Monday, August 31, 2009
Saturday, August 29, 2009
Finally finished the Brooklyn Dodger. 4oz. overweight, CG around 50% . Next step is to run engine then test fly at Muncie.It has had its share of problems during the building stage so maybe testing will go a little better. HAW!!
Thursday, August 27, 2009
Good Morning Thomas,
While I am waiting for the Sailplane graphics to arrive, I started cycling transmitter, receiver, and ignition batteries and I also changed out one engine yesterday. I have been using a Shilen Torpedo .29 ignition engine in the Class B Airborn since it was initially built. However, last year in a discussion with George Tallent out in Arizona, George said I should pick up a Jenno Torpedo .29 because they would outperformed the Shilen engine. Well, I did locate a Jenno Torp .29 (S/N 337) and bought it. I sent the engine to Bob Beecroft out in California who is not only a free flight modeler, but a good machinist as well. He drilled the three threaded holes that hold the backplate on crankcase all the way through the crankcase so the engine could be radial mounted as shown below.
I removed the rear mounted tank, changed out the needle valve assembly for an fine thread Enya needle valve assembly, and installed the Jenno Torp .29 in the Airborn as shown below.
The up and coming flight tests will be used to check out the Airborn's new Futaba FASST 2.4 gHZ receiver as well as evaluate the performance of the Jenno Torp .29........................
Wednesday, August 19, 2009
Report #159 from Tandy Walker on the construction of his Comet Sailplane for the 2009 SAM Champs in Las Vegas
Comet Sailplane Project
The picture below shows the integrated ignition unit consisting of (1) a 750 mAH NiMH battery pack, (2) a ModelElectric coil, and (3) Marv Stern's Aero Tech IGN-SW ignition module installed on the back side of the Sailplane's firewall with two 2-56 cap screws. You can see the (+) ignition pack charge terminal and the (+) booster terminal wires with lugs soldered to their ends. In addition, the landing gear has also been installed.
With the two wire lugs attached to the terminals on the back side of the hatch cover, this picture shows the two external terminals and the hook up for charging the ignition pack and attaching external booster batteries (note that the landing gear wire is grounded to the engine).
The green wire in the picture below is the landing gear's ground wire to the engine for the booster and ignition pack charge grounds on the landing gear shown above. I was doing a continuity check with the multimeter that you see in the picture.
This picture shows the ignition unit's ground and point wires. Notice that the high tension lead is too short to be routed up through the cowl and to the spark plug.
So I started making a new high tension lead. Larry Davidson sells the clip shown below that snaps onto the coil post. Years ago Dick Huang gave me bunch of very small aluminum brads that I use to attach the high tension wire to the coil clip. About a 1/4" of the insulation on the high tension wire is removed and the stranded wire is bent through the hole in the coil clip. The aluminum brad is also pushed through the hole and then flared out, which attaches the high tension wire to the coil clip. Black heat shrink tubing is used insulate the connection as shown below.
James Lollar is sending me some 1K and 10K resistors to use inline with the little spark plug clip that I make, but they have not arrived yet. I will probably use a 10K resistor and locate it as close to the spark plug as practical. Well, that it for today.........................
Tuesday, August 18, 2009
Monday, August 17, 2009
This afternoon I made up an all new mix of satin Klass Kote and shot the bottom of the wing around 1:30 p.m. Later on this afternoon, I decided the wing would be dry enough to spray the top. So around 5:00 p.m. I shot the top of the wing. When I had finished spraying the top, I took the picture below before the atomized Klass Kote epoxy particles had settled out of the air in the closed garage.
A little later when I went out and checked on how the wing was drying, I took this picture in an attempt to show you the beautifully smooth satin Klass Kote finish on the top of the wing.
I want to share with you a problem I encountered with the satin Klass Kote. Remember last Friday I sprayed the bottom of the stab. Since I let it dry overnight, I sealed the remaining 6 ounce Klass Kote mix in a jar and put it in the refrigerator. Saturday morning I removed the mix from the refrigerator, gave it a couple of hours to come up to room temperature, and then added just a touch of reducer to help thin the mix. I took the time to thoroughly stir up the mix. Then I mounted the stab on the second support fixture and sprayed the top of the stab.
