# Heavy-Duty Pulley Blocks



## brino (Oct 17, 2021)

Years ago I made a 2" receiver carrier for my 10,000 Warn winch to fit my truck :
https://www.hobby-machinist.com/thr...d-you-do-in-your-shop-today.14637/post-352173

Recently I needed to have some heavy pulley blocks to change the directions of pull. My father in law wanted to move his shed.
No pictures of the shed or the move, but here are the pulley blocks I made.

I did NOT like any of the commercially available pulley blocks for two reasons:
1) the radius of the pulleys was _way_ below the minimum bend radius of the 3/8" aircraft cable on the winch, and
2) most had grooves in the pulley that are NOT made for 3/8" cable so they would not support the cable, but make it go "flattish"
Both of these issues can cause the cable to stretch unevenly and result in a permanent "set" that means the cable gets warped/twisted and never lays straight again.

My pulleys are 8" diameter and are made from 3/4" thick plate steel. They were plasma cut and then cleaned-up.
First I tried cutting the 3/8" groove on the mill with an arbor in the chuck on the rotary table, but the threaded chuck would unscrew when cutting! 
So I bolted them down with straps to the t-slots in the rotary table. The bolted straps only gave about 150 degree cut before re-positioning. 
Waaaaayy too slow!
So I switched to the lathe.........they just barely fit on my 9" South-bend lathe. (sorry no pics, I was too busy!)
With the lowest speed, the compound pointed backwards and everything locked that could be, I managed to finish the job.....with minimal chatter....

The side plates are 3/8" thick plate steel, plasma cut and then barely cleaned-up of the sander..... this is not a precision tool.
The pulley axle holes were drilled up to 31/32" and then reamed to 1".
The pulley axle pins are 1" diameter stainless shaft with grooves cut for the e-clips.
The bow-shackle holes were drilled to 7/8". The shackles are rated 6.5 ton.
The side plates were tacked together and then welded in two MIG passes. It doesn't show in the photos, but the weld areas were rotary wire brushed before welding...I should have used a flap wheel.

Remove the shackle, and the two side plates hinge to allow the cable to enter. Then hinge back and replace the shackle.

Long term, I am considering modified pins with a zerk fitting recessed into one end (below flush) with a blind hole down the centre and blind cross-drilled in the middle of the pulley.

Pictures below to show that it really happened!  

-brino


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## Ulma Doctor (Oct 17, 2021)

nice work @brino


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## mattthemuppet2 (Oct 17, 2021)

wowsers, that's some serious fabrication!


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## woodchucker (Oct 17, 2021)

I'm worried the stainless will be up to the task. If it is, certainly the zerk and grease before you load it up with tonnage.
I would have done a 4140, or 4130.. ss is generally soft, and your metal is sought of soft, so 2 softs... gall...
grease please...

also if you do put a grease fitting in, maybe put a 4tpi thread on the shaft just a little deep to channel the grease.. but don't go to the edges, only give a little run or put a groove as a stop


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## cathead (Oct 18, 2021)




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## Eddyde (Oct 18, 2021)

Wow those are some seriously strong looking blocks! Nice job!


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## Braeden P (Oct 18, 2021)

wow thats a good chisel if it can cut 3/4 inch steel!


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## brino (Oct 18, 2021)

Braeden P said:


> wow thats a good chisel if it can cut 3/4 inch steel!



It's all in the technique!    

-brino


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## 682bear (Oct 18, 2021)

Very nicely done!

-Bear


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## Just for fun (Oct 18, 2021)

Good job! 

Tim


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## Ulma Doctor (Oct 18, 2021)

be sure to lube the SS pin with MoS4 grease or other extreme pressure grease of your choosing , to prevent galling of the stainless


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## brino (Oct 19, 2021)

woodchucker said:


> I'm worried the stainless will be up to the task. If it is, certainly the zerk and grease before you load it up with tonnage.
> I would have done a 4140, or 4130.. ss is generally soft, and your metal is sought of soft, so 2 softs... gall...
> grease please...





Ulma Doctor said:


> be sure to lube the SS pin with MoS4 grease or other extreme pressure grease of your choosing , to prevent galling of the stainless



Yes, thanks.

I could also see (if there's any problems in the future)
i) replacing the stainless pin with something else, or 
ii) boring out the pulley centres for a roller bearing.

-brino


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