Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


RIngmaster - Page 2 Babe_b10
Log in

I forgot my password

RIngmaster - Page 2 Pixel
Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Lil Roughneck kit on ebay
by balogh Today at 2:21 pm

» BHM Mosquito in MS-build
by balogh Today at 2:04 pm

» My layout as it progresses
by rsv1cox Today at 12:43 pm

» Something for Admin and the moderators to consider
by rsv1cox Today at 12:12 pm

» OK powered Dakota
by ticomareado Today at 6:48 am

» Cox train forum?
by getback Today at 6:40 am

» Kamtechnik turbo head on 290 red postage stamp backplate reedy
by 1/2A Nut Today at 6:20 am

» McCoy .19 Series 21 Needle Question
by NEW222 Yesterday at 7:06 pm

» Christmas Train Has Arrived
by NEW222 Yesterday at 6:26 pm

» Lookie Here
by getback Yesterday at 9:50 am

Cox Engine of The Month
November-2019
jmcalata's

"Pee Wee .020 throttled combinated"



PAST WINNERS
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


RIngmaster - Page 2 Empty
World of Aviation

RIngmaster

Page 2 of 2 Previous  1, 2

Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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

RIngmaster - Page 2 La_rc10

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.








ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  944_Jim on 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.
944_Jim
944_Jim
Platinum Member
Platinum Member

2019 Supporter

Posts : 610
Join date : 2017-02-08

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  GUS THE I.A. on 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!
GUS THE I.A.
GUS THE I.A.
Gold Member
Gold Member

Posts : 338
Join date : 2012-08-15
Location : Wichita, Kansas

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  Ken Cook on 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
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 3659
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  getback on 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 !!
getback
getback
Top Poster
Top Poster

2019 Supporter

Posts : 6415
Join date : 2013-01-18
Age : 62
Location : julian

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  944_Jim on 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
944_Jim
944_Jim
Platinum Member
Platinum Member

2019 Supporter

Posts : 610
Join date : 2017-02-08

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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.
ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ticomareado on Sun Sep 22, 2019 1:59 pm

Go spin your spanner and flip your airscrew.
ticomareado
ticomareado
Platinum Member
Platinum Member

Posts : 886
Join date : 2013-10-03
Location : NC

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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.

RIngmaster - Page 2 Kovera10

RIngmaster - Page 2 Kovera11

RIngmaster - Page 2 Kovera12

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.

RIngmaster - Page 2 Kovera13

RIngmaster - Page 2 Kovera14

RIngmaster - Page 2 Kovera15

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.

RIngmaster - Page 2 Kovera16

RIngmaster - Page 2 Kovera17

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.

RIngmaster - Page 2 Kovera18

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.
ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  roddie on Sun Sep 22, 2019 3:01 pm

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

Posts : 6638
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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.
ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  roddie on 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!
roddie
roddie
Top Poster
Top Poster

Posts : 6638
Join date : 2013-07-17
Age : 59
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  Marleysky on 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
Marleysky
Marleysky
Diamond Member
Diamond Member

2019 Supporter

Posts : 2431
Join date : 2014-09-28
Age : 67
Location : Grand Rapids, MI

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  Ken Cook on 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.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 3659
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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.

ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  GUS THE I.A. on 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.
GUS THE I.A.
GUS THE I.A.
Gold Member
Gold Member

Posts : 338
Join date : 2012-08-15
Location : Wichita, Kansas

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  Ken Cook on 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.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 3659
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  ian1954 on 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.

RIngmaster - Page 2 00110

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

RIngmaster - Page 2 00210

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

More dope applied - this time 50/50.
ian1954
ian1954
Diamond Member
Diamond Member

Posts : 2554
Join date : 2011-11-16
Age : 65
Location : England

Back to top Go down

RIngmaster - Page 2 Empty Re: RIngmaster

Post  Sponsored content


Sponsored content


Back to top Go down

Page 2 of 2 Previous  1, 2

Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum