MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 8:12:22 GMT -5
I’ve been waiting for over a year for my first cut, and yesterday was the day. I have a Highland Park 20”, a cheap Kinglsey 20” blade, Kingsley lubricool oil covering about 3/8 inch of the blade, and a simple conglomerate(?) rock to test. The rock is very firmly clamped and immovable. It started off fine, but then towards the end I saw a significant amount of smoke coming out of the saw. I cut it off and haven’t used it since. The rock was hot, the blade was hot. I am still unable to move to rock, it does not seem to have loosened. What might have happened? imgur.com/gallery/wIGV0X6Edit: video: imgur.com/gallery/c6YMTTLEdit2, video2: imgur.com/gallery/VNQp4pFEdit 3: the wood on the vice burned: imgur.com/gallery/PlymiEZEdit 4: pic: Blade now has a heat burn, all rocks acting hot/burnt only at the center near the arbor. Not touching arbor. No friction at fron or back of blade: imgur.com/gallery/nph7piG |
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AzRockGeek
has rocks in the head
Member since September 2016
Posts: 703
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Post by AzRockGeek on Jul 27, 2022 8:30:04 GMT -5
It is hard to tell from the video, but it appears that the rock may have shifted in the vise. The bottom part does not appear to be flush with the blade like the top of the rock.
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Post by liveoak on Jul 27, 2022 8:35:26 GMT -5
Smoking could be lack of enough lube ?
or /and
Maybe feeding too fast ??
Patty
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 9:30:15 GMT -5
It is a long rock, and there are 3 points of contact if you count the wood wedge up front/right. I think a twist makes good sense though.
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 9:30:44 GMT -5
Should I consider the blade damaged or questionable?
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aGates
has rocks in the head
Building a silver studio
Member since January 2021
Posts: 518
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Post by aGates on Jul 27, 2022 9:31:55 GMT -5
At the Rock club to remedy round rocks and square vices we use chunks of wood shaped in wedges and blocks to fill up any gaps and to create a good bite because the wood is softer that you add against the jaws of the vise another technique is to slightly cup impression into a block of wood then it would grab a rounded corner of a stone most easily. Hope this helps.
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Post by HankRocks on Jul 27, 2022 9:45:46 GMT -5
The rock you picked for you first cut would be one I would have hesitated to even try. The wood wedges would probably have helped, but there's just not enough rock against the vice for my comfort. One other thing I have done is cut off 2 or 3 inches off an end to give a larger clamping surface.
I will ask the obvious, you did have enough oil in the saw? It the blade is not damaged I think I would pick a nice smaller blockish rock that easy to clamp for a test cut. You can just spin the blade and see if it has developed a wobble.
There are several rocks in my "will not cut" pile. Waiting on an upgrade to the clamp my friend built to cut some of these problem pieces. It worked well with Choyas and Brazilian nodules which can be a pain with the normal saw clamp.
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 10:39:41 GMT -5
There are many helpful answers and learning perspectives here, I am grateful for all of them. I do believe the issue is a poorly seated rock. I really appreciate all the answers.
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 10:46:55 GMT -5
I will ask the obvious, you did have enough oil in the saw? It the blade is not damaged I think I would pick a nice smaller blockish rock that easy to clamp for a test cut. You can just spin the blade and see if it has developed a wobble. Hi there! I dont mind any questions obvious or otherwise. There is enough oil, yes. It full covers the sintering of the blade, about 3/8 of an inch. |
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 10:48:04 GMT -5
MetaMoose a rock like that will have a tendency to crumble under the pressure of the vise, it’s possible one of your contact points was compromised/broken while the saw was cutting. I cut a lot of thundereggs which can have crumbly exteriors, what I like to do once I have the rock firmly clamped is try to push, pull, twist the rock as if I’m trying to rip it out of the vise. Occasionally that will cause the rock to crumble/break just enough to allow the rock to move which you would rather have happen at that point so it can be remedied. Once I get the rock clamped and I can’t move the thing at all, I then retighten the vise one last time. The crumbly nature of conglomerate rock along with the size of that thing make for a pretty technical cut, I would suggest starting with a good hard agate or jasper that is slightly smaller. There is a chance of this, the outside of the rock is very weathered, it even shows a ~1mm ring of discoloration around, similar to a thunderegg. It was pulled from a river. |
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 11:02:11 GMT -5
When I removed the rock and pulled back the vice the wood on the vice had burned. It seems to have more friction at the center of the blade and it does at the front or the back. imgur.com/gallery/PlymiEZ |
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rockbrain
Cave Dweller 
Member since January 2022
Posts: 3,176
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Post by rockbrain on Jul 27, 2022 14:52:47 GMT -5
When I removed the rock and pulled back the vice the wood on the vice had burned. It seems to have more friction at the center of the blade and it does at the front or the back. imgur.com/gallery/PlymiEZI'm sure you're enjoying that good news! |
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 15:22:16 GMT -5
