Ch 16 Control System

Time to get the elevators connect to the stick and have that whole system set up. Yes, ailerons, rudders and elevators all working.

A smart person would have used the large truck he hired to move the canard with the rest of the plane over six months ago. A bright person would have waited for a friend to put it in his tray truck. I bothered another generous friend with a tow bar and hired the 12 foot trailer for my 12 foot canard.

Finally plane and canard are reunited.

Of course as my stick is offset from the plans the pushrod from there to the canard torque tube was never going to fit. Some hacking out of material was required.

More hacking. This is the stick at its extreme right position. You can see it is centered in the hole. So a bit of an offset worked out. I also had to do a LOT of adjusting of the side bracket to allow full stick travel. This took a few hours to say the least. Its all good now.

I spent a long time when I built the canard getting the elevators exactly together. Time wasted as it was just a little bit out. Maybe 1.5-2mm BUT this translated into 2.5 degrees. Not OK. I removed one of the torque tube bolts and spent some time getting this perfect. Then I used  5minute epoxy glued it in place as you see above. Then I checked it again and again.

All good and I drilled a new bolt hole just around from the old one. You can see my fantastic drill jig for tubes that came from Aircraft Spruce. No builder should be without one!

Once the elevators were perfectly in line I adjusted the pushrod from the stick to ensure I was still getting full down elevator…  oh I had to make that pushrod and install a quick disconnect and rivet it all in place. The usual stuff.

…and full up elevator.

I spent many hours with the back seat stick position ensuring is was not going to snag. The effort required to remove and reinstall the whole stick assembly would try the patience of a saint. Especially after the 3rd or 4th time. The rear stick has been moved forward one inch. Without the removable stick it is all clear. I will need to get a modified back set (GIB) stick made up with a slight offset so it is also fully clear. For now, my controls are finally good and working.

Now the rudder cable path was through to the firewall I needed to get it sorted out from that ‘hot side’ to the pedals themselves.

After much bending I got the 2024-T3 conduit tubes to make a good shape both sides to direct the cable and conduit from the upper longerons to the rudder pedals.

I used hot glue to position them before I got the flox out.

You can see here we have a direct line to the pedals now.

After flox and two ply of BID just 1.5″ wide I felt that I had this direction changed nailed. On reflection, maybe I didn’t need all this strength and could have just tacked on some bare nylaflow tube. We will never know.

Not pretty but solid as a rock. I also had a slight bend inward to get the cable away from the fuselage wall. That’s probably why I went for the hard outer tubing, so I could get this direction without supporting the tube at the front ends.

With the rear and forward outer tubes in place I could lay out the nylaflow full length. Of course I roughed up the entire surface in preparation for floxing it in place.

The angle to the pedals worked out well.

I prepped the fuselage sides and had to dig in at the canopy latch and the hinge points on the right side too. That took a little grinding after a little thinking.

The cross members are to ensure the tubing is flush with the outer wall so my canopy screws can still go in.

All done and cured well. After a bit of clean up I thought more about the length adjuster and that required spring. What you see above is never going to happen. I need to think of something else.

Aileron setup continues like its for real. This can be close to the final setup right now.

It is time to find out if the stick hits the window at full deflection with the ailerons hooked up and in spec.

Spec is 2.1″ at the trailing aileron edge inboard +/-0.3″. The ailerons are capable of 2.5″ deflection so I spent quite a while trimming that down and finding where they are perfectly equal at neutral. I went for 2.0″

I had to fabricate a joiner between the universal and the rear stick. Yes I should have had the nuts facing down. My bad.

When I was happy with the ailerons matching AND the bell-crank at a happy place close to straight up, I fixed it in place as you see above to drill out the ‘drive tube’.

I used my drill jig to get the thing started. It took a bit of drilling as the inner part is steel rather than aluminium.

Finally drilled out, I have ailerons connected.

Here’s the stick full left which is not a problem when seated in the plane.

