Ch 11 Elevators

The plans say get a piece of stiff tubing with .25″ ID and not the soft hardware store type. I went to 5 different places, tried to buy tubing on line and was unsuccessful Looked all around the house but nothing was .25″ ID and stiff plastic.

except…

The sort of thing you might use to write a list of where to find tubing. It turned out that the answer was at hand in a couple of biros! In fact they were .225 ID which was even better than the .25″ I was looking for. Happiness!

I microed the pens in place, less the ink and middle part, after drilling out the holes carefully using the hinge rod to line it all up. Once cured the next day I tidied up for a perfect solution to the end tubing.

I still have to drill a hole in the stainless rod. That job is for later…

Microed pen just the right size

Tip exit clean up

This is a simple little layup. Of course I spent ages carefully trimming the tip to ensure elevator clearances would be OK. Its one thing to have a really small gap. I’m thinking I don’t want it to jam in flight.

Once the gap was correct, time for a good clean out for the flox corner as in pic one. I filled the hinge pin hole with really stiff micro, did the usual slurry on the blue foam, pure epoxy on the glass bits and I made a template and cut out the one ply of BID with a 45 degree bias on foil. All the necessary steps despite such a small layup.

It all went well and I cleaned up the edges the following day as you see in pic 3.

Flox corner trough

One ply BID

Cleaned up

Just a clean up of the edges today which only took an hour, but I thought I’d add a few pics.

It will need some filler at the glass to glass edges per plans yet overall I’m pretty pleased with the shape and how it looks sharp and clean. Not quite what I thought it would be when starting the canard so a nice result for my little arty piece. I hope the airflow in this area will be happy too.

Tomorrow I’ll have a go at the inside edge after ensuring elevator clearances. These smaller jobs are a nice contrast to all the huge spar cap and skin layups.

Tip angle

Sharp edges

Plan’s curve

Here we are with a pretty fine edge for the glass to glass as in pic one.

The second shot I’m trying to show the flox corner. I’ve peel plied the edges as I’ll be adding a little filler because I had to do a transition in this area or the glass would bubble up. Plans say to fill here with micro. I thought the peel ply is better as it will say some sanding and I can use the lighter weight West filler instead of the usual micro.

What I’ve done is blend a flox corner into a glass to glass transition. Given flox is structural it seems reasonable as a way to get the shape I want and still have maximum strength. I’m looking forward to seeing how this works out.

The plan suggest you can get a little creative here. I’m going for a sharp edge. Mr Roncz says that the vortex created by the tips here hits the wing in a sweet spot so I’ll go with that idea.

It was another long days work today. I started in the morning and was doing the two ply UNI layup after dark. Its new years day. Guess no hangover was a plus 😉

Glass to glass tips

Flox corners

Peel ply ready for fill

The first pic is the rake angle I’ve gone with. I did spend an hour or so cleaning up the edges too and getting ready for the bottom shaping.

You know I still wasn’t sure how to do this. Somehow I wanted something crisper than the plans and what I have on my flying Long-EZ but not quite sure how to make it work. I leveled out the bottom as a start as in pic 2.

In the end I decided I could get a glass to glass bond AND a flox corner happening on the one edge. A bit of a different approach. It seems to make sense as I want the airflow to stay attached as long as possible and then just fall off into whatever vortex is happening at the tips. I also want a nice light look about it all.

So I made the shape I liked and then went back 0.4″ added a transition but this blends into a glass to glass bond. Hey if it fails… I’ll just cut it off and make new tips although that is never the plan.

Promised rake angle

Shaping process

Nearly ready for glass

Lots more carving and shaping and towards the end of the day I seemed to have arrived at an acceptable shape. I did go for a bit more rake angle than the plans… but not too much. I like some of the theories but also want a tried and proven canard. So just a tiny little bit of a mod to tip my hat to innovation without serious testing. I’ll get a photo of this angle for a later log entry.

I was wondering how to glass the top and blend the edges and felt uncertain of the best method. I ended up jumping in my car and going to the airport to see exactly what was on my flying Long-EZ. There was another one in the hangar too that I had a good look at, different to mine and I liked what was done. So I took a few photos and returned with a plan.

Confident now, I microed the two ends and laid up two plies of crossing UNI. You can see the layup in the third pic. The interesting part will be doing the bottom.

Oh ..I did a joggle for the tips when I made the canard and this worked out really well. A simple thing that will mean just a little less micro will be needed to blend the tips into the canard at ‘fill time’.

Top carved to shape

Blends into the elevator at zero degrees

Two ply of UNI in place

This was full time over a couple of days but I have joined these two logs entries. Hope you don’t mind. Hard to believe I spent the good part of the day just getting the tips microed on.

