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[Opal Mike]

I have referenced my slicing machines in other posts. These bad boys were built for me on 1989 by Herbert Hartl. Herbert custom made my first two machines numbered 1 and 2 which are still operational after slicing more than 5 million triplets, countless doublets (opal) and now lots of slabs of my more expensive non opal rough.

Herbert went on to produce a further 30 machines in batches of ten most of which are long gone, but a few are still in use by other cutters.

Herbert died a couple of years ago so you can no longer buy the blades for the machines.

I have plenty to see me and my kids out, and have taught myself how to disassemble the blades and make new ones to varying thickness so I can slice material to whatever thickness I want up to about 6mm and down to .15mm.

The blades are only .1mm thick, so very little waste. I slice material in 600 grit solution running through the machine so I get nice smooth perfect slabs. It takes a few hours to run each cut through,  but I just set it up and let it run and get on with other things. I can turn it on and off during cuts and leave it overnight in between cuts if I want.

The pics are of opal rough being prepared for triplet and doublet cuts, a triplet cut at .15mm, a doublet cut at 1mm and a narrow variscite cut at 6mm. Also a shot of a really good triplet cut coming off the wax after the cut has finished.

Hope this is interesting.

Cheers,
Mike

[socalagatehound]

Fascinating and very cool.
Thanks for giving us a look.
Craig

[Opal Mike]

That last pic shows how Herberts machines transformed the triplet industry and allowed us Aussie cutters to compete with increasing Chinese competition.

The opal pictured below in the red solution is the finished sliced block sitting in metho to dissolve the wax and release the slices.

This opal was 4K an ounce in the rough, and I used 5 ounces of rough to make up the block...that’s a lot of trust in the machine.

The other pic shows another triplet cut going through (above). You can’t even see the gap between the slices.

When I started using Herberts machines, the industry slicing thickness for triplets was .35mm and the blades were .15 thick...so two slices per mm. The opal would then be glued down and flattened (thinned down further) on a lap prior to gluing tops.

It took me two years and lots of smashed up opal later to achieve perfect consistent cuts at .15mm. I had to completely develop a whole new process for handling, and manufacturing the triplets over that time frame. The end result was a superior product....water resistant, solvent proof, and life long guarantee against lifting (delamination).

It led to me being able to buy the very best most expensive rough I could find and slice it into stunning triplets.

Herbert Hartl is an important person in the history of Coober Pedy. His machines and blades allowed me to double my yield which saw my business thrive, in an industry that saw most put out of business.

Thank you Herbert, May you Rest In Peace..

Mike

[vitzitziltecpatl]

Yeah, thanks for giving us another look into a world we'd probably never see otherwise... .

[hummingbirdstones]

That machine is the bees knees.  Thanks for sharing it with us.  I'd love to see a video of it actually cutting some stone.

[catmandewe]

Man I loooove old machines, this one is waaaayy cool!!

Thanks for showing us!

Tony

[Felicia]

Thank you. Always wondered how it was done. Didn't seem like it could be with a regular saw.

[gemfeller]

Thanks for posting that Mike.  I was going to ask you about it.  I've seen similar wire-saw machines used in the lens-making industry.  Fred Ward had an illustration of an opal-slicing one in his interesting book "Opal."   

[irockhound]

That is crazy and I was oblivious to something that had been around that long.  I was thinking each stone was still cut one at a time with conventional saws.  Your production is very well thought thru and looks like you have really dialed in through many years of experience.  My hats off to you!

[Opal Mike]

Still a lot of work. I glue the slices down onto specially painted 50mm microscope slides (got my own paint made that chemically bonds to the to smooth glass). I use UV glue for the whole process, and can glue down 80 slides a day (ave of 25 stones per slide...so 2000 stones a day.

Then tops are glued...on all the slices ...another day..

Then they are chopped out on the trim saw...another day

Then dopped using a wood glue ( at 600 an hour or one every 6 seconds...a bit over 3 hours). I sort them into sizes prior to dopping.

