Matador build by Big Bandit

[Big Bandit]

Well, after the weather of the last week, it's hard to get motivated, every time I go to the shed it's squelching up the lawn and every things soggy. Anyroadup yesterday was a day of trial and error on the cabin glazing front, first off the video blog was constantly interrupted by phone calls but I have to have my mobile on at all times for emergencies. Then the moulding process went pear shaped at every turn, so it was really a day wasted. I'm sure it can be done it just needs more time to perfect.

Plugs cut and sanded for the openings. Just need to be a good fit.

Made from 1/4" ply.

Take two empty pop bottles, the Coop own brand is only 29p a pop .

Cut a length of bottle to fit the plug inside, with a block of timber to take up the remaining space in the bottle.

Plug the old paint stripper in and start to shrink the plastic. It works the same as heat shrink tube on cables.

The end result works, but the quality isn't up to what I want. A bit more practice and experiment should turn out acceptable results.

Back for a bit more in a mo.

Cheers,

Chris

[Big Bandit]

After the on going fowl ups yesterday, today was a bit better, and I decided on plan B. Although the old Pop bottle works fine for cowlings and canopies on warbirds and gliders.

So cut more plugs from 3/16" balsa in this case, and fret out the inside to 3/16", and I have an internal frame. The secret I found was to leave plenty to sand by hand, as it's more controllable. The frames dry fitted.

Other side the same ready for painting.

In the meantime I've stuck some acetate to the frames I made last week, using a different adhesive on each. First two, RC modellers glue, and Formula 560.

Same with the unpainted side so I have double glazed panels. and leave to dry naturally.

Back to the Matty. Any model IC powered model with a partially or totally enclosed motor needs a drain hole, so that fuel doesn't collect and soak into the structure. My method is to use an eyelet with some brass tube soldered inside. The pipe cutters are from my plumbing kit and are brilliant for small bore brass tube.

 

Solder the tube into the eyelet.

And epoxy it into a hole in the bottom of the engine bay as low as possible.

Trim the outside underneath the fuselage with another eyelet, thats the one in the centre the other ones for the tank vent.

Tank vent in place.

The vent is the one through the side cheek infil. The others the filler that will go through the top of the cowl.

With the motor bolted back in place, don't forget the spring washers under and between the bolt heads between the engine mounting lugs.

With plain washers under the nuts, tighten with proper 8BA spanners.

The window frames have been painted ready for glazing, so tomorrow that's the first job, then the throttle linkage to do. So far it's a pretty tidy build so I'm happy again.

See what tomorrow brings.

Cheers,

Chris.

Edited By Big Bandit on 04/05/2012 23:14:53

[Mike Etheridge 1]

Chris,

Looks a good idea the internal framing and quite achievable. I think you are reaching close to perfection on your Matador.

Today I added the side windows on my plane which were not difficult, and I managed to avoid glue smears as no bending / setting of the heavy grade celluloid was necessary. Over the weekend i will sellotape mask the framing and paint it red to match the Solarfilm.

I have bought a quantity of the heavy duty 'Deans connectors' from the 'Component shop' to connect up the replacement brushless motor which i still need to fit. Once I have completed it I will add some photos on the oher blog.

Cheers,

Mike

[Big Bandit]

Thanks Mike,

The internal frames will look a bit neater I think, what glue have you used on your side windows. I'm waiting until the test frames I have done have dried properly to see what works the best.

Theres one really dumb mistake that is evident in the photo's regarding the motor mount on mine . I can put it right today, but I can't believe I've done it. I might as well adjust it now rather than wait for the maiden or I'll only be fly in circles at best.

You won't go far wrong with the deans connectors they are very good, and you might notice an increase in power over the Tamiya ones.

Cheers,

Chris.

[Anthony Billings]

OOOPS

[Chris Bott - Moderator]

Chris it's all looking fantastic- makes my part built Matty feel completely abandoned.

The only thing that makes me feel better is that left thrust you seem to have built in - It's good to see that other people do stuff like that, quite cheered me up.

I'm sure you'll have that sorted in a jiffy.
I'm afraid that if I want to finish mine, I'll have to just crack on and accept that it is going to look pretty rushed. Better that than no Matty at all I guess.

[Mike Etheridge 1]

 

 

 

 

 

 

Chris,

The two pictures above have been taken prior to painting the cockpit frames red. The Glue I used was 'Araldite Rapid' . The appearance I think will look much better after painting but of course I have now exposed the cockpit interior which looks like Steptoe's junk yard!

