Author Topic: Ringmaster Trainer started (Read 3995 times)

Clancy Arnold · « **on:** February 19, 2009, 02:49:56 PM »

Pat King offered to supply plans for a Ringmaster Trainer last year and I am now in process of building it. It will be as Pat designed it but I will add my U/Tronics Single Channel control to have throttle control for safety and ease of training.

Initial power will be a Blue Bird 25 RC engine from Frank Bowman. Thanks Frank.

The picture shows the wing framed out and the first sheet of covering going on.
The covering is 1/32 ply. Note all of the weight to keep the wrinkles out. LOL

Clancy

Bill Heher · « **Reply #1 on:** February 19, 2009, 04:21:57 PM »

Hey Clancy - the tall shiny cylinders you are using for weights look familiar. Do the happen to be wrist pins from a large diesel engine? I have a set of 6 also, I think they came from a Cummins engine. They also make nice jigs for squaring up vertical pieces like formers and fuselage sides.

Clint Ormosen · « **Reply #2 on:** February 19, 2009, 05:02:00 PM »

Quote from: Bill Heher on February 19, 2009, 04:21:57 PM

Hey Clancy - the tall shiny cylinders you are using for weights look familiar. Do the happen to be wrist pins from a large diesel engine? I have a set of 6 also, I think they came from a Cummins engine. They also make nice jigs for squaring up vertical pieces like formers and fuselage sides.

I think they look like guitar slides.

Russell Shaffer · « **Reply #3 on:** February 19, 2009, 06:18:11 PM »

Clancy, please keep us updated on the progress. Pat sure does nice plans and the Ringmaster trainer is on my to-do list.

Clancy Arnold · « **Reply #4 on:** February 19, 2009, 07:36:13 PM »

The silver cylinders are actually 3 inch deep 1/2 inch drive Craftsman sockets that I bought in 1959. They are part of a complete mechanics set that came in a 3 drawer roll around cabinet. Outside of a couple of lost sockets I still have the set in my garage.
Clancy

Clancy Arnold · « **Reply #5 on:** February 20, 2009, 07:20:22 AM »

I now have the bottom of both wings covered and the wing now weighs 7 ounces. I think it will work out fine. The attached picture shows the construction of the wing.
The shear web should make it very strong.

I have made one change, I moved the lower motor mount up 1/16 inch to better fit the 25 size engine, 1 3/16 inch in place of the 1 1/4 inch needed for the fox 35.

Clancy

Neal Beekman · « **Reply #6 on:** February 20, 2009, 02:55:48 PM »

Clancy nice construction , should look great and be strong.

Clancy Arnold · « **Reply #7 on:** February 21, 2009, 10:27:39 AM »

Finished the wing build today. It weighs 14 ounces including one ounce of tip weight ready for finish. If it does not fly, I can use it as a ball bat.

Now to building (laminating) the body!

Clancy Arnold · « **Reply #8 on:** February 22, 2009, 01:37:22 PM »

On Sunday afternoon I received the OS 25 FP from Ralph Wenzel. It had been put in the wrong mailbox.

Glad that I got the Blue Bird 25 first, saved a problem. I moved the lower motor mount up 1/16 inch to fit the Blue Bird. If I had gotten the OS 25 FP first, I would have raised it 1/8 inch and then the Blue Bird 25 would not have fit.

I am waiting for the slow set epoxy to cure on the body.

In stead of using fiberglass to reinforce the center seam on the wing I cut 1 1/2 inch wide strips from the scraps of 1/32 plywood and formed it around the wing and glued it on with the Gorilla glue. I am using the Gorilla glue that is waterproof and says that it expands 2 to 4 times while curing. I used a thin coat of glue on each rib and the glue foamed up and formed a fillet on each side of the ribs. I will make a sample piece and post a photo of it.

Clancy

Clancy Arnold · « **Reply #9 on:** February 22, 2009, 05:50:32 PM »

Here is what the finished wing looks like. Weight is 14 ounces with 1 ounce of tip weight built in.

Clancy

john e. holliday · « **Reply #10 on:** February 22, 2009, 08:38:11 PM »

Is this going to have external controls? To lazy to back and read. DOC Holliday

Clancy Arnold · « **Reply #11 on:** February 22, 2009, 08:50:45 PM »

Doc

The Ringmaster Trainer is the same size as an original Ringmaster but is built with wings skinned in 1/32 plywood and the wing and tail are retained with rubber bands.

It has exposed controls.

Clancy

Paul Taylor · « **Reply #12 on:** February 22, 2009, 08:58:43 PM »

Looks good Clancy

11290 · « **Reply #13 on:** February 22, 2009, 09:40:50 PM »

Where to get plans for this? Went to the "brotherhood of the ring" site and found no reference to this. Flew Ringmasters waaaaay back when and would like to build one again.

