MetalworkingFun Forum

Greg, any reason you didn't cut the keyway first and then spot the holes from the sprocket holes? 

I didn't realize that the sprocket would look like that, with the side guides, I just thought it would look like a reg. chainsaw sprocket.
The dia. is way bigger than a reg. saw sprocket so I see where you get the necessary chain speed.   

Steve

Its a pretty small bolt circle, might have got away with spotting them. I seem to have better luck going off dimensions when I can. Couldn't figure a way to index it off the keyway to locate the holes.
The sprocket is about 4 inches in dia, have it on the shaft backwards there, they have holes out the side to funnel sawdust out of the pockets.

(05-08-2015, 08:24 AM)f350ca Wrote: [ -> ]Couldn't figure a way to index it off the keyway to locate the holes.

Greg, I  was thinking cut the keyway anywhere on the shaft, slip the sprocket on and spot the holes with a transfer punch and Bob's your Uncle.
But! maybe the sprocket didn't come with the bolt holes already in it ?
Never mind.

Steve

So, you got lucky in the shop?

Actually on a couple of occasions. If the women don't find you handsome they should at least find you handy.

The sprocket had the holes Steve, think its heat treated, probably never drill it. What I meant was I've don't have great luck picking up the mark from the transfer punch on the mill, the holes are pretty tight to a 6 mm bolt.

Not many posts here today so I'll through up todays progress.
Made the clamp plate for the bar, the bolts will be replaced with studs and nuts. Still need to make a chain catcher for the outside of the sprocket. From what I've read its really not pretty when one of these chains break at 8000 fpm. Oregon recommends a guard around it and a chain catcher, just a shaft extension outside the sprocket for the chain to wrap around. We'll humour them and make one.
Not as interesting a picture as Ed's new mowed lawn but here goes.

Hi Greg . 


Really thick question coming   ( I freely admit knowing nowt about chainsaws ) ,,,,,,,,,,,,,,,,,hows the sprocket work ,what I mean is how dose it drive the chain ? 



Rob 

Rob, permit me to try and make myself useful here.

[attachment=10674]

The lower "teeth" engage the sprocket in the "slits" shown in Greg's pic.
The upper teeth engage the wood and cut it.
All my chainsaws have a much smaller sprocket that resembles a gear and doesn't have the "sides"
the chain is guided by the "bar".
Hope that helps.

Steve

Thanks Steve, that explains it better than I would Rob.