Jump to content

Original Sean Bannister Algebra VIII


John H

Recommended Posts

I just wanted as many interested people as possible know that I have just placed on eBay an original, unflown, Sean Bannister Algebra VIII F3B 100 inch glider. I fly F5J and was planning on sawing the front of and adding a motor.  But common sense got the better of me, I hadn’t the heart to disfigure such a piece of history.  Not only that it never would have been competitive these days!

post-3306-0-49821600-1424383042_thumb.jp post-3306-0-01642400-1424383138_thumb.jp

 

  • Like 2
Link to comment
Share on other sites

Yes leave it as it is as you say it would not compete today by the time you have added the motor battery etc due to the weight I guess would be quite high.

Pete Beadle might be interested for his collection :drool:

Link to comment
Share on other sites

  • Committee Member
On 23/02/2015 at 10:25, pete beadle said:

Recently appearing out of the job queue is my "Watts Up" so that's now sat next to my "Alacrity" waiting for the dates for the Bartletts League events........ over to you

Regards

Pete

BARCS1702

Have a look in the Event Calendar in the blue header at the top of this page.

Link to comment
Share on other sites

Thanks Pete

 

So, first round at Bartletts on 29th March

I'll  put it on my calendar - IN RED

Regards

 

Pete

BARCS1702

Unless we get some very dry weather, I cannot see the event on the 29th March being on. Went over on Friday and there is no way you can drive onto the field at the moment, shame as it will throw things out of kilter yet again.

Link to comment
Share on other sites

 

On 26/02/2015 at 19:28, Robin Sleight said:

...but the canopy air brake would have disqualified it as a 100S model. 

Robin

Really, Robin?

I have scoured the rule book for mention of the outlawing of a canopy air brake (as I had often thought that it would be a good idea). Can't find anything that currently suggests that.

Straight from the BARCS 2015 rules...

"3. 100S Definitions

In addition to conforming to the general model requirements, an 100S model must meet the following criteria:

a) Maximum projected span of wing 100".

b ) Directional control shall be by the use of rudder and elevator only.

c) The use of airbrakes or spoilers, excluding any such device used additionally for directional control or camber changing devices giving altered lift generation, shall be permitted.

d) Models using a flying wing or canard configuration are exempt from the wing control surface restrictions in rule above."

Was there a previous rule that has been written out (either intentionally, or otherwise)?

I need to know these things (and all model type rules) if I am to be the CD for RadioGlide's MLG event.

Jef

PS Moderators, please can you move this to a more appropriate area of the forum?

Link to comment
Share on other sites

Jef, I think the relative words in Robins post are:  "would have". 

As at the time the Algebras were the thing to be using, brakes or spoilers were not allowed in 100s.

I remember, around that time, turning up at a 100s comp with a semi scale 100 incher.

The scale detail and weathering was painted onto the covering, this included something that represented brakes.

After being reported by 'fellow' competitors, I was amused to be summoned to the irate CD,  who insisted that the brakes had to be taped up if I wished to take part in the comp!!

That was at South Marston airfield, Swindon.  Which was bought by Honda in 1985 to build their car production plant.

I imagine there are a few on this forum that would have enjoyed flying there in the past - happy days!

Regards,

Cliff

  • Like 1
Link to comment
Share on other sites

On 27/02/2015 at 22:12, Cliff H said:

Jef, I think the relative words in Robins post are:  "would have". 

As at the time the Algebras were the thing to be using, brakes or spoilers were not allowed in 100s.

I remember, around that time, turning up at a 100s comp with a semi scale 100 incher.

The scale detail and weathering was painted onto the covering, this included something that represented brakes.

After being reported by 'fellow' competitors, I was amused to be summoned to the irate CD,  who insisted that the brakes had to be taped up if I wished to take part in the comp!!

That was at South Marston airfield, Swindon.  Which was bought by Honda in 1985 to build their car production plant.

I imagine there are a few on this forum that would have enjoyed flying there in the past - happy days!

Regards,

Cliff

I used to fly there by invitation of the Vickers club, it wasn't too far away from our Marlborough club, gentle towing of my Graupner Hi Fly  8-)

My nephew works at the Honda plant now !

Link to comment
Share on other sites

Hi all, thanks for your interesting comments on the Algebra I'm selling, you obviously all know more about this than me! 

