Upgrading sheaves on mast base

[dgadee]

I want to put ball bearing sheaves in place of the current ones (some of which are stuck). Sheaves are 50mm and the pin size is around 15mm. Anyone done this? I can see several possible ways but you may know a better method.

 

[Rum Run]

I want to put ball bearing sheaves in place of the current ones (some of which are stuck). Sheaves are 50mm and the pin size is around 15mm. Anyone done this? I can see several possible ways but you may know a better method.


View attachment 196622

Those tack-welds make my teeth itch........
Summat like these Ronstan Race Sheave - Acetal Ball Bearing - 28mm(1-1/8") OD - RF1020: Pulleys: Amazon.com: Industrial & Scientific in the correct size, plus some decent machined 316 stainless parts as pins. I would probably go for making something like clevis pins but with grooves for circlips.

 

[rogerthebodger]

Yes I replaced the plain bushes in both my mast top and mast bottom pullies with stainless steel sealed deep groove ball bearings got from mast bearing suppliers.

I bored out the pulley to suit the deep groove ball bearings that has a bore ot match the spindle supporting the pully.

I got a local engineering works to machine the pullies to a push fit for the ball bearings

 

[dgadee]

Yes I replaced the plain bushes in both my mast top and mast bottom pullies with stainless steel sealed deep groove ball bearings got from mast bearing suppliers.

I bored out the pulley to suit the deep groove ball bearings that has a bore ot match the spindle supporting the pully.

I got a local engineering works to machine the pullies to a push fit for the ball bearings

Can I clarify? You bored out a sheave to accept a bearing of the correct axle size?

That was one of my options. The other was welding washers in or to the 15mm holes to accept the usual 10mm pin these sheaves have.

 

[rogerthebodger]

In my case My axel was 12 mm so I used a searing with a 12 mm bore and bred out the pully to allow the O/D to be a push fit in the pully.

There could be bearings of different o/ds to correspond with your axel das or you could adjust the axel to suit the bearings and fit washers or bushes to suit the holes in the side plates.

Many ways to skin that cat

You could also use needle roll bearings if the sizes suit you better

You could also use angular contact bearings back-to-back

https://www.bing.com/images/search?...tainless+steel+ball+bearing&form=IGRE&first=1

Its mostly about you can obtain local to you

 

[Humblebee]

Remove the existing sheaves and replace with a shackle, then choose whatever bearings you want?

 

[dgadee]

My plan is now: get blanks made on a punch, weld them in place, then drill for clevis pin axle. Seems simplest way forward.

 

[garymalmgren]

RE; Remove the existing sheaves and replace with a shackle, then choose whatever bearings you want?
The lines are fed down the mast internally. Shackles and "floating" blocks won't work.

Easiest way is to source sheaves with the same dimensions (with bearings if possible) , grind off the welds and refit and re-weld.
There is probably a good reason that they were welded to start with,; space or binding onto each other somehow.

gary

 

[Daydream believer]

Remove the existing sheaves and replace with a shackle, then choose whatever bearings you want?

Explain please

 

[dgadee]

RE; Remove the existing sheaves and replace with a shackle, then choose whatever bearings you want?
The lines are fed down the mast internally. Shackles and "floating" blocks won't work.

Easiest way is to source sheaves with the same dimensions (with bearings if possible) , grind off the welds and refit and re-weld.
There is probably a good reason that they were welded to start with,; space or binding onto each other somehow.

gary

Yes, but I would worry about welding damaging acetal sheaves. Stainless ones are about £50 each and acetal should do the task.

There is plenty of space for clevis pins.