Vielleicht you could simply leave a small tab at the top as well as at the bottom of the slot? If you're going to be cutting something away, why make it something you took extra time to add?

James

James, Vielen Dank! Of course I could leave a small tab. But what concerns me is that in the smallest of the ribs the tab would be still quite big referred to the rest. Glueing a little bar would leave the contourline exposed.

I'll try it that way.

Now I finished designing the outer ribs and if I find the time today I start the mill

Short update: today I milled the ribs for the outer wing. In the next days I'll start building the outer wing. This is a major milestone after one and a half year of planning.

Today also the Caps for my YGE 40 ESC came. These caps are soldered directly nect to the ESC and I won't have problems with my 1m (3ft) cable length to the ESC that will be mounted in the nacelle.

The YGE 40 V4 ESC allows using all four BEC parallel. Therefore I have 12A BEC from the for ESC. That's fairly enough.

Cheers
Alexander

Originally Posted by AlexanderB

Short update: today I milled the ribs for the outer wing. In the next days I'll start building the outer wing. This is a major milestone after one and a half year of planning.

Today also the Caps for my YGE 40 ESC came. These caps are soldered directly nect to the ESC and I won't have problems with my 1m (3ft) cable length to the ESC that will be mounted in the nacelle.

The YGE 40 V4 ESC allows using all four BEC parallel. Therefore I have 12A BEC from the for ESC. That's fairly enough.

Cheers
Alexander

Looking really good. Very cool stuff.

DAG

Thank you Dag!

I finally dared to keep the plans as they are now and started to build! Please see the pictures. I had a lot of concerns regarding this but when I had the ribs in my hand and mounted them on the building board everything looks fine and durable. It took me less than an hour to come to that state. To plan that part of the wing at least 20hrs were spent during the last one and a half year

Other than intended I was able to glue the stringers on the bottom as well.

I also pushed the CF rod in position which worked just perfect. But I think that without tubes it won't work. On the other hand everything is way smaller than I expected it and there is no room for a tube. I may have to open the sheeting to mont the CF rod. But that won't be a problem.

Cheers Alexander

Progressing quite nicely Alexander!!

Looks like all that planning is paying off. You have to love when everything fits well!!!

FF

must enthused following your design/build Alexander and the 1 mm balsa bars is well...brilliant

First of all thanks for the kind comments. And yes: it's great when all parts just fit! I now added the "spar webbing" or "shear webbing" (thats what I found for the German term "Verkastung" is that right?). Now the structure is even more strong. As a result I can push in the 2mm CF rot just like that. It goes straight through! Regarting the bars: it proved that they work just great!

I then added extra aileron ribs that are the second hinge next to the rib. You can see it on the photos.

But I also have a question (please see last two pictures):

What is the best practice for attaching the aileron? I want to mount the aileron servo on a 1.5mm ply sheet. This will be also part of the sheeting and attached with four screws to an inner frame in the wing.

The problem is: I will add the lower sheeting last. When I insert the frame first and glue the sheeting it won't work. On the other side I could cut the opening in the sheeting before glueing.

What do you do in such a case?

Thank you all for participating.

Cheers Alexander

What I did during my last build was glue the innner frame to the lower sheeting before you glue the sheeting. Glue the sheeting in place. After that I cut out the blasa where the servo ply would come. If I had to do it over, I would cut out the holes in the balsa sheeting first, then glue the inner frame, then attach the sheeting. Advantage of this, is that you can use rounded corners.

Bart

Bart thank you. Seems like a good solution. But I was not able to get this far this weekend (but almost).

Anyway: I got a lot of things done. First I milled a lot so all ribs for one inner wing are done. I can start next week.

Then I milled the ribs for the wing tip. I did this with Profili. Therefor I used a trick: I stretched the rounded wingtip so that all ribs fit into a rectangular wingplan. Looking good.

Then I covered the upper wing. Here I had some problems: since the ribs are only 2mm Balsa the building tabs broke when I pushed the pins too hard. Next time I'll strengthen the building tabs by doubleing the balsa. But without having checked it it seems that the wing is still in shape.

The best is: the outer wing weighs only 65g so far!

Hi Alexander, fantastic project!!
A quick question for you, when milling the balsa what diameter cutter (end mill?) are you using, and what RPM are you spinning it at? I have a little desktop CNC mill but have never used it to cut balsa, so was curious.
Keep up the good work and thanks for posting your progress, very instructive and entertaining to follow along.

Thanks,
Freddy

Freddy, thank you for your kind comment.

I'm using a 1.2mm end mill. I own a Kress 800 FME and use about 20.000 1/min. I cut with 900mm/min and a maximum depth of 6mm (if necessary).

Alexander

Yesterday I sheeted the outer wing. Most concerned me that the wing would bend or twist so that the washout will not be the way I designed it. What helped was a Tipp I got somewhere in a forum: build a bed of negative ribs where the wing gets attached when the second sheeting will be glued on.

That's what I did. I took every second rib and milled a negative from 6mm balsa wood (cheap second choice). I took the profili drawing and made sure that I use the same distance from the building tabs to the lower edge of the negative from (clear? I'm afraid not ). Anyway, in the end I had a bed for the wing and it turned out that it was already twisted a bit (what I expected). So I attached the wing to the bed and glued the lower sheeting on.

Before glueing the sheeting to the wing I opened it and glued the frame for the aileron servo hatch.

What to say? Everything worked out at least as good as hoped and I'm most satisfied with the result. Especially since the weight of this outer wing is (including the parts of the wingtip) approx. 80g (2.8oz) so far. Of course I will use grain filler and Oracover which adds some more weight. But I'm on the right track I guess.

Next will be sanding and cutting out the aileron. This is where I don't have any experience and I hope I can use the aileron.

Cheers Alexader

Looks great Alexander! And thank you for the milling info, very useful!
Best,

Freddy

Thank you Freddy. Great you could use it

This afternoon I cut out the aileron after sanding the entire outer wing. After all the planning and tipps from different forums it worked quite well.

Please see the pictures and the comments there.

Tomorrow I'll sand the aileron itself and fit in the hinges. Let's see how this works.