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Kent's Long-EZ project


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#241 Voidhawk9

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Posted 23 April 2018 - 08:51 PM

Oh yes, everything changes. But I just modified the drawings for the bulkheads, jigs etc, and got the CAD drawing printed and built from those instead of the stock drawings. No, I won't need to sit at an angle, it is wider through to about F-10. ;)


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#242 Kent Ashton

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Posted 24 April 2018 - 08:09 AM

Without pics, I'm skeptical.  (But start your own thread, plz).  :-)


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#243 Kent Ashton

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Posted 30 April 2018 - 09:44 AM

Posted for your interest:  There were several reasons I redrew this EZ nose.  (1) to make room for a battery, (2) to get a shape that pleased me, (3) to reposition the strut upper pivot for the different nose profile, (3) to try to get a little positive longeron angle and (4)  to use Cozy components because the manual lift and EZ wheel castings were NLA.  However, now I see that Nate Mullins is selling billet wheel components sized for the EZ. DUH!  However, I haven't seen his price yet so maybe the cozy casting is still a go.  The Cozy casting and wheel are a bit heavier, I expect.

 

Saw a discussion about weight on HBA which reminded me that weight does not have much impact on cruise speed but it makes a bigger difference in T/O and climb.  That is not to pooh-pooh the effect of weight.  A heavy airplane taking off on a hot day will get your attention.

 

I believe the plans manual lift could be used here if the arms are extended to get a little more extension so I drew-in the hardpoints for a manual lift.  It shouldn't be too hard to fab a whole manual lift if needed.  I could buy/make everything except the little spiral gear.  I believe Wilhemson's electric lift will work.  He advertises 7.3" of travel.  I show 7.33" so 7.3 might be enough but it's tricky when you are adjusting the switches for the full travel without encountering stops.  It would be nice to have about 7.8" of travel.  I built one of these lifts for the Cozy.  It takes some machining and welding but the longer shafts are available.

 

I like to build the canard to lift straight up and out for removal.  To do that, embed a threaded female long-nut or rod in the longeron and use a machine screw through a bushing as an incidence locating pin.  Cool huh!  :-)

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#244 Kent Ashton

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Posted 01 May 2018 - 07:49 AM

Good article here about Klaus Savier's EZ.  The most impressive thing to me is the low fuel consumption:  6.6 gph for 231 KTAS (at 17,500').  That is probably at WOT, leaned to a fair-thee-well.  For comparison, my Cozy would see 6.6 GPH at maybe 155 KTAS and the EZ would see perhaps 175 KTAS at that FF and altitude.

 

It is fun to think what that EZ might have done with a small canopy, small wheel pants and reduced intakes for lower cooling drag.  Maybe 185-190 KTAS which is still a long way below Klaus's speeds.

 

https://generalaviat...st-on-less-gas/


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#245 Kent Ashton

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Posted 02 May 2018 - 05:33 PM

I was talking to a chap about his cooling problems and thought to make an entry I can link to.  Here goes:

 

The best  way IMO to determine if you have an airflow deficiency or something mechanically wrong with the engine or CHT probes is to install a simple water manometer and go flying.  Lycoming says we need about 5.5" of water differential between the top and bottom cylinders to achieve adequate cooling.

https://www.aopa.org...-powerplant-(4)

 

I saw this idea to measure that differential at www.VansAirForce.com.  If you want to read the posts, search there for "piccolo tubes cooling".

 

Make 4 "piccolo tubes" out of soft small gauge aluminum tubes.  Make them the same length.  Drill them with tiny holes every few inches, pinch closed the open ends, and mount them above and below the cylinder heads in about the same locations (pic 1).  Use Tygon tubing to bring the tubes into the RCP and connect the tygon to two loops of clear PVC mounted as vertical as you can get them in the RCP.  Fill the manometer about half way with colored water and go flying. (pic 2)

 

On my EZ project, i could barely get 3.5" of differential and the engine would overheat so bad I could barely get up to pattern altitude.  After some changes I was seeing about 6" and the cooling was very good (325-340) in cruise (downdraft cooling, though)

 

I have found that aluminum-colored silicone sealant from the home stores is good to make cylinder baffles and seal gaps.  It sticks just fine to hot cylinders and the color blends better with the engine.  First make some poster-board templates, wet out a couple layers of BID with the RTV stuff, cut them to shape with the templates and stick 'em where you need 'em

 

Pic 3 is an idea for sealing around exhaust pipes, made from wood-stove gasket smeared with RTV and allowed to cure.  Pic 4 is an alternator seal.  You want some air going through the alternator to cool it but not around the alternator and not through any of those horrendous gaps between the alternator and the bottom of the engine.  Seal them somehow. 

