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Kent's Long-EZ project


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I often see posts from people who seem overly cautious about leaning.  I got 30 hours in a T-41 (CE-172) in Air Force training.  The instructors never leaned.  It wasn't the object of the training and we were always doing this and that with the engine.  I got a few single engine prop hours after that and knew the drill "lean to rough-running and richen slightly" but that was about it.  When I bought a Cozy III in 1995 I started reading about leaning and ran across John Deakin's great articles.   https://www.avweb.com/features/avweb-classics/pelicans-perch/pelicans-perch-index/   (See #18, 46 and a bunch more after that).  Great reading.  Nowadays there is much discussion of "the red box"--the lean condition to avoid in the mixture power charts.  I always found that overly complex.  So here's my leaning procedure on an O-360, Ellison TBI, two Lightspeed Plasma ignitions:

On the ground, about 10 seconds after the engine starts and runs steady, I lean as much as possible.  With my Ellison, I can pull the mixture back to the aft stop.  I want it lean enough that if I was to apply T/O power in that condition, the engine would cough or quit.  This keeps the plugs clean.  I push it up for the before-T/O ignition check.

I take off in full rich, of course, and passing 4000' MSL in a climb, I bring the mixture back to peak power as shown on the RPM.  Climbing further, I will adjust it to peak power every few thousand feet.

At level off above 8500', I let the airplane accelerate a bit then I pull the mixture back to suit my needs but generally below peak power.  I do not hawk the RPM or CHTs, or use any particular procedure.  I just pull it back over a second or two.  If I am in no hurry to get somewhere, I might bring it way back which will severely reduce the RPM and happily reduce the fuel flow.  The engine might stumble.  If so I richen until smoother.  If I'm in a hurry, I might pull the mixture back to peak power (with wide open throttle but with an Ellison, a slight throttle reduction increases RPM).  At 8000-8500' the engine cannot develop more than 75% power and Lycoming says there is nothing you can do to hurt the engine, leaning below 75% power so I am not to concerned with CHTs, EGTs or the Red Box.

On descents, I usually leave the mixture set where it was at altitude until I level off at a lower altitude, where I will richen.  In the pattern, I am usually going back and forth with the mixture:  Full rich for a touch & go takeoff,  lean quite a bit on downwind, back to full rich on short final or if I need lots of power.

For cruising below 8500 feet, I do not have a manifold pressure gauge so I take a guess as to what RPM might be 75% power and if I am below that RPM, I lean pretty aggressively but monitor the CHTs more closely.  For example, if putzing around at 3000' MSL, I might set 2250 and lean as much as desired.  I know this works for me but without MP, it may not be ideal.  See this Vans thread and spreadsheet  https://vansairforce.net/community/showpost.php?p=1086624&postcount=4    At 5000' MSL I might set 2400 RPM and lean.

When I had a carburetor airplane, it was much the same except the engine stumble came much earlier in the leaning process.   The Plasmas also allow much leaner operation than mags.

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

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Having operated primarily in training environments, leaning usually gets totally ignored unless flying high enough to gain noticeable power. Poor engines.

Prior to my last check-ride, I flew a practice flight, during which I leaned carefully (despite remaining relatively low). During the subsequent walk-around with the examiner, he  noted the healthy colour of the exhaust pipes. 😁

Aerocanard (modified) SN:ACPB-0226 (Chapter 8)

Canardspeed.com (my build log and more; usually lags behind actual progress)
Flight simulator (X-plane) flight model master: X-Aerodynamics

(GMT+12)

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Hat-tip to Joe Person for this pic of corrosion in a Varieze canard lift tab.  Wow, that looks pretty scary.  I wonder what the wing attach plates look like?  I saw a old Voodoo (F-101) parked in a coastal environment where 3/8" solid alumium structure in the wheel-well had almost turned to powder.  

Rutan published a procedure for replacing canard lift tabs.  It is not very complicated:  cut a rectangular hole to expose the lift-tab bolts, unbolt and use the old lift tab to make copies [and metal prep, alodine and paint], bolt in, refill the hole and put a couple of BID over it.  Piece of cake.   I do not like those nutplates.  There have been cases where they stripped after lots of bolting and unbolting.  I'd rather use a bolt and nut.

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

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Hi Kent:

Great picture!  I have been thinking about making an inspection panel for the lift tab area to allow inspections. No engineering review yet. 

The countersink & rivet holes (w/ too little ED) aren't a great idea. These 2 detail parts seem to me to be the most critical on the Cozy...

Do you still have wire for sale?

Regards,

James

James Russell

Electric Shadows, Inc.

841 Old Gardiner Rd.

Sequim, WA 98382 USA

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Hi James,  Yes I still have wire 16 and 18 AWG.  100' roll $20 + about $7.25 shipping.  PM me and I check what I have.

This pic is apparently the side against the FU-22 so it might not be inspectable without removing the canard.  It's pretty quick to pull the canard if you have the quick-disconnects on the elevator rods.  You could probably see just as much with a mirror and flashlight.  It is hard to imagine how he got so much corrosion on those those tabs.   Maybe they were a strange alloy.  I would definitely Alodine, prime and paint now but my Cozy has neither and they look OK.  😞

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

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washing with purple power will turn aluminum to corrode in short order.  Could have been a PO that washed it and did not get it all removed and sat their for weeks or longer!

Even Simple green warns about using around aluminium - they have a special "aircraft" concoction that is "safe".

M.

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A chap on the Cozy list said:

Quote
Mark, a 79 year old friend of mine sold his LongEZ (290 G powered) two days ago. The buyer had never flown or ridden in an EZ. They did the deal at Hood River, OR. The guy climbed in, took off and flew it home 250 miles to Spokane, WA. Mark said the nose gear was still down when he lost sight. When the guy got home he called Mark and said he did a perfect landing and just LOVED his new airplane.  

It reminds me that when I bought a Cozy III many years ago, I took a train down to Columbus, MS, flew with the owner once and the next day, flew it home to North Carolina.  I wish I'd had an advisor though.  It was a decent airplane but it had a high time engine and the auto paint started flaking off a year or two later.  Still, I had fun with it and learned a lot.   It only had a vertical mag compass for navigation and I had a line and tic marks on a sectional.  The compass must have been off about 10 degrees, too, but fortunately the weather was good.  Some years later I sold it to a rather new pilot from California.  I offered to deliver it and he asked if he could come to N.C. and fly with me.  We had a great time over two days and I got to do some flying with him in S. California--wow, the traffic around Chino was fierce!  He is still a good friend and he still has the airplane.  He picked up all the expenses, too!  By that time we had a Garmin 195.  Piece of cake and it is now even easier with Foreflight.

A couple years ago I ferried my Long-ez to a buyer in S. California.  It was late Fall and the west winds were blowing like crazy.  It had rained hard in the East for weeks and the Mississipi was a raging torrent of mud and floating trees.  The storms stopped me in Palestine, TX one night.  I took off the next day and overflew Texas at 500-1000' to keep out of the 50 kt headwinds.  Spent another night sleeping on a couch in the Chandler, AZ general aviation terminal when all the hotels were booked for a big race, and again got to experience the excitement of flying around in L.A. basin traffic for a couple of days.  Gosh how I miss going cross-country.  The covid and the winter weather have slowed me down but I hope to do that again a few more times.

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

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5 hours ago, Kent Ashton said:

A chap on the Cozy list said:

Please quote accurately - that was NOT the COZY mailing list, that was the Canard Aviators mailing list. Don't get me started on why there are 57 thousand different places to get canard fixes...

Good stories, though.

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There are 2 or 3 lessons in this.

Some years ago my Longeze was ready to fly after I fixed all of the things that Marc found to be wrong with it.   Two friends of mine were VERY experienced and did all of the flying for me.

I would say that I was in the back seat but that would have been illegal by FAA rules.

One liked the Longeze so much that HE BOUGHT HIS OWN.

He invited me to go "help" pick it up.  I had no idea how I could help.  It was in Tennesssee a couple of thousand miles away.    It was a beautiful, well done airplane with absolutely no provision to comfortably seat a passenger of any size.   He flew it once and paid.    I told them I could not fly in the CRAPPY back seat so they cut a sheet of plywood for some back support for me.   On a scale of 1 to 10 it became a 3 after being a 1 or less.   He check at the local, large airport and they had NO sectionals from there to Washington.   The Longeze had an autopilot so he set up the autopilot.  Next morning we started, landed to get gas and find sectionals.   SORRY, they had none.   On the second landing, my buddy landed, parked, got out and cranked the nose gear MOST of the way down; then went to buy sectionals.   I started to climb out but the nose suddenly dropped to the pavement.   O!   I knew we had a problem; I had done the same stupid thing before anyone had told me.   BUT I HAD TOLD HIM; don't put the nose most of the way down; it HAS TO BE  either up or down.   So the RAF metal gear was stripped.   We borrowed some tools and I went to work.   After some time we had the nose gear down and bolted in place.   We had 1300 miles to go with the nose gear down.   If you are a new guy building your own Longeze, take the damn RAF gear out and either (1) get a sturdy one from Cozy Girrrls or (2) Contact Wilhelmson for an electric gear.   Either way you will spend some money but you will not have to fly 1300 miles with the nose gear down.

Next problem:  he landed in Idaho at a good but short runway for gas.   He was used to landing on OLM's 5200' runway.   Running out of runway, he turned on the cross runway.  Broke a runway light and the wheel pants.   Got some gas and I carried the remains of the wheel pants back to OLM in my lap.   The rating for the back seat had gone from a 3 out of 10 to a 2 out of 10 but we survived.

IF you are a new guy:   (1) get an electric nose gear or contact the Cozy girrrls   (2) fix the crappy backseat so an average human can sit in it  (3) take a few tools just in case.

 

 

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Good story Bruce.  When I sold my EZ I gave the buyer "Notes, Cautions, and Warnings"--terminology they use in the Air Force for special things to be aware of.   A lot of them apply to any EZ:

WARNING – This aircraft uses an electrically-dependent ignition system. With any electrical failure, reduce electrical load and land as soon as possible.

WARNING: Takeoff and land with both boost pumps on. After takeoff, either boost pump may be turned off.

WARNING: Protect the Nylaflow brake lines from UV exposure and radiant heat from the brake rotors. When changing-out Nylaflow and fittings, use inserts and new caps to prevent leaks. Nylaflow is reliable if it is used properly

WARNING: Unlatch the (starboard) aux canopy latch before landing on or off airport. If there is trouble closing the canopy, insure the aux latch is not restricting closure.

CAUTION – Insure the 25 lb weight is hung in the nose gear when parked on three wheels with the cockpit empty. If the nose inadvertently rises more than a few inches, a tipback can happen quickly which will damage wheel pants and prop. Even with the 25 lb weight, use care to avoid a tipback.

CAUTION - When the aircraft is parked on three wheels pointed into a strong wind, the wind can lift the canard and cause a tipback. Parking the airplane on an upslope will also makes the aircraft easier to tipback.

CAUTION: The manual nose gear mechanism must be either fully extended over-center or fully retracted. If weight is placed on the nose in any other position, it can strip the gear in the mechanism. The gear can be reversed for one more usage.

CAUTION: For safe stall behavior, this aircraft requires 16 lbs. of ballast placed ahead of the rudder pedals with a 225 lb. pilot. This gives a calculated CG of 99.79” and adequate nose-bob warning. If the pilot is lighter, ballast accordingly, or if a more-aft CG is desired, carefully test the stall characteristics at altitude.

CAUTION: To prevent nose gear damage, avoid taxiing into potholes or ground-point depressions on the ramp.

CAUTION: Keep the swiveling nose gear adjusted so that that a hard blow with the fist against the tire does not freely deflect the tire, otherwise, the nose gear may shimmy and destroy the nose gear. The nose strut is properly rigged when the NG pivot shaft tilts aft at the top when loaded.

CAUTION: Change brake fluid every two years without fail. Old brake fluid absorbs moisture which lowers the boiling point of the fluid, raises the risk of brake fading, and contributes to caliper corrosion. Bottom-filling of brake lines is recommended. Suction old fluid out of the reservoirs with a large syringe and pump in new fluid at the brake caliper until fluid appears clean.

CAUTION: There is no warning of an unlocked canopy in this aircraft. Insure that the canopy emergency catch is bent so that it engages when the canopy is lifted.

CAUTION: Leaning during ground operations is recommended, however, lean so that if the throttle is inadvertently advanced for takeoff with the engine leaned, the engine will cough.

CAUTION: In the event of alternator failure, lowest current drain will be achieved by selecting E-bus power, then turn off the master switch. While on E-bus power, selectively turn off any E-bus-powered equipment that is not needed (i.e., com radio, transponder, Dynon D-10A, one fuel pump). Turn off Lightspeed Ignition #2 to save the backup battery for last use.

