summerwind

yes i said experts because that's who posts here and you guys will come up with the best solution.

OK here is the issue.
we all know and love the scallops that shape into the TE of the Fokker's (DR1 in this case) as the covering shrinks and pulls the TE wire into it's scallop shape.
if i were doing the real deal it would be an easy answer.........but this is a BUSA DR1 with preshaped TE scallops.
now traditionally we all (perhaps) cover the bottom of a wing first, then the top which overlaps to the bottom.

i'm thinking of doing the top first and then the bottom so as to hide the ugly line the developes when overlapping at the TE....................what do you guys think or suggest?

i am using natural finish Solartex.

TFF

That is a tough part to cover, for sure. My little Dr1 was covered one piece bottom first. When the top came over the trailing edge it was attached to the edge and then under a 1/4" with the best stretch/cut and tuck I could do. Not really an inventive way for sure. I would rather have the seam on the bottom just because it is harder to see. The real ones had the fabric sewn to the trailing edge wire, so there was a seam on the real ones. It is kind of a tricky plane on the covering; the real one breaks some rules. What most planes have reinforcing tape covering the seams and the rib stitching, there is evidence that the DR1 left it out in the breeze. Kind of a PC10 discussion on if its true. I put fake tapes on the ribs just because no one would believe and I was not wanting to stitch.

summerwind

it is a tricky bit....have done some mockups.
i am thinking to cover the top first, overlap to bottom as usual.............then cover bottom and trim flush with edge of TE and LE...............

the mockup has proven it to be difficult to get a consistent overlap width and that's what i am trying to hide.

just never done the top first then the bottom so i just don't know.

deljon

My Feedback: (4)

On my 1/4 &1/3 Dr.1's, I always do the bottom first, "rolling" it up around and ironing to the TE and about center of LE.
Then doing the top I brush some Stik-It on the TE scollop, then overlap the LE about 1/4" (the full scale had a seam there)
then after pulling snug, iron around the TE and trim even with the bottom, (like you discribed doing the top first).
It comes out looking good and haven't had a seam fail yet. Works for me.

Del Johnson

TFF

I see what your idea reasoning is now. Kind of like it. I would not trim it off until you shrink it. Just make sure there is enough margin so peel is not a problem.

eagledancer

IF it was me i would cover the bottom first with a large enough piece to do BOTH top and bottom. with the seam at the LEADING edge only. the rear at the scallops there will be NO seam.

has worked for me in the past many times.

abufletcher

If Achim Engels is doing things the right way (and I tend to think he is) then on the originals tube-like "bags" of fabric were prepared and then slipped over the wings. This bag is, indeed, stitched onto the TE wire (before doping). As far as covering the model, if I were you, I'd just go ahead and do it the traditional way, i.e. cover the bottom, then cover the top. The seam isn't going to be that noticeable. If I were using a wire trailing edge, then I'd do the 1-piece covering method with the overlap on the underside of the LE. Remember that solartex sticks to solartex better than it sticks to balsa.

BTW, the model is looking good and should be a blast to fly!

ARUP

I have two Fokker Triplanes that will get covered soon. The ribs are not flat bottomed and have an undercamber. My plan is to use Koverall. I'll start at the TE where the fabric will get attached underneath the TE. Then go up and over the top surface and then around the LE (and tips topside) to end at the underside of TE again (and finish tips). The fabric will get trimmed just inside the rear edge of the TE. Once the fabric is sealed with nitrate dope the seams will get lightly sanded and dope sanding sealer/filler will get applied to the seam to hide it. I covered a Triplane once before using this method but used Supershrink Coverite which is thicker because of the preapplied adhesive. If it worked with the Coverite it'll be a cinch with the Koverall! It might be an exaggeration but you could just about cover a basketball with one piece of Koverall and not have any wrinkles!

vertical grimmace

My Feedback: (1)