It took a while to get my head around what was needed and then work out a way to secure the ends. In pic 1 you can see I’m using pins and gaffa tape to get the job done. I just don’t have the heart to put giant nails in as the plans suggest.

The following day I did spend a while setting up the canard elevator so it was at zero degrees and glued in place with 5my epoxy. The tip template work from this data point to draw a curve as you can see in the second pic.

I used my permagrit curves, rough and smooth for the whole carving process except for a little 120grit paper at the end. It took many hours working slowly and carefully to get a shape I was happy with.

Micro tip blocks

Slow shaping

Ensure tips match each other

Today was floxing in the last two hinges. Relatively simple as the other four are in place and cured and the elevator is not going anywhere.

It is all correct. It has the 15 degrees up position. Plans say 12.5 degrees is the minimum. I really wanted the allowed 15 degrees given this plane will be fast and I may need the full range.

Down elevator has more than 30 degrees which is perfect. It will need a stop at that end before the counterbalance weights hit the canard itself. It is perfect where it is set. I can have a bit more than 30 degrees down if I want. I’m not sure if this is necessary as it might stall the elevator if I have too much travel. Nice that I have the range of movement for this to be an issue.

This elevator setup has been the most difficult part of the build so far. I took three weeks to do a job that might take a few hours if you got everything right the first time.

Good luck with your elevator if you are reading this and are yet to build one and fit it.

15 degrees up

More than 30 degrees down

A nice clean hinge secured

With one hinge floxed and cured, I took the weights off and tested my elevator range. Ahhhh still all good again… OK I did test before this too. I then went to work to clean out the far slot of all the little stick pieces and bits of glue.

I mixed my flox the consistency of honey and really worked it into the slot. There was a bit of movement of the hinge to help me ensure I got all that I needed into the slot. So with one hinge loose I still had the other 4 with the 5mt glue and one permanent. Of course I checked and rechecked for correct movement range before the flox went in and I ensured my 0.02″ spacers were in place too.

Once that one was in place I felt OK about cleaning up another slot and floxing that. The elevator was still 100% in the correct position.

I let it all cure overnight even though I was tempted to finish off the two remaining slots. Whats one more day eh?

Another hinge floxed in place

Inboard hinge and flox

This one’s permanent now

More hours and I started to see that if the elevator was about 1/16″ out from the end of the four canard jigs I could get the elevator in range. The jig position is a bit arbitrary as this depends on the final canard contour and there was a bit of slop in my unfinished item.

I had the hinges glued and wedged in place and after countless tries. It worked! All my parameters were correct I had the elusive up elevator 15 degrees and heaps of down elevator to the point where I’d need a stop which is what I’d assumed would be needed.

At this point I again removed the elevator and put the hardware in to be sure this was it! So I set up the elevators yet again, glued them in place with 5mt and drilled two holes. Well really I choose my bolt positions relative to the fuselage then drilled a hole on both sides. I marked these out using a bit of paper around the tube and marking half way. I did get a straight hole in the end.

I again set up the elevator and got everything correct. I wanted to be sure I could set it up twice and still be spot on. Happiness. I then decided to just flox one hinge in place, let that cure and then do more. Better this took a few days and get it right eh?

Of course I nervously tested the elevator range the next morning and it was all good!

Starting to win, hardware in

Yes we are in range

FLOX!

I had to be getting closer…right? After I realised I had to remove the jigs to check the down elevator I cleaned off the glue residue and used weights instead for the rest of the setting up. Much more efficient. I tried a few different ways of holding the hinges in place too.

Several times I cleaned the 5mt glue out of the slots so I could have a fresh go of setting the elevators. For some reason I was having a LOT of trouble getting the required elevator range and canard cove or slot gap at the same time. None of this was a discussion, I just had to get it right somehow.

I guess today is not the day I get it done, but I was getting closer than when I started and understanding what was required was in the bag… I just needed to do it.

Jigs and weights

Checking the angles

Jig placed per plans

The setup was still not working out as I’d missed an important factor. I also need to ensure I have a 0.2″ gap when the elevator is in the zero position as well as the 15 degrees up and 30 degrees down shown in the plans and on the templates.

So more hours of attempted setups. The torque tube joins failed a few times so I got to play with them a little more. I did decide that the two center bolts could go in, they looked pretty easy and I was confident now that these were in the right place.

What followed was a lot of playing around practicing my drilling to ensure I was in the middle of the tube. I set this up on the drill press, something that would not be possible with the elevator to NC12 join but I wasn’t up to that one yet and still relied on the 5mt glue. I progressively opened up my two holes and it was all good. I used slightly less bolt length than plans for the AN3’s I could be within spec with thin washers. Another weight saving!

Then more elevator trail setup practice, hey it wasn’t even dark outside yet. I still wasn’t within range for the elevator movement.

Ensuring the .020″ gap

Check that gap

A little hardware in place