Then each one is ground around and buffed (1400 a day 1 person).

Then removed from sticks, washed thoroughly, dried, classes and bagged...close to another day.

Two of us working pumped out 5000 a week...for many years.

Thank goodness I am done with all that!

Glad you find it interesting. I have been asked by a few industry people over the years to tell the full story ...I guess this is a little snippet.

Hope you find it interesting.

Here is a pic of a one small parcel of triplets..I think This batch was just a couple of cuts on the machine...a bit over 3000 pcs.

In this pic, the stones have just been chopped out (separated), with the trim saw. Next step would be to sort them into sizes, bag them and start dopping them. The most stones I have ever dopped in a day was 6400..I can perfectly grind around a triplet without touching the glass top in about 5 seconds...that is worth seeing!

For those who want to know more, have a look at Geoff Stock’s website and Facebook page Rainbow Rock Opals. Geoff is the only triplet cutter who I would consider a true peer in terms of his manufacturing process, and the quality of his work and stones.

He is still going after 40 years!

Cheers,
Mike

[ileney]

This is amazing! It’s kind of mind boggling to see. Wow!

[Felicia]

Wonderful to see, but makes me feel sooo slow.

[MineralSpirit]

This is awesome and I love the concept. Thank you so much for sharing it. Do you know what material is used in the blades? What is the useful blade life before they start to fail?

This machine seems perfect for industrial production. That cut time actually doesn't seem too bad, especially given how much attention a normal saw needs, with resetting the carriage and advancing the rock in the vise between each slice. At least with this machine you can spend that time doing something else instead of playing in messy saw oil every 15 minutes.

Also, not having to deal with oil cleanup on resulting slabs is another plus.

Does the coarseness of the grit affect the cutting time at all?

[Opal Mike]

It is not all beer and skittles (Aussie expression meaning it is not all good). The blades and spaces are made from German steel and have been rolled and punched out in a die press. Unfortunately there are no more blades available. The metal contains nickel to prevent rust.

I have to break down triplet blades to get the blades. I also have to clean old spaces (from old blades) to make up the blades. Slicing triplets, I get on average 5 cuts a blade, two small cuts, two medium size (height of stones) and one large cut.

Slicing my obsidian backing for doublets at 2.1mm and 2.4mm I get a maximum of two cuts out of a blade because I am slicing one large block at a height of around 30mm or even higher.

Slicing Variscite at 6mm, 40mm high, I get two cuts.

The blades have their limitations. I can only slice 3” square blocks of material, and usually a max of about 35mm in height.

The blades \ machine also doesn’t like harder material, so no good for agates or the porcelain jaspers.

I would say it slices material up to a hardness of 6 to 6.5 ok.

It is fiddle making blades, and sometimes time consuming to run big cuts, but for expensive rough it does maximise yields. The machine would be perfect for precision slicing of thin strips of material for intarsia. You can run a cut through at say 2mm ( slice width), then glue it to another slice of different material, lie them flat in the block and slice them again to whatever thickness you need..getting perfectly sliced already bonded strips. You could take it further and repeat the process to achieve perfect checkerboard slices.

I think there is a market in the US for such machines. They are a precision instrument, with the head of the machine perfectly balanced with a flywheel so the machine starts and stops gradually to avoid flexing if blades.

Cheers,
Mike

[MineralSpirit]

Thanks for those details, Mike! Do you know about how many oscillations/min it goes at, ideally?

One more question: The blades appear to cut from the top down, correct? how much downward pressure is applied, is it adjustable, and if so have you found an optimum pressure with regards to cut time/blade life?

The concept is awesome, and I agree that there should be a market for such machines among high-volume workshops using high-end rough. I actually think the market might be viable because even if there is only demand for one or two dozen new machines a year, the demand for replacement saw blades might be enough to make it worth someones while to actually produce both machines and replacement blades.

This seems like the kind of project the Rowland brothers at Highland Park might be into.