azarmul
off to a rocking start
Member since September 2012
Posts: 4
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Post by azarmul on Sept 4, 2012 20:06:13 GMT -5
Hi all - Can anyone tell me how to clamp a rock properly on a LS-18 Lortone saw?? I cannnot seem to get it to work and it is almost new. My problem is that the lever on the clamp flips/rotates up/down in an arc and hooks into the saw toth bar it slides on. However, one I flip it into one of the teeth, when I screw down them t-handle, it never tightens to any granularity that keeps it tight. I assume I am missing a very obvious concept here PLEASE help teach a complete newbie how to use this saw! I rrally want to start using it Thank you!!!! Peter
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Post by Bikerrandy on Sept 4, 2012 20:16:29 GMT -5
Yep, a vice alone will not hold a rock tightly into place and you'll destroy blades!! (I learned the hard way). Cut some wedges out of a 2x4, you need to tap them into place around the rock after tightening the vice, and then tighten again. It usually only takes one or two wedges. Also, after tightening the vice, tap the vice clamp once or twice with a hammer as well (not too hard though) and tighten again. A rock can never be too tight!!
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Post by deb193redux on Sept 4, 2012 20:32:12 GMT -5
good advice for irregular rock, or a circular nodule
but it should clamp if there are flat surfaces. can you get the clamp to tighten on a block of wood? if not, the clamp is defective.
you can also post a pic for possibly more ideas
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,487
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Post by Sabre52 on Sept 4, 2012 20:34:05 GMT -5
Yeah, another thing is you should put a block in the jaws in back of the stone, if there is room, so the jaws close roughly parallel to each other and pressure is applied more evenly to the workpiece. I cut a whole series of 2 X 4 wood blocks to match various thickness of stone when I had my 20" Hp saw. This helps keep the jaws from popping loose and freeing the workpiece to bend your blade. If the jaws get way out of parallel they are much more prone to come loose.....Mel
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Post by Rockoonz on Sept 4, 2012 21:07:55 GMT -5
I installed a jack screw on the back side of the vice on my HP saw with a similar vice. Be sure to grab the rock and forcefully try to remove it from the vice before cutting. Lee
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Post by Bikerrandy on Sept 5, 2012 18:51:48 GMT -5
That jack screw is a great idea!!
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QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,640
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Post by QuailRiver on Sept 6, 2012 0:04:07 GMT -5
For my 18" Lortones I have a selection of assorted sizes of wood blocks, masonite slabs, and wood wedges at varying thicknesses and angles to even out the clamp faces and to shim the rock for a better grip. Even with all of that sometimes it can be very challenging to clamp a rock securely. Rounded nodules are especially tricky. Some folks will use a milk carton for a mold and set rounded agate nodules in plaster or concrete so they have a square shape that is easier to clamp for slabbing. I got lax a couple of weeks ago, I had clamped a large Brazilian Agate nodule in the vice of an 18" Lortone cut the end off late in the evening. Didn't get back to slabbing for a couple of days and forgot to recheck the tightness of the rock in the clamp, set it for another cut and walked away. About 1/2 hour later went to check on the saw and when I got near the shop I could smell rubber burning. The oily Brazilian Agate had slipped and bound the blade. The motor pulley wore/burned through the main belt. I had to replace the belt and motor pulley but fortunately no damage was done to the blade. I think I'll wait until I have gotten more use out of that blade before I risk it on another Brazilian agate nodule.
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rockhunter60
off to a rocking start
Member since July 2012
Posts: 4
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Post by rockhunter60 on Sept 6, 2012 12:17:01 GMT -5
Randy,
If you will cut yourself an assortment of wooden blocks from a 2 x 4 in a variety of lengths (about the same widths as the rocks you will be cutting) these will help you clamp your rocks. When you place your rock between the two halves of the clamp, place a piece of wood about the same width as the rock in the clamp on the right side too. This will allow the clamp to tighten down squarely on the rock and the piece of board.
Always screw the tightening screw back far enough to allow you to fit the wedging bar into the ridge that is nearest to the clamp before you start tightening the clamp.
Most rocksl, up to 5 or 6 pounds with a fairly flat side can be glued onto a 4 or 5 inch piece of 2 x 4 with carpenter's wood glue. I always give the glue at least 4 or 5 days to dry good before trying to slab the rock. If you have your rock glued like this, all you have to do is place another piece of 2 x 4 in the clamp to even the clamping jaws out when tightened. Gluing your rock onto a piece of board also allows you to position the board holding the rock at the very edge of the clamp so you can slab your rock all the way down to that last slab where the rock is attached to the board. All you have to do then is drop the board and that last slab into a bucket of water and after two or three days the glue will loosen and the slab will fall to the bottom of the bucket.
I hope this helps.
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