 

Pic 5 is a dam on the upper cowl that the upper side baffles can seal against.  The plenum pressure s trying to push the cowl seal inward toward the top-center of the engine.  If the seal leans inboard, you can lose vast quantities of cooling air.

 

-Cylinder wraps- here I am just speculating.  Air must be forced to go through all the fins.   I eyeball the amount of open space between the cylinder fins (not just between the cylinders) and ask myself, "how big an opening do I need on the bottom side of the engine that will admit as much air as I need to push through and around the fins".  With that in mind, I build aluminum baffles or RTV wraps on the bottom to admit that many square inches of air. I usually have about a 3" gap, roughly.  I want to force that air to go into the bottom fins, then around the cylinders.   I do about the same on the top except I use the principle that an air exit must be bigger than an air inlet so the upper wraps do not wrap quite as much and have a bigger opening.  I figure that air that is blown up around and through the cylinders fins will exit the fins as soon as it has a chance and it does no cooling after that so the upper part of the cylinder fins need to be wrapped to force those pesky air molecules to stay in the upper fins until they've done their job.

 

Also  Lycoming cylinders have one side which has an obstruction in the fins that does not allow airflow from top to bottom.  In a pusher, it's the forward side of #3 and the aft side of #2.  The Vans folks have some ideas for making bypasses around that obstruction.  Hard to say if it's needed but one thing is for sure:

 

Those rascally air molecules do not like to go into dark, hot, confined places like cylinder fins and if you give them a chance, they will wriggle through gaps, holes, cracks and by the edges of the fins.  Bend them to your will!  :-)

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#246 Kent Ashton

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Posted 14 May 2018 - 07:15 AM

I was talking to a chap about winglet misalignment and thought I would post a better discussion of a jig you can make to check it.  The plans method for winglet alignment is not the best, IMO, and you can read my problems with misalignment in this thread starting at post #49, concluding with cutting a winglet off and remounting it.  From the geometry in the plans, the winglet chord should be parallel to the aircraft centerline (which the plans do not just come out and say!).  (Pic 3)  The dimensions are for a Cozy but the EZ chord incidence is the same--parallel to the centerline.

 

This jig (see dxf file) was useful in the hangar to compare the aircraft's extended centerline to the extended winglet chord marked on the hangar wall.  It is held to the wing with a bungee and flipped for the other side.  With the jig it was easy to see I had one winglet a degree or so angled outward (see Scan.pdf).   This major surgery might be avoided, however.  Over the years, people have cut the winglet vertically somehow and adjusted it.  In my case, I needed so much rudder deflection, I figured it'd be easier to remount a new winglet.  You can see pics of the process earlier in this thread.

 

If you need the jig drawing in another format, let me know.  I wish I had used one when I was  building both airplanes.

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Edited by Kent Ashton, 14 May 2018 - 07:23 AM.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#247 Kent Ashton

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Posted 28 May 2018 - 06:42 AM

Updraft Baffles-Cozy:  Mine are not show quality but they do the job.  The metal is 6061 .025.  I use aluminum-colored RTV from the home stores as a crack sealant and to make wraps.  For the wraps and patches, make poster-board patterns, clean the fins with lacquer thinner.  Tape a layer or two of BID to your table and squeegee the RTV into it.  Cut patches of wet BID and stick them in place.  Make them a little larger than you think and trim after cure as needed with a razor knife.  Around exhausts and the alternator, make seals out of wood stove door seal as shown in the next post.  I was taking pics today and noticed I have a big curve in the silicone down near the alternator that is rising up and probably losing air.  It needs slitting to lie flat.   

