ok.. Nebie question.

I am still learning to fly with my trainer and a TT46pro. But while I was at My Mother-in-laws I saw a couple old weedies in her barn. Tom(brother-in-law) said take'em if you want 'em... So I did. Turns out Father-in-Law (died about two years ago) wasn't good with the little engines, so there's probably nothing wrong with em. When he couldn't get em to go anymore he would go get a new one.

I stripped em down, and had to cut the case of one, cause it was the back plate. They both look in relativly good shape, and are already broke-in for me! I think I can figure mounting, and knocking down the fly-wheels a little... (and balnacing) but my qustion is What exactly is a prop adapter... Can I make one?
I have a degree in Homer Simpson Engineering and am pretty resourcefull... could even get the use of a metal lathe if it was needed...

Is it really as simple as making something to hold the prop on the shaft?? What Am I missing?
Is there a How-to sight somewhere that explains this a little better?

(Are 'big' props put on differently than the one on my 46??)

Thanks...
(told ya I was a newbie!) :stupid:

do a few searches for 'weedwacker conversions'
i am sure you will find something.

dont take any chances with big engines

daver29 . . . . Re: Prop Adapter...

Contact Scott Baldridge here: [email protected]
He makes what you want!

take a piece of round alum about the same diameter as the prop hub and thread it all the way through. make it long enough to hold the flywheel in place and still have threads left for the prop bolt. you can knurl the face or install a couple of pins to engage the prop and keep it from slipping.
easy enough?

dave

Zagnut,

The shaft on the engine I'm looking at isn't treaded all the way down... It sticks out of the case about 4.5 to 5 inches and is tapered slightly at the base (shere the keyway is for the flywheel). It is threaded about 1.5 inches of the end, is 'noched' on one side (not round) and it bored and tapped in the center.

So If I understand the concept correctly I need something that will go over the shaft all the way to the fly-wheel, to hold the flywheel in place and come out far enough to make sure my prop is clear of everything, and make the prop bolt tighten up to hold everything together. right!? and of course all has to be balanced and strong enough to take the abbuse.

essentially one big spacer!... seems simple enough!
What am i missing. (some seem afraid of this if its not bought!?)

would help if you psted the make/model of the weedie you're talking about, i pretty much explained what's needed for an engine that just has a few threads sticking out past the flywheel.
sounds like you have a long shaft engine (ryobi?) that has the clutch shaft as an integral part of the crank, in this case the prop hub really is just a big spacer. nothing to be afraid of if you have a lathe to use.

dave

Zag,

I don't know the model... but the weedie was a true weed-eater
green plastic case etc. The shaft originally had some do-hicky at the end that took the flex shaft to the weedeater head, then behind that was the clutch, then the pull start rope thingy, then the flywheel. The green plastic case was an integral part of the back of the crankcase, so I cut that down to save the backplat... this piece that I cut down is also the Carb mount. and the muffler is right above/below that (depending on which way is up! LOL)

Is there a specific place to look on the crank case or somewhere for model id? I already tossed the parts of the case that I am discarding...

Another question... what is the thickness at the shaft of the props that I am likely to try on this (dont want to make my 'spacer' too long).


Dave,

P.S. thanks for all the help!

sounds to me like a ryobi manufactured engine with the rear intake/rear exhaust but not sure, a pic would help.
prop thickness depends on brand/pitch/dia/material if you have 1.5" of thread then you shouldn't have a problem leaving about an inch for the prop.
maybe someone else knows just what engine you've got and would be a bit more helpful?

dave

ZAGNUT,

Thanks again for all your help...
I will try to post a pic when I get home tonight.

Dave

Didn't have the bar stock for my hub adapter (Ryobi Long shaft). Took a hole saw in drill press and very slowly cut a 1.75" hole in some VHMW plastic 1" thick, the plug (1.61") plug got dressed up and drilled out to 3/8" and tight slip fit it on the shaft, it left enough space for a spinner back plate and a 16-8 MAS prop.
16 & 18" props have a hub diameter range up to 1.5 to 1.65"+/ -.
The hub thickness ranges from .61" (16" wood) to .81" (18" composite)

Hole saw also make alum spacer plugs that can be edge dressed.
One large washer in front of prop and single nut and lock nut if available. Don't forget the Locktite!!

Lap the flywheel taper with some valve grinding compound. Give a nice tight fit to assist the keystock in holding the flywheel.

The VHMW is light (it floats but very dense.) Check out a plastics supplier for specs.