triger wheel for ms3x
Turbo Mini Forums

id like to have the shop mill my front pulley for the hall sensor is there any specific measurements for depth or size? i be leave it should be a 36:1 wheel just wanted to check if i had them measure the diameter of the pulley and divide that into 72 equal sections 36 high (non milled) and 36 low cut away parts? with the missing tooth in the 90 degrees out spot ?

I think the best thing to do is get someone to mill 36 slots in your MPi crank pulley.
This should be pretty straight forward for engineering workshop (mill every 10 degrees on a turning table).
I think they used a 5mm cutter (not sure, can measure if you want).
Then after you have complete construction ready, including VR sensor position, determine what tooth to take out with a dremel.

Have a look at this thread:
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=379085

Dazed and Confused....

i see cheers mate ill ask them about it before they balance the rotating assembly
so about a 5mm end mill on the turn table every 10 degrees
it will be on the two part "S" pully and damper ring id rather have it cut to use than but a different one since mini is brand new

I think I used a 7mm cutter when I did my S pully,

Any pictures of that S pulley?

Also, looking at it now I think I should have had the machine shop make the cut-outs a bit deeper (towards the multi-V part). Not sure if the 'edge' that is left will create noise in the signal.
Guess will have to wait and see; can always rework it.

Dazed and Confused....

theres a couple of the first and second page here...

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=119064

If you are using a Hall switch (rather than the more usual VR sensor) you can, in my experience, get away with a much lower valley depth than a VR would like. You did say hall switch in the first post ???

General rule of thumb for a VR is valley depth as close as possible to width of tooth.

But if you are using a Hall switch, look up its datasheet (the datasheets are usually available on the Web unlike generic VR sensors) and it will tell you.

The Hall switches I'm using for TC are quite happy with a 1/2 valley/tooth width ratio and have been tested on my lathe up to a 3.5mm sensor/wheel gap (a gap a VR sensor could never achieve).

Schrödinger's cat - so which one am I ???

Good info Rod,

Dazed and Confused....

thats the pulley + balance/dampener ring ill be using

yes ill be using two hall type sensors the threaded body type from DIY auto tune for cam and crank

so im after a 5-7mm wide cutter and 2.5-3.5mm depth with a 36-1 patten cutting the missing one by hand once the bracket is made decided where it should go