I have measured the span, the wings are 50inch each, and the fus adds another 2 ¾ inch to the overall span.

On the original drawing by Sean that I have for a built up wing the length of each wing is 1358mm (=53.5inch).  The wings I have are foam cored.

As I have mentioned somewhere else it was owned by a friend who bought it from Sean when he was selling them a few (Fus and foam wings) to members of a London club. My friend was having a clear out recently and I offered to finish it for him and fly it electric, but we decided in the end that it was a shame to saw the nose of so it’s up for sale, hopeful to someone that will appreciate it. 

  • Like 1
Link to comment
Share on other sites

Thanks for the enlightenment.

After spoilers were allowed, I started competing with 100"S models. That was in the nineties, and I never knew that spoilers were originally disallowed, but suspected that may have been the case - hence my first comment in this thread.

The lack of descent control does explain the rather unusual (large) landing area in the 100"S rules... which despite the size, some people whose models were fitted with brakes could still miss  :blush:

See you all at RG 2015

Jef

Link to comment
Share on other sites

  • 1 year later...

Hi guys

Would anyone have either a plan or drawings for the Algebra 8? I have them for the 800 and 1000 from Edmonds model products but can't find one for the mk8

Any help would be welcome. Email files are fine or I can scan and return a plan.

Thanks, Derick

Link to comment
Share on other sites

  • 1 year later...
Erik Dahl Christensen

Hi Robin, Is it possible to get a copy af the plan for the Algebra VIII. If the fuse is not drawn, perhaps with some measurements of different lengths and widths of the fuse, to make a lost-foam- copy?

 

Thanks in advance

Yours sincerely

Erik Dahl Christensen

Link to comment
Share on other sites

Erik Dahl Christensen

Hi Pete,

I'm sorry to hear that. I would be greatfull to get the old plan i some format, and also to behlped to get in contact with someone who cold take measurements of the fuselage and maybe details of the wingplanform and tail. TIA.

I found Clive B Halls contact in another forum, and mailed him. As I understand, he prodced the fuselages way back then?.

Thanks for the help.

Yours sincerely

Erik

Link to comment
Share on other sites

Hi Erik,

I could well be interested in an Algebra 8 fuselage. If you can find some decent details of the shape I may have a go making a fuselage plug.

My first proper glider used one of these fuselages and some home made foam wings.

Martin.

Link to comment
Share on other sites

I remember being lucky enough to spend a day back in the 90's with John Hall, in his workshop in Weston-Super-Mare. I learned a lot about laying up fibreglass fuselages.

If an original fuselage is available I will be interested. 

Martin.

Link to comment
Share on other sites

Erik Dahl Christensen

Hi Pete,

Thank you vey much. I agree with you that a fuse from the old molds will be the easiest, instead of a "start-from-scratch" copy. I'm waiting to hear about availability.

I didn't realise that the wings had been build up. I always thought that they were balsa/foam and I can see the such a version also were available. I also thought that the span was greater. My mind was set on something 2800mm-ish, but I appear to be wrong on this.

My feeling about retro-building is that the plane must look pretty-close to the orriginal, but in my point of view new airfoils can be choosen, to make the daily user better. My thoughts are that the MH32 could work very well as a substitute for the Eppler 193, without notisable changes to the looks.

cheers

Erik

Link to comment
Share on other sites

Erik Dahl Christensen

Heureka! From reading the plans, I see that the Algebra 8 is "an intermidiate stage development leading to Algebra IX which will have 4 in extra wingspan (=>112"=285cm) with full span variable camber flaps/ailerons". It says nothing about the airfoil of the Algebra IX. With a modern airfoil I would guess that an Algebra IX wouldn't do too bad today:).

Cheers

Erik

Link to comment
Share on other sites

Erik Dahl Christensen

Hi Pete, thanks for the input and the sketches. They are very informative, and the text I refered to were from the drawings.

I'm not trying to outwise you, but I have though a few corrections, coupled with additional airfoil info. or history.

You are quite right that (most) the Eppler airfoils were not designed for flaps. A few were though: Eppler 211. I flew the Simprop "Optima" (Rald Decker design, my model: http://i59.servimg.com/u/f59/13/85/70/78/optima10.jpg) in 1983-1985, that had a Eppler 193 root airfoil and Eppler 180 tip airfoil.

The HQ series by Helmuth Quabeck were designed specifically for the use of flaps. HQ airfoils were first used at F3B WC level in Sacramento, USA 1981 and made well known in 1983, York when Ralf Decker won (model: "No name", airfoil HQ 2,5/9 https://www.aerodesign.de/modelle/F3B/noname.gif) and Helmuth came second (model "Dohle", airfoil HQ 1,5/9 https://www.aerodesign.de/modelle/F3B/dohle-x-82.gif). Helmouths  own "Masterpiece" with HQW 2/9 were top of the pops in the middle  90'ies for F3B AND F3F. I used a slightly thinner variant - HQW 2/8 - on our F3B/F3J design "Trinitus" in 1997 https://www.aerodesign.de/modelle/F3B/trinitus.htm. HQ-airfoils gained popularity at the same time when flapperons coupling became available and hence active flaps in flight were used. 2,5-5 deg negative flaps for speed and 2,5-5 deg positive flaps for thermal. Zero flaps for speeds in between.

The RG airfoils (Rolf Girsberg, Shwizerland) where especially the RG 15 became THE airfoil for F3B from the middle/end of the 80'ies to the late 90'ies (Ellipse I and II among others https://www.aerodesign.de/modelle/F3B/ellipse2v.htm). RG were flown clean and does not benefit from neither negative nor positive flaps during flight. Only positive flaps at launch and butterfly brake for landing.

MH 32 (Martin Hepperle) were catching on with the Calypso Cobra (https://www.aerodesign.de/modelle/F3B/calypsocobra.htm) in the end of the 90i'es as well as the HQ variant HQW (very close to the original HQ series).

From the beginning/middle of the 0'es, blended airfoils started to gain advantage in many glider classes and most are secret today.

Algebra VIII/IX with perhaps MH32 or Supra -AG series (Mark Drela) and flaps+ailerons:

It wil have a slight issue with matching the fuselage with Eppler 193-root airfoil -> it's doable.

It will have better performance due to the poor middle Cl-performance of the Eppler 193.

Both airfoil modifications will have better high speed performance unballasted, than the Eppler 193 original.

You'll need to make the wings a little stronger I think.

You will not be able to see the difference in looks when flying.

Cheers

Erik

  • Like 1
Link to comment
Share on other sites

Erik Dahl Christensen

Hi Pete Beadle (and maybe others),

I'm sorry to have confused you, Pete, and I'm sorry if what I have written in my 5 posts, have offended you or others. That was never my intention. If anybody thinks I have hi-jacked this thread, that started with someone (John H) wanting NOT to convert an Algebra 8 to electrics, I appoligiese for that, and will ask the moderator to remove my postings?

I wrote wednesday 23rd of august at 16:09, that MY approach to retro-building, vintage planes, etc. is that the looks matter to me. Therefor an Algebra 8 retrobuild (ver. 2017) that looks like an Algebra 8 or perhaps 9 suits me fine. When Sean Bannister wrote on the instructions that the #8 was supposed to be followed by a #9 with flaps/ailerons, I think such a replika could be nice to do. I my self am not very into "everything has to bee the same as in 1980'ies" (except the music  :) ). I don't see anything wrong with vintageplanes with electrics or even vintage free flighters with 2.4 ghz RC, and hence I don't have a problem with changing something aerodynamical that can not be seen (very clearly). Changes that I think will make ME happier in everyday use, but that just my humble oppinion.

Again, If I have hijacked this thread in any way, I appologise, and will try to make the wrong right.

Yours sincerely

Erik Dahl Christensen, Denmark
 

Link to comment
Share on other sites

Erik Dahl Christensen

Hi Pete,

Thank you for you answer and input. My main reason for thinking about changing the airfoil, is as I write "daily use", and to me that is first glide and then sink ratio, and not very much high speed. I'm assured that a newer (better?) airfoil, will give better glide compared to the Eppler 193. I may be wrong. My first thoughts were about the Algebra 8 with ailerons as Sean also used, but when I saw his comments about his then further improvement-path about flaps/ailerons, I thought that I would also be a retro build, wtih even better "now adays" daily use.

Cheers

Erik

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.