Thread: Hercus lathe sprung loaded plunger

Try Hercus (08) 8346 5522

G'day China,

I sent an email to Hercus, several days ago, and have not had a word in reply.

A bit disappointing, but let's see what happens. Maybe they have knocked off early for Christmas.

Anyone have a personal contact there?

Ken

G'day Ken, my lathe is totaly different to a Hercus, but I think the plungers may be the same system, they are screwed on, I held the tip with pliers and unscrewed the knob, try puting some protection on the tip so not to scratch it, cheers,
Richard.

Hi Dano48,

Just tried that, gripped the plunger end with multi grips, and tried to unscrew it.

No go, just managed to ruin the end of the plunger with teeth marks, so now, it's out with the fine file to make repairs, or make a new pin when I find out how to pull it apart.

A young man put this together, so an old man should be able to pull it apart!

Where's my x-ray machine?

Any other suggestions?

Ken

Before you get to remove the outer shell of the bearings a careful weld around the centre ring it will nearly fall out from shrinkage.The cage if it is frozen a dremel cut nearly through then tap its out.Passed on today by a mate of mine. This is before the continuum.

Regards Peter

Hi Pete,

I can't quite follow your explanation. You mention the "outer shell of the bearings". Perhaps we are talking cross purposes?

If not, are you suggesting heating the plunger knob to release the sprung loaded plunger. This something I dare not do, as it will more than likely, soften the internal spring.

Ken

Hi Ken,

Do not know the Hercus, or this particular part shown. Some more pics close up would be helpful. Especially, head of plunger body & internal of shaft/ pivot.

The question, is not so much as how they come apart, but rather how to remove them from the casting.

A different kettel of fish as one must remove before taking them apart, which shall be another challange.

My only suggestion is (lack of knowledge and detailed pictures) is that the outer body is a press fit into the casting.

If you can sight from the end one may be able to use a tubular punch to tap it out, or with a dremmel or similar grind 2 pockets into the casting NOT recommended leaving insert shoulder intact and pry!!

Once removed you have the joy of dissambley of the plunger mechanism.

Regards Den

Wrong name it has caused confusion.I was referring to the main shaft races.

Peter

My guess is that it is held in with a retaining washer. I am not sure what they are called, but they are are circular waher with tabs running around the outside and angled slightly towards one side. You then push then into a hold and the tabs bite in and stop it being pulled out.

Michael

Dear members,

A young bloke assembled this plunger, and this old man can't figure it out!

It's got me tin fruited!

I've knocked up a quick drawing based on looking at the part in question, and the exploded spare parts booklet. The exact detail may not be correct, I don't have x-ray eyes.

Some how, the plunger is attached to the knob, but I can't see any evidence of how.

Ken, why not shoot Mick Moyles an email, and direct him to your post.

I have spoken with him for hours when the shop has been slow, and he is a wealth of information on Hercus stuff. http://www.moyles.com.au/

Thanks Fossil for your advice.

Have just received an email from Steve Durden at Hercus.

He tells me there is in fact a cross pin that goes through the knurled knob, locking the knob to the plunger. That makes sense, I do not doubt him, but where is the pin?

It is not shown in the Hercus spare parts booklet, and it's not visible in the knurled knob, even with the magnifyer's on.

I am determined to get to the bottom of this, so wait for the next episode.

I apologise for hogging the forum, but then, that's what forums are all about.

Ken

Hmmm... Mabey if you warm it up with a torch the pin may become visable.

Just a thought.

Hi Fossil,

A good thought, but I don't want to introduce any heat in case I soften the internal spring.

Is there a dye I can emerse the part into to reveal a cross pin's location?

Where's my bloody x-ray glasses?

Ken