Hi guys,

Could you tell us ( or share some photos on) how to make a prop hub with a magnet in/on it?

I am converting some engines which will work with elec. ignition but I need to see some examples of prop hubs with magnets in it.

I have read some treads about making hubs from alu. but I couldnt find a clear photo about that (that shows the magnet in/on the hub) . I have visited CH, RC ignitions sites already.

Thanks and regards.

Zafer

just drill a radial hole that's not too tight for the magnet and go slow to get the depth dead nuts...drop the magnet in, add a drop of green locktite or CA and then stake it in place with a punch or rusty nail...gently!


dave

you have to put the magnet in with the rite configuration ( pole position ) or the ign. will not trigger

I drill the hole undersize and press fit the magnet , Not a tight fit just enough to have drag with a little JB weld on the side first

Ken
Do you just pass each side of the magnet past the sensor to see which pole triggers the sensor? Can passing the wrong side by the sensor damage the ignition in any way? The magnets I have (from CH) are marked for side to mount next to sensor but others would not be so marked.

no it won't damage it , it just will not fire
Yes you pass it over the hall sensor some times the marks on the mags will disapear I also use C&H mags but sometimes by the time I handle them a few times and clean the oil and such the marker will be gone .

Ignition will not fire until it just passes the magnet. I drill and press it in with a drill press and put some epoxy in the hole. If you drill it to big then you will need to punch it with the point of a tap or something sharpe. Punch it in four places around the magnet (12 oclock 3-6 and 9 oclock)
I might have a pic i will have to check and see.


Thanks
smallplanes

One photo is better than one thousand words........ ( So you all know that I didnt understand a thing from all of the above)[&o]

Edited: What will be the size of the magnet ( and the hole to be drilled on the hub) . I understand that the hole should be a round one. Is only one hole ( and the magnet) enough?

Some photos will really make this clear... and I must confess that My English is not so bright...

Thanks and regards.

Zafer

I don't have any photos, but what I do is machine the prop hub. Then machine a collar that is a nice slip fit over the outside of the rear portion of the prop hub. I mount the magnet in the ring then hold the ring to the hub with a set screw. I adjust the timing by loosening the set screw and rotating the collar.

Mark

Ok Zafer these are just for you

Hear is a few pic's i might need to take another for you. I made the prop hub in the pic its on a 46cc poulan chainsaw. Time it at 28 degs.



smallplanes

here is a couple more just incase=

Zafer, could you tell us some more about the 'TYPE' of electronic ignition you plan to use. You fellas with more experience correct me if need be, I think there are some electronic ignitions available or that can be homemade that require more than just a single magnet passing a sensor. If may be possible that Zafer is planning on using one different than say the CH type that I use.

3 w is useing one that uses 2 magnets the poles are switch so one turns it on and the other turns it off , but i think it is the senser that makes the difference

Hi guys,

Thank you very much for the photos, So I know how the magnet is positioned generally.

I have a JWE ignition which I bought on EBAY. I have also some kind of ignition for 2 cyl. 3W engines. Here is the photo of the ignition. I think it is new. I plan to use this with a 21 cc Robin Weedeater engine ( must be a kind of Fugi - but it is nice, light and with 2 rings) which has a place in side the mounting plate. It has Walbro WY 25 carburator with 10,54 venturi . Maybe I change it since it lacks high end needle. ( I have also WT 20 and WA 46) I also saw a photo of a round magnet put on the shaft(back side) directly. But in that case I dont see how to adjust the timing....

Anyway, the only thing I need now is a hub with magnet.

Thanks and Regards.
Zafer

Here is the photo of rear mounted magnet on a G38 Zenoah.

Regards

Zafer

you do not have to adjust the magnet if it is put in the correct place for timeing to start with

The ignition in your photo looks like one of the older 3w jmo .

This is my OPS 30 Maxi that I converted to gasoline for a while, it didn't make a happy gasoline engine.

FYI, CH also has a smaller 1/8" diameter magnet. It came in handy on a couple of projects I did.

I made this hub so I could use tru-turn type spinners, it's in two parts because it was supposed to go on with the orginal ignition but when I broke the coil mount off I decided to go with a cd ignition.

Here's a shot with the spinner.