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KevinMaiorka

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#1
Hi all my name is Kevin and I am from central Texas and have been machining for about 10 years for myself. My regular day job is working on cars and I do enjoy it.

Here is a project that I have been making recently for some friends that own planes. These are for the front seats and allow the seats to move rearward and forward. The rollers are enclosed in a square tube that has a slot cut out in the top which is where the seat frame connects to the axle. The factory design is two plastic rollers and a axle with a hole drilled thru and no way of attaching the rollers to the axle. Most people use dental floss thru the hole to hold rollers in place while installing them but it is not a fool proof design. I came up with this design on my own and it works very well.
The axle is steel I believe a 1200 series steel. Can't recall at the moment and the aluminum is 6013. I use a standard 1/4 inch e-clip to secure the rollers onto the axle.

uploadfromtaptalk1469825380034.jpg

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wrat

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#2
What is this for?
What's the end goal?
 

KevinMaiorka

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#3
They are for aircraft seat track system to allow the seat to slide fore and aft. Different design than what the factory originally used that is a better design in my opinion.

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#4
you might have to do a new weight and balance for those...lol
 

KevinMaiorka

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#5
you might have to do a new weight and balance for those...lol
No need to start any trouble now lol.

My other project that I will be starting soon is to finish up my uncle's little engines Pacific 4-6-2 7.5inch locomotive. He passed away a month ago and never finished it and I am the only one in the family that knows how to do machine work. Thankfully I also have an interest in trains so this should be a lot of fun.

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wrat

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#6
Hmm... if these are for Certified Aircraft (Cessna, Beech, Mooney, etc.) then you're largely wasting your time and someone's gonna be looking at a really big fine if they use them.

Just for the record, and among the many factors involved, e-clips are disapproved for new design. So that part's right out.

Because people use dental floss during installation does not make it a poor design. At the factory, you can be assured they don't use dental floss. But airplanes are not cars and are subject to many, many more rules and regulations what, you know, with them flying overhead and all. Among those regulations are configuration controls. If it ain't factory, it ain't approved.. and therefore ain't legal.

But it can get to be approved. Find a DER that can get you through the TSO/PMA process and you'll be on your way. If you can get it approved (very time consuming and very expensive), then you're good to go.


Wrat
 

KevinMaiorka

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#7
Hmm... if these are for Certified Aircraft (Cessna, Beech, Mooney, etc.) then you're largely wasting your time and someone's gonna be looking at a really big fine if they use them.

Just for the record, and among the many factors involved, e-clips are disapproved for new design. So that part's right out.

Because people use dental floss during installation does not make it a poor design. At the factory, you can be assured they don't use dental floss. But airplanes are not cars and are subject to many, many more rules and regulations what, you know, with them flying overhead and all. Among those regulations are configuration controls. If it ain't factory, it ain't approved.. and therefore ain't legal.

But it can get to be approved. Find a DER that can get you through the TSO/PMA process and you'll be on your way. If you can get it approved (very time consuming and very expensive), then you're good to go.


Wrat
I do realize there aren't approved and I have a set in my plane as well. The big thing about these is that you have to remove the seat to even see them. So it's not like if you get ramp checked that an inspector would find them. Yes it is for a certified aircraft but we all have to some common sense sometimes and know that the faa isn't really that concerned about a better mousetrap. They have better things to worry about and this isn't one of them.

In regards to getting them approved it isn't really worth it as there aren't enough of these planes out there to justify the cost and time to do so. The return on them isn't enough and I don't charge a lot for doing these as it is more of a hobby for me than anything else

As for the e-clip it isn't doing anything more than holding the assembly together while lowering the seat rollers down into the track. Once inside the track the track keeps everything together. The clip has no structural support at all and is just an easy way to be able to remove them or install the rollers without them falling all over the place while installing.

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wrat

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#8
Get in a wreck sometime and you'll learn differently.

Like all bureaucrats, they don't make work for themselves. But when they investigate, they investigate (at least our local FSDO does).

Nothing like having a pranged-in plane and then get socked with FAA fines on top of it.

What you do with your plane is your bizness, as far as i'm concerned. And yes, you can travel under the radar, sometimes forever. Until the day comes you can't. But you've heard all that talk before, anyway, just like the rest of us.

Best of luck, anyway.

Wrat.
 

Bob Korves

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#9
Hmm... if these are for Certified Aircraft (Cessna, Beech, Mooney, etc.) then you're largely wasting your time and someone's gonna be looking at a really big fine if they use them.

