Slowing down a small crane hoist

[Jixer]

Hi,
I got a 250kg motorised crane hoist off eBay, but the thing is far too fast.
What is the best way of slowing it down, either with pulleys or elektrikery gadgetry.?
Thanx
Jixr

 

[knighty]

photos?

if you add a pulley onto it... so the wire comes out of it around a little pulley with a hook on it and then back to the hoist.... it'll go 1/2 speed and lift twice as much

(as long as the wire it has is good with twice the weight)

 

[carbonarc]

Have a look at a Belay Pulley to reduce hoist speed.

 

[Agroshield]

Have a look at a Belay Pulley...

Just to note that 'belay pulley' has quite a specific meaning in climbing (mountain or tree) and is not what the OP needs. I am only saying this so OP does not use that as a search term and potentially buy the wrong item.

A plain pulley that increases the mechanical advantage will do the job.

---

How is the hoist powered? 230v single phase AC?

If so, there is not much can be done on the electrical front; a complicated fix might be a three phase motor and VFD.

Is it a cable hoist or a chain hoist?

A pulley suitable for a chain could be challenging to locate.

 

[Jixer]

This is the hoist , yes 240volts

I need 1/4 to 1/3 current speed

 

[Woody.v8]

Can you not run a snatch block? It would double the pull and half the speed.

 

[jmp49]

They normally come with a separate snatch block, and a little hole to hook the main hook in while its in use, you can see it hooked into the hole in this image of one. Does yours have the hole somewhere and your just missing the snatch block perhaps?

 

[zzr1200]

404 page

 

[Agroshield]

A possible (but very limited) option is to use a smaller drum on the hoist.

If you have something 100mm diameter spinning at X rpm, something 50mm diameter spinning the same X rpm will pull in half the cable in the same time. Were it possible, winding the string around an M6 bolt would go real slow.

The disadvantage is that as the cable layers build up the advantage is lost, but if you shorten the cable so start with a nearly empty drum, it could help.

In addition, there is a minimum bending radius for a cable of given diameter (this could be reduced a little by swapping the cable for dyneema)

 

[Jixer]

Thanks guys, I will try some sort of block and tackle arrangement when time permits

 

[Agroshield]

...you can see it hooked into the hole in this image of one.

We might wish to consider that the OP's one states 250kg on single fall and the (visually identical) one you show states 250kg on two-fall.

Something in one listing or the other needs a pinch of salt. I hope that your one is underselling.

 

[jmp49]

We might wish to consider that the OP's one states 250kg on single fall and the (visually identical) one you show states 250kg on two-fall.

Something in one listing or the other needs a pinch of salt. I hope that your one is underselling.

Yes, I would guess the seller is a drop shipper and sells electric winches one day and hair restorer the next and has no domain knowledge about either. Its just it was a clear picture of the hook hole & I think the same brand.
Besides we're talking about rebadged chinese winches here, Ive got a parkside 250kg one of these that struggles to pull 100kg in snatchblock configuration. Its mounted so it can pull non running cars onto the 4 post and even for that its a bit meh when you come to pulling landrovers etc along the flat.

 

[Pete.]

photos?

if you add a pulley onto it... so the wire comes out of it around a little pulley with a hook on it and then back to the hoist.... it'll go 1/2 speed and lift twice as much

(as long as the wire it has is good with twice the weight)

The tension on the wire would be the same because you would double the lift capacity and also the number of falls. The thing to watch is that the structure of the hoist and its suspension system (the hook it hangs from) can cope with the doubled load.

 

[knighty]

I was always told make sure it's good for twice the weight (or a decent amount by the time you have it around 6 pulleys etc.)

in case it binds up somewhere etc.

 

[Erie Fred]

I was always told make sure it's good for twice the weight (or a decent amount by the time you have it around 6 pulleys etc.)

in case it binds up somewhere etc.

If it 2 blocks, it's gonna fall.

 

[Agroshield]

If it 2 blocks, it's gonna fall.

I think the red circle through the square loop in the pictures might be an automatic cut out to prevent this.

Considering its place of manufacture, it would be prudent to confirm it actually does what it is supposed to, both mechanically and electrically.

---

Another possible consideration for its use is the length of the pendant cable, as it is considerably shorter than the wire rope. That governs where you can stand when using it.

 

[Erie Fred]

I think the red circle through the square loop in the pictures might be an automatic cut out to prevent this.

Considering its place of manufacture, it would be prudent to confirm it actually does what it is supposed to, both mechanically and electrically.

---

Another possible consideration for its use is the length of the pendant cable, as it is considerably shorter than the wire rope. That governs where you can stand when using it.

Had one the other day, 30 ton bridge crane.
All (3) limit switches failed, two block in an instant, and it all came crashing down.

I have a few of the cheap chinese hoist's like the OP's.
That limit switch is pretty sketchy, and they get out of alignment very easily
unseen up there.

 

[oldbikedavey]

Got one of those hanging around, but tend to use chain hoists instead, on account of their predictability and subtlety.
The Vevor ones are adequate, if not as slick as the Tractel ones....