mjflinty
spending too much on rocks
Member since September 2011
Posts: 356
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Post by mjflinty on Jan 13, 2021 18:02:01 GMT -5
Dang, that's a nice job! Makes me want to fix up mine! Good work.
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Post by Bob on Jan 14, 2021 16:36:04 GMT -5
By the way, I have built a number of motorized things in my life, and have used two different belted motor mount methods: the one where the motor has a slotted mounting plate to allow for adjustments and the other using the hinged plate method. Both of these have some significant drawbacks. The slotted plate required 8 wrenchings to adjust, 4 to loosen and 4 to tighten. The hinged plate, unless the hinges are extremely tightly made and the plate spring loaded, never really keep the pulley truly aligned that way it should.
So I gave about a week's thought to designing something new. I wanted no hinge, a single adjustment mechanism, and something that would allow the motor to be mounted very close to the target driven shaft and not be trouble if it got dirty in use. It only takes 2 wrenchings to adjust, and so far so good. I don't plan on running this saw but maybe once/month so plan on sliding it under something in the garage when not in use. But, even w/o the oil in it yet there is some weight to it, and lifting it while keeping it level isn't easy just it being on that base of plywood. So I've decided to build a 2x4 base under it so that it's easy for me to pick it up and set it down w/o worrying about my fingers. I may also use that underside for switch wiring also.
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Post by Peruano on Jan 14, 2021 17:24:15 GMT -5
You will want a splash plate on the front side of the saw. That's where the majority of oil will be thrown. If you are standing there you will have a perpetual mineral oil necktie.
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Post by Bob on Jan 14, 2021 18:16:09 GMT -5
Peruano, I hope to pour some oil into it tonight, and see what happens. Thanks for the tip. I've seen those in photos and know how to do that.
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Post by oregon on Jan 14, 2021 19:07:24 GMT -5
Looks like a nice job, imagine you'll do mostly hand sawing on this - with that large pulley on the side, it's quite a bit above the table, kinda worrying to grab *something*. You might do well to build a belt guard before you're done and call it finished. 2c
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Post by Bob on Jan 15, 2021 14:37:23 GMT -5
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Post by Bob on Jan 15, 2021 14:40:50 GMT -5
Decided to build a base with 3" clearance front and back to make it very easy for me to grab and lift this whole thing up and down beneath a workbench, and 1" clearance on sides. Also want on/off switch to not be on top of anywhere oil might come into contact with it. Except for boxes in which to hold my rough rocks, this is the first thing I've built in a few years and I find the process very relaxing.
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Post by parfive on Jan 15, 2021 15:05:52 GMT -5
Bob, it looks like you’ll need a bigger hole behind the electrical box if you plan on using a cord connector.
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Post by Bob on Jan 16, 2021 19:24:48 GMT -5
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Post by Bob on Jan 17, 2021 20:38:31 GMT -5
Well, I poured in enough oil to cover the teeth of the blade, about 3/8" on the blade. Turned it on. I was surprised on gentle the oil was around the front of the blade slot and dripping from blade guard. Not very messy at all. I cut into a piece of chert that is pretty easy with the tile saw. It cut very slowly and with difficulty. After 5 mins, I stopped. I could tell things weren't cutting as good as should be.
Is it normal to see a light glowing at the cutting point in the rock? And a little spark now and then?
The blade teeth are not perfectly perpendicular to the center of the blade--they are slanted a little. There is no direction arrow on the blade. I noticed these teeth point backward a little instead of forward a little. Which is the correct positioning? Of course this is a used blade and I have no way of knowing whether or not is has been mistreated.
I had a bit of oil mist collect on the middle of my shirt just as predicted, so I will put up a splash guard of some type.
I also had oil leak from where the arbor penetrates the side of the table top. I will figure out a way to block that, maybe with a bit of foam weatherstrip seal. But overall it ran fine and solid. I'm excited!
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Post by Bob on Mar 21, 2021 20:34:41 GMT -5
Got a new blade, got oil leak fixed, cut perhaps 100 lbs of rocks this weekend. Works great! I can see how mineral oil gets consumed because rocks, and my arms, get covered with it.
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Post by Bob on Mar 23, 2021 16:24:24 GMT -5
I've now run it three times in cutting rocks. I've noticed that after sitting overnight in my garage, the next day the oil is clean and cool. After I've been cutting a while--may be 45 mins--the oil has become warm and also brownish as rock dust is suspended in it. Is there anything wrong with me continuing to cut when the oil is like that?
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,332
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Post by quartz on Mar 23, 2021 22:15:24 GMT -5
Nothing wrong whatsoever. Just don't let it get to a sludge thickness, the way you seem to do things and take care with things I doubt that will happen.
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Post by Bob on Mar 26, 2021 10:33:28 GMT -5
Man, at times I feel like I'm drowning in mineral oil! I built a shield at the end of the saw table out of plexiglass. It's full width, and about 12" high. I experimented first with cardboard to see how high the spray from the spinning blade goes. But during sawing, I get the oil all over myself almost up to elbows, and even though I'm wearing an eyeshield/work glasses, I get so much oil dripping from my nose that it drives me crazy.
Do those of you who do this a lot wear a hat and a full face shield?