Mike

 

Edited By Mike Etheridge 1 on 05/05/2012 13:52:21

Edited By Mike Etheridge 1 on 05/05/2012 13:56:48

[Big Bandit]

Hi Tony, Chris,

I can't believe I did that, as the missus says what a muppet. It's fixed now.

Yours should look OK Chris it's just that Nylon can be very difficult to use, I can't say I would recommend it and I think I got away with it lightly on my Super 60. It had the potential to go completely pear shaped on a number of occasions. Litespan ain't too easy to use and suffers hanger rash easily, I'll have to try other lightweight coverings but the big problem is getting what I want locally as the LMS only stocks Profilm and the like.

Cheers,

Chris.

[Big Bandit]

Mike,

That's looking better with the side windows glazed and will look even better when they are trimmed with paint. The test pieces that I've done using different adhesives needs to be completed and I'll try Araldite Rapid to see how it works..

Cheers,

Chris.

[Big Bandit]

I don't know about everyone else, but I'm getting totally fed up with the constant rain it's making every thing soggy. Even the odd CD's I keep in the shed now refuse to play properly, there's condensation inside the jewel cases and everywhere else for that matter.

I need to get on with converting the garage to a workshop but the first job is replacing the roof so until I have a couple of dry days to sand the new roof trusses and Cuprinol them outside, then a few guaranteed dry days to get the old roof off and the new one on, it ain't going to get done. So for now I'm stuck in a damp cramped shed.

Anyroadup, progress today first was the resetting the thrust line for the motor on the Matty. The existing holes bar one were filled with a bamboo BBQ stick with a drip of thin cyano wicked in. Then using my spare motor (it doesn't have a silencer so it's easier to mark out the holes) Re drill the bearers and refit the motor. That looks better with about 2 degrees of right thrust.

The next job was to setup the throttle linkage from 18 Gauge wire, at the servo end I've used a modern method of attachment to the servo arm.

And a ball link at the motor end, (screwed onto a 2mm adaptor soldered to the end of the wire). The reason I use these is to give some electrical isolation, as in the past I've found metal to metal linkages in these area's can cause radio interference.

Then I've drilled to let the exhaust out and painted the raw inside of the hole ready to lightly sand and fuel proof later. I may fit a small length of silicone tube to take the residue clear of the fuselage.

The window frame are painted ready to glaze and fit.

Theres also a couple of degrees down thrust, if I need more I'll pack the front of the engine mounting lugs with extra washers.

And where I am now with the build.

I need to fit the radio switch before I do the front glazing so I can get at it easier, and bury the radio battery behind the font bulkhead for the same reason. I also need to make my mind up which gear I'm using my 35 meg Futaba or my 2.4 Speccy. I have just brought an AR500 from Ally and that would save weight or one of the orange clones.

Cheers,

Chris.

Edited By Big Bandit on 05/05/2012 19:03:33

[Chris Bott - Moderator]

Chris you're an inspiration. A whole tailplane has been constructed here today in between other chores

I think I'll be going with Solartex for everything but the wing on mine, just 'cos I have it and to get it done.

Just a quick observation - you have mounted your engine below the bearers but my plan shows it inverted but with the flanges sitting above the bearers. I don't think it will be an issue at all, but your thrustline will be lower than mine, (further from the drag of the wing) so you may need a tad more downthrust.

Also while I'm here, how are you setting your tailplane incidence? I'd like mine to potter around like a free flighter but with a bit of guidance, so I was going with the FF option, but it just looks far too much.

[Chris Bott - Moderator]

And a fin is made now

[Big Bandit]

Thanks Chris.

The main reason for mounting the motor inverted below the bearers is that if I mounted on top the silencer would fowl the bearers, and they are quite deep. A tad more down thrust is easier just by removing the two front bolts and slackening the rear ones. I've some thin alloy washers that'll give about 1 degree per washer between the mounting lugs and the bearers.

The tailplane's as per plan, and I want mine to just potter about the sky like a guided free flighter, just like the Leccy Quiver. The radio is only used to keep it within the boundaries of the field.

I recon with the 1.5cc option, the power loading will be about right or possibly a bit too much as long as the airframes light. One of my FF Matty's in the 60's flew well on a Mills .75 but would only gain height very slowly. When I fitted the ED Bee Mk1 it was a potential fly away on every flight unless it had the compression backed off a fair amount. Both motors used an 8 x 4 KK prop.

