HPA

Quote from: Konrad on Jul 01, 2026, 10:10 PMIt's all good. Are you using the tubing as a sheath to go around the prop hook?

No, when I can be bothered, not often, I use heat shrink tubing for that. This sort of thing.  I used to get mine from Maplins, they sold one or two yard lengths for not much more than pennies, and I'm still working through it.

The tubing shown above is simply sliced to give a custom width "O" ring.

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

Thur July 2 2026       Reply #50

     This is going to be an enjoyable build  -  I can tell right away.     All of those tiny laser cut holes in the balsa parts are all  3/64"   0.047"   1.8 mm.    These holes are for the rigging and control wires !     And the kit has very comprehensive rigging wire diagrams and instructions.   This is a very modern kit that was released in 2016,  and now ten years later,  Dumas has,  unfortunately,  closed up shop.   

Pic #1     3747     All of the big long wing copies and files etc.  are pulled off of the Big Board,  and stored in the long  'Gipsy Moth Plan Copies'  folder(s) above the Big Board.

Pic #2     3749     Note the tiny holes in the balsa parts for the rigging wires,  and for the control wires,  holes and slots.

Pic #3     3751     My notes are written on the plan,  in pencil.

Pic #4     3752     The Landing Wires,  and the Flying Wires are not labelled in this pic,  but they are labelled in Pic #3.

Lastwoodsman
Richard

Yikes! I just found out why the thrust line shims apeared to have little or no effect while trimming. The Dumas thrust button will allow the prop shaft to gimbal 10° or more! I will need to come up with a rear suport on the prop shaft to actually allow the shims to effect the thrust line.

Quote from: Konrad on May 07, 2026, 01:05 AMThis Zero is being used to reintroduce my brother to the dynamic art of flying models.

Well that was hubris! It has been more than 20 years since I last flew a rubber band scale model. And that was a much larger Comet 24" Hellcat. It is obvious that I'm on the steep learning curve on making a workable power system.

Here is what the power system looks like as flown last weekend. The rubber is about 3 grams (4 strands of 3/32 nominal rubber). The rear spool (bobbin) has been working great. I'm about to disassemble the motor to incorporate the O-ring.

This is a good time to ask what do you use as a motor lube? I was using glycerine. Also how much to you preload the loop before folding it over during the braiding process.

A sheath seems like a good idea, but not one that I have bothered with; yet. A bobbin loose fitting onto the peg aids installing the motor and helps to reduce bunching. The bobbin can be seen to be wobbling and partially rotating as the motor unwinds.

Re installed Win 10 and downloaded nice fresh browsers .. = ? 
 I just don't know .

 I don't want to use W11 and Linux is not ready . ( Not for me - anyways )
So for now I am stuck on 10 . 

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

Wed July 1 2026       Reply #49   

Fresh Sandpaper

     We got out all of the sandpaper blocks and stapled on fresh  100  150  220  sandpaper.   To fold around the blocks properly,  the  'creases'  in the sandpaper were first slightly scored with an awl.    Actually,  all of my sandpaper cuts were made with several strokes of the awl,  using the long clear,  cm and mm scale,  Safelex Shatterproof Helix rule,  30 cm  300 mm long.   File folder cardboard was used as a cutting mat.

Pic #1     3730     Cleaned off the building board.

Pic #2     3734     Sanding blocks to freshen up.

Pic #3     3737     All new sandpaper.

Pic #4     3743     I just used staples to hold them together.

     Now we are ready ...

Lastwoodsman
Richard

I had a first run with the new Gasparin G160TS this evening. It's a lovely sounding engine which sounds and feels like a similar output, maybe slightly more than the flat twin GM300T in the Bleriot XI

It's all good. Are you using the tubing as a sheath to go around the prop hook? (Not allowing the wire to cut into the rubber motor)?

I'm using the S hook and rear spool to define the ends on my braided motors.

What I would do, is double strand double lenght than the motor to peg. I'm not sure on the size but in metrics I would go somewhere betweem 4,20 - 4,40mm.