Pulleys

[Monkeybusiness]

I have recently bought a new flail for the digger, and had a bit of an issue 3 hours into its first job.

The drive pulley came loose (which only became apparent once the belt cover was removed) - once re-tightened it appears to run fine so it could just be an oversight during production. I haven’t got another job immediately lined up for it to give it some proper work to ensure the issue doesn’t reappear.

My question refers to the compression fit of the pulley on the shaft - the pulley centre is machined for a keyway, but the driveshaft is plain/unkeyed. The retailer says this is correct - I’d have thought the pulley centre shouldn’t have a keyway if it was designed to mount a plain shaft? Would this matter?

Cheers

Dan

 

[V8Druid]

I have recently bought a new flail for the digger, and had a bit of an issue 3 hours into its first job.

The drive pulley came loose (which only became apparent once the belt cover was removed) - once re-tightened it appears to run fine so it could just be an oversight during production. I haven’t got another job immediately lined up for it to give it some proper work to ensure the issue doesn’t reappear.

My question refers to the compression fit of the pulley on the shaft - the pulley centre is machined for a keyway, but the driveshaft is plain/unkeyed. The retailer says this is correct - I’d have thought the pulley centre shouldn’t have a keyway if it was designed to mount a plain shaft? Would this matter?

Cheers

DanView attachment 9843View attachment 9844

it's called a taper lock MB .... needs to be reasonably tight ... especially as there is no key to stop any rotational slippage .... some sort of torque on that on start up ... can well see why it's drifted out to the end of the shaft
is that a new, new falil or just new to you ... i'd expect to see a keyway TBH ... what's the supplier say ?

 

[doobin]

Druid beat me too it. I’d want a key way. That’ll quickly destroy the mating surfaces of both the pulley (cheap) and the shaft (expensive!) if you run it loose for any amount of time.

 

[V8Druid]

I'd guess some one's forgotten to machine that shaft and the guy assembling it has thought fk it, banged it together and shipped it out

 

[Monkeybusiness]

New new, and the mating surfaces don’t look great already tbh.
The supplier claims it is supposed to be like this - I’m not convinced and think the keyway has been overlooked personally.

 

[Komatsu]

New new, and the mating surfaces don’t look great already tbh.
The supplier claims it is supposed to be like this - I’m not convinced and think the keyway has been overlooked personally.

“Not fit for purpose”...... take it back

 

[Monkeybusiness]

To be fair, I’ve just found pics of the demo machine they lent me earlier in the year and that doesn’t appear to have a keyway either.

 

[V8Druid]

To be fair, I’ve just found pics of the demo machine they lent me earlier in the year and that doesn’t appear to have a keyway either. View attachment 9845

so that pulley is on the motor shaft is it ?? most motors are keyed as std ..... as Ollie says ... sling it back at 'em before it causes even bigger issues
taper lock is not designed as a drive ... the key provides that ... it keeps the pulley in position ... as has already been said it won't take long to wreck the shaft and pulley centre

 

[Quattromike]

I’d say the taper lock is designed to be used with a key hence they have a key way in them. You can get shaft locking hubs without key ways but they are normally more expensive. Looks like they are trying to use the keyless hub setup but went cheap and used the cheaper version of the taper lock bush to save costs.

 

[Rob65]

If I had a new machine that had been built like that I would be having stern words with the supplier and if they would not sort the problem it would be going back to them for a refund

If it were an older machine I think I would be drilling a hole that was half in the pulley and half in the shaft, tap a thread in it and insert a bolt, maybe with a bit of weak Locktite.
Rob

 

[V8Druid]

If I had a new machine that had been built like that I would be having stern words with the supplier and if they would not sort the problem it would be going back to them for a refund

If it were an older machine I think I would be drilling a hole that was half in the pulley and half in the shaft, tap a thread in it and insert a bolt, maybe with a bit of weak Locktite.
Rob

I'd be tempted to drill a long grub screw into the pulley/shaft, half and half in the end of the shaft in a similar manner to the extraction screw in the taper lock .. fit pulley absolutely bang on, drill, tap and insert grub screw with, as you say a weak Loctite, or even red Hermatite, which goes off reasonably stiff, just to secure it ........ only after giving the manufacturers serious grief about it not being fit for purpose first ... and invoice 'em for all the time spent fannying with it, if they didn't acknowledge the issue

 

[doobin]

I'd be tempted to drill a long grub screw into the pulley/shaft, half and half in the end of the shaft in a similar manner to the extraction screw in the taper lock .. fit pulley absolutely bang on, drill, tap and insert grub screw with, as you say a weak Loctite, or even red Hermatite, which goes off reasonably stiff, just to secure it ........ only after giving the manufacturers serious grief about it not being fit for purpose first ... and invoice 'em for all the time spent fannying with it, if they didn't acknowledge the issue

I'd be more tempted to do it properly and remove the shaft and mill a keyway.

 

[Gecko]

Personally I'd like to see a key in there, but if not, I'd put it together with a high strength loctite like 601 (between the bush and the shaft).
Unlike a bearing mounted with 601 the taperlock bush will crack the joint when the pulley and bush are separated and it'll be easy to disassemble.

 

[Komatsu]

I'd be more tempted to do it properly and remove the shaft and mill a keyway.

I’d be more tempted to get them to sort it out then there is no risk of them turning round and saying that you have voided the warranty of it.

 

[V8Druid]

I'd be more tempted to do it properly and remove the shaft and mill a keyway.

agreed ........ if one has the capability ...... my suggestion is a very easy one with basic tools

 

[V8Druid]

I’d be more tempted to get them to sort it out then there is no risk of them turning round and saying that you have voided the warranty of it.

also agreed ...... but if no joy was had ... it needs summat doing 'fore it gets completely bollo-ed and gets expensive

 

[V8Druid]

Personally I'd like to see a key in there, but if not, I'd put it together with a high strength loctite like 601 (between the bush and the shaft).
Unlike a bearing mounted with 601 the taperlock bush will crack the joint when the pulley and bush are separated and it'll be easy to disassemble.

fair point .... but the start up torque on that is going to be SIGNIFICANT !! it should have a mechanical drive

 

[V8Druid]

If I had a new machine that had been built like that I would be having stern words with the supplier and if they would not sort the problem it would be going back to them for a refund

If it were an older machine I think I would be drilling a hole that was half in the pulley and half in the shaft, tap a thread in it and insert a bolt, maybe with a bit of weak Locktite.
Rob

just realised you were mooting the same as I was Rob

 

[Komatsu]

also agreed ...... but if no joy was had ... it needs summat doing 'fore it gets completely bollo-ed and gets expensive

If I had no joy with them, I’d be going else where to buy one.

 

[Monkeybusiness]

They've told me to tighten it all up and keep using it, and are sending me some new belts.
If it comes loose again it will be going back for a refund as not fit for purpose - the issue is logged with them and I’m following their instruction for now.