Your Matty on the Frog 1.5 should be a real steady flier if it's kept light.

Cheers,

Chris.

[Steve Hargreaves - Moderator]

Looking really good Chris.....

[Mike Etheridge 1]

Well if I constructed another Matty I would set both the wing and tail at zero incidence due to the bad experience with the existing model. I am sure that my Matador will free-flight as no trimming of the elevator was necessary when it last flew. Indeed I have flown my Junior 60 as a free flighter, the last time at the Nationals at Grantham. Other than introducing about 1/8 of balsa under the tailplane which has no elevator ,no other trimming was necessary.

I can't understand why the wing on the Matador is set so far off zero incidence? I wonder also how much effect using a tailplane with an aerofoil section and presumably lift has on the trimming? None of my planes currently have tails with aerofoil sections but in the distant past when my friends and I designed our own models we did have '60% Clark Y' tailplanes and may have been influenced by the MAP books 'Design for Aeromodellers' and 'Construction for Aeromodellers'. Excellent books but I no longer have access to them.

MJE

 

Edited By Mike Etheridge 1 on 06/05/2012 09:20:33

[Mike Etheridge 1]

I have just read the earlier blog on 'lifting tailplanes' that has some interesting comments from people who obviously know about aerodynamics.

My Matador which was built from an original kit has a flat tailplane whereas the new Ben Buckle models being constructed have aerofoil sections and must therefore be trimmed differently.

MJE

[Big Bandit]

Thanks Steve, just a few more mods today.

Cheers,

Chris.

[Big Bandit]

Hi Mike,

When the Matty was first designed it was for free flight only (won the 1957 Nationals) it was only later that it was converted to Single channel RC. My first Matty flew well on a Mills .75 although the climb was very slow but stable, when I fitted the ED Bee Mk1 it was transformed and had to be throttled back a lot to save flyaways.

Much later another Matty was built with RC in mind and when the gear was fitted (I can't remember the make) it was very heavy with high and low tension dry batteries, and used two Elmic escapements of which one was on blip throttle and the other on rudder. I think they were called the Commander and Corporal. That one flew very well on a Mills 1.3, I do remember the throttle was a cork on a length of piano wire that slapped into the Mills Venturi and was carved so that the Mills just wouldn't stop. I still have all three engines, along with my old Comp Special. They are all original from my teens although I never run them these days, just keep them in the study with my Who memorabilia.

As for the lifting tailplane issue again it was common practice to use a lifting aerofoil for tailplane's back then for sports free flight models, and I recon it's only when elevator control was introduced that the flat plate became popular along with the semetrical section for sports models. having looked through the 1970's KK handbooks the Matty doe's appear to have a lifting section, but in saying that the pici's are not good quality like we expect today so it's hard to tell.

At the end of the day I wouldn't suppose that for a slow flying cabin monoplane it would make a lot of difference, although a sports aerobatic model would be another matter.

Cheers,

Chris.

[Mike Etheridge 1]

Chris,

A bit of a mystery about the flat tailplane on the Matador then? I can remember the KK Pirate having an aerofoil tail, however the 1946 Southern Dragon had a flat tail. I can't remember what the Mercury Magna had for a tail?

All the engines you have on display my friends from the past and I have owned at some time. Only the two Mills engines were fitted to planes.The ED Comp Special I remember was particularly noisy and vibrated a lot. A friend of mine fitted it to a Mercury Skid Boat which we sailed at Richmond Park.. The mark 1 Bee was clapped out so that saw no use at all.

I have painted the window frames on the Matador today and have removed the masking tape. I will give the celluloid a clean tomorrow once the paint has dried. The installation of the brushless motor will follow.

Our club the 'scale day' had to be cancelled for the second time today due to rain, so some of the members are thinking about indoor flying.

Best Wishes,

Mike

[Big Bandit]

Hi All,

With the weather staying dry today and as the old saying goes "it's a lot less bover wiv a hover" I managed to give the lawn a crop today with the electric hover mower, although I would have liked to use the old Suffolk Punch but it's running so rich the float bowl can't keep up with the demand. That's another job that needs doing, so it's spanners at dawn tomorrow .

