DISASTER averted - Thanks to my awesome SUBSCRIBERS! (Ep48)

A disaster was averted thanks to my awesome subscribers! Before you watch this video, you might want to check out the previous video titled, "This MISTAKE is going to be EXPENSIVE!"
This is the follow on video where I show you how I took your suggestions from the comment section and fixed my issue with the nose wheel support block on the Zenith CH-750 Super Duty kitplane.
This fix cost me $0 and that's a price that I like!
I really appreciate all of your comments and I like how we can all learn from each other. Again-thank you to those who take the time leave comments (and thumbs ups!)
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Dremel Flap Wheel: amzn.to/3ztmXle
Air Hose: amzn.to/3wrqezA
Air Hose Fittings: amzn.to/3iIf2dB
Paint Gun (works GREAT for smaller parts): amzn.to/3vqDgMa
Air Filter for Paint Gun: amzn.to/3iHhfX2
USB Data Port (for Dynon): amzn.to/3iLsiOL
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Fly Cutter (for fuel sender): amzn.to/3gvgXzO
#flying #kitplanes #zenithaircraft

[@Dustin-Holstein]

This is why all builders should post their builds to KZbin! Power of the community!

[@tywebb9879]

Mark, your comment on the washer made me laugh, I do the exact opposite. I put the sharp (stamped) edge out against the nut so I don’t put a nick in the aluminum. Your point is probably the correct answer, do it the same every time. Love your videos, keep up the great work. On the nuts, you are correct. The handbook is the Bible but since no one has actual temperature readings it has become the “standard”.

[@danielbasovitch5087]

Mark, I am glade that you used the spacer (shim) instead of ordering New Parts! I am sure you saved yourself "Mutcho Deneros" doing it this way.

[@johnnunez17]

Nice sir. 👍🇺🇸✈️

[@mcorrive12]

I'm so glad to see you didn't have to redo all that hard work on the nose wheel structure! Phew! Onward!! 😅👍

[@ikay2102]

Washers i place round edge towards metal surface, I was told at school that sharp side cuts into surface more aggressive than other side.

[@Tommy-B.]

I get what you mean about loving hardware. Sometimes if you have a nice AN washer, that doesn’t have a top and bottom like a normal washer, there’s something satisfying about just holding them.

[@SASouthwing]

The only exception I can think of for the washer is to have the curved or beveled side on any component that can flex. What comes to mind is tail rotor driveshaft flex connections. If the washer is installed flat side to the component it can cause a crack and ultimately a failure when it flexes. There may be a case for having the curved edge on sheet metal if it has any expected flexing during operation. I'm enjoying your content! Keep up the good work.

[@daverobinsonTnT]

in such cases shouldn't a thin washer be used so that it flexes ? Washers are typically employed for one of the following reasons :- - To protect the surface finish (eg. paint) where frequent assembly - disassembly takes place. - To facilitate installation of tensile bolts with shoulder radii (beveled ID). - To accommodate a limited variation in grip thickness due to stack up of tolerance; multiple assembled parts - To increase the clamped area while lowering the compressive stress on the surface (oversize washers) However if the surface is flexible, I'm not sure a washer with a radius at the faying surfaces outer contact boundary is going to reduce the stress that much if the washer is thick enough to have an appreciable radius ? I'm thinking the washer is thus stiff and cannot flex, implying the stress concentration will be at the circumference of the hole in the thin part and not out near the OD of the washer. But I could be entirely wrong on this.

[@j.muckafignotti4226]

As an A&P, we don’t use any nylon locking fasteners in high temperature areas. Normally nuts with a crush neck self locking feature are used. Most large commercial aircraft use high temperature hardware in the engine compartment as temps in these areas can be well over 350 deg F.

[@n206ja]

Funny, I, too, always place washers with the "smooth"/ radiused edge up and the sharp edge down! Similarly, when I have a row of zip ties on a wire bundle, etc., I try to orient them so that the ends you cut off all face the same way. I think it just "looks better" and at least shows some attention to detail! Guess we're both obsessive-compulsive! Not a bad "mental illness" to have when you're building airplanes! LOL!

[@KitplaneEnthusiast]

I do that with zip ties too! There is something wrong with us.

[@johnreed8872]

Yes to all the above ! Among other things I also line up bolt heads and look for markings on all nuts and fasteners and orient them the same. It's a sickness that I don't mind having given the nature of the project! Probably the reason I don't care much for help from others. Glad you solved your dilemma, Thanks for sharing and Blue Skies!

[@josephcapps6416]

Yep ... multiple clues to the Pitts. Plus a glimpse in the background.

[@jeffreydurante662]

Can see it in the reflection on the TV screen

[@garyfreeman2254]

I have been an industrial assembly mechanic for almost thirty years and that's how I Install flat washers.

[@tfogelson3139]

When in the military my boss always insisted that Nylock nuts were a one time use only and insisted that we install new ones and discard the old. Wish I had kept them, I would have had a bushel basket full by now.

[@LTVoyager]

Yes, that is just crazy. Last I knew, even the military allowed 5 uses of Nylocks, which is ultra conservative itself. This is one area where the FAA is actually reasonable and makes the usage based on data - the prevailing torque measured. If the prevailing torque Mets or exceeds the minimum, you are good to use again. That is a sound engineering approach.

[@wpnspltUSMC]

Awesome fix Mark. Hopefully we meet at OSH

[@LTVoyager]

Not only do I orient the washers as you mentioned, I also line up the flats on the bolt heads if there are several in a row. I’d like to line up the nut flats also, but when torquing fasteners, torque spec takes precedent. 😁

[@robertlafnear4865]

Just bought that book "Standard Aircraft Handbook" off Ebay....... Sometimes the viewer learns something from a KZbin Video or in this case my Kitplane Enthusiast's Video......... Sometime the little things are really big things............ BIG THANK YOU.

[@georgeburns1561]

Absolutely. Flat side goes next to the metal for clamping force. I'm the same.

[@garyjones6914]

I am like that round edge out

[@davidrobins4025]

I thought you might try the aluminum spacer to solve your dilemma. I also thought about drilling out the holes to take a larger size bolt. The first solution is much "cleaner" than the second. Your "bolts, nuts and rivets supply looks like a high tech hardware store. You almost always have the correct "item," but it also saves a lot of time looking for the right one. I love that. It is next to impossible to find the exact one when they're just piled on top of the bench or in a box all together.

[@sunmanav8]

Washer orientation is the topic of Piper SB1366 due to the potential of the 90 degree edge to create a stress riser in an adjacent radius of the wing spar. Would love to come over and see your build; I live just south of 9G2. I have a Cherokee 140 and have completed the empennage, flaps and ailerons of a scratch-build CH650.

[@psuter80]

On my airplane with a continental o-200 aircooled engine the temperature right on the firewall was usually no higher than 180°F .. i've measured that because two egt probes could not be mounted to the exhaust, so the mechanic decided to just stow them away zip tied to a wiring harness along the firewall until i get a new exhaust with silencer which would allow to mount those probes as well. Air temperatures around here on a hot day are usually around 100°F

[@novicereloader]

I've always installed washers as you do. Well, since I worked for the power company for a few years after high-school. The type of lock washers used to build power pole cross arms only work one way, since they sit between a large flat washer and a narrow nut. There's just an order to things.

[@johnfisk4666]

All planes are fun but only one is SPECIAL! Too bad your secret project isn't a PITTS

[@KitplaneEnthusiast]

I know right?? I'd love to have a PITTS!!

[@martinp1544]

Great idea!

[@edwardmullen1581]

Putting the washers on that way will actually spread out the load slightly more.

[@sysfx]

It also places a larger washer area (with 90 degree edges) against the aluminum shell and a smaller washer area (rounded edge) against the steel nut, which is consistent with the metals' relative strenghts.

[@1shARyn3]

The rounded side goes towards the nut (or the bolt head when on the head side of the structure)

[@JustaPilot1]

The other way around. The rounded part goes on the workpiece (sheet metal), not the nut or bolt head. Piper just issued a SB on this very subject. It's to prevent faying of the sheet metal due to vibration.

[@wb6anp]

@@JustaPilot1 Yup it is right here. www.piperowner.org/talk/discussion/155196/piper-service-bulletin-sb1366-main-wing-spar-hardware-inspection

[@whitmats]

Glad you found an easier and cheaper fix. I always but the rounded side toward nut as well.