Here is problem I encountered: As late as yesterday evening the dry coat of satin Klass Kote on top of the stab was not as satin as the rest of the model's components #$@&? (it had kind of a shiny or semi gloss sheen). The only thing I can come up with as to why is that the mix had been placed in the refrigerator overnight and it had a little additional thinner added, which by the way according to Nate Dickerson was supposed to be OK.
I kept looking at the top of the stab and debating about what to do for a long time. Since I was never going to accept this miss matched sheen of the top of the stab, I remounted the stab on the second support fixture and resprayed the top of the stab this afternoon in between the time I sprayed the bottom of the wing and the top of the wing. As you can see below, by respraying using the fresh satin Klass Kote I had mixed up for the wing, the satin finish of the top of the stab now matches the rest of the model's components. I will call Nate Dickerson (Mr. Klass Kote) tomorrow and see if he knows what the problem could possibly be.
Now I will take my time and spend this coming week going through all of the final installations and assembly on the Comet Sailplane. I will perform a weight and balance to check for meeting the SAM minimum weight requirement and to check for the proper CG location. So I will have a couple more reports to send out before I begin the Sailplane's all important flight test program. But at least I am finally finished with all the covering, painting, and finishing activities!...................
Saturday, August 15, 2009
This morning, I sprayed the top of the stab with one coat of satin clear Klass Kote and brought it in and sat it on the model room work table for 24 hour drying as shown below. One point I want to make is that very little if any overspray got on the top of the stab from when the bottom was sprayed yesterday. This will also be the case for the wing as well.
An awfully lot of thought was put into how to hold the wing for spraying. The final solution came out unbelievably simple as shown below. Two fresh rolls of Viva paper towels were tied across each end of a long box with string as shown below. A folded rag was placed on top and at the end of each roll for trailing edge shims also shown below.
The Sailplane's wing was place upside down onto the rolls. The wing was gently pushed down into the rolls to form a kind of depression for a pseudo cradle as shown below. Then the air supply was attached to the empty spray gun and mock spraying was done to see if the wing was going to move under the spray gun's air pressure. The wing was as solid and did not move or rock at all.
Then the wing was turned over and placed onto the rolls without the two rags on the end as shown below. Again the air supply was attached to the empty spray gun and a mock spraying was done to the top of the wing to see if it was going to move under the spray gun's air pressure. Again the wing was as solid as rock and did not move at all in the upright position.
This is some good general information for spraying any big wing. Anyway, tomorrow afternoon I will get set up and spray the bottom of the wing first and then the top on Monday.......................
Two nice days at the Shelby Airport.
Attendees on the 13th: Jim Keppler, Cliff Riedel, Ted Williams, Tom Ryan, & Bucky
Attendees on the 14th: Gil Morris, Ted Williams, Joan Walter & hubby Bucky.
The corn fields took its toll. Cliff's towline glider after one beautiful flight. Ted's CO2 model. Tom Ryan's delta wing rubber job.
Gil was making adjustments on the model he flew in the world FAI Contest. Gil did not win, but what a whale of time and honor to attend and fly for the USA. Gil had quite a few stories he told about the contest. My wife Joan was all ears.
Jim Keppler made a great flight two minute flight with his California Champ. It stay on the field and out of the corn field. Any flight which stays out of the corn field is a very great flight. You have to wait for the right wind direction and use a very short fuse for the DT. Also hope you don't hit a thermal.
The two Earl Stahl models were built by Bucky. Bucky gave them to Jim Keppler to fly at the FAC contest. Bucky does not chase after rubber models anymore. Neither does Jim, but he can get the younger guys to fly the models and chase them.
The two gas jobs are an Ascender and a Brooklyn Dodger.
Enjoy the photos,
Friday, August 14, 2009
Today I started the involved process of spraying satin clear Klass Kote on the Sailplane components. I moved our cars out of the garage and into the carport and swept out the garage floor thoroughly. I mixed up an 8 oz batch of Klass Kote epoxy consisting of (a) 2 oz of Epoxy Clear #40, (b) 2 oz of Satin Catalyst #463, and (c) 3-1/2 oz of Reducer #500 (thinner). Typically, I like to air brush Klass Kote, but the Sailplane's fuselage is so large, I used my DeVilbiss automotive touch up spray gun shown below. If you ever use one of these, you will love it. For air, I use a standard small air compressor unit equipped with a regulator and a separator/dryer shown below. I adjust the regulator to a pressure 30 psi for the DeVilbiss gun. I intentionally took this picture very soon after spraying the edges and bottom of the stab so you could see the atomized Klass Kote epoxy particles still suspended in the air in the closed garage. This is a stupid funny looking picture I know, but I wanted you to see the North Safety (Model No. 3001) mask I have on below that I always wear when spraying any kind of epoxy. It has multi stage filters, including the all important charcoal stage, to help filter out and prevent inhaling the atomized Klass Kote epoxy particles that get suspended in the air. This is an interesting picture of the Sailplane's fuselage after it was sprayed with satin clear Klass Kote and the atomized particles allowed to settle out of the air. Several years ago I made a power rotating device that allows me to rotate the fuselage to any position while I am spraying it. I used a slow grill geared rotisserie with pipe on the end that the fuselage painting mandrel plugs into as shown below. Once the fuselage has been sprayed, it transported, by holding onto the mandrel, from the garage into model room and allowed to dry/cure for 24 hour. Several years ago I also made up a simple paint drying stand so I could store the painted fuselage vertically using the painting mandrel, which is shown below. This picture shows all of the Sailplane's components that I sprayed with satin clear Klass Kote today. They are sitting on the model room work table for overnight drying and they will not be handled or touched until tomorrow. All of the little support fixtures are so important during the extending drying time. Of course, only the edges and bottom of the stab were sprayed today. Tomorrow, the stab will be turned over and mounted on a different support fixture shown below and the top of the stab will be sprayed with satin clear Klass Kote. I called Nate Dickerson (612) 243-1234, owner of the Klass Kote company firstname.lastname@example.org, this afternoon and discussed how to keep the remaining 6 ounces of satin clear Klass Kote I have mixed up for use tomorrow. Nate said to put the mix in a jar and seal it tightly with a lid. Then place the jar in the refrigerator, which will remove heat and essentially stop the mix from curing. He said the mix can be used for up to two or three days. However, when the mix is removed from the refrigerator, it must be allowed to come up to room temperature before it is usable again. He said if it seems a little viscous, just stir in a touch of the Reducer to thin it out again for spraying. Nate went on to say that you can also store the mix in the freezer to extend the number of useable days.....................Tandy
Thursday, August 13, 2009
|Sylph. Bunch Mighty Midget (kit) powered. Original design 1940.|
I designed the Sylph during the Christmas vacation (high school) 1940. It was inspired by a picture of a flying wing model that appeared in Model Airplane News (photo by Kulick). That model was the "Bobtail Contender." It is surprising how much the Sylph looks like the Bobtail Contender. The original Sylph was powered with a Bunch Mighty Midget that I bought as a kit for $7.85. I really don't remember too much about it or what became of it. The plans were drawn in ink on shelf paper (I still have them). They were copied and approved as Old Timer by SAM. Jim O'Reilly has the plans and Bob Holman kits a 1/2A Texaco version.
I have since built one that I flew in 1/2A Texaco and another powered with a Burford Elfin for A ign. LER (the yellow one).
That's all I have off the top of my head.
SAM Hall of Fame
SAM Hall of Fame
The model has recently been built by a flying wing enthusiast in Germany (surprise) and featured at R/C Groups
|Sylph. Bunch Mighty Midget (kit) powered. Original design 1940.|