As for shedly doings it's been a bit of Mattyfying, after Chris Bott pointed out that the motor in the Matty is mounted inverted above the bearers rather than below them and as I have already said it's tight with the PAW fitted with a silencer. Anyway a challenge is a challenge, so it's out with the motor, tank and dismantle the feed from the tank. After a bit of fettling of the brass feed tube it's solder that back in to give a bit of leeway for the silencer. Re-fit the tank then with a bit of shoving, pushing, twisting, the motors back in with the silencer up against the bearers. I could have taken the easy route and using the mini tool cut some bearer away, but I'd rather not weaken them. The other mod was to turn the throttle arm through 180 degrees to line up with the linkage. It worked, Thanks Chris.

TBH the existing setup looked poor with the cowl on and I'd rather not build another cowl, I did anyway but that's for another reason. The motor re-fitted in the specified position, and notice the spring washers under the nut's.

I could only get two thin washers under the rear lugs to get the down thrust I wanted which gives about two degrees. Notice the new exhaust outlet with the old one filled, using the slug of balsa that I had to cut for the new hole.

The old cowling just looked wrong (left), so I built another.

Looks much better with a 2 1/4" spinner.

One thing I do with things of this kind is to give the inside a coat of Polyester Resin, it provides some strength with fuel proofing.

And I've maintained a couple of degrees right side thrust, it can be seen just how tight the tank silencer, bearers are with the engine bolted down. But I don't like using an engine without a silencer.

Now I've been fed and watered I'm off down the shed again to apply a bit of fuel proofer, and lock up for the night ready for an early start tomorrow with the spanners.

Cheers,

Chris.

Edited By Big Bandit on 06/05/2012 20:19:46

Edited By Big Bandit on 06/05/2012 20:21:47

[Big Bandit]

Hi Mike,

I've looked at the KK handbooks, The Pirate (I have one in the loft) and the Bandit which is my next build, both have a lifting tail. In the 1963 Handbook the Matty is inconclusive but the Wizard and the Magna both seem to have lifting tailplane's. 1975 handbook the Magna definitely has a lifting section and the Matty seems to have, 1978 both definitely have lifting sections. So as you say it's a mystery.

Anyroadup, the Ben Buckle cowl ain't going to work, even with the motor mounted higher up.

So it was worth building another one.

Cheers,

Chris.

[Steve Hargreaves - Moderator]

I'm intruiged by your decision to go for an inverted engine set up Chris......I always have the greatest respect for those who go for an inverted diesel....you can usually spot these modellers by the prop scars on their left wrist from reaching for the compression lever......

[Big Bandit]

Hi Steve,

LOL I can do that which ever way the motors mounted, That scars still there. I am enjoying this one though. Hopefully the inverted mounting will improve the starting a bit.

Cheers,

Chris.

[John Olsen 1]

One aspect of the lifting tailplane that you guys were discussing...back in the day with free flight models, the main aim was to get maximum duration from either a given engine run time for power models, or a given tow line length for gliders. To acheive that you need maximum lift, and the lowest possible wing loading, however the maximum total wing area was usually limited, as was the minimum weight. So apart from using highly undercambered high lift wing sections, one of the things people used to try to do was get some lift out of the tailplane. If taken to its logical conclusion, this means that the tailplane ends up at the same angle of incidence as the mainplane, and of course there is no longitudinal stability..so since there was no radio control it was not usually taken that far, however that might well be one reason why a model might have a lifting tailplane. But to fly free flight it is usually necessary for the tailplane to have a bit less incidence than the mainplane.

Another thing that was done is to reduce the tailplane size and use a long boom. This sort of thing is why free flight gliders in the old days did not look much like full size ones, which tend to be optimised for distance from height rather than duration...as a result a high lift drag ratio is the most important thing for them. Since the model was trying to fly as slowly as possible, right on the edge of a stall in fact, drag was not quite so important. There were two reasons for trimming right to the edge of a stall, one is that this is where you get the maximum duration from a given starting height, the other is that a model trimmed there will tend to turn towards lift, eg if one wing enters a thermal the increased angle of attack on that wing will take it towards a stall and the model will turn that way. It will thus tend to enter the thermal and then stay in there, often until it disapears, hence the invention of dethermalisers.

regards

John

[Big Bandit]

John,

Most interesting, There is a section in chapter 11 of Martin Simons book Model Aircraft Aerodynamics that looks at lifting tailplains and makes for quite interesting reading. I'm not convinced that on a model such as the Matty it makes much difference if any other than appearance. On FF contest models it's worth looking at to squeeze out as much performance as possible.

Looking though the Nexus specials it's evident that a lot of early rubber and power designs used lifting tailplanes and a high percentage of the remainder used a semetrical section built up tailplane.

Cheers,

Chris.