Hi y'all,

This is me Mody again with a new question and topic. My question is.

With my 2 planes Hangar 9's P51 Mustang PTS and GP's Escapade, I'm using metallic prop nut and using the APC 11X6 Two-Bladed props. I push the prop through the crank-shaft of engine, infact I turn it anti-clockwise to slide through the crank-shaft of engine and then I directly use the metallic prop nut to tighten the prop, I don't use any washer like the prop goes in first then washer and the last one is prop nut to tighten it.

Is it a good practice to use a washer? Using washer makes a difference or not? If I'm not using washer before the prop nut, is my motor in imminent danger?

Please shed your experience light.

Thanks

Mody

Hi,

The motor isn't in any danger but anyone infront of the motor when it is running may be. The washer is to spread the load from the nut to ensure pressure across the widest area to both hold the prop on and stop potential cracking of the propeller hub. Without the washer the forces are concentrated in a very narrow area of the prop hub immediately behind the prop nut.
Many years ago I had a wood prop on a control line combat model that was too thick at the hub to allow the washer to be fitted, so I just used the nut. One day on starting the prop fractured at the hub and stuck into the ground immediately below the model.

Your Choice,

Colin

The washer will help spread the force to a larger area of the prop center. Without the washer, more force will be centered on a much smaller area which could cause a failure if the situation is just right. I would personally use the washer.

I'm gonna go ahead and use the washer.

Guys thank you very much for your advices. Further advices are welcomed. Best bet is to use washer. As far as anything drastic may happen, it can happen anytime while plane's in the air or on the ground.

Mody

Prop washers supplied with some engines are fairly thick. I have substituted a thinner washer from my parts bin.

If you are using a spinner nut such as this:

http://www3.towerhobbies.com/cgi-bin...&I=LXE158&P=RF

There is absolutely no need for a washer. I use a lot of these and and infact the machined in nut face is superior to a typical washer, they are intended to be used without a washer.

John

Make sure you center the washer on the prop before tightening the nut. The nut on my OS 95 has a tapered end that automatically centers the washer as you tighten the nut. If you are just using something like a spinner nut and you don't center the washer (if still using one), you can get vibrations throughout the entire model.

I use these prop nuts like John is showing plus a couple of different types. On some planes these look good and work great. As John stated, no washer needed, they are designed to be used without the washer.

I have been building and flying models for 57 years, the last 37 years RC. In all of that time I never heard of not using a washer with a spinner nut. You learn something new all the time.

Bruce

DJ if you have to center the washer before tightening the nut, you have the wrong washer and should replace with a factory washer. The purpose washers that come with most engines are not neccessarily related to common washers of the same size.

For example engines that use the popular 1/4/28 threaded crank use a sized washer that is not the same as a common 1/4 inch flat washer which is much to loose.

Landeck I know what you mean and its always a great feeling when you pickup some snippet along the way.

Machined spinner nuts were the domain of high performance users in controlline speed, glow powered free flight and RC pylon untill around twenty years ago when the sport flyers started demanding them.

I consider them an absolute must in the training environment as hugh time savers and safer than the common plastics. For training those plastic spinners should be discarded for the flight time stealers they are.

Well,

Now I'm kinda perplexed whether I should use the washer or not. As per Dsegal yeah, my washer came with engine as one engine is Evolution .46 PTS other one I purchased was Magnum .46 XLS. The washer I have, has back side flat and front side is little arched/curved or concaved. Naturally flat side would be touching the prop and lil curved side would be touching the prop nut. I'm also attaching the pictures of My Mustang as well as Escapade. If you may noticed there is a little bit slit between the prop nut and the washer. I have now installed washer on both of my planes. I flew my Mustang without washer did not encounter any problem of spreading the pressure all around prop or confining the pressure at one spot.

Please clarify me, do I need washer or not, or if I may get the thin washer for me Evolution .46 PTS and Magnum XLS .46.

Thank you and pix are being attached for y'all to look closely.

Mody

I don't use washers on mine. There is a lot of contact area between the prop nut (I use Dubro Spinner Nuts) and the prop. I would be afraid that the little bit of contact area between the prop nut and the washer would make the prop nut come loose every time you applied the starter.

The prop nut you are using in your pictures will be just fine without the washer. It is a large diameter nut which spreads the force over a large surface area all on its own as others have pointed out. When I originally said that the washer was necessary, I assumed you were talking about the small hex nut that came with the engine.

Ditto,

Cheers,

Colin

mcline, ChuckW, Crash Campbell

You guys have much more experience and knowledge than me. I respect your advices. I'm gonna do as you say. Roger that. I I CAPTAIN

Only prop nut is gonna be used gotta loose 'em again[:@]

Thanks and happy flying.

Mody

Using the spinner nuts you have posted the pictures of you do not use additional washers. Agine no washers.

Thanks John,

I've replaced the washers, so no washers just spinner prop nuts

Mody

On your setup there Armody I don't think a washer is necessary. However, out of experience [:@], I found out why I will always use a washer. One day after taking of the cowl to clean the engine, I forgot to put back the washer when putting the prop on. As I tightened it, I found that it still goes and goes - when I looked down for inspection on what was going on - I was starting the turn the nut right into the 'plastic' of the prop. The washer stops this from happening aswell.

That will not happen with a Spinner nut which is designed to function without a washer. No one is suggesting that washers be omitted when using an ordinary nut.

John

Korps,

Thank you very much for a great suggestion, well that is also one factor where nut is shearing through the prop lol . You have seen the pix I posed, for that kinda prop nut which the term used spinner prop nut, I don't need a washer. I used it without washer and did not have any trouble, but after looking at the pix by many experienced people, I'm better off without washer on those prop nuts.

Happy flying and I'm gonna do the maiden of my Escapade, last week my idle was not set up pretty well the way I wanted and I tried to run after the plane and stepped onto my brand new escapade[] snapped the wing and aileron[&o]. Thanks to flyer in my club Harlin such a great multi-talented guy, I don't think there is anything he does not make, he fixed my plane as good as new, Thank God, it was not so badly damaged, but this Sunday I'm gonna do the maiden of my Escapade. Scattered thunderstorms are expected but we gotta fly and I hope we dont have rain. Hate to wait a whole week[:@]

Mody

That is why I said on his setup it's not necessary. I was just refering to my incident in the case that perhaps if someone else was reading this regarding the same question but with an ordinary nut in his setup.

I should have been more specific sorry.

Korps no need for any apologies And it was I who probably should have read your post a little more carefully.

John

John,

I am using the stock washer and nut that came with the OS95AX. The washer's hole is slightly larger than the diameter of the prop shaft. So the washer does not center initially when you mount it in front of the prop. But when you thread the nut onto the prop's shaft, it will automatically center the washer as you tighten the nut.

DJ I suspect what you have something similar to this with a shoulder nut and sized washer and of course this is yet another variation among others.

John

Yes these are the washers I used to use when I was using hex nut.