Thursday, September 29, 2016

Gizmo Geezer Review - Part 1

This is the first part of my review of the Gizmo Geezer rubber power propeller system which relates to my testing on a stand and the installation in an existing P30 free flight model I have.

Testing Gizmo Geezer on a Stand

Desirable features I saw in Gizmo Geezer Advertising

  • No additional method needed to hold nose of the model on such as rubber bands or magnets.

  • Method to do easy thrust adjustments without having to use shims.

  • Smoother unwinding of rubber motor and no need to braid the motor. 

  • The propeller would free wheel easily without the need to build additional mechanism on the propeller shaft.

  • The propeller has a higher PD ratio than similar propellers.

Getting Started

The rubber motor loops are attached to the Sleeved Clevis by inserting Sleeved Clevis Pins.  Attaching the rubber inside of the Sleeved Clevis can be a little tricky but if you gather the end of the rubber together in a bunch and work the hex wrench through the small loop with the Sleeved Clevis pin inside it goes into place fairly easy. Here I have 3 loops of 1/8” rubber.

Rubber has been inserted as seen from the rear.

As seen from the front.

The Winder Attachment is connected to the front of the Sleeved Clevis by inserting through the slot and then twisting.

Your winder is attached to the loop in the back of the Winder Attachment

After the motor is wound it is inserted into the rear of the Prop Shaft Drive and twist to connect.

After the motor is wound you can park the motor such that you do not have to hold the propeller to keep it from unwinding. When you are ready to launch you can engage the propeller again.   

With the Gizmo Geezer there is no need to braid the rubber strands in fact doing so will not let the free wheel mechanism operate properly.

Front view of Prop Drive Dog engaging the propeller.

Just before going into park mode which stops the rubber from unwinding further and propeller goes into freewheel mode. Keeping a level of tension should combat the problem of random bunching of a long motor that can negatively affect the glide. According to Gizmo Geezer website the tension is held to between 55 to 60 grams.

Propeller disengaged

There are three screws that can be turned for thrust adjustments.

Installation into Existing P30 Model

This is my NJAPF P30, note the ugly rubber band across the front of the nose to hold it in when all the tension from the rubber motor has gone out. Free wheeling is accomplished by 90 degree bend in the front of the shaft and the molded ramp with notch in the propeller. 

Gizmo Geezer PW95 propeller seen above which comes adjusted to a high performance 1.25 to 1 P/D (pitch to diameter ratio). Peck 9.5” propeller seen below.

To be continued..

Bill Kuhl


Friday, September 23, 2016

I Have a Short Fuse – on Guillows Lancer

Part of why I enjoy free flight model airplanes is there is so much to experiment with.  In the models I have built with a dethermalizer – DT, I have either used a viscous DT timer or with my electric free flight an electronic timer.  Using a burning fuse although a method that has been used for years is something I have avoided. In the two free flight contests I went to this summer I noticed many people are still using the burning fuse to bring their airplanes down.

Fuse DT on Guillows Lancer

Before building a new airplane using a fuse DT I thought I would start experimenting with an existing airplane I had, my Guillow’s Lancer would be easy to convert as the wing is held on with rubber bands. My thought was to popup the front of the wing to bring the airplane down; as the popup stab is not always adequate to bring lighter airplanes down from a thermal. Many people completely eject the wing off on lighter airplanes with a string attaching the wing to the rest of the airplane. On another airplane I will try this method. 

The Fuse is Burning

To get some idea how fast the fuse would burn and how well the snuffer tube worked, I cut some pieces of fuse and stuck them in an aluminum tube to test the burn rate using a stop watch. To light the fuse I was using a barbecue lighter which isn’t the most reliable method. Several people have given me better ideas on lighting the fuse which I will look at later.

Flying Upwards

The modifications I did to my airplane were to create a wire hook on top of the wing and on the top of the fuselage in the nose area.  From the hook in the middle of the wing a rubber band pulls the wing back while another rubber band running from the middle hook to the front hook holds the wing down in the front until the fuse burns that rubber band. Thin fishing line provides a limit to how far the wing can tip up in front. A short length of aluminum tube glued on top of the nose area is the snuffer tube that holds the fuse.

The Wing has Popped

Maybe Front of Wing Up too High

Last evening turned nice after a huge amount of rain so I decided this was my opportunity to try this out. Where I could fly from was far from where I parked so I stuffed in my pockets; fuse, scissors, small winder, rubber bands, and the grill lighter.  I knew the plane would not fly real long on the winds I could put in so I tried to make the fuse really short, and you thought I was losing my temper. 

Crashing, I Mean Landing on Grass

I made several flights and a couple of times it DT’ed about two feet off the ground. On one flight it did dt maybe 20 feet high and I snapped a couple pictures of it coming down.  The propeller was probably still turning as it came down but I was a little surprised how steep the nose was pointed down as it came down. It didn’t hurt the airplane and it should bring it out of a thermal.  The Lancer doesn’t have a good glide anyway but no doubt if it would wander into strong enough lift it could fly away.

Bill Kuhl

Related Links

Guillow's Lancer Model Airplane

Trying a New Idea on Nose Plug

Fuse I Purchased from Volare 

My Building and Flying Guillows Models Website

Monday, September 19, 2016

Aeromodeller Mention

I recently subscribed to the Aeromodeller model magazine online version, this being my first online version of a magazine. Subscribing to anything that is read online is something I have resisted but this might work out pretty well for me in that I can read it anywhere. If I have my smartphone along or can view on a bigger screen on a pc or other devices with larger screens.  Aeromodeller is an excellent model aviation magazine out of the UK that covers most aspects of model aviation.

Flash Fighter
This month I was somewhat surprised when in the October issue was a mention of my name and this blog in a review of the Flash Fighter capacitor powered model airplane that I had reviewed some time ago.  For a toy model airplane that looks like a jet aircraft it flies pretty well, the designer Rob Romash is very accomplished in model aviation competition.  These airplanes were sold for a time at a real discount at Radio Shack stores, I just searched Amazon and it appears it is still available from online sources.

Allegro Lite

Whipit DLG

Last week I had taken vacation one afternoon to do some model flying as the wind was really low for this time of year.  It gave me a chance to try the Whipit tiny RC DLG glider that I had replaced the radio gear in as one servo had a rough spot in it. With such tiny servos, the tiniest hitch in the servo gears will cause problem. Luckily I was able to find RC gear out of another model that fit.  After adjusting the trim I had it climbing in thermals but that is not real easy.  I also flew my Allegro Lite two meter glider which flew well but I realize now that it must be flown faster to get fast rudder response.

Gizmo Geezer Propeller System

Wilbur Rubber Model Stabilizer - O'Reilly Plans

I have been experimenting with the Gizmo Geezer propeller system for rubber powered free flight and will be writing a review. This device senses the rubber tension and stops the rubber from completely unwinding and puts the propeller in free wheel mode. Also I am building a nostalgia rubber model the Wilbur which uses some building techniques I have not seen before.

Launching a Supra Unlimited Sailplane

Last Saturday was local monthly RC thermal contest. Not ideal conditions, dark and windy at times. We started launching some DLG’s for fun. Even my heavy Hyper DL was climbing in lift. Around noon we started our simple contest, take your best 4 flights and add together. The first glider I was going to use the stabilizer was loose so I used my really heavy 2 meter as it penetrates the wind well at 50 ounces. Other people were flying lighter 2 meter gliders that were staying up better but the two Supra unlimited sailplanes had total flight times of over an hour.  A good part of this was the pilots as the guys flying these gliders can make a Radian fly really well.  

Bill Kuhl

Related Links

Rob Romash - Capacitor Powered Model Airplane

Aeromodeller Magazine

Gizmo Geezer

Jim O'Reilly Plans

My Whipit Review

About my Allegro Lite

Friday, September 9, 2016

Wonderful Summer of Model Airplane Flying

It sure has been a great summer for me with lots of model airplane flying including contest flying in both radio control sailplanes and free flight.  I made it to the International Aeromodeling Center in Muncie Indiana to compete in the Free Flight Nats and also to Minneapolis Model Aero Club for the August contest. For the most part the wind was rather light for those events, which is a really good thing. I also did some sport RC electric flying on a private flying field.

Flying at Free Flight Nats in Muncie Indiana

Friend's Large Cub Landing
Flying with MMAC FF Club in MN

My Pearl E202 at MMAC

In the spring and fall it seems the likelihood of windier weather is more prevalent and that is when I do more RC slope soaring. Last weekend I flew slope both Saturday and Sunday, on Sunday flew at a new to me flying site.  As the daylight gets shorter I spend more time building model airplanes and I have started on a couple of projects, one is a free flight hi-start glider the Gnome kitted by Retro RC. This is not a regular contest event but should be fun just to try. I have also started on a nostalgia rubber free flight the Wilbur with plans and parts from Jim O' Reilly's Model Plans.  The fuselage consists of all diagonal pieces, Jim O’Reilly said this is Warren Truss type of construction that is much stiffer for the weight. 

Slope Flying on New Small Slope

To improve my free flight contest performance I am trying to learn more about certain aspects of free flight contest aircraft such as DT timing and propeller free wheeling. I have worked with adjusting the spring tension on the viscous timer in my NJAPF P30 model so that it trips the DT after 2 minutes. To learn about a rubber power free wheeling setup I purchased a Gizmo Geezer and I have been running it in a stationary test setup. This looks like a neat product that not only free wheels the propeller but keeps enough tension on the rubber that the nose should stay on and allows easy thrust adjustments. I also purchased some DT fuse and have been lighting and timing the burn times.

Gizmo Geezer on Test Run

Thank you to everyone that has been reading my blog which just went over 150,000 views this week from starting in 2013. Now that school is starting my website traffic is picking up quickly too. 

Bill Kuhl

Links Related to this Article

Academy of Model Aeronautics

Gizmo Geezer

Jim O’Reilly Plans Service  

Retro RC  FF Gnome