Re: RIngmaster

ian1954 Fri Sep 20, 2019 10:33 am

944_Jim wrote:Anyway, I have questions regarding the two engines...have you run them yet?

I have two .15 LAs similarly configured...one with a Jim Lee supplied nylon venturi and through venturi NVA, and one that is factory "LA-S" with the aluminum venturi and remote NVA. Granted, smaller engines...the baby cousins (same colors too, blue and unfinished alum) of yours.

Q1: Do the engines appear to be similar outputs?
Q2: If unmatched output, which setup appears to have the most torque?
Q3: Which setup do you prefer?

I ask, because if I had to have a matched pair (I love my twins), I need to determine whether to pick up another nylon venturi with the NVA, or pickup another aluminum "LA-S" NVA.

Thanks,

The take apart also means it is easier to finish and a little glue would quite quickly make it "not a take apart" and seal the joins.

I have run both engines but they have only been bench run. Both easy starters and they have both been run with a range of 9x6 to 10x7 propellers. On the bench they are indistinguishable but "in the air" - I don't know for control line. I have not been up close and personal with LA25s or 15s with control line - only RC.

Now 40s and 46s are different. RC guuys are happy, to a point, with all the RC series but quite a few control line chaps use the 40s and 46s - they are not all happy with the rear mounted NVA.

They start off with a warm engine running rich and sounding as if it is misfiring and as they perfom a climbing manoeuvre it goes full two stroke but quite often and unpredictably - it doesn't return to the rich misfiring. They call it run on.

Because of this I have converted quite a few with a PTFE venturi and an ST type NVA. They have been happy with those but then drive me bonkers wanting differnet sized openings. I give them .240 bore and get them to drill them out themselves. Strange though - I am never told the size that they are happy with!

Whether or not this applies to the 25s and 15s - I don't know,

The blue 25 that you see wa originally a full RC version. The RC guys like the rear mounted NVA because it keeps there fingers away from the propeller - (they all use electric starters as well!) . They are also easier to buid around - the head of the needle has a hole bored in it with a grub screw and so it can easily be extended.

However, they are not robust which is why I have neded up with quite a few.

Here is the LA25 RC

If you look at the carb in the second picture you will see that the feed and connection to the fuel tube is some sort of plastic and it is not strong. They break easily and do not repair.

Similarly, in the third picture the NVA mount is quite prominent but, often, when this breaks it takes the backplate with it. A busted LA RC is cheap and with a little patience new backplates and be found. Hence the silver one on the blue LA,

The venturi and NVA are homemade but the NVAs take me a long time time to produce and not always successfully.

The pucker CL version of the LA is all metal up front but the rear mounted NVA is still a pretty weak point. Again, how they compare in flight I don't know.

I have 3 x LA15 broken RC to convert - just need to source backplates.

I am having trials and tribulations with a Super Tigre 40 (ex RC) and I will do a posting on that when finished. I have done OS and Enya but the STs with the offset NVA are giving me an issue.

**944_Jim** Fri Sep 20, 2019 10:35 pm

Ian,

Thanks for the write up! I guess I really need to build a test platform. Then I can check my two LA .15s back to back.
I tried finding aluminum backplates. Been all over StuntHanger crowd (Jim Lee, etc) and made a quick pass at CLStunt.com website. I even checked with shtterman from Florida.

For the LA..15, it looks like eBay is the best bet. Get another couple of plastic ones (or three in your case), and "control the break" by cutting the NVA off! One of the vendors is selling the remote NVA backplate for under $7 ( bare, no needle), plus shipping. I did this on my one with through-venturi NVA. I did keep the cut-off NVA as I may play with making a "bolt-on" remote NVA. This seems to be popular with the combat crowd...not that I'll fly combat anytime soon.

Again, thanks.