When I removed the rock and pulled back the vice the wood on the vice had burned. It seems to have more friction at the center of the blade and it does at the front or the back. imgur.com/gallery/PlymiEZI'm sure you're enjoying that good news! Not yet, still a little stressed. As the carriage slides down, all of the rocks are pinching hard against the center of the blade where the arbor is - the friction there is pretty tight. (edit: not by touching the arbor) Most of my cuts have black burn marks where they make it to the center of the blade. Even the "outside" of the blade shows a heat stain/burn (a spot or circle where the metal is discolored from heat. As the carriage slides down, its normal friction with the rock at the front, it gets real tight and squeaky in the center near the arbor (where all the heat is made) and then loosens up at the back of the blade. Its almost like the blade is concave...? It is a cheap 60$ 20" blade. But I'm also worried that there is something more fundamental wrong. I cant really do big rocks (which I'm totally wanting to do with a 20" saw), because something is wrong when they travel to the center of the blade. I'll see if I can edit this comment with a pic of the hot spot on the blade, but one of my videos in the original post shows the rock getting stuck in the middle I think. Edit: pic: imgur.com/gallery/nph7piG |
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Post by Peruano on Jul 27, 2022 15:53:21 GMT -5
I have not looked at all of your photos, but: 1. You don't want to saw your vice. Your stones should be mounted so that the cut is beyond the reach of the wood (or metal) of the vice. In fact when slabbing the cut is usually started a long way from the edge of the vice and only gradually moves closer as the stone is sliced.
2. Another issue is to make sure that if you are making a long cut (i.e. one that will take your stone beyond the center of the blade (where the nut and flange washer that hold the blade on the arbor) are located. .. . your stone must be high enough to clear the flange washer. Sometimes when stones project below the vice level, they can bind on the unusable middle are of the blade.
My advice is to learn to use the saw by cutting smaller material. You may be able to cut big stuff with this saw but it should be with an experienced operator (i.e. you with experience). You will get there but try to go with small steps and do not harm in the process.
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 16:06:39 GMT -5
Both of those points are good points but not the issue here.
I am currently cutting with clamp far away from the blade, it is only the rock that is creating friction with the blade. There was one cut where I started off close, but clear of the blade, that once it got to the center the wood of the vice made contact. But generally, all the cuts done since the rock has been the only thing in contact (vice is several inches away) and it is still generating a great deal of friction at the center of the blade.
The rock fully clears the arbor I do know that was an issue to pay attention to.
As the rock passes the front of the blade it is straight and has normal friction. As it progresses forward it is very very tight at the center of the blade near the arbor, then it eases at the back of the blade. All of my cuts currently are producing black residue and great deal of heat as the rock gets to the center near, but not touching, the arbor.
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 17:17:29 GMT -5
It could be the blade is slightly cupped. Remove the blade from the saw and clean it off, then lay it on a flat surface to see if it sits totally flat on both sides. I was thinking the same thing, it is a cheapy. I could also flip the blade it around and see what happens. Perhaps that moves the problem to the outside edge, confirming it is cupped. I dont know if I would see it from laying it down, I sanity checked it before I used it on a flat table, and I think the variation is going to be slight. |
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aGates
has rocks in the head
Building a silver studio
Member since January 2021
Posts: 518
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Post by aGates on Jul 27, 2022 18:00:45 GMT -5
Could the wood piece be out of square or let me rephrase that could the side of the wood that got burned be closer to the blade than the top part. Bolted askew or cut off square?
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MetaMoose
having dreams about rocks
@MetaMoosehead on Twitter
Member since July 2021
Posts: 74
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Post by MetaMoose on Jul 27, 2022 18:50:33 GMT -5
Could the wood piece be out of square or let me rephrase that could the side of the wood that got burned be closer to the blade than the top part. Bolted askew or cut off square? I don’t think so, even where the wood is not a factor and only rock is touching the blade, the rock does the same thing - it gets very bound at the center. I imagine it is either a cupped (dished?) blade, or worst case scenario the carriage is out of alignment. But likely the blade |
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,359
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Post by quartz on Jul 27, 2022 22:55:49 GMT -5
Another thing to have a look at is to make sure the rails are straight. If the inner rail has a sag in the middle, or the outer rail has a hump, it will dump the rock toward the blade, then take it back away as the rock moves past center. With the long rock shown, it wouldn't really get past center. This after making sure the blade is flat.
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Post by catmandewe on Jul 28, 2022 1:24:08 GMT -5
Sounds like a cupped blade to me, flip it and see if it changes how it contacts the stone.
Tony
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