Full right is within .3″ of the window and there is enough slack in the system to get it to touch the window. I am going to need some hard stops on the pilot seat edge to prevent this. I will play with the angles a little more first to see if I can get the stick a little further away  by adjusting the midpoint inwards.

Meanwhile I had a look in the wing root and I am NOT happy with bolts upside down. If a nut failed the bolt would drop out. That said metal lock nuts generally don’t fail. Its more about good practice. Mind you this orientation here is exactly what the plans tell you to do.

I have swapped out with an AN4-10A and reversed it to the ‘correct’ way around. I needed the longer bolt so that ALL of the shank is in the bell-crank. This is why the plans have it reversed. I found I could get the desired result AND have the bolt correctly orientated. It did leave a few extra threads past the nut. I know this is OK because I checked where the shank went to. So we are good?

OK I can see the other bolt is the wrong way around. In this case there is not room to turn it. So I have to live with that one.

After many many hours setting up the ailerons I found a lot of slack in the system. One place was at this Igus bearing. There is a long run to the front seat from here and it had some play laterally.

My solution was to put another bearing on the opposite side so the inner steel had more longitudinal support. This took many hours to fit (like more than 6!) and was a minor improvement. Worth doing. Getting slack out of the system is all about chasing down the small things.

My next chosen task was setting up the ailerons and the stick.

Issues here are that the engine mount is in the way and that I need to work out the full range of movement and ensure that we don’t hit that aluminium angle at full right deflection. This means I have to be mindful of where the bearing goes. This of course is limited by the incursion onto the back seat/passenger position. Nobody wants a control rod in their back.

After a LOT of fiddling I made a hole to fit the roller bearing that seats the aileron bellcrank.

Here I’m about to cut the tubes to length. I went to a LOT of trouble to fit and refit to ensure I had it right. I don’t have a lot of spare control tube on hand. Which isn’t the whole reason, I’m just cautious cutting things to length and I want to get it right.

Finally cut and in position. I’m using the wood and hot glue to position the bearing while I flox it in place.

Here it is on the hell hole side.

This is full defection, so I have no problems with interference. You might notice I have riveted the rods as well. This was probably a days work just getting perfect holes in the middle of the tubes and of course double checking rod lengths and so on.

This is really a modification. Instead of the plans bellcranks and pulleys for the rudder cables I am going from the fuselage straight through to ‘present’ to the wing. This has been long planned without knowing exactly how.

After many many days thinking and looking I finally got my long drills out and made a hole each side. I’m partly in the longeron, then skimming the top of the spar without penetrating it and out the other side.

Having the Melvill cowls meant I had to make a faring and this turned out to be a great place to get the rudder cable conduit through.

I dug out a bit of the pour foam to make a place to get the cable through. Now I realised its best to get the tubing sitting right on top of the spar. I may need to add some cooling air here so I like knowing I have this option with no ‘cable in a tube’ in the way.

I used some soft 3000 series tube to make a ‘model’. Then this is in 2024 T3 left over from the canopy controls. The tube is the perfect size to contain the nylaflow inside it.

This is roughly where the pipe will go and then pointing directly at the wing cable exit. You might notice I’ve really cleaned out a lot of the pour foam. I initially left it as I felt it was adding strength in case I rested on the bulge during maintenance. It is very strong with very little foam, so who needs the extra weight?

I tested earlier with a bit of tube and the cable slides perfectly around the corner with very little resistance.

After a LOT of work and checking I finally floxed the ‘outer’ tubes in place.

I added a piece of BID (2 plies) so there will be plenty of strength for when I introduce the nylaflow  into this area.

A few words on those AN111-4 fittings. I found that if you swage it up close and tight it looks like it would be a lot of strain on the cable turning so sharply.

I found that about this much slack works out pretty well once you get the nicopress tool on it.

This is still very secure but I believe not as much strain on the cable. Just my own idea, I’m not a cable guy. It just seems common sense.

While I was endlessly working on the cables I made up a set of quick release joiners and a set of rudder position cable length adjusters. 2024 T-3 and .063″

Although without the nylaflow in the tube yet you can see that the fitting is well clear of the upper cowl line. I might add I’ll be changing the fuselage side fitting to the AN111. I think I need 8″ of cable slack to get the rudders off without cutting the cable each time. There is very little margin here.

I have the idea that this would be a great place to put the cable length adjusters INSTEAD of the smaller quick release. This makes more room up front where the special double direction spring has to go. If I go with this I will have to redo all the cables and make the adjusters shorter. Shorter adjusters is kinda not the point! So I’m still thinking on this one.

Having done all this work with the plans 1/16″ SS (stainless steel), I am now told by real ‘experts’ that I should have used galvanized 1/16″ cable instead.  I’m nearly convinced, so I just might trash all the work and go again.  It will be very quick now I’ve sorted out the problems.

Another issue is that I’m unhappy with my rudder pedal position. I have plans measurements but they are not as comfortable as my flying Long-EZ, so I’ll be looking at sorting this out. Maximum comfort to reduce fatigue is very important on this build.

Swage a cable and fit it to the rudder bellhorn. It turned out to be a little tricky and three days work. I went to a huge amount of trouble fitting these bellhorns during the winglet build. This was to ensure there was room for the internal actuating arm on the bottom of the rudder to swing freely when attached to the cable.

I knew it would be tight in there so I got the teardrop fittings of the correct size and made them a bit smaller with a little grinding. Here you can see the gap where the clevis pin goes. I had those circle AN111 on hand as well, just in case.

Here we are all fitted up and I installed the rudder. I installed and removed the rudder several times over the coming days. I’m getting better at it.

What I found now was that when the cable was attached the rudders if you pull the cable hard and full deflection they would would stick! This is because the teardrop shape of the fitting gets caught between those black plates if you hit the rudders hard enough which I believe are not far enough apart for this size fitting.

This is despite the plans internal winglet springs installed. So the sticking out ‘stuck part’ was greater than the spring force.

This has been a lot of work and a process over a year or so to get this A!0 Warthog throttle installed.

This is a Warhog, not my plane, and you can see its throttle on the left.

This is the simulator Warthog throttle that I bought on eBay. While new ones are expensive this one had a few electrical faults and was cheap.

This is all I wanted, the shell of half the throttle. The electronics will not be used. I want better quality switches. The quadrant I got by contacting a guy who supplies for RV’s.  As I’m having ‘FADEC’ I only need a throttle, no mixture or carb heat required.

Here’s the shell of the control, slightly modified and a plastic insert that was machined especially for this build by Gary Hill of OEM Engineering. Gary has build a superb RV in his ‘spare time’ and did this for me with that sentiment in mind. It would be a very expensive job at commercial rates.

The challenge was to get the wires down some sort of channel without taking up much space and still have the throttle operating.

Here’s where the switch wires will go.

This is the unit assembled. I’ve since got some countersunk screws to again reduce the space on the right side. Why I need this may make more sense when you see the install.

I had to hack out a little side wall to get the throttle sitting flush.

I’ve made a couple of aluminium strips with nut plates for mounting the throttle securely.

I’ve taped up the throttle and floxed those aluminum strips in place. Of course I needed to cut away a bit of armrest for it all to sit right. While it was curing I’ve used hot glue to keep the unit where I want it.

After cure I added some micro to smooth out the transitions., After that cured I added a ply of BID to tie it all together. The pic shows the last of these layups with peel ply of course.

Here’s the throttle very firmly mounted with four screws. It was a bit too close to the side wall so I had to add a couple of washer on the inside upper two.

Seeing the throttle in place might explain why I wanted it as close as possible to the wall as my leg goes there too! I’m very happy with the positioning.

Here’s a longer view of the cockpit area. You may be able to see a hole on the left wall. That is so I can adjust the friction of the throttle anytime  with my finger, even while flying. I had to relive the pilot seat a little too so the lid can come up without interference from the throttle. A few small things still to tweak and of course the switches and wires. Overall a very good result here.

With the basic air frame now built it is on to jobs as they present themselves and I really wanted to get the Infinity control stick installed. Having bought it ages ago, I finally pulled it out of the box to find that the spacer was not going to work with my 0.6″ OD stick.

I put in an email to JD who makes these wonders. I have to say it is the best service I’ve had during this build, more like a friend I’ve never met. He phones me from the USA to help out what is really my problem and then followed up later. Here’s a link to the stick grips if you want to check them out.

This is the grip less its 4 screws with the insert I got from JD. I just needed another 3/4″ OD tube which turns out to be the supplied ‘stick grip’ if you get the Cozy Girrrls controls as well as a number of the push long rods anyway.  I checked the plans and lopped off a small section from the rod that goes to the firewall. There was excess length waiting for me.

For this insert to step up the stick diameter it needed a bit of drilling and filling first. To tell the truth I was a bit confused as to the best way to do all this so I checked out Wade Partons excellent site as he has a similar setup to what I’ve planned here, and it is installed.

The insert setup matches the one JD supplied. I later added the Infinity supplied plastic spacer and glued it in place. If you get one of these it is soon obvious what the spacer does so I’ll spare you an unnecessary picture (which I forgot to take today). <grin>

The control stick itself also needed a slot and I got to it with an angle grinder …very carefully.

Here’s the result so the spacer tube can now fit with the wires out to the side.

I’ve added an AN3 bolt to secure to the Infinity stick which is not glued but locks in place in a very well designed way with the 4 screws.

Now the stick is in place I really don’t know if it will have enough room to travel. I can always move the forward bracket left and widen the access opening if needed. The stick on my flying Long-EZ doesn’t have all that much range. I’m going to wait until the wings are on and controls in place and set up. If I need to tweak then, I will.

Now the stick is in place I can look at the fuse panel I’m planing on the right side forward of the stick to the side. I’ve been working on the throttle install too and thats nearly ready to show you.

As I was working on fuel lines it seemed a good idea to get the brake lines in place now. I have SS lines, no plastic. Its something I want to install without any concerns.

I ran the lines both sides and then use micro and 1 ply of BID to secure them to the fuselage sides. They are just exiting at both ends for now. It does mean I can get on with putting the fuel system in place.

I had to add some foam fillets in the rear exit area so the lines would sit without strain. I really would like to do it all again a be a bit tidier. The micro on the fuselage sides doesn’t look pretty. No one will see it except me, which is not the point.

Secured with micro and BID

Rear exit line supports

Line support glassed

I’d previously set my stick to sidewall placement to allow for the Cozy type stick controls that I bought. These were .75″ displaced from the plans location. Having set things up I found that many other clearances now had problems.

I went back to my flying plane and very carefully measured the stick throw and position and came home with a plan to displace my front stick by .5″ towards the wall and the rear stick back .75″ to plans position. Why do I make things so hard for myself?

I first filled in the control bearing holes in the front and rear stick ‘holders’ with equivalent plywood using flox for my adhesive. I’d intended to apply glass to each side after it cured but found the glue job so successful that I’ve just recut the holes and its all good.

Pic 1 shows my plywood disc floxed in. I was pretty careful with the fit and it worked out well as you see in Pic 2 with that now cut out. Pic 3 is the front stick after the cut and refit.

All good, we move on..

Rear stick holder filled

Rear stick hole reset

Front stick reset

About 6000 hours ago on this build (Chapter 4 page 2), I made the rear seat back. The plans said do a hole on the left side a certain distance from the side and the right side a different distance.

Now a bit later on….hahahah I realise that the plans referred to where the part sits in the plane NOT how it looks on the bench. So the gap I cut so nicely as you see in pic 2 should have been where I drew those marks to the side of where the CS121 control push rod is exiting.

Pic 3 shows the correction. I may or may not fill in that gap a bit. I’ve left a note on a bit of masking tape to remind me to seal the edges depending on what happens in this area.

A mistake easily fixed all these years later. Now I am thinking L/R in relation to the flying plane rather than whats on the bench. I guess thats some progress.

Rear stick position

Left/Right error

Corrected opening