Friday, March 23, 2018

New Gollywock Build Report

What fun would it be if I did everything the same? At least that is my excuse for trying a new covering method and new DT system on my build of a New Gollywock this winter. Building another larger rubber model the Wilbur the previous winter, taught me much about building a rubber model larger than a p30. Again I ordered a prop blank from Volare and I knew what I needed for prop assembly hardware. Several people have suggested that I should try the tissue over mylar covering method, this time I gave in. I also ordered the Will Hubin electronic timer for this plane.

New Gollywock

Gliding from Small Hill

Along with the Jim O’Reilly plans I had ordered the Bob Holman laser-cut ribs for this plane. Construction was easier than the Wilbur that had the angled cross members in the fuselage. Covering with mylar I had done once before in building the Polecat X p30. What I wasn’t paying attention to when I ordered more ¼ mil mylar was that it was silver in color. The bottom of the wing was covered with clear mylar but then I had to use the silver mylar for the top of the wing. No doubt the silver is slightly heavier. 

Clear Mylar

Silver Mylar

When shrinking the mylar I got a little too much heat on it with the heat gun and it started turning brown in a couple of spots but never burned through. I tried to cover this up with the tissue colors that went over the mylar. Doping the tissue over the mylar I do not think I followed the proper procedure which is to use thinner to soften up the nitrate dope surface and attach the tissue. I attached it by brushing in the nitrate dope into wet tissue. Most places it worked fairly well but other spots mainly one fuselage side, there are spots that the tissue sags. I left the tissue off the upper side of the wing tips to save weight and try the silver-look.  On the fuselage I sprayed Design Master Floral paint over the orange tissue because it did not look good with the silver base. The fin was covered with silkspan and painted white for visibility. 

Mylar on Fuselage

From a few feet away the plane looked fine. The structures feel very rigid and the weight seems to be similar to other Gollywocks. Where I did add a little more weight was the installation of the Will Hubin electronic timer. Weight of the timer is around 3 grams, I found a servo with a case that weighs 1.8 grams, there is the weight of connectors and a 30 ma battery so total weight is around 7 grams. With this electronic timer you have to do the wiring but that makes it flexible as to what can be done. There is a programming box that is needed to create and download a program into the timer. The big positive is you can program to the second when the model will DT.

Will Hubin Electronic Timer

Programming Box and Testing Setup

So far the model has been test glided without the rubber from a small hill which looked straight ahead and a few real short power flights with a rubber motor and 40 turns. Adding rubber did change the CG but then I noticed the wing was sliding ahead with no stop on it, this has been corrected. With power it appeared the model would climb rather steep and go left. I am going to add the recommended thrust adjustments before more test flights.

Bill Kuhl

Related Vendor Links  Hubin Timers at Retro RC  New Gollywock – Volare Products prop blanks

Friday, March 16, 2018

Spring Flying and My New Stuff

Last weekend I was still cross country skiing and flying model airplanes over the snow but this weekend looks to be snow-free and low wind. There is still much I want to do as far as building new models, the last part of projects always seem to take the longest. For quick builds I had built a couple of small catapult gliders from J&H Aerospace and have been test flying over snow and this week grass. Small gliders take tiny adjustments to get flying well, I am learning. The gliders I built are the Aleda and Carbonette 8.  I did get in some test glides of the New Gollywock I built from O’Reilly plans, glide looks good, time to braid a rubber motor.

Extreme Closeup of Rotary Damper for Building DT
Close-up of Plastic Clock for building DT
Carbonette 8 Catapult Glider

New Gollywock Test Glide

My home computer was getting really old so I purchased a new Dell pc that is really tiny but powerful. I want to make more videos and a computer cannot be too fast for that. I am learning the Corel Ultimate video software which is similar to what I have used but yet different. For more electronic toys I purchased two different USB microscopes. The first one seems to only focus really close but the next one I purchased will focus farther away.  As I am working on an article on viscous DT timers I took many close-up pictures of rotary dampers and springs. On researching viscous DT I found many people build timers for rubber powered free flight model using what Hank Nystrom calls a “plastic clock” and other people refer to as Tomy Timers. Someone sent me a sample with the pendulum made from a quilting pin, with the spare pin they sent I created my own and it runs really well.

Timer Sample and One to Build From

As an investment in my model building I have purchased several items. For my health in the airbrush painting I am doing I purchased a respirator mask. For bending music wire I purchased a small needle nose pliers and a new wire cutter with longer handles. After so much use the old wire cutters become just about worthless. 

For Spray Painting

Witch Hawk 500 Stab

BMJR Streak

My first large glow powered free flight the Witch Hawk 500 is coming along well. The wing and stab were covered with Polyspan and then I used the dye Larry Davidson sells. It went on better than I thought it would. To finish the Flying Aces Moth rubber model I have to build a freewheel device and install the DT. One of the two ½ A NOS models I am building requires just the DT installed and another is ready for covering.

Related Links  Witch Hawk 500, Streak, and Smarty kits  - Polyspan & Dye  Aleda and Carbonette catapult gliders  New Gollywock  - Plastic Clocks  Corel Video editing software