 

An aluminum piece below the alternator is removable with a few screws so the alternator can be removed more easily.

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#248 Kent Ashton

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Posted 28 May 2018 - 06:49 AM

Duh!


Edited by Kent Ashton, 28 May 2018 - 06:52 AM.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#249 Kent Ashton

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Posted 28 May 2018 - 06:51 AM

Ideas for exhaust and alternator seals.

 

See the note on my flywheel?  That has saved me a lot of cussing!

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Edited by Kent Ashton, 28 May 2018 - 06:56 AM.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#250 Kent Ashton

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Posted 04 June 2018 - 06:59 PM

I finally go around to making limit switches for my pitch trim.  The problem is to make something that doesn't overly complicate removing the canard.  It might have been better to attach a rod (purple line) to the traveling nut and mount the switches to the back of the instrument panel; the movement of the rod would actuate the switches.  However, I didn't have a good mount point behind the panel.  This should work OK and the canard can be removed by loosening the trim motor hose-clamp, loosing the two screw-and-nuts clamping the springs in the traveling nut and pull the nut off the spring wires.

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#251 Kent Ashton

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Posted 10 June 2018 - 07:59 AM

Saw this idea from Bill Allen for pitch trim.  I like it but I might change the geometry as drawn.  The trim spring always has to pull forward to pull the elevator down and it requires good friction to hold the position which makes the trim handle hard to move.  Changing the geometry would give better leverage for the trim handle and required less friction to hold the trim adjuster.    You would just have to insure that you can get enough forward trim spring travel for a full frontseat load but it'd be easy to add an extra adjustment point on the rod.

 

I might have to take out my clunky electric screwdriver and try this.  

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#252 Kent Ashton

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Posted 14 June 2018 - 07:25 AM

Nobody like my spring trim idea!  What's a girl gotta do to get a date?  :-)  The lever trim above could be used by welding on a tab at the bottom (pic 3)  vs. the threaded piece.  You DO own a welder, right?  Tig preferably.

 

Speaking of Tig, this fellow has an interesting bike-building channel with lots of discussion of Tig.  He is very meticulous and does some nice work.

https://www.youtube....eCgviyj_E0VEy9Q

 

Ain't the internet great!  So many things to learn.  I  fixed my old air-conditioner with the stuff on Youtube.  Really found this chap's discussion valuable.   He talks like the good folk around me.

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#253 Kent Ashton

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Posted 16 June 2018 - 06:27 AM

I bought one of these "Digital Thermocouple Thermometer" thingys on Ebay to do some HVAC measuring.  They are cheap but seem pretty accurate.  I tested it in boiling water and there is a way to test them with ice cubes.  It occurs to me that if you want to do some CHT measurements you could clip the leads to various places on the cylinders and prop the device up in the back seat or extend the leads to to the front seat.  Autoshutoff after 8 minutes.  You can buy the thermocouple wire from Omega.  Probably find it on Ebay too.

 

There are all kinds of neat, cheap devices on Ebay these days.  I use the little PWM devices for LED dimming.

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#254 Kent Ashton

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Posted 17 June 2018 - 07:50 AM

A couple of thoughts about baffles, the subtilties of which i have only lately come to appreciate.  Duh:

 

Pic 1  from Berkut13.com.  Leaves (plural of leaf) of baffle material have a large outside radius while standing up but they fold to a smaller radius when the cowl goes on.  If there is no break in the material, it ripples as the radius gets smaller and leaks air.  Using individual leaves lets them slide and overlap each other, decreasing the radius without rippling.  However, every break in the leaves is a potential air leak so the material must overlap neatly and the fewer leaves used, the better, as long as they lie down without rippling.  Riveting the leaves to the aluminum with some overlap seems to help, too.

 

Pic 2.  Sometimes you need a baffle to curve a little or a lot.  Riveting a straight side of the material on a curve will force the outer radius to curve.

 

Using a bit of #2 along with #1 will give an initial curve to a flexible baffle so that when the cowl is installed it wants to go in the right direction.