Just for the record, and among the many factors involved, e-clips are disapproved for new design. So that part's right out.

Because people use dental floss during installation does not make it a poor design. At the factory, you can be assured they don't use dental floss. But airplanes are not cars and are subject to many, many more rules and regulations what, you know, with them flying overhead and all. Among those regulations are configuration controls. If it ain't factory, it ain't approved.. and therefore ain't legal.

But it can get to be approved. Find a DER that can get you through the TSO/PMA process and you'll be on your way. If you can get it approved (very time consuming and very expensive), then you're good to go.


Wrat
+1 on that, Wrat. I was biting my tongue to keep from posting the same response. At the next annual inspection, any IA inspector worth his shingle will ground the aircraft until the approved parts are reinstalled. It is his job to find "improvements" like this. A seat sliding back to the rear stop on takeoff is not a trivial matter...

I have watched IA's carefully inspect seat rails and parts, and they take seat reliability seriously.

If your street rod fails on the way to the swap meet, you call a tow truck. With an aircraft it is often the coroner who is called...
 

KevinMaiorka

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#10
This design is a very small change from the original factory design and is not going to cause a plane to have an issue by any means. I do understand your point of view but I have to disagree with the fact that if you don't know this plane then you would never know that this wasn't factory designed to begin with.



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KevinMaiorka

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#11
+1 on that, Wrat. I was biting my tongue to keep from posting the same response. At the next annual inspection, any IA inspector worth his shingle will ground the aircraft until the approved parts are reinstalled. It is his job to find "improvements" like this. A seat sliding back to the rear stop on takeoff is not a trivial matter...

I have watched IA's carefully inspect seat rails and parts, and they take seat reliability seriously.

If your street rod fails on the way to the swap meet, you call a tow truck. With an aircraft it is often the coroner who is called...
I completely agree with your point about a seat sliding rearward on takeoff and being an issue. I have had a Cessna do that to me once and I will never forget it either.

This plane uses a pin through both seat rails that positively lock the seats into position relegating that issue to Cessna's and others with an inferior design from the factory. When you lock the seat into position the pin goes thru both sides of the square tubing and the seat rail is trapped in the middle. Only way a seat could slide is if both pins were to fail which is damn near impossible.

This is only for the rolling portion and that is all. This plane does not use seat stops to prevent it from moving too far rearward as it has never been an issue with it at all.

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wrat

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#12
Maybe I came across wrong. Often i do.

I'm not critiquing the design. I have every confidence that it is a 'better' design. Too many times, the exigencies of regulation and approval have forced the hand of engineers to compromise on an inferior design. Been there many times, myself. This is not a question of your design. I'm sure the seat is better for it. No question. No doubt some poor sap at the factory has been fighting this fight for years and years to a deaf FAA.

(They very closely resemble the IRS, you know...)

This is just a question of ever-expanding government regulation. One of my little bits of life I do are 8110-3 forms for a favorite customer of mine in China. It doesn't matter if chinamen are good aircraft mechanics or good designers or even good pilots. What matters to the FAA is the *paperwork*. That's it. And it's getting harder and harder because what with our bizjet industry getting personally trashed by the Oval Office, the FAA has less and less to do and so they're out for more points to score wherever they can get them. Be warned.

As Bob said:
I have watched IA's carefully inspect seat rails and parts, and they take seat reliability seriously.
+1. This is real. If you've not experienced it, good for you! Happy day. If you can get away with it. Good for you. It's like going 70 in a 65. You're right, they got bigger fish to fry. Right up until they don't. Then it's a very bad day.

Good luck.

Wrat
 

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#13
I completely agree with your point about a seat sliding rearward on takeoff and being an issue. I have had a Cessna do that to me once and I will never forget it either.
I've had that happen also, that instant CG change makes things interesting :eek:
 

Bob Korves

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#14
I also have no issue with the part itself, which is probably just fine. I have owned half a dozen aircraft, under both standard and experimental (exhibition and racing) registrations, and have several friends who are A&P's and IA's, so I have a pretty good idea how the system works. There is not too much wiggle room, and what there is can be quite variable from day to day and by who you are dealing with at the time.
 

KevinMaiorka

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#15
Maybe I came across wrong. Often i do.

I'm not critiquing the design. I have every confidence that it is a 'better' design. Too many times, the exigencies of regulation and approval have forced the hand of engineers to compromise on an inferior design. Been there many times, myself. This is not a question of your design. I'm sure the seat is better for it. No question. No doubt some poor sap at the factory has been fighting this fight for years and years to a deaf FAA.

