Author Topic: 1/2A Ringmaster from Brodak (Read 4133 times)

John Rist · « **on:** October 16, 2013, 02:42:44 PM »

I just bought a Baby Ringmaster from Brodak. I plan to put a stock TD 049 on it. What is a good target finished weight? Hopefully it will be a good stunter. What's a good starting line length?

Jim Thomerson · « **Reply #1 on:** October 16, 2013, 03:03:39 PM »

I'd use 42 ft lines. Build it as light as practical, as it is, I think, a fairly small airplane.

Phil Krankowski · « **Reply #2 on:** October 16, 2013, 03:44:43 PM »

With a Cox .049 reedy sub-6oz would be desired.

With a TD you can get pretty heavy and still have plenty of power to spare (say 10 oz) but the wing loading will be crazy high and performance will suffer.

Shoot for 6 oz finished with engine and everything, without fuel. A reasonable goal that should not take epic efforts.

Phil

John Rist · « **Reply #3 on:** October 16, 2013, 04:33:17 PM »

Quote from: Phil Krankowski on October 16, 2013, 03:44:43 PM

With a Cox .049 reedy sub-6oz would be desired.

With a TD you can get pretty heavy and still have plenty of power to spare (say 10 oz) but the wing loading will be crazy high and performance will suffer.

Shoot for 6 oz finished with engine and everything, without fuel. A reasonable goal that should not take epic efforts.

Phil

Thanks Phil.
I just ordered it today. Hope to start building next week. 6 oz sounds like a good number to try for. I am learning that CA is heavy but you don't need much. Will keep all posted.

I understand their is a colored tissue that all it needs is clear dope. I think it is called Jap tissue? any thoughts?

Phil Krankowski · « **Reply #4 on:** October 16, 2013, 04:44:48 PM »

Rubber band people like it. Works pretty good, I have used a form of it, but it might have been gift wrap tissue. I have never tried it on a CL plane I always thought it was way too delicate.

Phil

Ron Cribbs · « **Reply #5 on:** October 16, 2013, 08:55:25 PM »

If it were me I would go with modern covering.
much stronger and easier to repair. Tissue and dope looks better though.I have a 9oz Baby Clown and the TD pulls it effortlessly. However, it's been modified to have a 167sq" of wing area. I can do the entire OTS pattern with it. The Baby Ring is a decent flier nothing spectacular.

I think in the end whatever works best for you. I wouldn't worry if it tops 6oz. The original Sterling version was designed around a Babe Bee and I have flown a BRM with one and it did ok. The TD weighs less.

Good luck!

Ron

John Rist · « **Reply #6 on:** October 17, 2013, 06:36:55 AM »

Quote from: Ron Cribbs on October 16, 2013, 08:55:25 PM

If it were me I would go with modern covering.
much stronger and easier to repair. Tissue and dope looks better though.I have a 9oz Baby Clown and the TD pulls it effortlessly. However, it's been modified to have a 167sq" of wing area. I can do the entire OTS pattern with it. The Baby Ring is a decent flier nothing spectacular.

I think in the end whatever works best for you. I wouldn't worry if it tops 6oz. The original Sterling version was designed around a Babe Bee and I have flown a BRM with one and it did ok. The TD weighs less.

Good luck!

Ron

Ron By Modern Covering do you mean iron on plastic film? It is sure is easy and quick to apply.

Larry Renger · « **Reply #7 on:** October 17, 2013, 08:28:03 AM »

Coverlite from Tower Hobbies or Hobby People is lighter than Japanese tissue, tougher and fuelproof. It is an Iron-on heat shrinkable material. You do have to coat the framework with an adhesive like Balsarite or SIG Stixit. It it lasts forever. I finally stripped my first Sky Sport to rebuild it after 8 years of regular use. I love the stuff. Oh, and you can paint directly over it for trim.

John Rist · « **Reply #8 on:** October 20, 2013, 04:55:09 PM »

Well the Brodak Baby Ringmaster arrived yesterday and I just about have the wing built. Wood is nice - could be a tad lighter but nice. Hardware package is very complete. Should be an easy build and a good flyer. My other Baby Ringmaster is powered by a Cox 049 product engine. It is a little underpowered. This one I am building for TD 049 power. It also should be lighter.

