Ch 20 Winglets/Rudders

The foam block A has to be level in the middle and just slightly rounded at the edges. Easy enough except you get a really weird and interesting shape. I don’t mind, its just not in the plans about this little bit of art work.

The UNI plies are a set length and width and I spent a LOT of time laying these out so it made sense over the winglet. The previous inner layup under Block A is structural so it follows that the outside layer would cover this area of 12″. You end up with an interesting ply pattern need to keep everything straight. I used bits of cotton as you see in pic 1 to lay it out and even made foil pieces and checked that they would sit correctly over the bend.

After marking out the winglet I worked out the two BID plies and decided to do the UNI on foil. Then I cut all the glass, more foil and plastic and was ready to go.

I split this log into two entries but I did it all on the one huge day…I was crazy tired at the end.

Shaping and checking

Strange lines

We are in the pattern

This step has me floxing in the rudder bellhorn and then hiding it in the hope that all will work out later when I cut the rudders out.

I made a foam cap for the section that becomes permanent in the rudder. Some say one ply of BID then the bellhorn then 2 plies on top. Others say 2 plies first the 1 ply. I went with two below and two above, hang the extra weight in this case. I tested for space with dry cloth and all was good. Two plies went down on top of microed bare foam making up the bellhorn pocket and then I floxed the part in place. A couple of sticks down the other end stopped it sliding around.

Next two more plies of BID on top, all done on foil as usual and finally I fitted the foam piece you see in pic 1 but permanently with micro and then gaffer tape on top for position while it cured overnight.

At the other end I fitted the two pieces you see in pic 2 with a small amount of 5 mt glue. These get removed later but I needed a top for the structural layup to come. I’ve seen others just remove the structure over the bellhorn. I may still have to but I’m hoping this method will let me leave the last inch of it all in place. We will see!

Permanent foam

Filler foam

Glass and flox

The bellhorns took a couple more days to finish. Most of yesterday was sanding and shaping and making nice. I spent a while drilling out the holes for the rivets after having glued the end pieces to the larger aluminium. Then more cleaning up.

Next it was alodine for the 2024 T3 aluminium and the green zinc phosphate for the 4130 end pieces. Thats not the really nasty stuff but still worth a face mask and outdoor spray.

I riveted it together today after checking my books for rivet lengths and a few more practices with the hand squeezer on scraps. No rivet was harmed in the operation, just squished a little and it worked out well. These look so pretty and no one will see them after they get embedded in the rudder.

Next I was back on the winglet and squared up the A block insert. A bellhorn glassed in place with foam pocket filler is the next step, then the outside layups.

Bellhorns ready for coating

Completed bellhorns

Starting on the A block shaping

This is the second winglet join structural layup. I spent the first part of the day still working on the rudder bellhorn pocket. Then it was warm up the room to 26 C and cut the glass for the foil layup. I made the pieces about 8″ wide with the first two 17.5″ long and the other 3 pairs of 2 12.5″ long. Pretty much plans in design but I didn’t go all the way to the trailing edge of the winglet. Just to the cut line of the rudder. I’ll do a separate layup for the bellhorn pocket.

Given that layup #1 had flox filler and this one needs flox corners I went with a flox slurry on the foam before the glass went down. First time for this. I just didn’t want to mix micro and flox here so either pure epoxy or flox slurry was my idea. The extra weight is minimal over micro in this small area… it seems to make more sense as I already have some exposed flox from the previous layup that we are bonding to. I sanded what was showing that so we have glass to glass or some flox where its not a perfect mate.

I did the 8 plies of BID using foil as you can see completed in pic two. Pic 3 shows my previously fitted foam block that you can see in pics 1 and 2 microed in. Yes micro, per plans, which makes sense as its going onto the foam and it needs to fill any and all air gaps. I did slurry the foam before this as usual, then troweled in some micro to the join and squeezed it out.

Finished up with some weights (not exercise, just as in pic 3) and another long day where I didn’t even go outside.. just worked through from morning to a late dinner.

Flox on foam

8 ply layup

Block A microed in

This was an all day effort, just again reading and re-reading plans and web posts. I think I’m getting my head around this. The rudder bellhorn goes in a sort of pocket angled so when the rudder moves it matches where the cable is coming from. Of course the rudder is canted or rather the winglet is … so that it moves down when it opens or up if you are inverted on my table… got that? So I’ve allowed about 3/8″ and just hope its pretty close.

Then more thought and careful removal of foam to get the bellhorn sitting right. Oh and allow for some BID later too. Also think about what happens when the rudder is sawn off… where are the cut lines? Better think about the internal bulkhead too. I really don’t need flox and glass at the join where I’ll be putting plies on anyway.

Oh yeah and it looks like my rudder gets another bit put on it as part of the structure and a bit more again if I want a little bit of protection but not a full lower winglet. Seem like I add to the rudder area later… who knew???

Far too much thinking on this…

Location, location

In the pocket

Allowing for cant

There are 8 plies required and I decided to go for four lots of two ply laid up on foil first. Its quite a tricky layup because you have to get the right angle of glass nicely set in place without it folding over on itself. There is not a lot of room to play with here.

I found putting the lower half of the 4″ wide piece in first worked best. You need to cut a bit of a nick out where the shear web is too. Then those mixing sticks for positioning tools to help ensure the glass was laid out smoothly. The foil technique, sticks and fingers worked well. Sorry there are no pics during the process, I had epoxy and flox all over my gloves.

Once all 8 plies were down I really covered the blue foam inserts in a lot of flox and then let it ooze out as I pressed them slowly in place. I didn’t spare the flox and it took quite a lot although I did get a fair amount to wipe away too. I think several foam pieces work better than trying to do it all in one, less chance of air voids. There was no micro involved as usually happens with foam on glass. I ensured the flox mix really got into the foam cells before inserting them.

