eclipse hss tool broken in 2

[lug lordParticipant @luglord]

Just ground myself a really nice facing tool for plastic very sharp etc and when i took it out of my tool post it was broken in 2

what would cause this is the tool post uneven am i tightning the screws too much

or is it just a very old hss tool piece probably older than me maybe been dropped on the floor

any ideas thanks

[lug lordParticipant @luglord]

[David Standing 1Participant @davidstanding1]

What sort of tool post is it?

Was there swarf under one end of the tool?

A photograph would help.

 

 

 

Edited By David Standing 1 on 24/10/2017 17:37:54

[not done it yetParticipant @notdoneityet]

The position at which it fractured should give you some indication of the likely cause.

If not a straightness of holder problem, it could be caused by tightening down beyond any packing pieces.

While the tightening screws do not need to be extreeemly tight, over-tightening should more likely damage the screws/threads of the holder.

[Mick B1Participant @mickb1]

I've done that to a 1/4" square bit when I tightened all 3 toolpost screws down onto it, but had forgotten that the packing only extended under the front 2. Didn't know I'd done it till I took the tool out.

[lug lordParticipant @luglord]

Its a 4 tool post myford super 7 i think it might have been swarf under the tool maybe as i broke 2 tools one after another

[David Standing 1Participant @davidstanding1]

Always brush your tool holder out before putting a tool in!

But you know that now………

[David Standing 1Participant @davidstanding1]

By the way, with my reply to your RDG thread, it isn't 'pick on lug lord' day, honest

[SillyOldDufferModerator @sillyoldduffer]

Posted by lug lord on 24/10/2017 16:16:26:

…

or is it just a very old hss tool piece probably older than me maybe been dropped on the floor

any ideas thanks

Are you sure the metal is HSS? I wonder if you have tool-steel – it's more brittle.

Dave

[Mike PooleParticipant @mikepoole82104]

I was taught to put a piece of packing between the screws and the tool bit to minimise any tendency to a point contact.

Mike

[lug lordParticipant @luglord]

Posted by SillyOldDuffer on 24/10/2017 18:49:08:

Posted by lug lord on 24/10/2017 16:16:26:

…

or is it just a very old hss tool piece probably older than me maybe been dropped on the floor

any ideas thanks

Are you sure the metal is HSS? I wonder if you have tool-steel – it's more brittle.

Dave

not sure there very old tools for sure came in an old wooden cigar box ian

[HopperParticipant @hopper]

Posted by Mike Poole on 24/10/2017 19:00:08:

I was taught to put a piece of packing between the screws and the tool bit to minimise any tendency to a point contact.

Mike

Now there's a good tip. I learn something new on this site every day.

[lug lordParticipant @luglord]

Posted by Hopper on 25/10/2017 05:52:32:

Posted by Mike Poole on 24/10/2017 19:00:08:

I was taught to put a piece of packing between the screws and the tool bit to minimise any tendency to a point contact.

Mike

Now there's a good tip. I learn something new on this site every day.

Cheers for advice in future I will use a thick shim on the top to stop the point of the screws on the tools and make sure no swarf on my tool post thanks ian

[SillyOldDufferModerator @sillyoldduffer]

Posted by lug lord on 25/10/2017 10:13:33:

Posted by Hopper on 25/10/2017 05:52:32:

Posted by Mike Poole on 24/10/2017 19:00:08:

…

…

… and make sure no swarf on my tool post thanks ian

Not just on the tool-post. Swarf goes everywhere it's not wanted. D*** stuff is a pain in the rear-end, sometimes literally!

Well worth keeping chucks and leadscrews etc clean with a toothbrush. In theory I wipe off bearing surfaces like tapers and chuck backs every time I change tool. (In practice I often forget but that's a different problem.) Quite small bits of swarf in the wrong place can throw accuracy off as well as cause damage.

Dave

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