NOTE: Before removing fuel tank caps for refueling, attach the fueling ground wire to the step. The step is bonded to each fuel cap ring via internal wiring.

NOTE:: For normal operation, maintain Ignition 2 Pwr Select in the “aux batt” position. This checks the condition of the aux battery. Before takeoff and periodically, test aux battery voltage.

NOTE: Lightspeed ignition #1 is powered directly from the main battery. Ignition #2 is normally powered from the aux battery, each through its own switch. If alternator failure occurs, reduce any other electrical load and turn off one igntion (normally turn off #2) until the main battery is exhausted, then turn on ignition #2

NOTE: Gravity fuel flow (i.e., both boost pumps off) has been tested at 7500' MSL and 2400 RPM, and at 3000' MSL at 2200 RPM.

NOTE: Spare fuses are stored in a red bag in the right strake hole.

NOTE: If the fuel valve begins to bind, disassemble and lube the spool with a tiny smear of Fuel Lube. If too much Fuel Lube is used, bits of it can lodge in the gascolator screen (where it will not desolve!).

NOTE: Tire pressures are 50# main wheels, 65# nose gear.
NOTE: This aircraft uses DOT3/4 brake fluid and EPDM o-rings in brake hardware.

NOTE: The Dynon D-10A EFIS and uMonitor are powered via the E-bus and will indicate approximately one volt less than battery voltage because of loss in the E-bus diode. The aux battery voltage meter reads actual aux battery voltage.

NOTE: Water is seldom found in the tank or gascolator drains of composite airplanes but if any water is found in the tank drains, then also check the gascolator for water.

NOTE: With the Ellison TBI, the highest RPM is normally obtained by retarding the throttle slightly off of wide-open-throttle (approximately 1/4”).

NOTE: This Ellison carburetor set-up exhibits a slight engine surge at medium RPM using very lean mixtures. If bothersome, slightly richen the mixture.

NOTE: For instrument access: remove the canard cover, remove two long pins securing the instrument cover, remove instrument cover and disconnect the connector for the cockpit flood lights.

NOTE: To remove the canard, remove the instrument cover as described above, remove the footwell access hatch/cover, disconnect the elevator control rod quick-disconnect (starboard side), loosen two screws holding the trim spring wires in the trim mechanism (port side), disconnect Dynon remote compass sensor on the canard, disconnect antennas in the canard, unscrew & remove two screws through the canard incidence-setting tabs, unbolt the canard lift tabs, lift the canard up and out.

NOTE: The fuel vents crossover. The left fuel tank is vented under the right strake. The right fuel tank is vented under the left strake. Preflight the vent tubes for mud-daubber wasp blockage.

NOTE: Use of mogas/auto fuel is not recommended. Mogas formulations are not uniform and mogas left in tanks may soften the tank epoxy.

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

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16 hours ago, fshort said:

Great list! I can see a modified (for Cozy Mk IV) version in my POH.

Ha!   If I had one you could certainly see it.  You probably need to cut and paste and make your own.  Every airplane is a little different.

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

Saw this problem on the "Cozy List"--yes, that one.  Or more precisely, the "COZY Builders Mailing List Google group".   🙂    In pic 1, the nose gear setup will not allow the nose wheel to swivel 180•.  I see that the MKNG-15 casting being sold now has thicker ears than my older casting that came from Brock (pic 2).  The thicker ears cause the usual tire to hit the bolt heads when the wheel is swiveled.  The Brock model had thinner ears and came with a steel plate made with a trough (pic 3) that gave more space for the bolt heads.   If I was using the newer casting I would machine off some of the forward face of the casting and make the piece with the trough which I have made before in a stout hydraulic press (20 tons or so).  (and use self-locking nuts, MS21045-428)

Make the plate a little wider than you need.  The width will shrink when you form it.  Then drill it after forming

When I made the foot in pic 2, I thought I had the geometry right but the wheel hit the foot when swiveled so I had to make it twice!  It's always something!   Also, you will see a nick in the metal (yoke) at the bottom pic 1.  Best to file that out and relieve all the sharp edges on the wheel yoke.  On EZs, the yokes have cracked before.