[@timlahr7149]

I’ve done structural steel work for 27 years and can tell you that yes there is a proper way to use a washer and yes you are right in the way you put them on !!!!

[@daverobinsonTnT]

For nuts with a nylon insert to facilitate locking, you just need to ensure that if the nylon locking feature fails, the bolt cannot fallout and the failure isn't 'dormant' (meaning it won't be easily detected, either during frequent inspections or immediately via a physical noticeable sign such as rattling or vibration of the fastened part). Note : Regarding orientation of washers, it depends upon the type of washer and the type of application. For regular applications one might prefer to have the full flat surface of the washer against the part. This maximizes contact area, prevents dirt and moisture from accumulating in what would be a 'gap' and helps prevent stuff from being caught on the sharp edge of the washer. However, also the radius edge (special thick washers) of a washer can be used where there is a radius (often referred to as a "fillet" radius) at the junction of two perpendicular parts and the fastener is close to the fillet. In fact, we often call for special washers called 'Radius Washers' however, they tend to be square or rectangular in shape, where the fastener's location is so close to the fillet radius of a part that the outer edge of washer would actually sit (dig into) in the fillet. Of course the radius of the washer then must be bigger than the fillet radius of the part; this actually helps reduce local stresses (stress concentrations) where clamp-up loads are high or there is a concern regarding low loads together with high vibration cycles, leading to stress fractures along the fillet's tangents.

[@LTVoyager]

I suspect many parts of the engine compartment exceed 250 F on a hot day while taxiing. Keep in find what CHTs routinely run above 300 and the exhaust pipe likely is 500+ depending on power output. So, anything close to the exhaust of cylinder heads is likely to see 250 when airflow is low such as idling in place or taxiing slowly on a hot day. Better safe than sorry.

[@RHD56SD]

It might not get that hot during the flight, but what about after shutdown with no airflow.

[@craigtrout380]

Do the same. My slight case of OCD and time as a turbine mechanic in the Army makes me put a washer under the bolt head also. (Same orientation)

[@RetiredRoadTrips]

I usually install washers round side up (pretty side out). From my USAF aircraft maintenance training we were taught the flat side might dig into the mateing surface so they recommend to go rounded side down, but other than scratching risk, it doesn't matter from a structural standpoint. The only down side in aircraft environments is that with the rounded side down it can catch and trap small dirt and moisture easier, but we're splitting hairs here.

[@swiftbuzzerd7497]

Yep, I always put the rounded edge out.

[@alanrice8614]

So, Nyloc nuts are not safe for holding on a NYLON spacer?

[@georgeburns1561]

My thoughts exactly....

[@charlescashell5645]

I do the same thing with washers

[@JMOUC265]

I always put the rounded side of a washer against the metal so as not to scratch it. I don't want to create a stress collector point in the metal, nor do I want to remove any corrosion inhibitor (paint or anodized layer) from the surface.

[@williamstrome5271]

yeah Mark because of exhaust manifold and pipe temps you would be in that temp range inside the engine compartment

[@Arjuna86004]

I also turn the sharp side of the washer down. Safes the edge, looks better and if you're consistent, the build will have a more uniform appearance.

[@LTVoyager]

Same here and my wife thinks I am crazy to bother with things like that. 😁

[@marksmith7896]

Cool !!!!!

[@hipsterkennyrogers909]

A shim was my first thought. I'm building a Zenith 650B and it's nickname is already shim-city.

[@KitplaneEnthusiast]

I like it!

[@dcrahn]

Excellent solution to the problem. And a good choice on the nuts. But also be aware, where I worked we considered them a one time use hardware including the bolt or screw it was used on.

[@KitplaneEnthusiast]

Yes that is true. The lock nuts do 'cut' into the bolt more.

[@kennethsmolana9865]

@@KitplaneEnthusiast Looks like that top bracket may have to come off again to rivet the powder coated structure onto the fire wall.

[@Cavalier-lp8tr]

The side of the washer having the most surface contact, goes against the piece being secured. That's how I do it.

[@davidwhite2011]

Always wait a day or two before spending money.

[@KitplaneEnthusiast]

Absolutely! Any timeI have an issue I "sleep" on it for a few days. Eventually I probably would have thought to put the spacer on the bottom, but thanks to you guys the idea came a lot quicker!