(They very closely resemble the IRS, you know...)

This is just a question of ever-expanding government regulation. One of my little bits of life I do are 8110-3 forms for a favorite customer of mine in China. It doesn't matter if chinamen are good aircraft mechanics or good designers or even good pilots. What matters to the FAA is the *paperwork*. That's it. And it's getting harder and harder because what with our bizjet industry getting personally trashed by the Oval Office, the FAA has less and less to do and so they're out for more points to score wherever they can get them. Be warned.

As Bob said:


+1. This is real. If you've not experienced it, good for you! Happy day. If you can get away with it. Good for you. It's like going 70 in a 65. You're right, they got bigger fish to fry. Right up until they don't. Then it's a very bad day.

Good luck.

Wrat
I agree that they usually do have bigger fish to fry.

My ap ia is a very good friend of mine and is okay with the design that I made. So are several other I/A's that actually specialize in this airframe. I say if they are good with it then why shouldn't the faa? Of course they want the paperwork but for the small price I am charging I would have to triple that amount to pay for the paperwork and it would not be cost effective to switch to this design. If at any time a mechanic or someone else say the faa sees these and doesn't like it then it is a simple change to go back to original. I have instructed everyone that has bought a set to keep them and not throw away the originals.

Have you seen the recent trend with the faa allowing non certified avionics in certified aircraft? I think it is an awesome deal and really opens up some new doors for the aviation world regarding private pilots with their own aircraft.

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#16
I've had that happen also, that instant CG change makes things interesting :eek:
Yes, and when the seat goes back, your first instinct is to pull yourself back forward by the yoke, which you quickly figure out gives you an even better view of the sky, and then try to sort things out before you hit the ground nose first. It all happens quite quickly...
 

KevinMaiorka

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#17
My thoughts exactly Bob! It is a scary ride for few intense seconds but I also had a really good instructor who purposely pulled my seat handle one day in a c-172 to demonstrate what it is like on takeoff to have a seat slide rearward. I was really glad that he had done that so that when it did indeed happen to me on my own I knew what to do and not panic or put the plane in the ground by trying to pull myself forward with the yoke.

Thankfully I am taller at 6ft and so even at the rearward most limit of the seat I still am able to manipulate all of the controls with very little trouble so that helped quite a bit as well.

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My thoughts exactly Bob! It is a scary ride for few intense seconds but I also had a really good instructor who purposely pulled my seat handle one day in a c-172 to demonstrate what it is like on takeoff to have a seat slide rearward. I was really glad that he had done that so that when it did indeed happen to me on my own I knew what to do and not panic or put the plane in the ground by trying to pull myself forward with the yoke.

Thankfully I am taller at 6ft and so even at the rearward most limit of the seat I still am able to manipulate all of the controls with very little trouble so that helped quite a bit as well.

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I was in the RH seat when it happened to the PIC, so I was able to help sort it out without much issue, but the experience was definitely eye opening. We did not need any coffee that morning after that experience.
 
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David S

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#20
Hi Kevin,
First let me welcome you to the Forum. This is an awesome site and hope you will continue to share.

Just so I am clear, what you have improved is really an assembly aid. A method that holds the parts together while they are being assembled, and once installed the cir-clip could disappear and all would be good.

My friend is a pilot and when I met him he was flying a Lake amphibious certified aircraft. He is also an AME. I know at work he was forever bringing in some of the hydraulics for the landing gear to install new seals etc. Also I remember rebuilding the controllable pitch prop, and vaguely remember him having to get some sort of oversite.

Since then he has sold the Lake, and is currently flying experimental RV-7, which I helped him build. Next we built A waiex Y tail with the VW modified engine. And are currently building a Panther with a Lycomming (don't recall the model...narrow something??).

I am only mentioning all this because I can now relate to what you have done compared with all the decisions one has to make when building a plane from "almost clear" plans.

And yes I know there is a world of difference between experimental and certified.

Looking forward to your future posts.

David
 
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#21
This design is a very small change from the original factory design and is not going to cause a plane to have an issue by any means. I do understand your point of view but I have to disagree with the fact that if you don't know this plane then you would never know that this wasn't factory designed to begin with.



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30 years ago if an A&P (such as myself) signs off on it...it falls under repair,,"like new or better"
 

KevinMaiorka

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#22
Hi Kevin,
First let me welcome you to the Forum. This is an awesome site and hope you will continue to share.

