I am a newbie mounting my prop and plastic spinner to my engine. The directions for my Tower Trainer 40 tell me to turn the prop counter clockwise until it fits snugly against the little knobs on the back plate. I have to assume this is while facing the engine because the instructions don't specify. If I follow those directions, though, then the screw holes for the cone don't line up with those on the back plate. If I rotate the prop in a clockwise direction, however, (which is left to right or I'm losing my mind), then when the prop meets the knobs on the back plate, the screw holes do line up so I can put the cone on...

I'm not sure if there's a mistake in the directions or if I'm just not getting it. Regardless, now I'm paranoid about the prop flying off. I guess I have three questions, then:

1. What is the purpose of the little knobs on the back plate?
2. How important is it to have the prop snug against the knobs?
3. Does it really matter what side of the knobs the prop is snug to (other than the fact that the cone won't fit as in my case) I'm certainly not a physicist, but the way it looks now, it seems like when the prop is turing in a counterclockwise direction while the engine runs, those knobs won't do anything to help hold the prop on...

Thanks for any help you can give me!

The knobs on the backplate are to rest the back end of the prop to them so the spinner lines up with the screw holes. The prop does spin counter clockwise when the engine is running and the knobs do not prevent the spinner from flying off. The only sure way to keep your prop from flying off is to tighten the prop securely to the engine. I use the prop wrench to get the prop tight then I follow up with a crescent wrench to make sure the prop is very tight against the backplate. Be careful not to tighten wooden props like this because it may crack the prop in the middle. Out of 40 plus flights I have not had one fly off yet (knock on wood). Just be sure when starting your engine to not stand in front of it (for many reasons) and set it to idle. Then get behind the plane and put your legs between the LE of the stab and the TE of the wing and rev her up.

another good tip is to set your prop before tightening horizontal to
the wing on the engines compression stroke.. So if you"never say this"
dead stick your prop will stop inline with your wing.. Maybe saving your
prop and or more....

You'll be turning the prop CLOCKWISE to get it onto the backplate. You might have to actually "screw" the prop on. Careful, though, you don't want the prop to fit so tight to the shaft that you have to work to screw it on, you just want it to slide on, or screw lightly on. I learned this the hard way. It can be very difficult to get the prop back off if you have to work hard at screwing it onto the shaft. Anyway, just push the prop LE up against the little knobs, and tighten away. As stated earlier, those are so the spinner will fit onto backplate after all is tightened down. More than likely, these little knobs will break off during the first few flights. Mine always do. I think the torque of the engine shears them off on the prop. Now I just line the prop up with the reminants of those little knobs. Fun stuff!

The prop nut holds the prop on. However, those little plastic nubs are guides, I think. If you look inside your spinner, there are no receptacles for those knobs. I believe that as you twist the prop on, you will be looking to have each blade going between the plastic nub and the screw receptacle. Then, when you put the spinner on, after the screw shafts are lined up, make sure the blades do not touch the sides of the spinner. There will be hardly any clearance, but there should be some. If the blades touch the spinner, loosen the prop nut and rotate the prop as needed to make sure the blades don't touch. When set, tighten everything up.

Hope that helps.

Raideron,
That may be the single most anal thing I've ever heard. Whatever works for you!!

I always cut those nobbies off!!! [sm=bananahead.gif]

2slow...... I think that says it all... You do have to think tho..

I think you orienting your spinner a certain direction on an engine pretty much says it all. you'd be loads of fun to fly with. I'm through with this conversation before the flaming begins. But, I guess you've already started that.

:Quote: You do have to think tho :Quote:

Thanks for the help and advice, all. Obviously my fears were unfounded. Never can be too careful when dealing with propellers. I'd hate for it to fly off and hit my neighbor's cat that thinks my garden is its litter box... [8D]

It appears 2slow the only flaming in this thread has been perpetrated by you. Possibly I am also anal but could you explain just what is wrong with orienting a prop to avoid brakage when deadstick and a possible noseover. Perhaps I,ve been wrong all these past 48 years.

John

2Slow... As my #8 post suggested... Think about this...

Say your engine dies well flying.. The prop will stop just before the
compression stroke, The forward motion of the plane/air will hold the prop
there also.. Hence if the prop is tightened down just before the compression
stroke(inline with the wing) it will stop there on a dead stick and on *landing*

If it's tightened without setting it and it happens to be in a vertical position
(inline with nose wheel) it will stop there also........MMmmm..... Now lets see..

Would you not say if it did that..

You would have a greater chance of hitting the prop on a dead stick landing??

Which will give you a greater chance for damage to the prop, engine and or
plane with a nose over...??? Simple... Easy... "GOOD"... Tip.... Huh.....


I started the Flame.... Read the posts, And who called who what because of
"not" asking why that would be correct. And "not" knowing a good tip, Instead
of...

My Dad ALWAYS said.... **Think** before you speak... It Works

I would have replied with a PM... But you stated not to PM you anymore.. So..

Be Good and Have fun....

Maybe it's just me, but anytime someone puts a out beside a comment, then that should be considered a joke. Do I think it's anal? Yes, but again, like I said, whatever works. And the comment was made with a slight of tongue. Is it good advice? Only if you follow it. That means it's good for some, and not good for others. Isn't that the reason this board exists? Someone should be able to disagree with your advice without you getting all upset.
Oh, and the PM stuff? Your PM's headline was "gotta problem?" That's chicken crap. That is not what PM is for! Is that how you act at the field? If someone is giving you a hard time about something, you go over and say "Gotta problem?" I don't think so. And you sure wouldn't do it to me, so don't do it on some message board.

Hey 2Slow2Matter, the only thing anal on here seems to be you!!!!!! Gimp!!!

Just glad I dont fly at your field.

Raideron, good tip. I'll try and set my prop up like you said.

Well I should not reply But just one more thing... I can agree to disagree
that's no problem.. But that depends on how it's said.. On a forum or in
person.. You can COUNT on me asking if it's a problem.. Always have
and always WILL!.... Perfer to talk it out, drop it and/or go separate ways
But as you said..... What ever works!! Have a Great Day!!