GUS THE I.A. Sat Sep 21, 2019 2:12 am

Back to the Polly-Wog airfoil...
I was not concerned with the Kovering adhering to the under-cut ribs on my Ringmaster. The internal rear spar is providing lots of strength, which might be the job that the Kovering might do- if it were attached to the ribs. Of course, the trailing edge provides an anchor point for the Kovering, and the structural stability that the Kovering provides, is probably a comfortable trade-off for it not being attached to the ribs. But, everyone knows: You build to fly; not to crash!
They say that the big rear spar is a "Rib Ripper", in the unfortunate event of a crash. What happens is: it destroys the wing internally, because the big spar does not allow the wing to flex a little bit, at a "sudden stop". So Ian... Don't worry about attaching the Kovering to the ribs- it won't affect the flying or the strength of your plane's wing. Carry on!

Ken Cook Sat Sep 21, 2019 7:12 am

Jim, Curtis Shipp is responsible for LA metal backplates. Jim Lee doesn't make them because Curtis does. Curtis has a small machine shop business and doesn't readily respond to e-mails. I'm not sure if this is current, m14m21@bellsouth.net

getback Sat Sep 21, 2019 8:05 am

Well that is one strong construction if i ever seen one Very Happy

Like the way it can bee took apart to get to the field Looking Good !!

**944_Jim** Sat Sep 21, 2019 8:18 am

Thanks Ken,
Mr. Shipp was also contacted. He had none for the little .15.

I have resigned to picking up a couple of plastic ones and cutting the NVA off

ian1954 Sat Sep 21, 2019 3:13 pm

GUS THE I.A. wrote:Back to the Polly-Wog airfoil...
I was not concerned with the Kovering adhering to the under-cut ribs on my Ringmaster. The internal rear spar is providing lots of strength, which might be the job that the Kovering might do- if it were attached to the ribs. Of course, the trailing edge provides an anchor point for the Kovering, and the structural stability that the Kovering provides, is probably a comfortable trade-off for it not being attached to the ribs. But, everyone knows: You build to fly; not to crash!
They say that the big rear spar is a "Rib Ripper", in the unfortunate event of a crash. What happens is: it destroys the wing internally, because the big spar does not allow the wing to flex a little bit, at a "sudden stop". So Ian... Don't worry about attaching the Kovering to the ribs- it won't affect the flying or the strength of your plane's wing. Carry on!

Thanks Gus.

I am almost ready to start covering the wing now.

ian1954 Sun Sep 22, 2019 1:25 pm

Before I proceed with the build, the term "Polywog" got me a little confused. I had heard it before in one of Windy's videos when he pulled out a box of rubber shapes to stick some sandpaper on for reaching into awkward corners. I could guarantee that during any one of his videos he would use a term or word that I either didn't understand or was not familiar to me.

An example of this was "sheet rock", he did a lot of work with "sheet rock" and I thought he meant slabs of rock like those used for paving slabs. Anyway, after a while - it was pointed out to me that he was referring to plasterboard. He also referred to "spackle" and it was not until I saw a picture of a tub of it on this site that I realised it was filler.

However polywog or polliwog had me stumped as it meant " a sailor who had not yet crossed the equator".

But - you mean a tadpole! We need a dictionary on this site - Horizontal and vertical stabalizers when you mean fins and tailplanes (and the Z should be a S).

Ah well, my confusion is resolved.

ticomareado Sun Sep 22, 2019 1:59 pm

Go spin your spanner and flip your airscrew.

ian1954 Sun Sep 22, 2019 2:08 pm

Back to the build.

I applied two coats of sanding sealer to the wing frame and the rear of the ribs followed by as delicate a sanding as I can manage and a 50/50 coat of non shrinking dope.

Then I used the same mix to attach the Koverall.

I was surprised how easy it was. For a start, because the material wasn't wet - it was much easier to handle. I thought it would be difficult to pull straight and true and around corners but it wasn't.

Unlike silk, it could be pulled without distortion.

Then I realise that there was no need to hurry. The Koverall wasn't about to dry and shrink and I wouldn't have to do opposing sides to stop warping.

Now I have to say that I didn't do a perfect covering job. I got a few wrinkles at the tips and on the trailing edge but a few finger rubs made them passable.

After I had covered the other side I used my heat gun and all the creases in the covering (where it had been folded in a bag for years!) disappeared and it tautened with the minimum of heat.

I was pleased with the overall finish but the Koverall was standing proud of the tadpole. Not much but still enough to annoy me.

