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mhodgson

EMP Algebra 2.5m

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mhodgson

Decided to visit the Free Flights Nationals and it has been quite enlightening particularly watching the glider flyers and their ciecke towing.

Not much in terms of buying and selling but I did manage to get, of all things) a complete kit for an Algebra 2.5m, glass fus, for a staggering  £25!!!

At moment plan will be to build it as an aileron/flap calm weather slope model and to keep generally to the plan/kit (other than glassing the wings), unless anyone has any other suggestions.

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pete beadle

Hi mhodgson

Is the kit for a mark one or a mark two? The mark one had a dihedral point at roughly half the span of each wing, the mark two had lots of tip dihedral

Dick Edmonds (EMP) never produced an Algebra with a four servo wing (flaps and ailerons) , the Algebra was always noted for its simplicity

Congratulations for getting this kit for £25.00 though - I'm envious.........

Over the years I've had about a dozen Algebras with foam wings and glass fuselages but I haven't fitted flaps to any of them - I've only glassed one set of wings and noticed absolutely no improvement whatsoever, in fact, because the glassed wings were a lot heavier I'd say the soaring performance wasn't as good as any of the others

By all means fit ailerons, with a servo in each wing, but I'm intrigued as to why you'd want to fit flaps........airbrakes, either Graupner or  Multiplex type, by all means, but  flaps? I'm assuming you're not going to use the Algebra in competition why do you think you would you need flaps? I'm genuinely puzzled......

Also, you haven't mentioned ballast tubes yet......Dick used to fit 1/2" OD Dural tubes as ballast tubes which really stiffened and strengthened the wings.....my Algebra 2M has them, and they are really effective, but my 2.5 mark two doesn't, IMO it doesn't need them.......

Good luck with the build .....pics of my 2.5 mark two Algebra (left) and my 3M - both R/E as you can see.........simples!

Regards

Pete

BARCS1702

Algebras 6th Sept 001.JPG

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mhodgson

Thanks for the reply. I think it is  mk1. The wing panels are in one piece but the plan shows three different options for dihedral.  Straight, poly (equal split panels) or tip (with flat inners).

It also shows aileron option.

Balast tubes are in kit.

Thought of using flaps mainly because I am terrible at fitting airbrakes cleanly and getting them to work properly, flaps are just easier to do. May go with just ailerons and use them as spoilerons- that worked well on another soarer I had.

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pete beadle

Hi mhodgson

Thank you for your prompt reply

My suggestion would be to go with the KISS principle and fit ailerons with one servo per wing, and use the straight dihedral wing panels, as they'd be the simplest to convert to ailerons......then use the ailerons as spoilerons as you suggest

Fitting the ballast tubes would be a good idea too, the strength they impart is out of all proportion to their weight, and you could place them at 35 - 40% of the root chord so they don't move the CG position when used.  it's also quite easy to file the outer ends of the tubes  in a serrated pattern and use the tubes as a cutter......

I wouldn't glass the wings either, two or three coats of hard (outdoor) varnish would be plenty to harden up the wing skins

Then you'd have a strong, light plane that would roll axially and which should cope with most aerobatics and wind speeds:)

Good luck with the build

Regards

Pete

BARCS1702 

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Witch_1

There was a 2.5m Algebra version with single wing panels that had a thinner wing profile (RG14). Worth confirming which you have as that version would benefit from flaps/crow brakes.

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mhodgson

The 'racer' version.

I did check carefully. The wing is definitely flat on the rear lower surface and the box has S3021 written on it.

Still pondering on what I will do exactly but no rush.

Building a vintage Suzy Que at the moment.

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pete beadle

Hi mhodgson

The Selig Donovan S2021 is a very good all-rounder sports type section - it was the section that EMP replaced the Eppler 205 with:yes:

Great to hear you're not in any rush.....that's the way to get the most out of any project:thumbsup:

Suzh Que eh! - now you're talking!:)

Regards

Pete

 

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satinet

Or was it the s3021?

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MMD

Something about the Algebra fuselage (especially the front end) design/shape that is a classic...Looked like a thoroughbred straight  from the get-go back in the late 70's if memory serves. Especially the straight winged variant with ailerons and airbrakes.  

It would be tempting to kit one out with ailerons and flaps instead of pop-up air brakes...  

You certainly got an amazing bargain/and a kit with a lot of potential  mhodgson! Well done and happy building and flying :)

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MMD

Like this one

 

 

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mhodgson

Nice vid.

The kit has been re-issued with a cnc cut built up wing by the guy whi sells Pat Teakle designs.

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MMD
29 minutes ago, mhodgson said:

Nice vid.

The kit has been re-issued with a cnc cut built up wing by the guy whi sells Pat Teakle designs.

Great stuff! Thx

Looks like he is going to make foam wings variant soon as well, with crow brakes.

https://patteaklegliders.co.uk/shop/algebra/

I imagine the cost would increase a fair bit thought. I wonder how solid/rigid is the open rib/film structure? Certainly lighter.

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pete beadle

Hi Slap

Reminds me of when Dick Edmonds decided on "Calculus" as the name for the new big 'un whereas SeanB was ruminating on "Loga".......subtle:)

Regards

Pete

BARCS1702

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MMD

Hey Pete. Interesting...

Also of interest, what are those two cracking looking v-tails  you got in your profile pic?

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pete beadle

Hi Slap

Unquestionably  the best F3B/High end sports planes I've ever owned/flown/enjoyed - herewith a bigger pic and a drawing:yes::thumbsup::)

Regards

Pete

BARCS1702

current planes 123.jpg

current planes 126.JPG

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MMD

I think that is one of the nicest looking sailplane/design I've ever seen Pete! Love the elliptical part of the wings leading edge and the subtle line going in on the trailing edge near wing tip...Like a cross between an albatross and a spitfire :). Fuselage looks clean & strong like a javelin.  

 

I'm sure one could do a little modification on the Algebra wings and tail to make her feel euphoric :)

Do they still make this kit? How do V-tails pan out (never used one before)?

 

Such beautiful wings.....

 

 

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pete beadle

Hi Slap

Have a look at www.weberschock-developement.de

Sadly the Europhia is "old tech" now and only made to special order.....not that anyone would want one these days, the requirements for the various classes of international competition have changed drastically over the last 10 or so years....and yes, the dear old Europhia 2V is now well over 10 years old!!!!

Algebras and custom built mouldies are apples and oranges, chalk and cheese.... design and builds......Dick Edmonds knew his market in the UK and targeted the clubman flyer, Martin Weberschock supplies to a very different market.......and please  don't mention the relative prices for their products

The "V" tail configuration was initially used as it removed a third of the tail's flying surfaces, thus reducing tail weight dramatically.......in use, slope soarers liked the "V"'s as it kept the tail clear of the long grass you were landing in, whereas flat-field, winch or bungee launched gliders preferred the better authority on the launch that an "X" tail or "T" tail gave - horses for courses

Beauty is very much in the eye of the beholder but, these days, it seems the better maxim is "Yer pays yer money and you takes yer choice" 

Regards

Pete

BARCS1702

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