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

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Saw on FB.  Think about it: Owner with the shark's teeth goes to an airshow.  Civilian says "Cool airplane.  What is it called?"   What do you say?  "It's a Cozy".  😞

Nat picked about the worst name you could pick.  Fortunately we don't have to use it.  How about "Mako IV"

Screen Shot 2021-02-06 at 10.37.44 AM.png

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

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Would work great at an airshow if the aircraft was in grey primer, and maybe some Hellfire replicas instead of external fuel pods.

Put a sign next to it with some nonsense about close support and optional pilot, and you have the next big thing!

Aerocanard (modified) SN:ACPB-0226 (Chapter 8)

Canardspeed.com (my build log and more; usually lags behind actual progress)
Flight simulator (X-plane) flight model master: X-Aerodynamics

(GMT+12)

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Accident porn:  What can happen if you don't have some sort of heat shield between the main landing gear strut and the brake rotor (pic 1).  I use a sandwich of hardware store aluminum flashing and fiberfrax.  Safety-wired it to the strut.  Got the idea from pic 2.

Sounds like the pic 1 owner might have been a new owner.  The previous owner should have warned him.  Put that in your "Notes, Cautions and Warnings"  🙂

Also, it's not good practice to hang your brake caliper by the brake line.  Sort of asking for more trouble.  And I would wrap that black line with aluminum tape, too

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Brake heatshield 1.jpg

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Edited by Kent Ashton

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

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I see that Charles Furnweger(sp?) sold his Cozy project.  He was asking $18K for the airplane and $8K for the rotary engine, engine mount, and Real World Solutions redrive so I imagine he settled for close to that.  Fuselage and canard mostly complete.  No wings or winglets.   http://cozy.caf.org/index.php     A chap named Tom from Florida was the buyer.

Interesting that he started in 2005 and got this far.   Taking too long tends to sap one's enthusiasm.  I see guys today that seem to be taking about 4 years.  IMO, that's about what it should take.  He did nice work though.  Maybe we will see that one flying soon.

Edited by Kent Ashton

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

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  • 2 weeks later...

From the Things That Make You Go Hmmm department:  poster says:

Quote

[DeWalt]  is a common brand of cordless drill. Hamp Aviation Service hold STC#SA02604CH for this. A ring gear and drive plate is mounted at the propeller end, a pinion attached to a driveshaft is engaged in the ring gear by the same action that moves the drill to pull the trigger. Power is applied gradually by the trigger. Last time I looked, they were asking US$1,900 for a complete kit with STC. It is particularly relevant for A65 through O200 fitted with accessory cases that make no provision for a starter. You can have a starter with no electrical system at all. Or have a little B&C 8 amp PM alternator and a little battery with thin cables, for a solution that weighs much less and still gives you radios etc... So for long trips, you would need to charge the battery every now and then, which in any case, would be better done outside the aircraft. The STC also covers some Lycoming models, I don’t know which. It looks crude, but I like it better (for pushers) than another experimental technique that uses much the same technique and a centrifugally clutched whipper snipper engine to do the starting. The latter technique works pretty good with tractor propellors, where you can keep an eye on things and make sure that the pinion disengages and the “donkey” engine is shut down and secured. You pull the cord to start the whipper snipper, use a foot pedal to engage the pinion at the same time as the throttle is opened, then disengage and shut down the whipper snipper after engine start. That one works quite well for magneto ignition air cooled VW conversions in aircraft without an electrical system.

I hand-propped my O-320 for a while.  It was not too scary after I did it a few times. I did not have a primer in that airplane--it had a pumper carb--so it was sometimes tricky to get it to start.  If I'd had a primer system I might have continued but I finally put on a Skytech starter.  I've watched many Variezes start with just a flip of the wrist.  Not sure why someone would prefer this DeWalt rig. 

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

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Just saw a post from a Czech builder wanting a Long-ez POH for an O-320 engine to satisfy Czech authorities.  Probably someone has done this but I don't know one offhand.  I told him to just revise the few pages in the regular POH that discuss the engine.  Every EZ is different anyway.  Found the POH here

https://www.rutanaircraftflyingexperience.org/post/2017/07/05/rutan-long-ez-poh

Also get a copy of Lycoming's Operator's Manual.  Good stuff in that too.

https://www.lycoming.com/sites/default/files/O-320%20Operator%20Manual%2060297-30.pdf

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

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On 3/26/2019 at 7:19 AM, Kent Ashton said:

A rollover seen on FB (pics 1,2).  Credit Bob Hutter.  It is fun to see how people do these things.  The 3rd pic is what I built for my Long-ez.  I found that making the longeron angles in four pieces allowed it to warp a bit when welding--better and stouter to have continuous angles at the sides, I think.  If I was building one again, I would put some strips of Fiberfrax on the longerons to protect the glass before tacking it up.  Also plan a recess for the angles before glassing the wood longerons.