Just so I am clear, what you have improved is really an assembly aid. A method that holds the parts together while they are being assembled, and once installed the cir-clip could disappear and all would be good.

My friend is a pilot and when I met him he was flying a Lake amphibious certified aircraft. He is also an AME. I know at work he was forever bringing in some of the hydraulics for the landing gear to install new seals etc. Also I remember rebuilding the controllable pitch prop, and vaguely remember him having to get some sort of oversite.

Since then he has sold the Lake, and is currently flying experimental RV-7, which I helped him build. Next we built A waiex Y tail with the VW modified engine. And are currently building a Panther with a Lycomming (don't recall the model...narrow something??).

I am only mentioning all this because I can now relate to what you have done compared with all the decisions one has to make when building a plane from "almost clear" plans.

And yes I know there is a world of difference between experimental and certified.

Looking forward to your future posts.

David
Yes what I made is really an assembly aid and you're completely correct that once assembled the clip could be removed if feasible and all would be well with it.

Thank you for welcoming me and I will continue to post for as long as I possibly can. I read quite a few of the posts on here before I became a member and so far I like what I have seen.

As my experience progresses (which it has since the beginning over 15 years ago) I plan on bringing more complicated projects to my table.

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#23
<big sigh>
You know, i hope this isn't too little too late, but David set the correct example.
Welcome!
Welcome to this forum. This *is* the friendly machining forum and I sometimes drop the ball in that regard, so i shall endeavor to improve henceforth.
Interested in how this all turns out.

Wrat
 

KevinMaiorka

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#24
<big sigh>
You know, i hope this isn't too little too late, but David set the correct example.
Welcome!
Welcome to this forum. This *is* the friendly machining forum and I sometimes drop the ball in that regard, so i shall endeavor to improve henceforth.
Interested in how this all turns out.

Wrat
No issue Wrat, by replying you basically welcomed me to the forum and that is okay with me.

As far as them turning out, I mailed another set this morning to a customer. I don't do many of them and I doubt I will but it is fun to do and I enjoy helping others out where a larger machine shop would shun them away due to worrying about profits. I try to share my experience and also my time by not charging a fortune to do something for someone. I will not usually do anything that is over my head but have taken on some unique projects for people. Some want a part turned down for a faucet so they don't have to replace it, or to machining a knob for a experiential air scoop on aircraft. (early project years ago) I feel that too many people are worried about making money now a days and forget that we all inhabit the same planet and that at times we should help out our fellow brothers and sisters. Of course I don't do any illegal machining regarding guns or such as one I don't have the knowledge and second I'm not up to date on the laws and don't feel like spending time at the cross bar hotel lol.

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brino

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#25
Hi Kevin,

I also wanted to welcome you to the forum.
Hopefully you don't feel like you hit too much "turbulence" in this thread. :)

I know nothing of avionics, but would be very interested in a picture of those seat rails.
I am always looking for different ways to accomplish things.
It sounds to me like your rollers are a big improvement over the factory parts.
No doubt they use plastic for low cost........and if they get to sell you a replacement set every few years then all the better.

I try to share my experience and also my time by not charging a fortune to do something for someone. I will not usually do anything that is over my head but have taken on some unique projects for people. Some want a part turned down for a faucet so they don't have to replace it, or to machining a knob for a experiential air scoop on aircraft. (early project years ago) I feel that too many people are worried about making money
I wholeheartedly agree with that!
I know some people here get their income from machining and I respect that, but for me it it strictly a hobby.
I may never know the process of quoting a job, and the limits of having to turn a job down.
However, it gives me the liberty to work for free or for favours and also to believe that "no job is too small".
Many times I do work literally for beer.

One thing I need to get better at is estimating the value of some things. Generally people that value the service/parts want to "pay" me for my time and materials. If the materials are "new" then setting a price is easy, however, often the materials are scrap from something else.

Anyway, enough philosophy, I need to get out and work on some automotive brakes........

Have fun!
-brino
 

David S

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#26
<big sigh>
You know, i hope this isn't too little too late, but David set the correct example.
Welcome!
Welcome to this forum. This *is* the friendly machining forum and I sometimes drop the ball in that regard, so i shall endeavor to improve henceforth.
Interested in how this all turns out.

Wrat
Hi Wrat it is awesome that you took the high road and welcomed Kevin. We are all passionate about some things and your passion came through.

I think it is up to us members to keep us all on the "Friendly" voyage, without having the moderators having to step in.

On the other hand we should feel free to contribute when we feel safety could be compromised.

David
 
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