I agree with Deljon's method. The Stix it or balsa rite will be key here. Also after you get the paint on, it tends to seal things up a bit. Never really thought about it, but I guess they did not put a rib tape on the trailing edge? I know the Fokker DVII did. If you added a rib tape to the trailing edge, that would certainly be beneficial to holding the seam together. I am kind of thinking out loud here!

jtisch

I did my DRIs and DVII the same way as Del and liked the way they came out. If you cover the top first the seam at the TE will be on the top (unless you can trim it perfectly on the edge, in which case it doesn't really matter).
One thing to mention is that my first DRI had a balsa TE, which I am assuming your DRI has. That made things more difficult, but the method still works. The GTM DRI has a small reed dowel at the TE and that worked so well I have used it on every wing with scallops since. Also, while I do tack to all the ribs and seal the TE seams well, I don't do the final shrinking until after the wing is covered and the TE seams have had some time to set. I even put a coat of dope on the TE seam area before final shrinking, but that may be overkill.

Best Regards,

J

summerwind

i can't thank all of you enough for all the ideas and methods of which i'll be combining..........nothing like getting enough input to overcome something and i am glad i asked this question here.

to Abu-
you obviously see that landing gear, hard to notice i lobbed off 1.5" from the width.
with the good news that Glenn is going to make the 1/4 DR1 available by end of year, this plane has so much purpose other than just showing the guys here that builders still exist.

gabriel voisin

Hello,

I would not overdo it, because this is not a full scale model DR1.

I'll tell you once a simple but very effective and great-looking type of coverage, I use this for models with wire edges and a concave bottom.
This method is not by me but by a good friend called Jörg Vogelsang.

1. We do not use a wire, but a Kevlar cord.

2. These Kevlar cord please twisted and then glued with superglue to the ends of the ribs.

3. Let the cord between the ribs a little longer, so we creating the typical bat form.

4. Now we cover the bottom, I use the "Proficover" tissue by Toni Clarke.

5. Cover the bottom as usual, from the center to the leading edge, then from the center to the end edge.

6. Let the fabric at the end edge about 5 cm longer than the wing.

7. Now cut the tissue between the ribs into individual 1 -1.5 cm wide strips.

8. The longest middle strip between two ribs, pull forward over the Kevlar cord and 1,0 cm of the tissue over the Kevlar cord firmly ironed.

9. All central strip and then all remaining ironing.

10. If you have cut between the ribs for 7 strips, then the sequence is so.

11. rip - 6 - 4 - 2 - 1 - 3-5 - 7 - rib.

12. Then cut off the excess material, and all ironing.

13. Please only ironing, not the tissue shrink.

When all is fixed, now the special trick.
Place the wing on the leading edge, in a angle of 80 °.
Let run a drop of thin superglue on the left and right edges of the ribs, but please on the inside of the covering.
This method prevents the detach of the tissue on the concave underside.

14. Cover now the upper side with the steps 5 - 12.

Everything is covered, you can ironing still a fabric strip over the end edge.

Now you can shrink the complete wing.

All is ready, all is good,…..have fun.

greetings gabriel

deljon

My Feedback: (4)

gabriel..........Do you have some pictures, I'm comfused.........[]

gabriel voisin

No, Photos I did not.

It was even published with pictures by Jörg.

What do you not understand?

greetings gabriel

abufletcher

These seem to be the key steps (for covering a wing with a "wire" (kevlar) TE). If I'm understanding this correctly, the trick to getting a good scalloped shape is to cut the TE end of the fabric into multiple narrow strips. Then, you pull the middle strip over the kevlar to get a good curve. You do this middle strip for each bay. After the scallop has been established with this center strips, then you go back and iron on the other strips in the sequence shown in step 11 (basically alternating left and right starting in the center).

gabriel voisin

Abu, yes so it is.

 You understand it accurately and with some practice you will get excellent wings.

 I've seen that most of the people here build their models much too massive. Such strong wings would never work on the original Fokker aircrafts.

 I'll even take a photo of my Wright wing rib, then you can see what I want to say.

gabriel

Oberst

I'm no expert, but I do know a nice looking Dr1 when I see it. Nice job on the frame!