So I dabbed 50/50 over the rear of the rib, rubbed it down with my fingers and then used by clean fingers to hold the Koverall down while it dried. rib by rib.

It is now ready for full doping. I thank Ken for his suggestion and If it it doesn't stay stuck - Gus for telling me not to worry about it.

roddie Sun Sep 22, 2019 3:01 pm

Nice work Ian! Do I recognize that divan from the London flat?

ian1954 Sun Sep 22, 2019 3:33 pm

roddie wrote:Nice work Ian! Do I recognize that divan from the London flat?

Roddie my old friend - a divan is a boxspring based bed. I believe you are referring to what we refer to as a couch, settee or sofa.

Yes, it did indeed travel from London along with the matching armchairs. Not many things furniture wise made the journey.

roddie Sun Sep 22, 2019 4:18 pm

ian1954 wrote:
roddie wrote:Nice work Ian! Do I recognize that divan from the London flat?

Roddie my old friend - a divan is a boxspring based bed. I believe you are referring to what we refer to as a couch, settee or sofa.

Yes, it did indeed travel from London along with the matching armchairs. Not many things furniture wise made the journey.

Vous le vous couche.. avec moi.. se soir.. Laughing

(Overlord/Lieven would not approve of my "translatione de Francois")

Just trying to insert a bit of colour... I really need to finish my Sterling S1 and it's good to see that you're settled.. and back to building airplanes, my friend!

Marleysky Sun Sep 22, 2019 4:47 pm

The only thought that went thru my mind after watching that Video was “Gee, Michael Jackson left quite the impression on these young girls”. Shocked

Ken Cook Sun Sep 22, 2019 7:54 pm

One thing I will say with Koverall is that when you dope the covering after the attachment is that you brush your initial 1st coat with the direction of the framing. If you brush across the ribs, the dope will push through the covering and puddle up against the rib as it comes up to it. It then drips down the rib and onto the inside of the bottom covering. This not only adds weight, it doesn't look good. I carefully brush the leading edge and trailing edge and while moving quickly in the open bays I brush onto the open bay from the front and then return brushing the trailing edge into the middle of the bay. Brushing into the work rather than brushing off the work prevents this pushing of dope through the covering.

After it dries, you can brush it as you would any other covering.

ian1954 Mon Sep 23, 2019 6:15 pm

Thanks Ken.

I did the first coat last night before I went to bed. Although I miss your post, I had remembered your advice on this from when Ron was building a Ringmaster Jr and covering it with his dress material.

I did have a few run throughs even though I was using neat dope. These things happen.

But this morning when I checked the wing - I had a slight twist at the inboard trailing edge. About a 1/4" movement over three bays.I used non shrinking dope so I was a little puzzled.

I used a heat gun and pull the wing straight and have applied two more coats of dope. I am letting this fully dry to make sure that it stays straight before I go any further.

So another advantage of using Koverall!

The disadvantage for me is that it is not easily obtainable in the UK but I believe that there is a much cheaper alternative.

Ceconite light -

https://www.aircraftspruce.com/catalog/kitspages/copingvsrebuilding.php

Over here, this is about £1 a square yard.

GUS THE I.A. Mon Sep 23, 2019 7:53 pm

Hmmm,
Ron uses his dress material to cover airplanes.

That sounds funny, but I know what was meant.
Just trying to tease you a little, Ron.

Ken Cook Mon Sep 23, 2019 7:56 pm

Ian, while it's available here it's becoming increasingly expensive. The local hobby shop that I would go to closed it's doors 4 years ago and this was devastating to the control liners in the area. I was buying qt cans of Sig from them for less than $10 while Sig was listing it for $29. They had cans, bottles and spray cans of Sig from the baseboard to ceiling within 2 entire rooms. Sig thinner skyrocketed so much I gave up buying it and switched to a alternative which I bought from a local paint supplier. Then that source went from $30 a gallon for thinner to $80. Koverall is Ceconite.

ian1954 Wed Sep 25, 2019 6:06 pm

Quality thinners here are £50 per imperial gallon and not so high quality, £30. The price increases dramatically with smaller quantities.

Dope has been a couple of days drying and the wing has done another Chubby Checker on me.

Luckily. again - more heat and it straightened out. I get a tad nervous doing this because I can be ham fisted .

It may be difficult to see bit the trailing edge is beneath the aluminium straight edge,

More dope applied - this time 50/50.

ian1954 Tue Dec 31, 2019 9:03 am

This one still take apart

Here it is with Junior

Ken Cook Tue Dec 31, 2019 2:14 pm

Ian, I was thinking of you when I received this kit which is a combat kit. The plane is the Warlord for a .15 size diesel. The leading edge that comes in the box is unlike any balsa I ever used as it's hard as a rock. The leading edge is currently a 1 1/4" square 36" long. I'm looking forward to this build but I'm undecided on power. My son feels we should use the diesel as some of the guys in the club want to do "Stinky Combat".

ian1954 Tue Dec 31, 2019 3:25 pm

Ken Cook wrote: Ian, I was thinking of you when I received this kit which is a combat kit. The plane is the Warlord for a .15 size diesel. The leading edge that comes in the box is unlike any balsa I ever used as it's hard as a rock. The leading edge is currently a 1 1/4" square 36" long. I'm looking forward to this build but I'm undecided on power. My son feels we should use the diesel as some of the guys in the club want to do "Stinky Combat".

I have seen quite a few Warlords flying recently - all diesel powered, either PAW or Olly clones. The leading edge in the original Pegasus kit was often replaced with something less hard but all the ones I have seen have been plan built with rock hard balsa leading edges and nylon or silk covered.

One weighed 20 oz all in and was used as a trainer. Most came in at 15 oz but a 13 oz model didn't survive a not so hard landing.

I believe the Warlord was the winning model in the British 1970 and 1971 Nats.

Very hard balsa is very taxing to shape. A few of the Vintage combat builders I know use a plane a a power sander to shape the leading edge before building.

Dave P. Tue Dec 31, 2019 7:54 pm

Here's my S1. It's from a Brodak kit from my local hobby shop. I buy everything I can there to do my part to keep him going. Tough times for the LHS with the Internet and all.

It's ready for final assembly, covering and finish except for the hardware needs some refining, and the stab and elevator need to be replaced as they are both pretty warped. I got the elevator straight spanwise but it's cupped, the stabilizer is too warped and cupped to use even after several attempts to save it.

The engine I'm going to use is a Brodak 25. He has a nearly perfect McCoy red head, but he wouldn't sell it, so I had to settle for this. I gotta say though, it's a nice engine. I pulled the head and backplate like every new engine and the machining is beautiful. The instructions say not to turn it over until its first run so I didn't, but I did give it a little twist just to see and it is really tight. I'll probably have to heat it up to crank it the first few times.

I'm planning on covering it with Brodak Heat Shrink fabric, again from Bill at my LHS. Does anyone know if that's Ceconite? I suspect it's all the same stuff.

I love that we can share this stuff here. Thanks for letting me step on your toes a little Ian.

Mike1484 Wed Jan 01, 2020 5:41 am

I would shorten the needle a bit if I where you . It will not last long if the plane flips over .Nice looking plane and engine .

Mike1484

Ken Cook Wed Jan 01, 2020 7:07 am

Dave, I have had some problems with the Brodak needle valves. Once debugged, I like them better than Tiger assemblies. I've turned a few down to the same dimension for Fox .35's. It's as if they didn't run enough threads up the shaft. You just can't lean the engine out enough due to the threads bottoming out in the locknut. I just used number drills to obtain a slightly looser fit which after running the needle in and out allows the unthreaded portion to pass through. You more than likely will need a heat gun as these have a lot of pinch up top and once fueled, the piston will get stuck at the top. Brodak also at one time made a announcement in regards to problems that occurred with the spraybar.

John offered a small addendum with some of the engines indicating to first run the needle into the spraybar working it in out several times. This would break the chip at the bottom where the threads stopped. If there was no resolution doing so, he would replace it. I did indeed experience this problem. I figured it out on my own as I couldn't get the needle in enough.

Another thing to keep in mind if when you do get around to flying it is the speed. If the engine doesn't seem to offer enough power, you may want to consider opening the venturi slightly. To many, the Brodak .25 seemed anemic. The venturi size on some of these were very small.

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