Clancy Arnold · « **Reply #14 on:** February 23, 2009, 03:32:24 AM »

11290

The plans for the Ringmaster Trainer are available from Pat King by Email at:
PATDK@AOL.com

Short kits are available from RSM Distribution. Web: www.RSMDISTRIBUTION.com

Clancy

Clancy Arnold · « **Reply #15 on:** February 23, 2009, 12:21:30 PM »

It is starting to look like a Ringmaster. At this point it weighs 20 ounces. Remember this is to be a trainer, not a competition model.

You can see the red rubber bands holding the tail on. The ones on the wing are natural color and do not show up in the picture.

Clancy

11290 · « **Reply #16 on:** February 23, 2009, 10:23:19 PM »

Got the plans, thanks.

Clancy Arnold · « **Reply #17 on:** February 24, 2009, 03:53:40 PM »

No new pictures, but I did a lot of detail work on it today.

Hinged the stab. Drilled the motor mounting holes. used a piece of coat hanger wire and bent up a trial size pushrod, it is about 1/8 inch too short but that is why I aways make a trial pushrod to test for fit/function. Next one will be a hair over 15 inches.

I am out of nylon bellcranks so I made one out of 1/16 inch fiberglass. Used the dimensions Pat showed on the drawing. The bellcrank is mounted to the outboard side of the body and retained with nylon wheel straps. It is held in position with washers soldered to the 1/8 inch steel wire above and below the bellcrank. Simple and rugged. bushed all of the holes in the fiberglass bellcrank with 1/8 OD copper tubing eyelets flared on both ends. Made a "bearing" using a piece of copper tubing inside a piece of next size larger brass tubing. Easy to say but a lot of hand filing to get it to work correctly with out a lot of slop in the bellcrank. Reminder: order more nylon bellcranks for stock.

After reading the posts about ringmasters on the ringmaster forum about how much control range they need, I decided to check the controls out. I have been told that any thing greater than 20 degreesand the elevator starts being a speed brake.

I have limited the range of travel of the elevator to allow up or down movement of 20 degrees, 40 degrees total travel. As Pat King designed the Ringmaster Trainer using a 3 inch bellcrank and have the pushrod hole only 1/2 inch from the pivot and the elevator horn set to the hole farthest from the hinge line it measured 15 degrees of travel up and down, 30 degrees total movement. I also tried placing the pushrod in the hole next closer to the hinge line and it allowed the elevator to move up or down 20 degrees, 40 degrees total travel. Just what the experts recommended.

Farthest hole for training new pilots and second hole for fun.

With the Blue Bird 25 engine set for 1/4 inch prop clearance from the front of the body, I have just over 1/8 inch space behind the engine. The 4 ounce plastic clunk tank I purchased will not fit between the engine and the wing so I will mount it on the inboard side and that will allow me to place the U/Tronics unit, batteries and servo on the outboard side.

I am enjoying this build,
Clancy

Clancy Arnold · « **Reply #18 on:** February 26, 2009, 09:59:05 AM »

Back to the build.

Yesterday I drilled all of the holes that will be needed to assemble the plane. Engine mounting holes, Bellcrank mounts, landing gear mounts, Fuel tank mounts and battery pack mounts. Actually the fuel tank will be inboard for space and the battery pack will be on the outboard side and the retainers for the tank will also hold the battery pack.

Wired up the U/Tronics Control unit and made a small bracket to hold the connector for the electronic input from the flying lines and an ON / OFF switch.

Today I applied yellow oak stain to the birch plywood wing skins to bring out the grain of the wood. After it dries it will get clear polyurethane.

The body will be painted with Painters Choice blue.

Clancy

Clancy Arnold · « **Reply #19 on:** February 28, 2009, 08:07:05 AM »

Had a small setback (about a day) in the build of the Ringmaster Trainer. I had tested for compatibility between the Polyurethane and the Painters Choice latex paints. I tested putting the urethane over the latex and it looked good. BUT I did not paint my AMA numbers on the bare wood, I first stained and then coated the wood with 2 coats of urethane then masked and painted my numbers on over the urethane using the latex paint. WRONG! The masking tape was harder to pull off than the latex paint.

I will try to obtain some clear decal paper that I can run through my printer and then apply them to the wing.