Pete

gabriel voisin

Sorry @summerwind and Pete,

 this is a wonderful model and beautifully built  ,.... so I did not mean it.

But you need not necessarily copy the original covering method, that you get a good result.

That's what I want to say.

greetings Gab

summerwind

Gab,

there is no reason for an apology.....if anything, i apologize for building such an inaccurate model of the the triplane........the model constructed is what it is............a standoff scale version of this famous fighter. this one will however serve well as a trainer for the future.
not true scale by any measure, but rather a fun flyer to represent what was a mean and terrifying tool of the German AF.
most builders of this fun version simply use film and other quick and dirty covering methods...............i myself am more detailed oriented, so i look for the best finish i can do no matter what or how the model is built.

my next project of this aircraft is the same WW1 design, but from a much more accurate kit that represents this aircraft...............the finish on that one will represent the real one as accurately as possible.

this thread has so far brought out many ideas on how to get covering techniques and methods to look somewhat perfect for this version, and is proving to do so nicely.
really appreciate your input and methods...............it will help very much in the finish of the 100% scale version to be built later.

ARUP

Hi Summerwind! Here are some pics. One pic shows the origional cutout- yuck! I had to rebuild that plus a few other things to make this wing look proper.I started the Koverall at the bottom of the TE and wrapped it up and over the top, around the LE across bottom to the TE. I did the middle wing since it is the most difficult. I used one piece of covering and got the decking covered too! Stretch here, shrink there. I put no Stix-it on the top or LE. It only got applied to the lower ribs, the goofy rear spar this arf has (I removed the upper one) and the perimeter of tips. Any place that needs holes cut also gets the Stix-it to keep the fabric in place. Once everything covered I shrunk it down. Now it just needs sealing with 50/50 mix nitrate dope and thinners to seal the weave. The butyrate dope can be hand painted onto it lastly. Just five more wings to cover- I'm assembling two of these!

ARUP

Me again! The first pic shows origional cutout. I cut that out (pun!) and re-did it. You can see where the Stix-it is applied to the underside and where it isn't. After wrapping fabric across top I got top of tips covered. Same for bottom. Nitrate dope and a little sealer will make the seams disappear. You could cover wing as Deljohn does. There really isn;t a wrong way. I just like to use minimal pieces and have lap seams on bottom. The underside of this wing has a tiller that will get driven by a servo. Cables go from tiller to pulleys, thru wings to fairleads and connect to a pushrod. Each end of pushrod connected to belcranks to drive aileron horns. Kinda Rube Goldberg but it works very smooth and is adjustable. Looks very scale, too! Any questions just ask and maybe I can answer.

summerwind

ARUP,
thx for posting your images and technique.............we definately use the same process and dope for covering with Koverall.

i'm going to work on the wings today and will try using 1 piece to wrap from bottom to top.
with Solartex i too like Del's way of attaching at the TE.
with a full wrap tho, i like not having another seam along the front edge..............i know it's really not a big deal, and heck, 99% of the flyers i fly with would never notice any kind of a seam, but i will, so that's why i am so friggin anal about anything i do.

funny story, i recently built a 40 yr old trainer design called the Headmaster for which to use as a breakin model for some vintage ST 23's.
the wing, stab and rudder were finished with Ultracote, but the fuse and tip were finished with Butyrate and then cut and polished to a glass finish............no one in the club thought it was paint, but rather the most fabulous film covering job they had ever seen............LOL.........i doubt they will notice even the largest overlapping seam on the Tripe

ARUP

Put up a pic of your Headmaster (Top Flite?) As a kid really pining for RC, a teacher had a Headmaster (covered like the box top) and I was able to see him fly it! Will never forget it. There is someting therapeautic about dope finishes! Poor film and pre-finished fabric guys will never know!

summerwind

sure...here are a few....one is to show the finish on the fuse............amazed that my buds have never seen a hand rubbed Buty finish

ARUP

Very nice finish! Thanks for posting! Did you alter the fin-rudder profile?