 

In pic 1, the side baffles appear to stick straight up and the cowl will tend to force them to flop inward--the wrong direction.  It's a good place to rivet them with a little outside curvature.  On the Cozy, I "fixed" the problem by using short baffles and making a dam in the upper cowl for the baffle material to seal against.  Doing it again, I would probably try riveting them with some outward curvature.

 

Boy, my next airplane is going to be perfect!  :-)

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Edited by Kent Ashton, 17 June 2018 - 08:16 AM.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#255 Kent Ashton

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Posted 21 June 2018 - 12:39 PM

Here is how to rewire a Denso alternator for an external regulator that will permit over-voltage protection.  There are other ways found on the net but this works and explains a bit more.  A few things to know: 

 

(1) The output of the alternator is controlled by the field voltage which is normally set by the internal voltage regulator. We want to bypass the internal regulator and have the field controlled by an external regulator in order to have over-voltage protection.

 

(2) Most Densos are “N” type alternators that regulate the field voltage downstream from the field windings.

 

(3) It helps to know that before modification, ringtab C on the brushholder (SEE PICS) is connected to the inner brush, the diode array and the IG input.

--------------------

Remove three nuts and the plastic insulator on the large output stud and remove the cover.

Remove two screws [C, D] that secure the brushes. Caution: when reassembling: don't over-tighten screw C which goes into plastic is easy to strip.

 

Remove small screw [E] and two long screws [F].  Lift out the voltage regulator and brushes.

 

With a Dremel wheel and pocket knife, remove plastic on the arm [G] that connects to the plug's IG or B+ tab to the brushes.

 

Cut off the ring terminal on arm [G}. Solder a 22AWG wire to the arm bend it up and shrinkwrap the joint. This disconnects the IG/B+ connector from ringtab C/inner brush, however, the inner brush will still be connected to the diode array if reinstalled so we also need to disconnect ringtab [C] from the inner brush. Here's how to do that:

 

-----Unsolder the lower brush at the back of the brushholder (i.e., the inner ringtab C brush). Remove the brush and spring. Solder an AWG 22 wire to the brush wire and cover the solder joint with a piece of shrinkwrap.

 

-----Drill out the hole in the brushholder big enough to accept the soldered brushwire/AWG 22 wire/ shrink wrap.

 

-----Bring the AWG22 wire through the brush hole and secure the brushwire/AWG22wire/shrinkwrap in the former solder hole with RTV. Allow to cure. The shrinkwrap will now isolate the inner brush from ringtab C.

 

-----Connect the two new AWG 22 wires with a 1A diode to make a pigtail that will hang out of the alternator when the cover is replaced. The diode should “point” to the brushes.  It  prevents feedback spikes to the external regulator when the field current collapses at turnoff.

 

Note: When the brushes are reinstalled, ringtab D makes contact with the case (ground) via internal wires in the voltage regulator. Some sites say to dig out the regulator and fill with the hole with inert stuff. If you do that you will have to install a jumper from ringtab D tab in the regulator to the ground tab in the former regulator. That jumper is shown if you go that route. The tabs inside the former regulator are not as you might think. Comfirm the intenral regulator tab for ringtab D and the tab for ground with a DVM.

 

When you're finished the current path is from the IG post, through arm G to the diode, to be back of the brushholder to the inner brush, through the field windings, back to the upper brush, to ringtab D and through internal wiring in the regulator to the case/ground.

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Edited by Kent Ashton, 21 June 2018 - 12:43 PM.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold


#256 Kent Ashton

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Posted Yesterday, 03:47 PM

Maybe I posted this before.  Dunno, getting old and can't remember what happened yesterday.  Anyway . . .

 

This is how I make CHT sensors for Lycomings.  Take some CHT wire from Omega, slip on a hardware store brass fitting (sorry, don't recall the thread.  See, gettin old!) and a spring.  Ball the wire up and silver-solder the ball.  I am not sure it even needs to be silver-soldered.  The spring holds the ball up against the hot metal.  But if you'd rather pay $87 each, be my guest.  :-)

http://www.aircrafts...rs_cht/gem3.php

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold





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