Front Pulley Issues

Status
Not open for further replies.
Have you tried a standard Norton front engine sprocket ( a known good example ) on the crankshaft taper to confirm it is the shaft's taper is the problem it maybe that the belt pulley internal taper is incorrect ? That key is sus if it falls out .
 
HRD said:
Have you tried a standard Norton front engine sprocket ( a known good example ) on the crankshaft taper to confirm it is the shaft's taper is the problem it maybe that the belt pulley internal taper is incorrect ? That key is sus if it falls out .
Click to expand...

Like I said it fit perfectly on the other crank. I don’t know where a standard sprocket is, probably buried. I’ll see if I can find one.

New key on the way from Old Britts.
 
interesting situation...

i just put my primary back together. i can't recall any specifics about the key but my old one was a sloppy fit and it looked like somebody had been filing on it. so i ordered a new one. the new one was not a tight fit in the shaft... so how tight are they suppose to be (thats the part i can't remember)...

thanks
 
850commando said:
interesting situation...

i just put my primary back together. i can't recall any specifics about the key but my old one was a sloppy fit and it looked like somebody had been filing on it. so i ordered a new one. the new one was not a tight fit in the shaft... so how tight are they suppose to be (thats the part i can't remember)...

thanks
Click to expand...

I believe the primary purpose of the key is to locate not hold the pulley/sprocket. The taper and nut should do the actually holding.

Anyone want to correct me?
 
Snug fit for keys. Not drive fits. One doesn't want them to chatter with vibration. Some applications use wedged keys or shimmed keyways to lock auxiliary items onto shafts to prevent movement. So many ways to screw a pooch that it boggles the mind.
 
jbruney said:
Snug fit for keys. Not drive fits. One doesn't want them to chatter with vibration. Some applications use wedged keys or shimmed keyways to lock auxiliary items onto shafts to prevent movement. So many ways to screw a pooch that it boggles the mind.
Click to expand...

I’m glad I’m not a pooch.
 
Is there enough material on the pulley, and enough width for the belt, to face the back of the pulley down the make the taper effectively smaller? Would be an simple turning job
 
myjota said:
Is there enough material on the pulley, and enough width for the belt, to face the back of the pulley down the make the taper effectively smaller? Would be an simple turning job
Click to expand...

Interesting approach. The belt width is exactly the same as the pulley so you can't reduce the pulley width. At the front there's not a lot of room.
 
swooshdave said:
Interesting approach. The belt width is exactly the same as the pulley so you can't reduce the pulley width. At the front there's not a lot of room.
Click to expand...
What width is the pulley/belt width?
With the norvil kit I believe you can run a 32 mm or 30 mm belt on a 32mm wide pulley, I'm not certain on this though
Cheers
 
I dont think myjota means the whole back face of the pulley, just around the hole where it mounts.
 
swooshdave said:
I believe a beer can will be too thick.
Click to expand...

Average beer can wall is 0.004. That's pretty thin unless you still have some steel cans around. I'm a big believer in creative play, but mostly I like the idea of having a beer while pondering how to sort out the problem.
 
rvich said:
Average beer can wall is 0.004. That's pretty thin unless you still have some steel cans around. I'm a big believer in creative play, but mostly I like the idea of having a beer while pondering how to sort out the problem.
Click to expand...

Is there an advantage to brass over aluminum in this case?
 
Brass is most suitable of the two. Aluminum is soft by comparison. Steel would be best.
 
myjota said:
Is there enough material on the pulley, and enough width for the belt, to face the back of the pulley down the make the taper effectively smaller? Would be an simple turning job
Click to expand...

Good idea and if facing off the back made it fit but left it too narrow then the outer guide plate could be shimmed to give the width back. Just an idea, or would it throw up other issues?
 
Dommie Nator said:
Good idea and if facing off the back made it fit but left it too narrow then the outer guide plate could be shimmed to give the width back. Just an idea, or would it throw up other issues?
Click to expand...

Overly complex compared to shoving crap in the gap or getting a blank pulley machined to the right taper.
 
Last edited:
Don't you folks the other side of the pond still have food in tins/cans? They are mostly still steel. Baked bean cans have provided me with the odd steel shim over the years.

Aluminium wouldn't be tough enough I reckon.

Ian
 
Status
Not open for further replies.

Similar threads

S
  • Locked
Radial clearance, belt drive front pulley
Replies
1
Views
493
Fast Eddie
Fast Eddie
Chris
  • Locked
Timing disc for front pulley
Replies
1
Views
602
norbsa48503
N
Back
Top