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Post by HankRocks on Mar 26, 2021 10:45:24 GMT -5
Man, at times I feel like I'm drowning in mineral oil! I built a shield at the end of the saw table out of plexiglass. It's full width, and about 12" high. I experimented first with cardboard to see how high the spray from the spinning blade goes. But during sawing, I get the oil all over myself almost up to elbows, and even though I'm wearing an eyeshield/work glasses, I get so much oil dripping from my nose that it drives me crazy. Do those of you who do this a lot wear a hat and a full face shield? Unless you can come up with an "auto-feed" / "hands-free" design that allows for a complete cover you are going to be facing oil outside the cutting area. You definitely have the skill to attempt a gravity feed system. About 50 years ago I used a friends hand-feed saw, enough to know that I did not want to ever have one. Good luck
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Post by Peruano on Mar 26, 2021 13:06:11 GMT -5
I'm going to bet that you are using way too much oil in your system. You want just enough oil (perhaps 1/4" on the bottom of the blade) to result in a line of oil being thrown in front of the blade, but not significantly up on the vertical shield you built there. You clearly want oil to reach your cut and probably even want it dripping off of the front edge of the splash guard over the blade, but no way should you be indulging in oil splatter like you are describing. I have a simple 8" trim saw (no cover) in which I run oil, and yes I wear a shop apron and try to not wear my good glasses, but dont get oil on everything even when cutting multiple rocks. I'll admit that oil spray is more common when you are cutting slabs from round rocks as opposed to trimming slabs. When the oil hits a surface that is not parallel or perpendicular to its trajectory it goes shooting off to the side and up into the air, but thats still controlable with strategically placed shields. Try lowering your oil and see what results you get.
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Post by Rockindad on Mar 26, 2021 14:13:38 GMT -5
I'm going to bet that you are using way too much oil in your system. You want just enough oil (perhaps 1/4" on the bottom of the blade) to result in a line of oil being thrown in front of the blade, but not significantly up on the vertical shield you built there. You clearly want oil to reach your cut and probably even want it dripping off of the front edge of the splash guard over the blade, but no way should you be indulging in oil splatter like you are describing. I have a simple 8" trim saw (no cover) in which I run oil, and yes I wear a shop apron and try to not wear my good glasses, but dont get oil on everything even when cutting multiple rocks. I'll admit that oil spray is more common when you are cutting slabs from round rocks as opposed to trimming slabs. When the oil hits a surface that is not parallel or perpendicular to its trajectory it goes shooting off to the side and up into the air, but thats still controlable with strategically placed shields. Try lowering your oil and see what results you get. It's an issue even with our little 6" trim saw. Ruined a few shirts and ate a bunch of oil before I smartened up and realized the blade did not have to be half submerged in the oil. My arms from the elbow down where never so soft though . Al
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Post by Bob on Mar 26, 2021 15:03:31 GMT -5
Thanks for all 3 of your tips! The Barranca continuous rim cutting toothy edge is perhaps 3/8" deep, and I thought I had to have it that much in oil, so I probably have 3/8" to 7/16" deep in oil. I'll bet when I decrease that to 1/4" a lot will improve.
I am not slabbing, but just trimming rocks to tumble, so I have no desire to develop a feed system. My gosh, if I had to place each of these rocks in a vise clamp it would take forever. In some cases, smaller rocks take only 10 seconds to cut, so I'm reaching down to get another and another quite often. They are all handheld, with always one part of the rock on the table for safety. I have strong hands and fingers so doing this is easy for me w/o screwing up and straining the blade sideways. No way I want to experience a blade jamming in a rock. Did that once long time ago in a table saw with wood and it was scary. This rock saw blade is flexible I can tell and with the lubricant I'll bet jamming doesn't happen that easy.
The part you wrote Peruano (man I love your name!) explains a lot about what has probably been happening. I've wondered at times why it seems all of a sudden oil is hitting my arm and not at other times. I'm often cutting potato size and shaped rocks in two, so that oil must be just bouncing right off that curved surface.
At least it's easy to wash off. It seems there is a fine mist after in my garage. I think I should probably get a mask. Do you guys wear a true respirator?
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Post by Peruano on Mar 26, 2021 17:12:03 GMT -5
When I built my shop I install a powerful attic exhaust fan in the roof, even tho I don't have an attic. It can clear the air when it appears to be misty, but I don't use it often. A clear face mask will keep a lot of the mist off of your face, but they do get a film that obstructs vision so I tend to just wear my old glasses or safety goggles over my glasses and probably breath a bit of oil mist (however, most of my big cutting is done under cover with the larger saws, so I'm not exposed as much as I would be if this was my primary sawing outlet. Before covid hit, I bought a bargain case of n-95 mask through our habitat for humanity restore, but careful reading of the mask spec disclosed that while they were good for many particulates and medical situations, they were not officially suited for oil (I suspect they might clog up with oil and fail that way and not necessarily let oil pass through). So the word is read the specs on the mask you choose to trust. Many shields of the front of trims saws are transparent plastics, but no one I know looks through they, but instead looks over them. They get grunged pretty quickly so they are not good windows to the work surface. I hope the reduced oil level works for you. The saw is not meant to be messy.
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Post by Bob on Mar 29, 2021 9:30:13 GMT -5
Well, I have now cut perhaps 200 lbs of rocks, including some grapefruit size. Letting the oil be only 1/4" on the blade really cut down on the mess, so I guess my oil was too deep. I've got to build a belt cover because I can see the oil mist is getting on the belts and pulleys. The main oil loss looks to me like it's in all that oil that gets on the rocks and then is lost to the cat litter.
When I filled the tank in the beginning, it took about 90% of 1 gal. I had to top it off several times. Two days ago, I noticed oil wasn't as clear the next day when cutting, so I wondered about the sludge in the bottom. So I took off the saw table top and saw nothing but filthy brown oil. I suppose depth is about 2". Drained it through plug by using putty knife to get it all out. Went fine. The oil has been sitting still now for about 30 hours in bucket and there is only about 1/8" of clear on top.
Does this mean I used the dirty oil too long or am I okay? Could I even have run longer? Will that 1/8" just continue to increase over time as the sludge continues to settle?
I don't mind how long it takes as I already have more new oil.
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