Big Red Pull Knob

[Marauder]

Anyone know where to get a replacement mixture knob to fit a quadrant style? Mine felt apart on me today and although I glued the pieces together, it ain't gonna last. Any ideas?

[201er]

Apparently Seth broke his too. You guys should try to get a bulk discount lol

[DrBill]

I broke one on my Beech and made a replacemnet out of wood.  Worked and looked great.

BILL

[Marauder]

I broke one on my Beech and made a replacemnet out of wood. Worked and looked great. BILL

Thanks Bill. I wondered about using wood. Looks like a Dremel project in my near future.

[bumper]

I'd make it out of aluminum on the lathe, mill indents if desired, anodize red.

 

bumper

[Rwsavory]

http://www.aircraftpartsandsalvage.com/advanced_search_result.php?keywords=Control%20Knob&page=1&sort=4a

[Marauder]

I'd make it out of aluminum on the lathe, mill indents if desired, anodize red. bumper

What kind of shop in the non-aviation world would be able to do this?

[Marauder]

http://www.aircraftpartsandsalvage.com/advanced_search_result.php?keywords=Control%20Knob&page=1&sort=4a

Thanks for the lead. Looks like their Mooney stuff is pretty slim pickings at this time.

[NotarPilot]

I got excited because I really thought this was going to be a discussion about flying LOP.

[Rwsavory]

Thanks for the lead. Looks like their Mooney stuff is pretty slim pickings at this time.

I thought maybe you could use another brand in its place.

[201er]

I got excited because I really thought this was going to be a discussion about flying LOP.

It is. Only LOP pilots yank hard enough on the red knob to actually break it off. ha

[Jamie]

Looks like a perfect application for a 3D printer.

[Marauder]

Thanks for the lead. Looks like their Mooney stuff is pretty slim pickings at this time. I thought maybe you could use another brand in its place.

I hadn't thought of that!

[Marauder]

Looks like a perfect application for a 3D printer.

Hmmm... How does one got about finding someone who knows how and is willing to do this?

[N201MKTurbo]

To make it in a 3D printer you will need a model in Solidworks or ProE. There are places that have a laser scanners that can produce the model from the old part. Find some mechanical engineering student somewhere and give him some gas money to make the model for you. He might even have access to a 3D printer.

 

A 3D printed part will not look as good as a machined part. They don't have a very smooth surface.

[carusoam]

If you broke the real one, the 3D printed one won't last either...

Polymer strength comes from long, entangled, molecules, aligned in the direction of the implied stress.

The 3D printers are good at building a 3D image, but their history has been one of making brittle products, slowly.

Applying layer over layer of an easy to melt polymer inherently builds a weak structure of weak molecules.

Wow, I never thought I could opine on polymer science here!

I would consider calling the folks that make the owner supplied parts and see if they have a knob that goes with the rest of the mixture control that they sell.

Or don't yank it so hard...

Best regards,

-a-

[Marauder]

Or don't yank it so hard... Best regards, -a-

You know what they say. "Yank on your knob for 48 years, it is bound to break"

[bumper]

What kind of shop in the non-aviation world would be able to do this?

 

In the "non-aviation world", a hopefully local machine shop and a plating shop. Though admittedly it would probably not be cost effective compared to anything off-the-shelf.

 

I have a non-CNC  "hobby" machine shop as well as an anodizing set up at the hangar and would nonsensically spend way too many hours making the &%$# thing if I needed one :c). 

[Jamie]

To make it in a 3D printer you will need a model in Solidworks or ProE. There are places that have a laser scanners that can produce the model from the old part. Find some mechanical engineering student somewhere and give him some gas money to make the model for you. He might even have access to a 3D printer.

 

A 3D printed part will not look as good as a machined part. They don't have a very smooth surface.

 

You don't need anything that fancy. Google sketchup, blender, etc. work fine, and you can have someone else print it for you... sculpteo.com, shapeways.com, etc.

 

True the parts aren't perfectly smooth, but a friend at work just bought a home 3D printer, and the high resolution mode is very impressive. A little bit of sanding and it'd be ready to go. Laser scanning is probably overkill for this part. Just eyeball it and check the dimensions against a laser printed paper outline, or use calipers / micrometer if you must.

 

The are other ways to produce this part, obviously, but if you have the interest, a 3D printer would work great.

[tomn]

You know what they say. "Yank on your knob for 48 years, it is bound to break"

The entertainment value alone on this site is worth the price of admission! I'd have felt sorry for him if it was a blue knob....just sayin...

[Rwsavory]

I hadn't thought of that!

Of course if you use a Piper knob you will lose 10 knots.

[DrBill]

What kind of shop in the non-aviation world would be able to do this?

If you live near a University with a Mechinical Engineering dept or Mech Engr Technology dept,  call and ask for the shop manager.  He may put you intouch with a student or do it himself. You have to pay for "shop" time if it is a state supported school.  Better to find a student who will make it for you as he can use the shop.

Luckily I retired from such a school and I can use the shop to make all kinds of good stuff.

 

BTW, I agree with the strength of 3D parts.  I made the trim piece for the fuel selector for my "E" and thickened the walls to make it more robust.  Works great.

 

BILL

[Marauder]

I hadn't thought of that! Of course if you use a Piper knob you will lose 10 knots.

My understanding is that like all of our Mooney anatomy, if I installed a Piper knob backwards, it will be faster

[Seth]

Actually, Alan helpe me fix mine at the Mooney fly in at GED.  We unscrewed it, put the bolt back on, tighetened it, and good to go.  Mine did not fall apart, a nut just came loose.

 

Thank you Alan!

 

-Seth

[DrBill]

Found this knob in my hangar box today. Left over from my Beech. Guess I sold the plane with the wood knob and had this waiting for it to break.

Looks similar to the one pictured.

$20 will get it shipped to your door.

 

Bill