av8tor1977

My Feedback: (6)

Hi,

Just thought I would share my method of making prop hubs. It's fairly easy, and very cheap.

I use a drill press to drill holes all around the center hub of the magneto. Then I break out the center part and grind it round and smooth. This part will fit on the tapered part of the crankshaft, and be drilled to accept the magnet for the ignition. On the one I just finished, it had a protrusion in the center that perfectly fit into one of my hole saws, and I used the hole saw instead of drilling all the holes. It was super easy.

On some of my conversions, I have been able to use the original magneto bolt to hold the prop on, as it had a long thin shoulder. I just drilled the prop(s) out to accept this shouldered bolt, and it had full thread engagement and held the prop securely against the hub I made above.

On others, I just use a piece of 1" solid round aluminum to make a prop hub. Just cut the aluminum to the length you desire, drill and tap it to bolt onto the crankshaft on one end, and to accept the prop bolt or stud on the other. You can grind flats on the new hub to accept a wrench for tightening it.

This method solves the problem of how to make the tapered part that fits onto the crankshaft for our prop hubs. The aluminum can be found cheap at a metal supplies store. Just ask for "drops". That's what they call pieces of metal that are left after cutting metal for another purpose, but are too short for them to use. If you can't find it there, buy it from Aircraft Spruce & Specialties in California. (www.aircraftspruce.com) They list a foot of 1" 6061 aluminum rod for $2.90, and 1" 2024 aluminum rod for $4.90 a foot. A foot would make a bunch of prop hubs!!

Take care,
AV8TOR

kiv

You can also use a 1 1/4" or 1 1/2" hole saw. I use it in a lathe, but a drill press will also work fine if you can center it cleanly. You have to be a bit careful to avoid hitting the magnet, thoough. Eats the teeth up right now!

Costs a few bucks more, but for a guy, investing in a tool can always be justified, right?

Kiv

KenLambert

My Feedback: (106)

we have been doing that for a few years now works great .I cut mine out on the lathe Kenneth

airbr

My Feedback: (4)

It would be greatly appreciated if you could post some pics of that, it would help.

Nunotec

Dear AV8TOR


You say that is easy to make a prop hub with a piece of solid round aluminum.
In my Opinion is needed a lathe with a dial indicator , to guarantee the concentricity of the hub.

I think we don´t wan´t unpleseant vibrations , do we?

Tell me about your opinion

Ps. I am converting an 40cc engine, and i am doing a Prop adapter , i removed the flywheel , because i want to use CDI ignition instead of magnet , it is for my own experiences just!
When i got it finished i will post pictures

I have got is this moment a Ryobi and a poulan featherlite converted both to swing propellers , with Flywheel both


Best Regards

Nuno Monteiro from Portugal

av8tor1977

My Feedback: (6)

Yes, you really need a lathe to make prop hubs. It is all but impossible to try to make one with a drill press; you need a lathe.

When I make prop hubs and use the magneto center, I cut the magneto center out with a hole saw using my drill press. I then chuck that into my lathe using a cut off piece of an old crankshaft to mount the magneto center and I dress the piece perfectly round. Once it is round, it is also a good idea to chuck the piece itself into the lathe, and make a clean up cut on the face where the prop hub will mate. Then I make a prop hub to use that goes up against the round magneto center. It takes a little time, but less time than setting up the lathe and making a really true prop hub with an internal taper to match the crank.

Note: When doing this, cut the center of the magneto out as large as possible without hitting the magnets during the cut. Then don't dress it down any further than necessary on the lathe. If the diameter of the magneto center gets too small, it can break right at the key way when tightened down on the crankshaft.

Sorry, I don't have a picture of the magneto center to show, but here's one of my prop hubs that is made with an internal taper; no magneto center.

AV8TOR

Nunotec

Hello Dear AVI8TOR

How are you?

Thank you very very much for your last reply freat in deed!!


Here it goes some pictures , for you to get an idea of what i want to do

The hub is not finished YET!!

To this moment everything was made with 0,05 ( milimeter) readed in dial indicator ( sorry i don´t work with imperial units)

It is hard for me to get more precision with my chuck i don´t know why... perhaps Unimat ? maybe...

I think won´t be a major problem , if doesn´t work i try by another process or in a bigger lathe with a compound slide.


Best Regards

Nuno Monteiro from Oporto Portugal

av8tor1977

My Feedback: (6)

If you use the other 3 lathe chuck pieces that have a longer surface to clamp onto the outside of the hub, it is much easier to get the hub dialed in centered and it stays centered better while you are working the piece.

Looking good so far!

AV8TOR

ZAGNUT

My Feedback: (1)

if the hub is done in a single setup runout will be non existent...you can leave your indicators in the drawer.

av8tor1977

My Feedback: (6)

That's the way I try to do it all the time, though I have been guilty of double checking for run out midway through making a hub just because I am such a worry wort perfectionist...

AV8TOR

Nunotec

FINALLY JOB DONE HERE IT IS MY FINE WORK ART


40cc Weed eater Engine

Nunotec

Dear AV8tor Finally i made my job here it is :

40cc Weed eater Engine