[@n206ja]

@@KitplaneEnthusiast I like to "think out loud" on the Zenith.aero Forums for a similar reason - you frequently get some alternate ideas about how to deal with a problem. It can sometimes save a lot of money and a lot of grief! Ha!

[@johnfitzpatrick2469]

G,day from Sydney Australia. I like your quality: but, I worry about "galvanic corrosion" between aluminium and mechanical fasteners. "Wings level" 🌏🦅

[@235buz]

Awesome video. My guess is, you would use nylon instead of metal to reduce weight? Are there torque spec's for the nuts?

[@challenger2ultralightadventure]

I'm not trying to be "nit picky", but aren't you replacing nylon locking nuts for metal ones. To hold a nylon bushing? Seems to me to be a little odd. Also, I place my washers the same way you do. Flat side to the surface and rounded to the nut. Love your videos. Cheers from Winnipeg.

[@paulslevinsky580]

I had an inspector reject a man-lift I'd designed because the screw drive used a modified (lubricated) nylon drive nut. Fire safety concerns. The open air man-lift could fail from heat with an occupant on it. The guy was an idiot...

[@hotironaircraftshop]

I've found that the more square edge of a washer digs into the paint more than does the rounder edge. Which is better is a matter of whether or not you want the washer to dig in.

[@daverobinsonTnT]

Interesting observation John. In the case of one coat of primer and perhaps two coats of topcoat (less than ten thousandths of an inch of total paint thickness), is it that pronounced if you use aircraft grade epoxy enamel paint and allow it to cure for the full recommended period ? I can possibly see a problem if the thickness of the paint constitutes a lot of layers and the bolts are tension bolt applications (higher torque for higher axial loads) but not any problem for shear bolt applications. I'm learning new things about Experimental and Light Sport Aircraft builds, as my background is Transport category aircraft, so my question is from the perspective of that of a 'newbie' to the kit building community.

[@hotironaircraftshop]

@@daverobinsonTnT Just to be clear, I've never built an airplane before. That's why I watch this channel. My reference to washers and paint comes from a powder coated hobby project (not aviation related). In this case, the 90 degree edge of the washer, which was in contact with the powder coat, created a crack in the powder coat in the precise outline of the washer, and allowed moisture to reach the steel underneath. I had to sand down the area under the washer and apply some touch up paint to seal it up again, this time putting the smoother rounded side of the washer in contact with the paint. Naturally the thickness of the paint, along with its composition would make a difference. The biggest effect that I've observed is that, during the process of tightening the nut, the rounder side of the washer scuffed the paint underneath less.

[@daverobinsonTnT]

Thanks John, I've learned something new as I was under the impression that "Power coating' would employ a paint that provides a hard surface but as you've pointed out, it may be too hard a surface finish; more brittle than I had thought. I learn on here as well mate - especially from the comments of builders like yourself who have varied background specialty expertise from other interest which can be applied for Experimental Aviation. So thanks for the 'heads up'. Cheers.

[@thomasmitchell6921]

I was wondering if there is a suggested torque for the locking nuts ? I have used the smaller Demi Torque Wrench ( 3 - 15 Newton Meters version ) when required below the standard 3/8 drive levels. Great move not using the nylon nuts - why guess on the temp changes in different ambient situations

[@mikemorgan8792]

Awesome way to avoid spending money and time, also it’s safe and will not efficient it’s function,

[@MIKE.RACING963]

Lol, I even do it to copper washer on oil drain plugs.....why... no reason.... just because. Lol

[@scsirob]

It's kinda interesting that you steer away from using Nylocs, that are used to mount a green block made of... nylon? The Nyloc nuts may be rated for 250F, nylon itself melts at a much higher temperature. It probably ages faster when constantly exposed to elevated temperatures, but by the time the nuts in that location are reaching 250F or higher, you have quite a different problem at hand ;)

[@JustaPilot1]

Ahhhh, A 1962 series 1 Ferrari 250GTO. You sir have excellent taste in cars.

[@KitplaneEnthusiast]

Just need the real one!

[@JustaPilot1]

@@KitplaneEnthusiast I just want to see one in the wild. $53,000,000 is a little out of my price range.

[@KitplaneEnthusiast]

@@JustaPilot1 ya at that price I could only afford two of them...

