Author Topic: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)  (Read 44896 times)

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #825 on: May 06, 2019, 01:48:30 PM »
The ironic thing is Cliff, I just tried the MP12 probe and holder in the machine, and the IR of the OMM isn't reaching the window of the probe.  :bang:

The MP12 is intended for the vertical spindle of a milling machine of course.

All is not lost, as the probe mounting is universal to a few Renishaw probes, and I have another (an LT02S) that has the window pointing in the right direction !






Andrew Mawson
East Sussex

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #826 on: May 07, 2019, 06:34:47 AM »
Sometime these 'Gotcha's ' creep up on you unawares. Looking at the two probes side by side it is dead obvious that their windows point in opposite directions, outwards and left for the LT02S for a lathe turret, and upwards (if in a spindle in a mill) for the MP12

I've handled these things numerous times but the fundamental difference never dawned on me.

Oh well, honour redeemed by mounting the LT02s on yesterdays adaptor and I've proved that it works as fitted.
Andrew Mawson
East Sussex

Offline tom osselton

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #827 on: May 07, 2019, 04:26:53 PM »
Glad it worked out! So why the difference in window direction? Or is that dependent on where the receiver sensor is positioned?

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #828 on: May 07, 2019, 04:37:23 PM »
The "Wrong" one is intended for the vertical spindle of a milling machine so the window points upwards with the OMM sensor at a highish level out of the muck and bullets.

Theoretically I could have moved my OMM to the roof of the enclosure but in practice the sliding door curves up there and stops that being  a solution.
Andrew Mawson
East Sussex

Offline tom osselton

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #829 on: May 07, 2019, 05:19:30 PM »
Ok thatís what I thought my Son had ours moved from the right side to the left to accommodate the 4th axis on the Haas.

Offline JHovel

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #830 on: May 09, 2019, 11:42:30 AM »
Andrew, reading your exceptional progress with great interest.
Could you use a mirror to redirect the IR signal back to your sensor? While probing, I imagine there would be no coolant interfering with the mirror. Perhaps mounted high in the enclosure (even near the top of the door) might just work....
Cheers,
Joe
Cheers,
Joe

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #831 on: May 09, 2019, 12:41:37 PM »
Joe, I had considered making a prism that would sit on the existing window but 'look the other way' , but I'm not sure what optically clear (at IR wavelengths) plastics there are that are available, easily machinable, and able to be polished :scratch:

Today I started gluing up a wooden box to house the LT02S probe and holder, and 3D printed a cover for the ruby probe itself. Hopefully tomorrow the PVA will be set enough to finish it off and fit catches and hinges. I used the offcut of the 12 mm ply that I got for the counter top of the Versatool cabinet. What horrible stuff modern plywood is - looking at the cut edges it was full of voids.

 
« Last Edit: May 09, 2019, 04:21:31 PM by awemawson »
Andrew Mawson
East Sussex

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #832 on: May 10, 2019, 10:00:16 AM »
So while the first coat of varnish is drying I did an experiment to see if the MP12 probe would work though glass. Casting about for glass in suitable sizes I came to the conclusion that it is surprisingly rare in my workshop  :ddb:

Eventually I settled on my 100 mm  magnifying glass that sits at my desk - it has the advantage that the glass is pretty thick.

End result is that the probe is quite happy to function both sending and receiving through the glass, so I've splashed out and bought some small prisms on eBay. Coming by slow boat from China so not expected until the end of the month. To get the size right I need to mount two 10 mm x 10 mm x 10 mm next to each other so a bit of fiddling required.

I seem to recall that there is a special optical glue used for lenses in contact, but actually I don't suppose it'll matter in this case that half the signals go through one prism and the other half through the second one  :scratch:
Andrew Mawson
East Sussex

Offline charadam

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #833 on: May 10, 2019, 11:24:16 AM »
Canada Balsam used to be used for lens gluing, but has been superseded by synthetics.

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #834 on: May 10, 2019, 11:42:14 AM »
That's the stuff  :thumbup:

Not to be confused with Friars Balsam  :clap:
Andrew Mawson
East Sussex

Offline nrml

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #835 on: May 10, 2019, 05:32:18 PM »
Friars balsam smells wonderful. If someone accidentally spills some at work, everyone in the area drifts that way to have a sniff.

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #836 on: May 16, 2019, 09:39:05 AM »
At long last the sticky backed green baize to line the Renishaw Probe box arrived this morning so I was able to finish it off.

First I made a closed box, pinned and glued which was left for the PVA to set hard. Then the closed box was sanded down to a fair finish which revealed the rubbish quality of the "12 mm 7 ply" that I was using. It turns out that actually it's 9 ply, with the extra two plys being paper thin and effectively just colouring at 5.5 thou thick! Bits got sanded off which proved to be very difficult to disguise with the stained varnish that I used.

Then the box was sawn into a top and a bottom, thus ensuring that they matched in 'unsquareness' though in fact they were pretty good.

Umpteen coats of dark oak varnish stain later I was able to fit the hinges and corner protectors. With water based and oil based paints I always suspend my brush in water to prevent it drying out over night, as it easily shakes / wipes dry ready for the next coat. Saves ages washing brushes :ddb:
Andrew Mawson
East Sussex

Offline awemawson

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Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Reply #837 on: May 16, 2019, 09:42:06 AM »
And then this morning the baize went on. Knowing this stuff is great fun even on open flat surfaces, I thought that I'd be clever and make a paper template. It 'sort of worked' but this stuff stretches all over the place and when it's 'down' it stays down resisting movement. I'm not entirely happy with the result as it's not absolutely flat in places but it's definitely functional.

Some time earlier I had 3D printed a protective cap in ABS that slips over the actual probe itself, preserving the ruby tip (hopefully!)
Andrew Mawson
East Sussex