Quark 2M - Back to cutting innocent trees!

[Fred]

Another successful first flight, and another happy Quark owner!
This time, from Pavel (see posts on top. Pavel is the designer of the Quark Logo).

And a nice video from his friend Zbynek Cernik (aka Acroholic)

https://vimeo.com/64004175

Well done!  :clap:  :clap:

[Fred]

And another successful first flight for a Quark. This time in Germany  :clap:  :clap:

Pilot's report no issue, a very easy machine to fly and that will do pretty much everything you ask for. He is now waiting for stronger winds to push the Quark to its limits!
Nice one Alexander!  :clap:  :clap:

[MicheTN]

Hi guys! I'm Michele From Trento (Italy), and I love to build my models from myself, especially from wood. I've just began to scratch-build this plane, from the V2 plans.
I've found some problems printing the fuselage plans on a plotter: I print from Adobe Acrobat but I get a completely out of scale plan. No problem instead with the wings plan. I downloaded the V2 plans from there (http://jivaro-models.org/quark_2m/page_quark_2m.htm).

Now a building-question:
I've seen on RC-Groups that someone used a spruce-spar with shear webbing. Honestly I've ever built my spar in this way, instead of CF spar. What's better, in terms of torsion-rigidity and weight?

[Fred]

Hi there,

Welcome to the forum!  

Hmm, strange fro the plan, I print them from this PDF, no issues  :?:
On top of my head, they are seen as oversize for the fuselage, so you might need to make sure that there is no scaling when printing (100% printing or actual size depending of the software you use to print).

For the spar, to be honest, this is pretty much the same, especially with webbing, this hardly move!
It's more a question of cost, as the price of carbone these days make the build very expensive, and you will build the same glider much cheaper at the end if you use wood spares.
I'm building one with wooden spares, I'll try to put some photos  

[MicheTN]

Thanks Fred for your answer!

I will retry tomorrow to print the fuselage plan, i will double-check to the scaling on Adobe.

For the spar:
- on RCG they say 3*10 mm spruce spar and 3mm balsa share (vertical grain of course); could be good?
- wing joiner in this case? spring steel (12*2mm) and brass tube(13*3mm)? how long?
- is really needed to have a full-sheeted wings or can I save some weight with it?

[erwan]

hello

I finish mine today, 1730 gr with plan respecting. It's not heavy

[Fred]

Thanks Fred for your answer!

I will retry tomorrow to print the fuselage plan, i will double-check to the scaling on Adobe.

For the spar:
- on RCG they say 3*10 mm spruce spar and 3mm balsa share (vertical grain of course); could be good?
- wing joiner in this case? spring steel (12*2mm) and brass tube(13*3mm)? how long?
- is really needed to have a full-sheeted wings or can I save some weight with it?

No problem

For the spar, on mine is 10x5mm hard wood, no webbing, but I will sheet the wing from LE to spar, so that gives you a sort of "D" box if you see what I mean. Rigid enough for me

Wing joiner, like the plan. 10mm OD tube with a 8mm rod as a wing joiner.
On top of my head, they are 2 ribs long, this is enough as the load is then taken on the spars if you see what I mean (front joiner is between the 2 spars)

No need to be fully sheeted. Add  some spar webbing and off you go

Also note, that the V2 plan makes the glider lighter than the first version. You should be around 1.5kgs at most!

Hope this helps, but let me know if you have more questions of course  

[MicheTN]

Thanks a lot for your details...

So the V2 version isn't jut a longer nose and different ailerons?

[igull]

Hi All

Thought I'd post yet another Quark - this time from across in Scotland  

I'm lucky in having my own homebrew laser, so cutting wasn't an issue  

Used liteply for the fuselage sides rather than 5mm balsa, so I'll see how much lead is needed in the nose :-)

Only had a couple of minor structural issues during the build, the servo plates were only attached front and rear on the formers - consequently, they were really weak at the servo cutout and just cracked when installing the screws (there was also a lot of flex when the servo operated). I changed the design to have the servo plates the same width as the fuzz - also stops the fuselage flexing where it's gripped. The other one was the vertical stab, the top half of the stab is held only by a couple of small areas of horizontal grain - I added a 6mm spruce spar at the fin TE which ties in to the end of the fuzz.

AUW is around 960g naked - I'll post some more pics when covered.

Great looking plane - thanks for making it available - good job!!

BTW, anyone struggling to get carbon tube etc in the UK - I got mine online from Woolmer Forest Composites ...
https://www.woolmer.co.uk/
Not cheap, but nicely made and well packed - real pultruded too - not black chinese dust and epoxy :-)

Cheers

Neil







 :lol:  :lol:

[Fred]

Hi Neil,

Welcome to the forum  
Thanks for showing us your build, very neat  :clap:  :clap:

For the tubes etc, I have now changed the plan, and wooden spars are now used, and this makes the build even cheaper without compromising the strenght / rigidity of the airframe  

Keep us updated for the first flight Looking forward to it  

[igull]

Thanks for the kind comments!

Eventually got the machine covered - film courtesy of Mr Cod - seems like good stuff for the price. I've covered the underside in white with the intention of putting big dark blocks of colour on.
Pix attached, always was a frustrated PSS'r  :lol:

With any luck, should get it out on the slope this weekend.

Much prefer the idea of a wood spar - aircraft spruce is much cheaper than carbon tube !

Cheers

Neil

[Fred]

:oops: Sorry, only see your post now!  :oops:

Anyway, me like it a lot!  :clap:  :clap:
Original colour scheme, that suit it very well on top of that!  :clap:

So, have you done the first flight?  

[Fred]

Another day, another Quark  
This time from France  

First launches on the flat went well... First slope session this week end  

[alibodin]

Well after nearly a year I had time to maiden my Quark. Had my EPP model just to check the lift, but ailerons were not working, broken lead   Oh well lets try the Quark.

Assembled the Quark (note to self need some wire with hooks to do the bands to hold the wings on).




Thought here we go and chucked her off, no problems at all quite twitchy, so switched in rates which helped. very docile and fun to fly. COG looked forward then I had added 2 1/2 oz of lead to be safe for first flight.

Landed, took out lead, added in spoiler for slowing down on landing.

Off we go again, great fun rolls are good as are loops, inverted still needs some 'down' so will look at removing more lead. Gained height and from level dived and did outside loop.

Lift suddenly died so just headed for landing area and just got there in time.

Third flight was great fun, lift still a bit marginal.

Overall great model and really enjoyed the build and the flights.

Note to self fly more and add some white to underside of wing. Ohh and finish Gunau Baby

Alistair        

[Fred]

Nice one Alistair!  :clap:   :clap:

Glad the first launches went well, and of course, wish you more fun with the Quark  :clap:  

So, now, you are right, where is the Grunau??  :?: