On Sunday, I had a great day after church cutting up a downed tree and hand splitting the wood.  Actually it was a lot of fun using an ax instead of a log splitter.   A bit of work but great exercise. 

  I have shifted directions on the down draft cooling system.  After carefully looking at the cowl, Pat and I decided that the reduction of the height above the cylinder (due to the DD cooling plenums) did not warrant chopping up a beautiful cowl.  If I had not cowl it would be a different story.    Overall, I would save a considerable amount of time by keep the cowls a close to original as possible.  The first step is to reattach part of the original fairing. 

Foam was bonded to the inlets, shaped for glassing. 

There is an Alum ring (which you will see later which will be used as a support for a silicon vibration isolation tube.   The inlets both have about 12 sq in per side.   It should be plenty for cooling as it is about the same as my plane and my cooling works exceedingly well. 

Tomorrow, I will reshape this area, and start working on the inlet tube to the engine.   I feel shaping of the inlets is the hardest part of the down draft cooling.  The rest of the work is very simple.

We had a historic snow fall in Charleston on Feb 12th.  A record 3.5 inches!  The first time it has snowed since 1989.  It was incredibly beautiful but unfortunately, gone by noon Saturday morning.  I would really enjoy a good snow every year!    

 The baffling is now done.   This is a picture of all the parts (45 ea) which is used for downdraft cooling that I removed from the plane.  Total weight was a little over 4 lbs.     

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The is the new cooling system.  The part count is 24 pieces, and total weight is 2 lbs.  I am very pleased with the way it turned out!    

As installed on the plane    

I am now working on the inlet ducts.  Here is the port duct being fit into position.    The duct is covered with duct tape prior to glassing.    

The Port duct is glassed.  I will glass the stbd one tomorrow.    

Want to know how to change a nice new 2 ft x4 ft sheet of Aluminum

To a pile of beautifully cut and formed scrap pieces? 

All you have to do is to cut a pile of scrap pieces of paper and spend a LOTS of of time prototyping an entirely new down draft cooling design…..

I have spend the last few weeks trying to develop a down draft cooling system totally out of aluminum….  Why you ask.  Well if you think of production costs, it is much cheaper to make stuff out of aluminum then fiberglass.  Just look at the cost of RV parts.  They are really inexpensive when compared to fiberglass, hand molded parts.  Machines automate the manufacturing process. 

When I started assembling a DD system on Pat’s request (change from updraft cooling), I felt the project needed to be modeling in Acad.   Faster than manually drawing lines on paper.  

Then I got a bug up my b*** and it became a real challenge after I hit on a really simple way to seal the engine.  Using seals around the push rod tube.   They were very difficult to get right but they work!  The tube baffle has grommets for the spark plug wires and fuel injection tube.  These seals proved to be the key for the box design.  Normally, the only hard part of sealing the engine for DD cooling is the case.  As far as the cylinders, they are all the same and there are no variations.   So why not just seal what you really need to seal.  

Overall, the purpose of this exercise is to to eventually design a kit of precut/bent parts which could be waterjet cut in mass, sold cheap, which allows a builder to assemble a VERY TIGHT down draft box and reduce plane cowl height.  Never been done for a canard aircraft.    What, we could actually have a something manufactured for our EZ’s which is cheap?  Who would have thought….    The kit is applicable to a 320 or a 360, pusher/tracker setup (I think it would be great for an RV).    RV’s could get rid of that red silicon seal material. 

What I like most is when the builder is trying to balance the cooling on the engine, you only have two cylinders to work (the box only covers two cylinders on each side) with and since the cylinders furthest from the inlet are the coldest, it is very easy to block the box at the half way point to raise the temperatures of the remaining cylinder.

I went though a number of different designs…..

Many different tube seal designs, lots of paper prototype parts

Finally, got it!  Here is the final design (the Al still it has the protective plastic on the metal).  Late after the cowl is finished, the plastic will be removed.

There is a sliding hatch held on with one screw which allows easy access to the spark plugs. 

All the parts just seem to majicly lock together almost like a chinese puzzle with a minimum of parts.  Sometimes I even amaze myself!    Now the parts can be mass cut with a waterjet machine which means the kits will be very cheap and easy to reproduce. 

If nothing else and they are never manufactured, when I get around to modifying my other planes for DD cooling I’ll be able the box in a day.    I’ll finish assembly of the box tomorrow.

Work continues on the down draft conversion.  I am making the lower part of the DD cooling system in aluminum and the curves and upper part will be glass.  I am starting to realize with the close tolerances and difficulty of working with Al, that in the future, I would probably just make the head support in Al, and all the rest in glass.  It will be interesting to see after I am done if the effort is worthe the result, and which method might be the best in the future.  I’ll be doing this all over again for my cozy 4.  I must say, it does make for a nice clean installation ….

#1 Cylinder  

#2 Cylinder 

Received the in instrument panel test panel from the fabricator.  Overall it was GREAT!  All the instruments fit as planned with just a few minor adjustment on the holes.  I cant wait to see it populated and fit into the plane.

I also made a blended winglet test model to test out a new construction method I developed.  Pat wants blended winglets on the plane.  I figured out a very quick way to build them that is self jigging, self leveling and leaves no possiblity of error or misalignment.  A complete coversion should take about two weeks.   Stay tuned for further developments.

Today was spent working on the cooling system inlet design.  After making a few plugs I wasnt happy with, I turned to AutoCad to model it on paper before building.  It is so much easier when you can see exactly what you’ll end up with before you start.  I really do need to start learning 3D model.  It would make my life much easier.

Initially I started out with a few hot wire cut pieces.

Pat was happy with this design, but I was not.    I am not comfortable with a funky NACA scoop instead of the tried and true ram air inlet.   The current plan is to first make a ram air inlet, then add the ramps (so Pat is happy) and if things don’t work out, I’ll have a fall back position.  Chop off the ramps and I am back to ram air!

This is a pdf file of the cowl design/cooling system design I came up with.  It is as tight to the engine as I could make it (1/2″ clearences over the spark plugs and plentum box).   

cowl design  1

Tomorrow, I’ll glass the inlet tube I made, then start working on the ducts.  Much to do, much to learn.

Pat has changed my direction a bit.  I was working toward updraft cooling with his plane.   I am now working on downdraft cooling.   He also wants the cowls reshaped to make them more streamlined.     It will keep me busy for a month or two….  oh well, what else would I be doing…maybe retire?

Today was spent cutting and cleaning up of the strakes and planning for the down draft conversion.

I also stopped by Tony’s house to check out his work on DD cooling.  Funny, a few months ago, I was trying to convince Tony to use DD cooling and gave him a bunch of ideas, now I am checking out his work for ideas.   He is a terrific builder so it was interesting to talk about his techniques and experiences. .

It is the beginning of a new year. 2010. How does one say that these days? Is it ” Two Thousand Ten” or is it  “Twenty Ten” ?

My pronouncement would be Twenty Ten, since the only reason we called the 20th decade as ” TWO THOUSAND AND ##” is because of the movie “2001, A Space Odyssey”. The naming of the movie influenced the entire next decade of yearly naming conventions.  Can you imagine calling 2004 a “twenty oh four”.   No, it is only because of this movie this decade was different.

Well, I am finally back to work on the plane. The last time I physically worked on Pat’s plane was on 27 Nov.  For the month of Dec, I worked exclusively on the wiring diagrams of the plane.  When I finished on 30 Dec, I had put in 132 hrs of drafting time.   That’s about 25 hr with the holidays.  I ended up with 35 pages of drawings and a half completed spreadsheet (it will be filled in as I wire the plane).

I decided to document the wiring in a similar way to my Toyota Truck Wiring Book is written. The drawings are broken down by systems like charging, starting, lights, com panel, etc.  

This way if Pat has a problem with something electrical, it will be very easy to trouble shoot JUST that system. A light doesn’t work, it will be easy to see at a glance the entire lighting system without trying to dig out the wires of interest amongst other unrelated wire on a schematic.  It is a MAJOR PITA to document everything this way and a little more difficult to wire but the effort was definitely worth it.

Now that the really hard part is done, the wiring plan, I can start back on finishing the things necessary to get me to the point of wiring. The engine is next. Pat wants composite baffles on the plane instead of the aluminum type for more ridge baffles and better sealing of the cooling air. The currently installed baffles have massive air leaks around the perimeter.

Lots of red RTV is on the old baffles.

Composite baffles are more time consuming to make, but the advantages are perfect sealing of the engine, no cracking and you can do compound curved to attach the flexible baffles to. The extra effort creates is the best possible seal. We need the best possible cooling for the extra HP this engine is going to generate (estimated at 195 hp from a IO-320).  The baffles will look a little strange, as it will be comprised of both composite and fiberglass but it is best to match each material to it’s unique physical properties.

Here is the bottom engine baffles.   

They were re-imagined in composites.  The form is foam and the glass is lay-ed out in order of use.

The part is vacuumed down to the table after coating with epoxy. 

Carbon sure does look good when you are done and uncover your work.   I’ll uncover the rest of the part tomorrow after the epoxy has had a chance to get a little harder.

This has not been a busy of a week for me.  I was sick the first part of the week and with Thanksgiving thrown in, the work on the plane slowed a bit.  I was able to complete a few items.  I built a O2 bottle support which came out very nice.  The bottle is the same size as a 4″ PVC pipe which I used as a form to lay the glass on. 

Attaching the support for the closure clasp.

Finished.  Painted flat black.

Insturment Panel

Pat changed the plan a bit and now wants a carbon instrument panel.  Quite a few hours this week was spent finalizing and rechecking the Acad drawing so it can be cut out on a CNC machine in LA.  I should have a test panel in a week or so.  After I finish installing the supports and lettering it,  the panel will go back LA for clear coating and polishing. 

WIRING

I also started working on the wiring system.  I have been avoiding the wiring just becauseI know how much work it is truely going to be.  Many, MANY hours sitting at the computer drawing and documenting the wiring harness.  After installation, there will be many hours of correction the drawing for final printing.   I laid out all the major electrical components on my spare bed and looking at all the wiring ahead is daunting!