I have a question. The plans show the lead outs coming straight out from the bell crank. To me it looks like this puts the aft lead out way far back. My other Baby Ringmaster has the lead outs about an inch apart. When hung by the lead outs it hangs slightly nose down. I only have a couple of flights on the current one but line tension seem OK. Does anybody have a suggestion on best lead out location for this bird?

John Cralley · « **Reply #9 on:** October 20, 2013, 08:44:56 PM »

I would use adjustable leadouts.

John Rist · « **Reply #10 on:** October 20, 2013, 08:57:15 PM »

Quote from: John Cralley on October 20, 2013, 08:44:56 PM

I would use adjustable leadouts.

Cool Will do! Thanks

John Rist · « **Reply #11 on:** October 24, 2013, 11:40:42 AM »

Quote from: Phil Krankowski on October 16, 2013, 03:44:43 PM

With a Cox .049 reedy sub-6oz would be desired.

With a TD you can get pretty heavy and still have plenty of power to spare (say 10 oz) but the wing loading will be crazy high and performance will suffer.

Shoot for 6 oz finished with engine and everything, without fuel. A reasonable goal that should not take epic efforts.

Phil

Well it looks like my Brodak Baby Ringmaster will come in at 5 oz.

Recommended props from another thread are "APC 6x2 for 35', an MA 5.5x3 for 40' and an MA 5.25 or 5x3 for 45' ". I have a 5x3 - 3 blade (Cox) and an APC 6x2. I probably will start with 42' lines with the 5x3 - 3 blade prop.

I have a question about the APC 6x2. the hole in the center is too large. It is .187 dia. the TD prop screw is .125 or so. I am guessing that brass tubing makes a good reducer?

Pictures and flight report to follow.

Phil Krankowski · « **Reply #12 on:** October 24, 2013, 11:56:00 AM »

http://www.ebay.com/itm/310736063319?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I bought these, message the seller and he probably can make or has more. These are a treat!

I have also used fuel line which is a fair deal. It works, but not as well as these brass inserts.

Phil

Tim Wescott · « **Reply #13 on:** October 24, 2013, 12:43:46 PM »

I've been told that APC has reducers, but I just made my own. If you don't have a lathe handy you may want to call APC and ask.

Cox 049 engines us a 5-40 prop screw, which has a nominal OD of 0.125. That means that the actual OD is a bit less, but not by much.

Duke.Johnson · « **Reply #14 on:** October 24, 2013, 12:51:35 PM »

Quote from: Phil Krankowski on October 24, 2013, 11:56:00 AM

http://www.ebay.com/itm/310736063319?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I bought these, message the seller and he probably can make or has more. These are a treat!

I have also used fuel line which is a fair deal. It works, but not as well as these brass inserts.

Phil

I know other Cox guys that use these fittings with APC props and love them.

ray copeland · « **Reply #15 on:** October 24, 2013, 02:01:27 PM »

I use the yellow tygon fuel line for APC inserts, the kind you buy at a ACE hardware for weedwacker fuel, you can make a bunch on 2 foot of hose.

Phil Krankowski · « **Reply #16 on:** October 24, 2013, 03:14:18 PM »

Quote from: ray copeland on October 24, 2013, 02:01:27 PM

I use the yellow tygon fuel line for APC inserts, the kind you buy at a ACE hardware for weedwacker fuel, you can make a bunch on 2 foot of hose.

That tygon probably works better than soft silicone fuel line like I have used prior to getting those brass inserts. I wish I had thought about it before, I have a few feet of it lying around.

Phil

Larry Renger · « **Reply #17 on:** October 24, 2013, 08:34:34 PM »

You can also stack a few thicknesses of K n S tubing to fit.

