Topic: Fokker D.VIII 1/4 scale build

Don't know if this is any help, it's a 1/4 scale D6 in GTM fabric, the only piccy I have of his 4 color fabric in use. Might give you an idea of scale 



This is a UK model apparently.

anyone help...on this one...

the full sheet size of printed lozenge pattern was 4' 3" 1/4 width according to windsock data file........any others people know about?

printed out at 1/4 scale......giving a sheet size of 352mm seems alittle on the large size.......

According to Dan-San Abbott...

The four color fabric was 1320mm plus or minus 10mm wide and the five color
fabric was 1350 plus or minus 10mm wide.

if that helps any?

Mark.

Thanks Mark, it was Dan's figures I was looking for, he knows his fabric

Steve

thanks chaps.......i was nearly right with 325mm....i'll make them 310mm.....

first time on it's wheels this morning....had some problems last night with the setting up of the subwing...getting the correct angles etc......made a boob!......did i say that...yep......anyways sorted now.......will need to make up a jig of some description to get the wing to seat correctly...that will be next....

ran out of 1mm brass rod to finish off the other wheels spokes.......get some some inwoods this morning...

Looking good Dave, tyre paint looks top, can you get me some mate? 

Did you brush or spray it?

Steve

hi steve...it was painted....

it's ...ok......it looks as if it may crack over a period....but it's easiler touched up....i gave them 2 coats...it's worth a try

send me a PM and i'll sort you out

cheers

PM sent 

  DAVID TILBURY ......What on earth are you up to! .....Do I see a "Super Air" in the back ground of your shop 
"and you call yourself THE Scaleman"

 tut...what is the world coming to these days. I'm in shock Mt T...in shock 

"where did it it all go wrong Dave"  ......I strongley surggest you go stand in the corner and having a word with yourself, then
 put that offensive thing away never to see the light of day again.

You've lost the plot pal....an age thing nodoubt   

afraid so..Al.........trust you to pick that up..... .......was thinking of entering a stand off scale comp with it....

i hear they do rather well........

just making up my wing jig blocks......measuring off the plan...the wing has slight lift at the front leading edge.....it's probably about 2.5 degs. off center......sound about right?

dave

Dave

This is from a report on the E5 which was compiled by the RAF



Hope it helps

Steve

"just making up my wing jig blocks......measuring off the plan...the wing has slight lift at the front leading edge.....it's probably about 2.5 degs. off center......sound about right?"

2.5 degrees relative to what, a datum line?  What angle is the tailplane to the same datum?  Also the thrust line.  The three are interelated.

just making up my wing jig blocks......measuring off the plan...the wing has slight lift at the front leading edge.....it's probably about 2.5 degs. off center......sound about right?

dave

FWIW, the D6 has 0 deg top wing and subwing.

Mud

Give me 1/2 an hour Dave, I'll open my new box and see what Glenn's plan says

Okay I've had a look, and the distance between the bottom of the wing, (at the fwd strut attachment and the trailing edge of the wing), and the top longeron  shows as being parallel

Mark.

ah........ ...

i'll make them the same then.....cheers

dave

Have you a scale wing section then Dave as per the GTM jobbys? I don't know if that will make a difference, Glens destructions do say that it's ok to have a slight positive incedence if thats how it works out.

Just a thought 
Mud

hi Mat,

no the wing section is flat on the underside.........

also the plan gives the strut fixing centers but nothing else......the bearers for these points are running the same direction as the ribs.......the FS has these running along the length of the wing...it looks like being fitted to the spar's...

so some modifications will have to be done here to take a scale fixing......meaning a slight redrawing to the wing....

the brackets for the struts will made from brass and bolted to the spar like the FS......

otherwise things look quite normal......shouldn't take too long to build the wing......i also need to draw up the front view of the wing with the dihedral and andihedral (hope i got that one right?)...it tapers top and bottom to the wing tip, more on the bottom....

anyway....better get on

been thinking more about the wing this morning......

the outer panels will be constructed on a flat...then the last rib angled to take the twin tapers.....these will then have to be joined with spars...none of this is shown on the plan......also i've never built a wing this size....or come to it even at least 60" size without putting vertical 1/16" or 1/32" strip down between the ribs so making a box section with the 1/4" square spars........ .......the plan doesn't again show this.....i think the wing would twist without this....ok the speeds i will be doing aren't the same as a WW2 fighter.....anyway that's my thought.....will do this as i'm building the sections....

there's no indication of what hinge to use either for the alerion.....GTM uses a Ali section running the total length of the alerion and is fixed in the end ribs.....i guess like the FS?.........anyway this seems a good solution....



strut fixing brackets on the wing



alerion



hinge point on the alerion clearly visible

Front & rear spar will definately need shear webbing..................1/16" balsa vertical grain will be ample

that's what i thought phil......

start cutting some ribs!.........

oh well .........first big problem the outer wing panels.......as you can see the wing tip rib is slighty out.......

now.......the wing measuring off the plan at this point is 259mm...x4  =1036mm...1:1....

my scale dwgs say this should be 1006mm at 1:1.....divide by 4 =251.5mm.....that's looking closer to the rib in the picture...once the leading edge is put on.....so do i ignore the plan?.........good question......