The wiring diagrams are absolutely CRITICAL to long term maintenance of the plane and they need to be as complete and clear as possible.   After flying these planes for years, I find most of the maintenanceissues in the future will mainly be wiring problem.  Fixing a screw, bushing or engine component is quick and easy.  Finding out why a light or radio stops working is really tough and almost impossible without a well documented wiring schematic.    The type of connectors, switches, plugs, type of crimper used, wire, etc should be of the highest quality possible, because it will bite you in the butt if  you dont pay really close attending to this critical aspect of the plane.    Of all the work I am doing on the plane, I approach this area with the greatest concern and closest attention to detail possible.    This is why it takes so much time and effort.  I spent 3 hrs yesterday working on just 4 pages of wiring and I am still not done.    I will probably have 30 or 40 drawings.   

Some people approach the electrical draw from the aspect that you should put everything in an area on one page.  An example is the power system should show all components and where they all go (charging, starting, lights, lines to the radios, etc).  This is great for wiring the plane, but doesn’t help as much when you are trouble shooting a sub area of the larger system.  Lets say you are only working on the alternator part of this system.  

I like drawing the areas out in sub systems.   The alternator system is drawn separately from the starting system or the ignition system.   In the future when you are trouble shooting  problems with the charging system, it is MUCH easier to look at just the system of interest and visually see what is going on.  You dont have to separate it from a larger drawing with lots of other stuff on it.  It makes wiring the plane more of a pain but is much easier to trace wires.   

Anyone can wire a plane… it is not rocket science and is fairly easy to do.  Run a wire from A to B and you are done. Easy.  I have seen so may planes (certified and experimental) where if you ask the owner for a wiring diagram, you’ll get a blank stare.    I have seen very few few wiring diagrams and they were by obsessive compulsive engineer types who really knew the value of having one.   Most builders just wing it.    I had to rewire my plane because of a crappy wiring job and no documentation and did a fair job drawing out the wiring on Tweety.  On Pat’s plane, it will be the mother of documentation because I plan to reuse most of it on my cozy 4 (Bubba) and Toan’s plane so it is worth the extra effort.    Beside, I want to do it right for Pat.

Wire Bow Ties

One thing which has always bothered me was how do you attach the wire bundles to the plane.  In my plane I used click bonds with Adel clamps which are heavy and awkward to use.  I wanted something easier to install and more versatile.    So I made up some attachment point I call bow-ties.

First I layed some glass over some small diameter rods.

After slotting the glass layup (I used a radial arm saw), you can cut them up to little bow ties into individual ties or as strip and flox them to the surface of the fuselage.  A zip tie to hold the wire bundle to the bow tie and you are done.  I weighed a single bowtie it works out to .5 grams each.    What I like about it is if you wish to have a number of separate wire bundles (my favorite choice) you can cut a strip of bow ties and flox them down as a group.  Then the wire bundles are equally spaced out along the wire run.

I think may make another strip of ties which will improve my original design.    The first set used a rod as the form and was a very easy way to make a strip of bow ties, but the top of the ties is rounded and a bit taller than I want.  I plan to make a gig which will be squared on the top (3/16″) about 1/4″ high and use 2 layers of carbon.  It will hold the zip ties better and I have plenty of scrap materials around to try it out.

I completed a quite a few items the last couple of days….  the instrument panel cover, the passenger foot rest/storage area, and the panels for the arm rests.

After presenting Pat with 8 different options, he chose this shape for the pilot arm rest area.  More cushion than needed but it is for the overall effect he wants to achieve with the plane.

Finished panel weight 8 oz. 

Stbd side.

Back seat.

Today work was started on making a O2 bottle support bracket and installing the fire control system bottle.

This was an AWWWwww SHIT today.  The cable which activates the fire suppression system is too short so it is necessary to make some sort of adaptor to lengthen the cable.   A simple tube with bushing seemed the way to go.   Good….done…   Well when I looked at routing the new cable in the plane, I f0und you can not use this method as it will not fit through a hole in the instrument panel.  I need to have a way of attaching/detaching the extention cable from the main cable.   Tomorrow, I’ll remove it and start again. I personally would use halon for fires not foam….

Work started back on the plane.   I finished the cover for the belly board motor.    It came out nice.  Today it was glassed to the foot rest.

The instument cover actually came out better than I expected.  The carbon graphite is incredibly stiff and it made a really nice cover.  I like the rounded look of the carbon weave. 

Pat is going to clear coat the cover which will make the carbon really stand out.  It will end up looking great!

I tried lighting it with the LED strip light which fits under the lip of the panel.   The lighting is nice and even.

This is the plan for the arm rest.  Typically I like to rest my arms in the strake opening.  The sharp edge of the stake is very uncomfortable on the elbow, and it occurred to me to pad not only the flat surface but some of the strake area too.    After glassing the panel it will be covered and RTV to the plane.   I use RTV in my plane to hold my arm rests which has worked out very well over the years. 

Stbd side.

Port side