Hegner HDB lathe - changing belt - removing spindle

[howlingbaboon]

Hi Guys,

I'd like to replace the belt on our Hegner lathe as it slips with the lightest cuts and it's on full tension. I've got hold of a belt with matching specs and now have to figure out how to put the thing on. I'm going to have to remove or at least loosen the spindle as the belt is captive. It seems like the only place to start are the allen bolts around the front of the spindle and the one close by on the side. Apart from that, there's a grub screw on the stepped pulley. Anyone got any experience with these machines and jobs like this? I'm just trying to gather what advice I can before starting the job as I don't want to end up doing more harm than good . Any advice, most appreciated! Cheers

Dave

[Derwent Woodturning club]

Hi Dave,
I can't offer any advice specific to the Hegner lathe but one thing that has caught out more tnan one of my students and club members is that many pulleys use two grub screws, one on top of the other to lock the pulley to the shaft. So if you find the pulley is still tight after removing the grub screw, have a look for another one lurking underneath.

[Sandy]

Hi Dave,
That's a very good tip you've highlighted as it's fairly common practice.
Thanks for sharing.

[howlingbaboon]

yeah cheers I never would have thought of that one, good tip!

[Derwent Woodturning club]

Hi Dave,
I had another thought about my first comment about the double-decker grub screws. Are you sure it's the belt that's slipping on your lathe? Could it be the pulley slipping on the shaft? If you aren't aware of the doubled up grubscrew, it is easy to think you've got it nice and tight to hold the pulley to the shaft but all you've done is tighten the locking grub screw, the one underneath may not be tight on the shaft. You need to take out the top grubscrew, tighten the lower one to hold the shaft, then put the top grubscrew to lock the first one in place.
May be worth checking as it may save you the hassle of changing the belt.

[seventhdevil]

try cleaning the belt and pulley first as it may have got a tiny bit of lubricant causing the slip.

[howlingbaboon]

Good points guys! I'll try both of those solutions before I go breaking stuff! Cheers
Dave

[howlingbaboon]

The good chaps at Hegner, despite no longer producing or supporting these lathes, have dug up this set of instructions and diagram for me. For anyone in the future with similar problems, I've condensed them into the PDF that you will see attached below. If you need a bigger diagram, just look on the 2nd page.

I'll try and have a go this afternoon and will let you know how I get on.

Cheers
Dave

[howlingbaboon]

So Here are my conclusions:

Removing the spindle was very straight forward and didn't have to get involved with the circlip on the outboard end as it slid out fine with a bit of WD40.

The most likely cause of the slippage was the gunked up pulleys and belt so hopefully a good go with an old toothbrush fixed it (only sanded on it so far so will see if it still slips when I make the next big bowl)

These lathes don't have a 2nd hidden grub screw on the pulleys

I probably didn't need to remove the spindle but It gave me a good chance to clean and lube everything (not the belt and pulleys! )

Thank you all for your advice!

[Derwent Woodturning club]

Good news Dave. Thanks for the update.