No I dont think it wise to ignore the plan, that wing section is so far out it just cant be the right bit of wood,is it the only one out cos if it iis then make one that fits ..Ken  ;copper;

Dave, does the plan measure up ok, I had an issue recently where the plan was streched in width but the length was ok. This must have happened when they were printed/copied.

Steve

hi Ken, it was the right piece of wood 

had a visit from JC....alias planeman....this afternoon......and all's sorted.......MANY THANKS JOHN

he was shocked at the plan as well...in the end all the ribs were re-cut....each getting more added to them.....it was the only way to get it right...the wing tip will now be the correct width......and taper.....

what was a shock was the wing had negative incidence......john, worked out the tailplane/incidences and they were wrong...with some simple calculations and a protractor the wing has now 1 deg of incidence......there's also no down thrust which i didn't know.....thought there was..

john also agreed with my new re-think on the wing fixing plates etc....always good to have a second view...

it's funny...but i showed john some scale dwgs of the D8 that prooflooney had sent me.......drawn up in 1973.....he said in hinesight it would have been better to have re-drawn these in Autocad and blown it up to 1/4 scale...at least you know what you are working with.......have to remember this next time....

thanks john

just when you thought things were getting better...another set back.......

built one wing panel to the plan.....started building the other side....and it's 15mm out in length!!.......i think this plan's going in the bin .....from now on i'll be doing the rest in autocad...at least it will be right!......



hope you guy's have better luck than me...check everyting first......that's a must....

Thats bad news, you must be really narked off, I know I would be  . Have you considered another plan, maybe a well known one? might save you a load of time on the PC  Assuming these things take a while to draw up 

Mud

Dave

Try this one:  Reverse the plan sheet you used to make the first wing and wipe the paper over with turps (lightly) this should make the paper opaque and you can then build from the reverse side.  Test a corner of the sheet first in case the paper used won't accept this treatment.  Worth a try to save redrawing the whole thing.

JC

Dave

Try this one:..........opaque.......
JC

I think translucent would be better  it's already opaque! 

'see through' then.

thanks john.....another great tip!!!

  .......problem now is the over length of the wing is 80"...it should be 83" at 1/4 scale......so which ever i do using this plan is wrong.....it will need re-drawing in autocad......have to re-cut those ribs as well now they have been glued.....

plan's in the bin!.......

Before yopu get carried away can i suggest you check the 'actual' scale of the thing i.e check the fus scale as well.  If the overall shape is in proportion it may be that the whole thing is, for example 1:4.5 scale or something like that rather than the stated 1.4 scale.  Just a thought, it might lead you to save your work so far and retieve the plan from the bin!

Hi Dave,

Sad to read that the plans you are using are not correct 

I did build my D-VIII only using the phillip Drews drawings and uses the original wing profiles which are Gottingen 386 and 388.

I flew with great succes my D-VIII yesterday for the first time. She is 1:3.5 scale and weigth 15kg. The only thing that went wrong was a little crosswind during landing.  See

HERE

a little movie for your impression.

Teus

well john you are correct again...measured the scale dwgs i have ...the same as Teus has used...you saw these the other day......the Arizona plan isn't 1/4 scale....it's 4.16 not 4.0......so this is the mistake......trouble is i've taken most of my info from the scale dwgs i have ...scaling them down to 1/4 scale....when it should have been 4.16......so if i build the new wing to 4.16 which comes out as 80" it should look correct for the rest of the airframe.....i think i'll carry on with this now as a stand off scale rather than a true scale comp model...far too many errors to qualify for clubman/F4C.....i think i should have listen to you Teus....

anyway...love the video Teus...glad it went well...she looks great in the air

well done

what wa sthe overall size of yours in the end Teus......?

Stick with it Dave.  Depending what the scale deviations are and where they are (i.e highly visible or maybe in the cockpit?) it might take an extremely sharp eyed judge to spot them.  I have 'got away with it' in the past!!

JohnC

yea you now seeing why anytime I build anything for myself I cad the plans up no matter who drew them unless its someone I know cad drew the plans. because I find buggers like that. one of the ziroli planes I think it was the P-40 the sweep back of the LE edge of one wing was 1/4" further back than the other one. I only remember that because it was so bad just not sure which plane it was

I had this with my BUSA 1/3 Scale Cub, the port wing was 40mm longer than the starboard one, of course I didnt notice until both wings were built and I stood them together. You dont spot the difference of course, and I still flies on rails.....
The best drawings I've ever used are the Proctor ones, I've built the Jenny and the DVII and they are a total joy to build..... Jim

AZM strikes again.....   

actually isnt azm as he doesnt draw the plans I would assume they may be dave johnsons plans they should say  in title block so whatever the designer put  in the title block for the scale is what azm goes by. remember azm is just a kit cutter that sells the designers plans also

what wa sthe overall size of yours in the end Teus......?

2.41 mtr Dave,

I also designed the wing as per plan and covered it like the full size with 0.4mm ply. And I can now say;  It works 

Teus

thanks Teus......

the plan is a Dave Johnson....wonder why no one has in the past brought up these problems?......unless i'm the first over this side of the pond....