I like these better than the composite rollovers I see.  You can weld mounts for a GPS or GoPro and they make a good grab-bar for getting out of the back seat.

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Kent,

I see this is an older post, but I was wondering if you know of folks retro fitting a rollover structure in older flying models?
 

your structure looks nice.

cheers

Trevor

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7 hours ago, Bugstrider said:

I see this is an older post, but I was wondering if you know of folks retro fitting a rollover structure in older flying models?

I don't know anyone off-hand.  They generally have to be built to fit the airplane.  A welder could do it if you cut and fit the parts yourself.  I suggest making a simple jig for the welder to get the width correct; the tubes can twist during welding.  You want to make sure it will fit on the airplane when it's done!  I think I used a bend like this   https://secure.chassisshop.com/partdetail/C42-290/    and you can buy other smaller bends to complete the structure.  A mistake I made was to use four pieces of angle vs two longer ones.  Relieve the longerons generously for the angles and reinforce them with UNI and BID to replace the glass you remove.  Here are some other ideas.  Another place that sells the bends is MarkWilliams.com

rollover5.jpg

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Rollover.jpg

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

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4 hours ago, Bugstrider said:

Are you removing just a small amount to allow the angle to sit flush since it would be a retro-fit instead of a building install?

Yep.  You don't necessarily need to do that but I think it makes it easier to construct a canopy-to-fuselage seal later.  On an existing airplane, there are several layers of UNI along the longerons to stiffen the area.  If you cut into them they should probably be replaced.  On my EZ project I overlapped the old UNI a few of inches and tried to make the transition rather gentle but I still didn't get the angles recessed enough and it was more work to make the longeron smooth.

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

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Saw a guy complaining on the National Fake News Site of a dry layup (pic).  He had lo-vac'd and peel-ply'd this bulkhead.  in my opinion, the answers he got were bad.  Perhaps he could have used just a touch more epoxy to wet-out the peel ply but there is nothing wrong with this layup.  What we are seeing are tiny voids left between the peel-ply and the glass that will not hurt anything.  If you have squeegeed a glass layup well, it takes a fair amount of extra epoxy and stippling to wet out the peel ply layer.  The extra epoxy fills the waves in the fibers and leaves a smoother surface but it does take extra epoxy to do that.  If you use a little less, it will leave tiny voids between the glass and the PP.  That's what we're seeing here.  These are harmless.

If you suspect you have a dry layup, look at the layup with a jewelers loup before peel-plying.  If individual strands in one thread of fiberglass stand out, or you can see into the weave between threads, you didn't use enough epoxy or you over-squeegeed which presses the epoxy out of the wet layup.   It's not so much that you are looking for bubbles--you're looking to see if the weave is filled with epoxy but not so much epoxy that it looks like your yard after a heavy rainstorm.

BTW, this was the F28 bulkhead ahead of the instrument panel.  Why waste time vacuum bagging this bulkhead?  It gains nothing and only slows down the build.  I would suggest not using PP until you get a feel for what an adequate wet-out is.  When a surfaces is PP'd, you can't see into it any longer.

dry?.png

Edited by Kent Ashton

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

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Saw this on the National Fake News Channel.  Broken exhaust pipe crusing at $11000 feet.  Landed OK.   Fortunately he had the broken pipe safety-wired to the other pipe so it did not go into the prop.  It looks like this fellow's pipe might have been rewelded once before. 

I like the pipes in the Cozy plans better.  They use a slip joint and two springs that hold the pipe on the slip joint (pic 2).  Only one spring visible in the picture and you will see that I ran some safety-wire through it.  I got the springs from McMaster.   It's a little more fiddly to build but not much..  The outside pipe slips over a smaller pipe welded to the flange.  I suppose one of the springs or hangars welded on the flange could break but the other would likely hold the pipe in place.

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

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