How to use thrust bearing to make pulley block spin?

[gasket999]

Hi all.

Should be an easy fix, but I'm just struggling a bit.

I have a pulley block (actually part of some gym equipment), which has a fixed eyebolt on the top. I'd like to make it so that the eyebolt can spin freely.


There isn't a lot of thread left on the existing M10 bolt, so planning to buy one with a longer thread off eBay and cut the thread down to suit.

My brain keeps trying to tell me to use 3-part thrust washers on each side of the black bracket - but not sure if there's an easier way. Maybe just using a pair of Oilite M10 penny washers of maybe a standoff.

Any suggestions for an easy solution? It is only used for vertical lifts and weight up between 25kg and 150kg.

Thank you.

 

[Hood]

Two thrust bearings would be the best, one on top, one below and tighten the nut fully.

 

[Hood]

if there will be force only in a downward direction then you may get away with one thrust bearing and just leaving the nut slightly slack.

 

[James1979]

Like these is what I would use. You can have a couple of pairs but I only have one size....

 

[James1979]

Failing that is there enough room to leave existing eye in and put a swivel inline with it?

or just a swivel eye:

Swivel Eye Bolts for Lifting and Lashing - LiftingSafety

Swivel Eye Bolts for Lifting and Lashing - A vast range of swivelling/pivoting lifting points/eyes from the world's industry leaders.

www.liftingsafety.co.uk

Bit spendy but it’s rated

 

[tom2207]

would two ptfe washers do , or do you actually need thrust bearings , probably one on the bottom would be plenty with a small amount of free play in the assembly.

 

[gasket999]

Wow - thanks for the quick responses!

PTFE may well do the job actually, but may as well fit a true bearing by the sounds of it.

James - thank you for the photos and the offer - Simply Bearings are just up the road from me so I can pop through to collect.

So a pair of 3-part needle bearings look like the ticket - these ones from Simply Bearings look the part and will physically fit. Two for a fiver.

Glad I wasn't missing a really obvious solution.

 

[tom2207]

Wow - thanks for the quick responses!

PTFE may well do the job actually, but may as well fit a true bearing by the sounds of it.

James - thank you for the photos and the offer - Simply Bearings are just up the road from me so I can pop through to collect.

So a pair of 3-part needle bearings look like the ticket - these ones from Simply Bearings look the part and will physically fit. Two for a fiver.

Glad I wasn't missing a really obvious solution.

and a good spreader plate/ washer under the nut , to get the good out of the bearing

 

[hotponyshoes]

If you are struggling for space you could fit a button head bolt from the inside out and use an eye nut rather than an eye bolt

 

[Al Strachan]

and a good spreader plate/ washer under the nut , to get the good out of the bearing

like my old man always says, you've paid for the whole shaft of the hammer, so use it !

 

[tom2207]

two small taper rollers would do as well , slightly bulkier though .

 

[tom2207]

like my old man always says, you've paid for the whole shaft of the hammer, so use it !

A guy I used to work with ,,, who had a '' powerfully developed lower chest '' read that as big beer belly , used to say ,
'' you need a big hammer if youve got big nails '' ,

always made me smile ,, still does actually.

 

[hotponyshoes]

Or you can get ones ready made
"Swivel eye bolt"
The load rated ones can get a bit pricey though

 

[gasket999]

all sorted and ordered.

Hotponyshoes - great shout re: the eyenut. I'd just ordered the bolt, but I'll keep that idea as backup if the bolt turns out to be the wrong size.

Right:

Slim locknut @9mm + the needle bearing @4mm + thickness of bracket @2mm + 2nd needle bearing @4mm = 19mm.


So I've ordered a M10x20mm eyebolt (direct from china for £2.58 delivered - shocking that its so cheap, good job I'm not in a rush).
A pair of AXK1024/AS1024 Budget Needle Roller Cage with 2 AS Washers 10x24x4mm for £5.66

So £8.24 and a perfect solution. Nice when it all works out.

Thanks again for the tips guys. I would have fitted thick ball bearing thrust washers if I hadn't seen the above.

 

[Brad93]

Bronze would be a far more reliable option.

 

[tom2207]

Or just undo the nut half a turn and let the wire spin it back on its own ,,, almost seems rude to mention it at this point though.

 

[Agroshield]

...you could fit a button head bolt from the inside out and use an eye nut rather than an eye bolt

Using an eye nut limits your options for stopping the whole thing unscrewing and dropping on your head.

About the only way with a nut is to use loctite. It would be very difficult to peen the end of the bolt over because the eye is in the way.

Even with the eye bolt and thrust bearing, I would use a new nylok and loctite to be sure to be sure. For really critical stuff, I'd drill and split pin as well.

The photo of the original is not great as the thread from the bolt does not fully engage the nylon of the existing nut.

 

[8ob]

I would have opened up the hole and used/trimmed down an M10 shoulder nut using a ball thrust both sides of the hitch and used the original M10 eye bolt

1280 × 960

with one of these either side

 

[gasket999]

Using an eye nut limits your options for stopping the whole thing unscrewing and dropping on your head.

About the only way with a nut is to use loctite. It would be very difficult to peen the end of the bolt over because the eye is in the way.

Even with the eye bolt and thrust bearing, I would use a new nylok and loctite to be sure to be sure. For really critical stuff, I'd drill and split pin as well.

The photo of the original is not great as the thread from the bolt does not fully engage the nylon of the existing nut.

Tip re loctite noted - I’ll do just that thanks.

yes - wasn’t too happy with either the eyebolt or pulley bolt as neither engaged with the nylon area of the nut. Have ordered a longer eyebolt and have a longer pulley bolt too that allow for full engagement along with new nylon nuts when I come to assemble I’ll use loctite too.