John Rist · « **Reply #18 on:** November 01, 2013, 03:55:26 PM »

Well for the most part it is ready for it's second flight. I went with a balloon tank rather than a bladder tank. I tried the bladder and it worked but seamed like too much hassle for a sport plane. My first attempt with the balloon tank was a disaster. I did not have it in a container. When I went inverted the weight of the balloon allowed it to flop away from the wing, cut off the fuel supply and killed the engine. It only did minor damage so repair was easy. I now have the balloon in a dog house mounted on top of the wing. Ground test indicate a good run at all angles including upside down. With a APC 6x2 I am running at 20K peaked out. Set slightly rich it turns around 17K to 18K and leans out with pointed noise up. Looks like Monday will be the next test day. I will try 42' lines.

Joey Mathison 9806 · « **Reply #19 on:** November 01, 2013, 04:54:35 PM »

Looks like a lot of fun in a little package to me nice effort John!!!!

RknRusty · « **Reply #20 on:** November 01, 2013, 08:51:41 PM »

Looks good, John. If you find that gravity starves the engine when you fly inverted, you might want to try mounting the balloon under the wing so it's more in the same plane as the engine. It'll benefit from a shorter fuel line too. That's always a good thing. And hidden out of sight under the wing, you can secure it with a less glamorous method like a tube of panty hose or something.

She's a pretty plane, you're making me crave some wild 1/2A time. I've been chugging around with my stunters so much lately, I need to take the Streaks and the Li'l Satan out and set the circle on fire this weekend.

John Rist · « **Reply #21 on:** November 02, 2013, 01:37:28 AM »

Quote from: Larry Renger on October 24, 2013, 08:34:34 PM

You can also stack a few thicknesses of K n S tubing to fit.

I did and it worked. Added a drop of CA to lock in place. Thanks!

John Rist · « **Reply #22 on:** November 11, 2013, 07:38:04 AM »

Well with the APC 6x2 installed and my TD 049 came alive. It launches at 18500 and unloads at over 20000 (calibrated ear

). Went for a test flight last Sunday afternoon. No mater how I set the handle it took a lot of up to maintain level flight. However aircraft was very responsive so I tried a loop. She did not pull out on the bottom. The resulting crash did some damage but is easily repairable. Ronnie Thompson was pitting for me and came over to take a look at my Baby Ringmaster. It took him about 2 seconds to spot the problem. It was push rod flex. I had used .050 wire instead of the .062 that came in the kit to save weight. However I had forgotten the push rod support that is pretty much mandatory. And I knew it was mandatory. So we can chalk this crash up to a brain fart. Ship is already repaired and ready for the next try. I do need to pick up a 6x2 from the LHS. If I can get my act together this is going to be a fun ship.

John Rist · « **Reply #23 on:** February 17, 2014, 07:44:50 AM »

Quote from: John Rist on November 11, 2013, 07:38:04 AM

Well with the APC 6x2 installed and my TD 049 came alive. It launches at 18500 and unloads at over 20000 (calibrated ear ). Went for a test flight last Sunday afternoon. No mater how I set the handle it took a lot of up to maintain level flight. However aircraft was very responsive so I tried a loop. She did not pull out on the bottom. The resulting crash did some damage but is easily repairable. Ronnie Thompson was pitting for me and came over to take a look at my Baby Ringmaster. It took him about 2 seconds to spot the problem. It was push rod flex. I had used .050 wire instead of the .062 that came in the kit to save weight. However I had forgotten the push rod support that is pretty much mandatory. And I knew it was mandatory. So we can chalk this crash up to a brain fart. Ship is already repaired and ready for the next try. I do need to pick up a 6x2 from the LHS. If I can get my act together this is going to be a fun ship.

Well the weather cleared and I finally put a test flight on the Ringmaster. However I still have a problem that it takes a lot of UP elevator to maintain level flight. It has been suggested it could be engine thrust line problem. I will also check the elevator angle with respect to the wing. I will check all and report back.

Balsa Butcher · « **Reply #24 on:** February 27, 2014, 11:50:24 PM »

Take the LG off and hand launch. Eliminating the parasitic drag the LG induces can make a difference in a plane this small. May help the trim issue as well. Check CG. Sounds like it may be nose heavy.