioning.

    We will see what happens tomorrow morning.

    All in all,  the Beaver flies well with the  strongest 0.938"  motor also,  maybe not as long time wise,  but running out the rubber OK.   

End of 30 Inch Beaver Flight Report #29  of  Sunday July 12 2026.

Lastwoodsman
Richard

[Lastwoodsman]

GIPSY MOTH DH 60  DUMAS KIT 336  RUBBER POWER PARK FLYER  30 INCH

Thur July 16 2026      Reply #66

Back to the  30"  Gipsy Moth

Cabane Struts Additional Supports

     The plan calls this  "optional",  but since I am building for the abrupt stop,   this becomes mandatory,  so I don't have to worry about it ...  I plan on more additional reinforcing also.

     Small balsa reinforcing strips of  1/16" x 1/8" x 3/8"  are glued to the inside of the Fuse Side Frames  (six little strips) ,  at the junction of each Cabane Strut,  where the lower legs of the struts,  lay on top of  the  1/8" sq  longerons.

Pic #1     4019     Here is my setup to glue three balsa tab strips on the inside of the fuse side frames.

Pic #2     4021     The six supports are now glued in place.    The top left side fuse frame,  has those  tab/strips pinned down flat with a long balsa plank.   The bottom RH fuse side frame shows the tab/strips glued up,  but not pinned down yet.

Pic #3     4026     They are now dry and solid,  and have passed the 'wiggle test'.

Pic #4     4033     Here is a pic of the frames on the big board.     I was thinking that I should have used larger strip tabs,  but at least I got these ones glued in,  and they are solid.   All systems are a go.

     I also have one,  eight strand,   7" motor (prop hook to rear peg is 8 inches),  made up ahead of time,  for the Gipsy Moth,  for initial trimming.
Eight strand motor with total x section of rubber of   0.813".
Six strands (3 loops) of  3/32"  rubber
Two strands (one loop)  of 1/8"   rubber.   

Lastwoodsman
Richard