mikeinsjc
spending too much on rocks
Member since June 2010
Posts: 329
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Post by mikeinsjc on Jan 3, 2011 14:43:42 GMT -5
I just got a magnetic base dial indicator cheap just to check the runout on my 18" blade. I have taken my saw completely apart to clean and change oil, and thought I'd check runout just for grins.
My blade has about 50% life left, so a new blade is in the near future. I am going to check the runout on whatever new blade I purchase. What would you consider an acceptable figure?
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chromenut
fully equipped rock polisher
Member since December 2009
Posts: 1,971
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Post by chromenut on Jan 3, 2011 18:09:43 GMT -5
Pardon my ignorance, but what is meant by "run out"?
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jan 3, 2011 18:15:52 GMT -5
Ha Ha Robin, I was waiting for somebody to ask before I did. Run outta diamonds,dont cut no mo'. .... ;D.I'm sure someone will fill us in on the correct definition,I've never heard that term that I remember.
snuffy
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NDK
Cave Dweller
Member since January 2009
Posts: 9,440
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Post by NDK on Jan 3, 2011 18:35:22 GMT -5
Runout is "The radial variation from a true circle."
Google is my buddy! LOL!
Nate
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snuffy
Cave Dweller
Member since May 2009
Posts: 4,319
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Post by snuffy on Jan 3, 2011 18:40:20 GMT -5
Yeah,yeah,I googied it too,still aint too clear on it.
snuffy
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chromenut
fully equipped rock polisher
Member since December 2009
Posts: 1,971
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Post by chromenut on Jan 3, 2011 18:42:07 GMT -5
Where I grew up, runout had a connection with other terms such as, "Theresa Two-Step", "Mud Butt", and "Montezuma's Revenge"....lol....
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drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
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Post by drjo on Jan 3, 2011 18:54:12 GMT -5
Runout has to be very small or you get a hammering effect in your cut ans the blade self-destructs.
Did you mean wobble?
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Post by Bikerrandy on Jan 3, 2011 19:32:54 GMT -5
Normally, the larger blades don't experience too much run-out. (guessing that you're speaking of the up/down motion?) I get this a lot on my 10 inch blades but only because I cut by hand and I'm really rough on them. I would say try cutting a slab of obsidian. You'll either get a smooth slab or nothing but splinters.
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Post by cpdad on Jan 3, 2011 21:57:32 GMT -5
wouldnt to much worry about it ;D...just look at your blade after you fire it up...if it aint wobbling cut away ;D.
as far as your question about how much is acceptable...i would think no more than .008...maybe .012 for 18"...i only base this on equipment i build.
depends on where you check the runout also...you may only have runout of .001 at the blade closest to the shaft...but as you go further out to the outside of the blade.....that .001 grows considerably as you move outward....kinda like jump rope....not much at the hands.....but gets worse towards the middle.
i build some saw mill machines that require blades to run within .002 run out at 24" outside diameter....i am at the mercy of the blade manufacturer....but these blades are much thicker...and not as prone to inertia.
oh shucks.....if it cut before...it gonna do it again ;D...kev.
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rockhound97058
freely admits to licking rocks
Thundereggs - Oregons Official State Rock!
Member since January 2006
Posts: 760
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Post by rockhound97058 on Jan 3, 2011 22:18:08 GMT -5
Are we sure the run-out were talking about is blade wobble or the distance between the vise as it feeds into the cut. If you have the saw completely tore down and putting it back together I'd align the vise as close to straight as you can get it. I rarely see a rock saw that the blade doesn't have some sort of wobble (Curse you slick skinned brazil!) or a Thundereggs which desides to slip from the vise LOL.
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Post by mohs on Jan 3, 2011 22:23:53 GMT -5
kev’s true! ;D
prevent run out don’t run hot
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Post by johnjsgems on Jan 4, 2011 9:40:59 GMT -5
A good quality blade on a saw in good condition with proper blade flange washers (1/6 the blade diameter) shouldn't wobble noticeably until screwed up by the user. Don't tighten more than needed to prevent blade slipping also. And yes, run out refers to wobble. And Kev, with your building saws, getting married and a new dog, how do you find time to jump rope?
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Post by jakesrocks on Jan 4, 2011 10:12:32 GMT -5
I hope you didn't remove the rails your vise runs on when cleaning your saw. If you did, you're going to have to use that dial indicator in the vise to check at the front and back of your blade. It has to measure within a couple thousandths, if not you'll bind and dish your blade. Depending on the type of saw, you may be able to make the adjustments at the arbor bearings. I had to do it when I changed the bearings on an old 24" H.P. saw. Don
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Gem'n I
freely admits to licking rocks
Member since March 2008
Posts: 980
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Post by Gem'n I on Jan 4, 2011 13:34:03 GMT -5
With out getting too complicated, a blade is like a tire...it can be out of round or slightly oval measured by TIR (total indicator reading) or out of side to side relationship to a fixed plane (read vise) called runout. Both are important but, in my opinion the first out of round condition should be less than .003" and the second should be no more than .015" on an 18" saw. Both will cause a blade to bind and wear prematurely the further out of true position a blade is to these X and Y axis of the vise. Larry
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