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[lithicbeads]

A big  (24 or 36 inch ) drop saw is overdue on my place as I have a lot of very good rough that is huge. I have been around a few drop saws and seen them work  but was always uncomfortable with the idea of building one. I need to do it this year before I get any older. Anyone ever see any plans for a big freestanding water cooled drop saw or perhaps have experience with one? Thanks and Merry Christmas.

[Downwindtracker2]

I was going to build a 18", even bought the blade, but we were able to purchase, at the moment non working, homebuilt 24" horizontal feed one.

Some thoughts I had on the build.
I picked up a long hydraulic cylinder for an engine hoist from Princess Auto, a Canadian sort of Harbor Freight. This would give me an adjustable down feed. I planned on mounting the motor, a 1hp , inside the pivot to add weight. I think I picked up a piece of 8x4 square tube out of a bin for the arm. For the pivot, I would double bearing it, flange through  the square tube and pillow blocks on the frame. The adjustment would be at the pillow blocks.
For the vise rails, I was going to use square cold rolled steel .
For a  machined true bed for them ,I purchased machinist's V-blocks from BusyBee, a Canadian Grizzly . The imported small ones are cheap on sale.
For the vise bearings for the rails I was going to use cam followers, they are already mounted to a shaft.

For the arbor I told the wife I needed a metal lathe. My son and I went together on a new 10x22. When he moved out it was "I'll buy you out" "No, Dad I'll buy you out"  I ended up buying a used 12x24. I still haven't made the arbor.

My motto has always been if you can't make it right, at least make it adjustable. I planned on using a lot of square headed set screws(pusher) and shim stock.  When I was young I could plan it out in my head and build it, doing the engineering as I went.

I hope this gives you some ideas. Good luck.










 

[Slabbercabber]

Be careful about how much weight you put on the blade.  I use pneumatic drive for my saws.  On a 24" blade cutting full depth I have never needed more than 25 pounds force.  If you put the full weight of a large motor on the cut you may destroy the blade.  A sliding weight would be my preference.  Adjustable force allows you to cut at optimal speed for any size rough.

[vitzitziltecpatl]

Sometimes on the LS14 we have I'll use counterweights for softer or more fragile rough. I don't know how much the original motor weighed on this saw so it seemed logical. I just hang them off the back end of the saw arm under the motor. It was the easiest "adjustment" that came to mind... .

The manual for this saw said up to 5 lbs of additional weight could be added to the arm, but I don't know how much downforce there was with the original motor on the back end.

[Downwindtracker2]

The big factory drop saws use hydraulics . I spent some time studying them at Quartzite.

[lithicbeads]

As this will be a field saw  a basket will be on the arm for weights as needed.

[vitzitziltecpatl]

Frank - took the dimensions off the LS14 here if that's of any use to you.

Box is 20x20", with 2" reservoir under the table.
Crossfeed Shaft is centered 9-1/2" above the table, 1" in from the back wall - on a 2" channel. Top of channel at 8-1/2".
Arm is 26-1/2" long, with the crossfeed bearings centered at 9" from the back of the arm.
Motor is centered 4" from back of arm.
Arbor is centered 19" from back of arm.

Weight at front end of arm in horizontal position is 7.7 lbs. A 3 lb counterweight hung from back end of arm reduces weight at front end to 6.2 lbs. I use the counterweight for most things, removing it for harder material.

I can give you more specific info if you want. The angle and channel iron for the framework and arm all look like 3/16". I didn't measure any of that.

For a guy like you, though, just knowing the distance from the crossfeed to the arbor is roughly 2X the distance from the crossfeed back to the motor should help a little. Especially if you're going to add weight as needed.

[lithicbeads]

Thanks folks. In the new year I will try to get some close up photos of one  and I will post them. Between the advice , ratios and pictures I think I am good. How do you like the drop saw?

[Stonemon]

I have an LS 14 and my experience has been mixed. My screw feed saws have been more consistent. The drop saw works well with some material but will dull and stall with others. Or more to the point, it requires closer attention to the weight and coolant than the others.
I am basically lazy. My attention span is decreasing in a linear relation to my age.
If you have the opportunity to acquire a large HP or Frantom or Hilquist I would consider it as an alternative to the drop model. It is just easier.
IMHO...
Bill

[vitzitziltecpatl]

Yeah, I have to add two counterweights to cut Picasso or it will bog down. No counterweight in hard material, and some of that takes a long time to cut. Hard rock glazes the blade, too.

The old Frantom 18" we got is much easier to use, but I used the drop saw on everything for about seven years. It's a simple design that works, but does require the extra attention that Bill mentioned.

[lithicbeads]

I have to have a drop with the rock chained in place as the pieces are far too big to put in a saw.

[vitzitziltecpatl]

Could you drill and split them down to smaller sizes, or are you looking for "tabletop" size slabs?

[lithicbeads]

Some are too valuable like a solid 300 pound piece of crazy lace  and while jade drills fine with carbide sds hammer drills it does not split well and some of the jade is just too valuable.

[Stonemon]

These are problems! Not like bad things but I understand your hesitation to get rough with them. I looked around a bit and found an old thread on another forum about a home built drop saw, 24", but was not very impressed with it. I think Tony (catmandewe) has a 36" over in Gooding but I can't remember if it is a drop. You might ask him for a pic if it is.
Jack, (lapidaryrough) has quite a bit of knowledge of such things and maybe one of them will chime in.
Looking forward to updates as this process evolves.
Merry Christmas all.

[vitzitziltecpatl]

Yeah, it must suck to have problems like that ... .

Totally understand. I'd want to window them and be able to re-orient as needed.

Are you planning to put them into some kind of pan or trough and then pump oil to the cuts? Maybe lift them with an engine hoist or something? I've been wondering about that since I read that it was going to be used in the field.

Yeah, I'd like to have problems like that... !