Pillar drill return spring

[MadNick]

Afternoon,

Would anyone have an idea on how to repair this -



The spring popped out of its housing and I cant put it back it! Its impossible to put the tension back into the damn thing.

Any suggestions or comments would be very welcome.

Nick

[75Plus]

Hi Nick,

You can use a lathe to rewind the spring so it can be put in the housing. Start with a piece of suitable round stock and saw a slot in one end, chuck it up in the lathe,. Make another bit to hold the other end and place it in the tool post. slowly, by hand, using the chuck key, wind the spring, advancing the cross slide as necessary, until the cover will slip over it. Now release the spring slowly until it is captured inside the holder.

Joe

[MadNick]

Love it!

Many Thanks

Nick

[sparky961]

I had pretty much the same thing happen when I was exploring my new mill/drill/lathe purchase many years ago now.  I made up a slotted piece pretty much like Joe has described here but I went a different route and drilled a hole through a plate that the slotted piece fits through, and drilled another hole for a pin in the same plate.  With the plate held in a bench vice, I used two wrenches to carefully wind the spring until it was tight enough to fit back into the case.

I still have the slotted piece still but the plate has long since been used in another project or scrapped.  From what I recall, I turned the shoulder on my lathe but cut the flats and slot with an angle grinder.





-Sparky

[MadNick]

Thanks Sparky,

All sorted now. I used the actual slotted pin from the drill after taking the 3 arms off and putting it in the 4 jaw chuck.

Wound it up beautifully with the toolpost wedged against the end to keep its shape - I held the end with a pair of molegrips until it was small enough to slide the retainer over it.

I wore protective glasses and thick, leather welding gloves all the way through through - It gave me the willies to think about what could happen if it came undone suddenly.

Nick

[sparky961]

Nick,

Glad it worked out for you, but in general you want to avoid wearing gloves near anything that rotates with significant torque/momentum.

-Sparky

[75Plus]

I have had lots of experience working with this type of spring. While pillar drill return springs are about twice the thickness of those used in clocks they are only about half the width so I would think they are comparable. Before I developed the winder tool shown in this video I used my lathe quite frequently to service these springs.

http://www.flickr.com/photo_embed.gne?id=3134426494

Joe

[Jonny]

There was an easier way and no need to remove.

Just fit centre on the shaft slot and start wrapping round itself.
When wound up a bit, fit in to the slot in the cover cover and push over the wound up spring 1 minute job.
How much tension is trial and error.