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View Full Version : to wobble or not to wobble



compfranon
28-03-2010, 12:14 AM
When I worked with CNC mills many many years ago, to set the datum on X and Y we used a wobbler, basically a 0.2 dia ball mounted tip that deflected when very close to datum edge.

What is used now to set the datum on X & Y axes.

irving2008
28-03-2010, 12:40 AM
same thing - a wiggler or an edge finder, unless you have some clever laser-y video-y thing...

compfranon
28-03-2010, 12:44 AM
same thing - a wiggler or an edge finder, unless you have some clever laser-y video-y thing...

Ah, the old school techniques, tested and proven.

Where might I source one of these wigglers or wobblers now.

irving2008
28-03-2010, 12:54 AM
eBay... or Chronos have a good range here (http://www.chronos.ltd.uk/acatalog/Chronos_Catalogue_Centre___Edge_Finders___Touch_Po int_Sensors___264.html) - I have the 4mm EFZ4 only 7.95 inc p&p

compfranon
28-03-2010, 02:17 AM
eBay... or Chronos have a good range here (http://www.chronos.ltd.uk/acatalog/Chronos_Catalogue_Centre___Edge_Finders___Touch_Po int_Sensors___264.html) - I have the 4mm EFZ4 only 7.95 inc p&p


7.95 .... is that a typo perhaps, only prices I found were 79+

at those sort of prices I would be looking at modding a pocket laser.

Just looked at the edge finders you mention, would you mind explaining how they work.

irving2008
28-03-2010, 10:47 AM
you put them in the spindle, set it spinning, then jog to the X-axis datum edge until the edge finder 'splits', raise the Z, jog in a further 2mm (for a 4mm one) and zero the DRO or set the axis zero as appropriate. then repeat for the Y-axis... see video


http://www.youtube.com/watch?v=f0od-cp_9dg

compfranon
28-03-2010, 12:07 PM
Thanks Irving, they operate pretty much the same as the wobblers I remember. Might look out for the led version on fleabay, looks useful if datuming a rear edge.

bogstandard
28-03-2010, 12:35 PM
Forget about the light up ones, they are just a gimmick, designed to attract moths that think they will do a better job. Just try using them on a non conductive material, you will soon realise why. I actually gave one away a couple of days ago. As useful as a bowler hat with sleeves.

The ones from Arc Euro do a great job.

http://www.arceurotrade.co.uk/Catalogue/Measurement/Edge-Finders

Bogs

compfranon
28-03-2010, 12:45 PM
Forget about the light up ones, they are just a gimmick, designed to attract moths that think they will do a better job. Just try using them on a non conductive material, you will soon realise why. I actually gave one away a couple of days ago. As useful as a bowler hat with sleeves.

The ones from Arc Euro do a great job.

http://www.arceurotrade.co.uk/Catalogue/Measurement/Edge-Finders

Bogs

Yep, I was just trawling fleabay as I wondered how the led version worked, then I found it's only useful on conductive materials. Standard wobbler it will be then.

Must admit I thought the led was a good idea for an awkward datum position, flap flap.:whistling:

John S
28-03-2010, 01:14 PM
I have tried everything over the years, wigglers LED's, lasers, playboy [ but we won't go there ] and I have always gone back to the wiggler / edgefinder.

I recently bought a pair of the ones Bogs linked to from ARC and these are my tool of choice only because I work in metric and my old bent up wiggler is still in imperial.

I bought one of the audible and light up ones, cost me about 50 quid so for that money it has to be the best thing since sliced bread ?
Nope, because of the brightly lit workshop and running machinery on the first edge I didn't see the light or hear the beep so that was 50 quid thrown into the bent bits scrap bin.

Oh well another flat battery in the car park of life.

compfranon
28-03-2010, 01:22 PM
Theres certainly something to be said for low technology, built to last and not a chip in sight.