Clancy

Clancy Arnold · « **Reply #20 on:** March 02, 2009, 07:12:05 PM »

The Ringmaster Trainer is ready for test flight, if I can remember to buy it a set of wheels. All up weight is 40 ounces, remember it is to be a trainer. Pat King's plans show the CG at 2 inches behind the leading edge, mine checked at 2 1/4 inch so the wheels should bring it right on. I can set it for use as a Trainer with 15 degrees of elevator travel, 30 degrees total travel, or for fun flying I can move the pushrod in one hole and have 20 degrees of travel, 40 degrees total travel.

I just could not bring my self to cover up that nice wood grain.

The Red piece in the second picture is the U/Tronices unit.

The third picture shows how I connect my flying lines electronically to the model.

The model is powered by a Blue Bird 25 RC engine using my U/Tronics single channel unit for electronic throttle control.

Clancy

pat king · « **Reply #21 on:** March 03, 2009, 07:47:41 AM »

Clancy,
She looks great. Now you will have to tell us if it is tough enough to beat the ground into submission.

Pat

Clancy Arnold · « **Reply #22 on:** March 03, 2009, 12:23:35 PM »

Pat
The ground looses!!!
Clancy

Clancy Arnold · « **Reply #23 on:** March 05, 2009, 11:27:05 AM »

Here are a couple of pictures of the finished Ringmaster Trainer, less 10x4 prop. I had to forget something. LOL

All up weight 40 ounces, power is a Blue Bird 25 RC engine with U/Tronics Control.

I had a lot of problems trying to make the decals for the lettering. Manufacturers instructions called for setting my printer for "Photo Paper" and printing in "Best Quality" for the most ink on the decal. Then I was to spray the decal with Krylon Crystal Clear to seal the ink. All that happened is the ink would bead up even if I waited 12 hours before misting the first coat of Krylon on. I ended up printing using the printer settings for regular paper and covering the ink with thin sealing tape.

Richard Grogan on the Ringmaster forum named my new model. See second picture. LOL

The line guide has saw cuts into the leadout holes so that the lines can be removed. You first slide the lines through the saw cut to the hole then press the eyelet, which is captive on the lines, into the hole.

Now for some nice flying weather.

Clancy

pat king · « **Reply #24 on:** March 07, 2009, 11:56:57 AM »

Clancy,
You will have to tell us if it will turn tight enough on outsides to stretch the rubber bands.

If you go to slow combat lap times you should probably add rubber bands.

Pat

Clancy Arnold · « **Reply #25 on:** March 13, 2009, 08:13:32 AM »

Pat
Flight tests to be when the temperature gets to a reasonable level, it is 25 right now in Indy.

Here is a drawing of how the U/Tronics Single Channel control is hooked up.
Clancy

Clancy Arnold · « **Reply #26 on:** March 18, 2009, 08:21:45 AM »

On my March 2 post I stated that the CG was 2 1/4 inches behind the leading edge. I ran Line III and checked the model to the computed numbers. I had to remeasure the CG and it was actually 1 3/8 inches behind the leading edge.

The Line III computed that the line guide needs to be about .65 inches behind the CG for .015 lines but with the nylon jacket on the insulated lines they measure .025. This computed to a line guide centered 1.1 inches behind the CG.

Lucky me. That is where the line guide is!! The next thing was to hang it by the leadouts to determine the vertical CG. The model as built would hang with the outboard wing flying high. Lowered the line guide 1/4 inch and it helped but still not wings level. Lowered the line guide an additional 1/4 inch and it is almost perfect.

Clancy

FLOYD CARTER · « **Reply #27 on:** March 18, 2009, 11:22:46 AM »

One has to work really hard to get a Ringmaster up to 40 oz.!

The two I have weigh 17 oz. and 24 oz. ready to fly.

Floyd

Clancy Arnold · « **Reply #28 on:** March 19, 2009, 03:59:21 PM »

Floyd
I sent you an Email to bring you up to date on the Ringmaster Trainer. Hope it explained why it weighs 40 ounces.

Finally got some decent weather and test ran the Blue Bird 25 from Frank Bowman.

Sorry Frank, you cannot have it back!! Filled the tank and made sure the line to the carb was full. Set the throttle at about 1/2 open. Clipped on the glow lighter and bumped it with my electric starter one time and it was running. Good throttle control but I will need to set the idle screw as it would die if I brought the throttle too far back. Seems strange talking about throttles on a Control Line Forum. LOL

Tried it first with a Rev Up Pro Series 3 that is marked 10 x 6 W, Tach showed 10,200 and good pull. Then tried a Top Flite Power Point 10 x 4, tach read 14,000 and almost as much pull as the 10 x 6 W. I think either prop will fly the Ringmaster Trainer. I have some Zinger 10 x 6 props to try also.

Maybe when Jack Sheeks gets home from VSC, we can try flying the Ringmaster Trainer.

Clancy