Author Topic: A Moments Inattention  (Read 4269 times)

Offline awemawson

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A Moments Inattention
« on: December 01, 2013, 09:24:03 AM »
I've been setting up to make some work clamps for the wire edm machine out of 304 stainless steel. Simple single hole tapped M8 and an 8 mm slot. Needed a few so drew it up in Featurecam to make on the CNC mill.

To set tool lengths my 'zero tool' is a Heidenhain touch probe so the procedure is:

A/ Use Heidenhain Probe to set Z = 0 as top of Vertex Z-Gauge (controller automates this)

B/ Set each tool length measured to top of Vertex Z-Gauge (led lights up on contact) then put values into the 'Tool Table'

C/ Use Heidenhain Probe to reset Z=0 to be the top of the work piece
Andrew Mawson
East Sussex

Offline awemawson

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Re: A Moments Inattention
« Reply #1 on: December 01, 2013, 09:30:37 AM »
Now this process works spiffingly if you remember to do ALL the steps  :bugeye:

Yesterday in a moment of inattention I failed to do the last step - probe the work piece. Result being that instead of being the top of the work piece, Z=0 is now 47mm BELOW the work piece.

Generally this isn't considered good, and most definitely the first tool to be used, a centre drill, was most unhappy being asked to enter a good way into a piece of 304 stainless that it was only supposed to go in 0.5 mm !

Net result was one heck of a big bang, the stepped jaws being sheared off the vice, the centre drill disintegrating, and the BE200 / CAT40 collet holder being consigned to history
Andrew Mawson
East Sussex

Offline awemawson

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Re: A Moments Inattention
« Reply #2 on: December 01, 2013, 09:35:26 AM »
Now those HT socket cap screws are M8 and sheared clean off - what force does that take? Not surprisingly the control reported a 'Gross Positioning Error' but amazingly after a reset, other than the damage shown in the photos the Z servo and bearing SEEM to have survived

A bit of tidying up and sorting out, and a replacement holder installed and calibrated resulted in the first SS EDM Clamp - but this sort of happening is not really wanted  :scratch:

Nine more clamps to go.
Andrew Mawson
East Sussex

Offline John Stevenson

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Re: A Moments Inattention
« Reply #3 on: December 01, 2013, 10:15:35 AM »
Clumsy bastard
John Stevenson

Offline awemawson

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Re: A Moments Inattention
« Reply #4 on: December 01, 2013, 10:44:04 AM »
I very nearly added that comment myself John as I just KNEW that'd you'd be along shortly  :ddb:

Andrew
Andrew Mawson
East Sussex

Offline AdeV

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Re: A Moments Inattention
« Reply #5 on: December 01, 2013, 10:52:43 AM »
That's why I use wax..........

I did something similar (put the wrong tool in, which had an 11mm additional stickout), result - fast plunge into material (what air crash investigators call "controlled flight into terrain").

Being wax, I didnt get any of the drama you got, probably a similar amount of cursing mind...
Cheers!
Ade.
--
Location: Wallasey, Merseyside. A long way from anywhere.
Or: Zhengzhou, China. An even longer way from anywhere...
Skype: adev73

Offline awemawson

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Re: A Moments Inattention
« Reply #6 on: December 01, 2013, 04:23:17 PM »
Sadly Adev using wax wouldn't have saved me here, as I'd still need to probe the workpiece  :(

If my Googling is correct it took something like 9 tons force to shear those cap screws  :bugeye:

Andrew
Andrew Mawson
East Sussex

Offline awemawson

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Re: A Moments Inattention
« Reply #7 on: December 02, 2013, 04:11:51 AM »
Well it all turned out ok in the end - finished the clamps this morning
Andrew
Andrew Mawson
East Sussex

Offline stirling lad

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Re: A Moments Inattention
« Reply #8 on: March 03, 2014, 03:23:35 PM »
I like them,,
 :clap:

...Mike..

Offline Stilldrillin

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Re: A Moments Inattention
« Reply #9 on: March 03, 2014, 05:40:55 PM »
I retired, after some 25yrs of happy, Machining Centering, some years ago.  :thumbup:

I still remember the occasional, (annual?), crunch.
As your slow motion limbs carry you towards the Big Red Mushroom. The toolholder glows, and sparks fly.
Everyone cheers, as the machine overloads and stops. Before you can punch the button.
THEN, you notice, the prog says Z-3., not Z.3......... :palm:

Happy Days!

Nice clamps Andrew!  :clap: :clap:

David D

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!