The room was about 26C and I left the heater on overnight and through the next day for cure. Its winter right now and cold outside. Then several hours careful grinding away with the dremel to clean things up ready for the next structural layup after I work out where the rudder bellhorn has to go and what is happening in that lower rudder area.

Glass prep on foil

Foam in place

Clean up after cure

I did this step and the layup on the same day. It turns out that 8 plys of BID are the same thickness as the tongue depressors I use for mixing sticks. Good to know right? My filler blocks just needed to be a good fit with a few sticks thrown in as you see in pic 1 & 2.

The end stick is just to keep any flox away from the rudder cable area that I have spent some time getting clear. I used a heat gun to shrink the envirojoin in the antenna which melted a little bit of the blue foam. I used a heat shield but it still got around that. I’ll be more careful on the other wing..its just a tiny bit but I am being very careful with these major structural layups.

Fitting foam blocks

More block fitting

Foam blocks upper and lower

Some time on the plans again marking out the rudder position. I 5mt epoxied the bellhorn together so I could place it more easily. More reading and thought suggested that the conduit for the rudder cable needed to be cut back so that the eyelet has clearance to move with the rudder and obtain full deflection. You can see this in pics 1 & 2.

I’ve put this in to save someone else cutting into the wing later if they miss this point. Probably everyone else has it sorted hahaha

Pic 3 shows how I have router the HF and VHF antenna cables. I also joined the folded dipole HF with M81824 Butt splices. I practiced several cheaper butt joins first as I really don’t have the perfect crimper for this item …yet. I did get a good result however. I’ll sort out the rest of the cabling run on the left of pic 3 later. I have an idea to use the Aveo Andromeda tip lights and make a blend at the wing tip to match the light. We will see later if that works out or if I find another solution.

Bellhorn placement

Conduit trim to fit

Antenna cable setting

I’m using the hidden bellhorns and the high performance rudder plans for this step. VERY long story short… the open EZ pdf plans for the rudder bellhorns when printed out full size are in fact undersized. So if you are dumb enough to go ahead and make parts from this… better scale the rest of the plane down to suit or you might just get another source for the bellhorn plans instead.

I did get some right size drawings for my second set of bellhorns. Its all good. I’ve just glued photocopied plans pics to the metal and cut out the pieces. I used my ‘undersized’ ones in pic 1 to practice hole drilling and riveting. This all gobbled up a couple of days…

I’m using Wayne Hicks’s Cozy site for guidance and the method on installing these bellhorns BEFORE I cut out the rudders. It is smart work. I’ll document my take on it in coming log entries but Wayne’s site was the source. Yes, very smart guy. My idea is to get this clearly in mind before the first internal layup is done. I need to have the rudder cable conduit pointed and trimmed first. This will all save lots of potential grief later.

Full size pdf files??

Inline

Full deflection

The first pic shows some of the bracing I used to help get the winglet home without problems. It took a while to remove but worth it. The plans do say to use bondo but I went for 5 mt epoxy with flox. Sets like a rock which is needed for road transport.

With the outside brace removed I started on prep for the first inside layup. The dremel permagrit bits are great for jobs like this. A few tongue depressors with sandpaper glued to them are gold too!

I spent a lot of time… about three days being super careful around the antenna wires and reading and rereading the plans. Its not done yet! All the exposed micro has to go and it needs to be at least 2″ deep in a wedge shape. I also did a lot of searching on other guys sites.

Looks like I need to do the hidden rudder bellhorns now. Problem is that although I ordered them 18 months ago I’ll be making them myself as I need them today! That’s OK, I am making most of the plane anyway.

Transport bracing

Careful dremel work

Sanding sticks

While not technically part of the build now the winglets are aligned as well as other things it was time to get the project back to my home workshop. The airfield hangar at YMMB has been great but that window has closed.

I again had absolutely invaluable help from Darren to get things home on a hired trailer. So its goodbye to the other planes where I keep seeing how much work I still have before me.

Pic 2 shows that I can just get the spar mounted fuselage in with the window panels removed. There is 6″ total clearance at the sides.

Pic 3 shows how little space there is. The canard is on the wall and the other wing on a shelf I’ve just built. The whole workshop has been rearranged for this using a scaled plan I made up.

So I allowed no extra build time in this log as ‘arrangements’ don’t really count in the build…but there was a very full week’s work getting this done.

Leaving YMMB

Just fits at home

A tighter working space

The left winglet went on today. By that I mean its lined up and secured with timber and 5mt glue. Somehow, and I don’t know how, my minor errors of 0.1″ or 0.2″ here and there seemed to disappear went we checked the line up of the left winglet (and right) before gluing on its positioning sticks.

We took the exact center of the wing spar assembly and strung a piece of special non stretching fishing line to check winglet position. While I had made a spot at the front seat some thought suggested this other center point wouild be a better reference.

I first set up the left using WPRP which I felt may have been about 0.2″ out of place. Not so it seems. We measured from the center point to the winglet LE, TE and upper TE and got the exact same distances left and right after careful checking.

Next I mixed some 5mt with flox and made sure it stayed there. Special thanks again to Mr M Wood who directed operations for the measuring and checking. I usually learn to do things better from these encounters.

Here in the pics is the airframe together. It will be some time before I see my project looking like a plane again. Soon it will be transported back to my tiny workshop where I’ll start on structural layups on the winglets and much more of the build. For now, it looks something like an aeroplane.

Winglets in position

Winglets braced in position