Teeter bolt end play

[Alan Coats]

How much end play should there be on the teeter bolt/bearing? I measured mine today and it is about .023". Is that about normal?

Thanks,
Alan

[chuter]

Hi Allen,
I was told .002 to .010 of an inch when I bought my Dragon Wings.

[Alan Coats]

Thanks, Michael.

That sounds more like what I would expect.

It looks like I could reduce the end play by machining the end of the adjuster that is used to center the teeter bar in the rotor head. The bearings clamp to the adjuster when the teeter bolt is tightened up.

The other option would be to find thin washers that would fit between the shoulders on the bearings and the rotor head. Seems like they would be hard to find.

The rotor head is a Calumet. I can't seem to find them on the net.

I would appreciate any suggestions.

Thanks,
Alan

[chuter]

Alan,

My RFD rotor head came with some washers to fit between the shoulder of the "hat" and the rotorhead like you described. It looks like they were cut from soda cans. (not sure how they did that)

I found some at Ace hardware that would work. They're pretty thick, can't remember right now how thick, but they might help you get the clearance down.

[Doug Riley]

The accepted state-of-the-art material is aluminum beer can. Cut with scissors or razor blade.

[Alan Coats]

It sounds like I was able to describe my situation well enough for you guys to understand what I meant! The terminology is all new to me.

We have a washer cutter where I work, and I bet they have some shim stock. I'll calculate the thickness of shims I need and get the guys in the shop to cut me some washers.

Thanks again,
Alan

[gyropilot]

The accepted state-of-the-art material is aluminum beer can. Cut with scissors or razor blade.
Precision cut shims can be purchased at a reasonable price online from McMaster-Carr (http://www.mcmaster.com/). They're available in just about any material.

http://www.mcmaster.com/catalog/110/gfx/small/98055ac1s.gif

For a plain steel shim assortment (various thickness) to fit your teeter tower bushings, go to their web site and type in the part number in the search box for more info and pricing:

3/4" ID x 1-1/8" OD = 3088A934
7/8" ID x 1-3/8" OD = 3088A935
1" ID x 1-1/2" OD = 3088A936

Regards,

John L.

[gyromike]

You are da man, John!

I need some too.

[Aussie_Paul]

Ah Doug. Many an end play problem and rotor tracking has been fixed in the field with the old "Alloy beer can" trick.

After you have drunk the beer from the can to get the material, the rotor shake was gone no matter which way you put the shims!!!!!!!!!!!!!!:):)

Aussie Paul.:)

[Alan Coats]

Now, how could I not think of McMaster-Carr - they have everything!

The beer can thing seems like more fun, though.

Thanks,
Alan

[Jonvee]

I just purchased a RFD head and it has shims made of soda cans. I have used beer can shims to fix the tracking on my prop. I would like to see an FAA accident report after they pull apart a machine and find beer can shims. Could be funny.

[Chuck Irby]

Alan, I took all of the slack out on the outside of the teeter tower and made sure there was just enough room between the top hat bushings and the rotor for it to swivel freely. This is the way Rod Reed suggested that I do it and it worked for me. So I have no play outside the tower and maybe .002" inside.

[Chuck Irby]

Alan, I was thinking about my Teeter bolt end play just a few minutes ago and it dawned on me that the way I have it set up right now is not the best way for my teeter tower. The bolt holes through the two plates that make up the Dominator teeter tower have needle bearings in each hole. This is a clear indication that the designer, maybe Ernie, meant for the teeter bolt to teeter in the tower.

The way I have mine set up now, the rotor will teeter on the teeter bolt. Therefore, I will change mine back to the way it was, so that the bearings can be utilized as they were meant to be.

[MikeBoyette]

Come guys my dad uses only the best soda cans to make the washers. They are made from Sam's soda cans. They are made on a tool that friend of his made years ago. I quess it's a punch, you put the can material and wack it with a mallet and there you have a washer. Dad uses soda cans because they are a consitant thickness and they are cheap. Sometimes it is better to use the K.I.S.S. method of engineering rather than the latest greatest.

[Doug Riley]

Mike, amen.

Chuck -- yes, use those bearings as they were meant to be used. Keep them clean and greased. The whole teeter bolt assembly, from the head of the bolt through the two "hat" bushings and the central teeter block, should be a rigid, non-moving stack of parts, clamped tightly together by the teeter nut. All movement takes place between the barrel of the "hat" bushing and the needle bearing.

This is much better than the old systems on early Bensens, which used plain metal-on-metal pivots for the teeter hinge.

[Chuck Irby]

Thanx for the conformation, Doug.

[mceagle]

When making the shims, use material from "light" beer cans. Shims from full strength beer cans are too heavy.
In Queensland Australia they make a beer called XXXX. (four X) Apparantly they have trouble spelling Beer.