[@JustaPilot1]

@@KitplaneEnthusiast ONe for the week and one for the weekend. ;) ;) ;)

[@brandtmeyer]

So Mark, if I think of all the projects I’ve built around the house, I would have to say that I would completely agree with you on the placement of the washer. Now, I am starting my Kitfox build and I am questioning if that is correct or not. I don’t know. When I saw that part of your video I was in agreement but then I thought, would I want the sharp 90 degree edge against the powder coat or metal possibly digging into the surface? I am not sure which way is technically correct.

[@KitplaneEnthusiast]

In 25+ years of aircraft maintenance I've never once seen a washer cut into paint or powder coating. In theory I could see how that would happen, I just don't ever recall actually seeing it.

[@brandtmeyer]

@@KitplaneEnthusiast Perfect, great info. Thanks for the response.

[@danielbasovitch5087]

The flat side off the washers have slightly more surface area.

[@jamesrea8454]

My A&P friend says that Cessna uses nylon lock nuts in their certified aircraft engine compartments. Also Zenith specifies them in its plans. I know Mark is a wonderful builder and in now way criticize his discussion to use metal lock nuts.

[@KitplaneEnthusiast]

Hi James-that's what I mean when I say it's controversial. Some people will say they are ok to use, others say not to use them. Obviously I've never done any scientific testing to know one way or the other, so in my case I just chose not to use them. I just wanted to relay my experience with the FAA inspector who wanted me to change them out. Other inspectors may not have an issue with them!

[@brianberezowski5352]

Putting washers on with the 90 edge in and the "rounded" side by the nut is NORMAL .. at least I thought every one did that. Maybe I'm weird too? 🤣

[@mrsaskriders]

Kitplane enthusiast, I hope you read the comment about the washers need to be the opposite of how you placed them. There even is a bulletin about it!!! (A piper service bulletin) which at least is a valid point even if it is a kitplane?? Hawkertech's comment has the SB link inside of Gwen Walcott's comment.

[@garyjones6914]

At what temperature does that green plastic melt?

[@LTVoyager]

I am not sure what attaches to that bottom bracket, but are you confident that shimming it down won’t through something else out of whack later?

[@KitplaneEnthusiast]

Yes.

[@wonkothesane3482]

You've bought yourself a biplane...it was in the last episode as well.

[@Tommy-B.]

Washers definitely have a top and bottom.

[@scottmiller4711]

Have you checked on "wait times" for engines? I have heard that some manufacturers are backed up for months and aren't even taking orders right now...

[@KitplaneEnthusiast]

Yes I realize there's a backlog, but I have a lot of work to do before I actually need an engine!

[@SkyRayden100]

Continental/Titan is around 9mo lead time and only taking orders from OEM's. As a data point, I ordered my Titan IO-340 November 2020 and still waiting... Just a thought.

[@rmr24]

Secret project = Pitts

[@KevinJones-pj8kx]

I see you did not torque those fasteners as you assembled it with the metal nuts. By not using a torque wrench there is a possibility of overtightening them because 10/32 don't take that much torque. Feel can be deceiving.

[@LTVoyager]

There is zero need to deburr holes drilled through multiple layers IF the layers are clamped snugly together while drilling. You only need to deburr the exterior of the holes where a rivet or bolt will touch. The interior will not have burrs unless the layers of metal are not clamped together.

[@KitplaneEnthusiast]

That's not entirely true. The burrs will be small, but there will be a slight burr. In the case of the engine mount holes, there's really no way to clamp the layers tight-especially the bottom two. Even holding them as tight as I could while drilling, when I took them apart every single piece had a burr on it that needed removed.

[@aggibson74]

when it's on fire, it might be over 250 degrees

[@hongshi8251]

Sorry- forgot what engine you will install. ??? PLZ

[@KitplaneEnthusiast]

180hp Lycoming Thunderbolt

[@dicel87]

What engine is going on the front?

[@KitplaneEnthusiast]

180hp Lycoming Thunderbolt

[@Texxas750Cruzer]

If the engine wait gets too long , you can still get my old engine. Low hrs 😜

[@KitplaneEnthusiast]

Booooooooo!

[@i.r.wayright1457]

He who hesitates is lost. Spend the money for the engine NOW, or inflation will bite you in the tail feathers.