|
Post by sheltie on Jun 13, 2013 15:11:59 GMT -5
If the gap is uniform, it is not as bad as if the gap is uneven. if the feed is too fast and the blade is walking a bit to the side or cupping slightly, the lower speed should help. if the blade is a bit cupped, that may not go away by itself. sometime I like to turn my saw off mid-cut. I watch/listen for how much time to stop. instant stopping and feed is way to fast or alignment way off. some spin down and you are likely OK. blade should be movable w/o too much difficulty, and should be able to restart w/o motor problems. the point is that there is not supposed to be a lot of pressure. consider how much pressure a few bricks on a gravity feed gives. you want the blade to grind, not be pushed through the rock. deleted, duplicate post.
|
|
QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,640
|
Post by QuailRiver on Jun 13, 2013 16:47:51 GMT -5
Not sure if I'm having a moment of phantom Dyslexia or not but shouldn't the largest pulley on your POWERFEED ARBOR produce the slowest speed feed rate, and the smallest pulley produce the fastest speed feed rate? And don't you want to use your slowest feed rate for harder materials and not the other way around? Also I just looked up the specks on your 16" saw on the HP site and it reads: "-POWERFEED – 3 speeds. Approximate workpiece infeed rates: 1) 13-3/4 inches per hour, 2) 17 inches per hour 3) 22-3/4 inches per hour". Your medium speed of 17" per hour is too fast for agates, petrified wood and other hard materials. You definitely should be using your slowest speed of 13-3/4" per hour for agate and high-silicate jasper. If you've had your belt set on the smallest pulley, and it was feeding at 22-3/4" per hour while cutting anything hard, then I think that explains all of the blade problems you've been having, including the pieces breaking out of the edges of the 301 blades. 22-3/4" and hour would be outrageously fast for cutting agates or jasper. I would suggest double checking those instructions again as to how to set the pulleys and belt for the SLOWEST feed rate. Then dress your blade a couple of times and try sawing again and see what happens.
|
|
|
Post by Bikerrandy on Jun 13, 2013 18:24:31 GMT -5
I get that tab on a lot of my slabs, just one more thing that my tile saw is good for fixing.
|
|
|
Post by sheltie on Jun 13, 2013 18:51:18 GMT -5
Not sure if I'm having a moment of phantom Dyslexia or not but shouldn't the largest pulley on your POWERFEED ARBOR produce the slowest speed feed rate, and the smallest pulley produce the fastest speed feed rate? And don't you want to use your slowest feed rate for harder materials and not the other way around? Also I just looked up the specks on your 16" saw on the HP site and it reads: "-POWERFEED – 3 speeds. Approximate workpiece infeed rates: 1) 13-3/4 inches per hour, 2) 17 inches per hour 3) 22-3/4 inches per hour". Your medium speed of 17" per hour is too fast for agates, petrified wood and other hard materials. You definitely should be using your slowest speed of 13-3/4" per hour for agate and high-silicate jasper. If you've had your belt set on the smallest pulley, and it was feeding at 22-3/4" per hour while cutting anything hard, then I think that explains all of the rpm changed the blade problems you've been having, including the pieces breaking out of the edges of the 301 blades. 22-3/4" and hour would be outrageously fast for cutting agates or jasper. I would suggest double checking those instructions again as to how to set the pulleys and belt for the SLOWEST feed rate. Then dress your blade a couple of times and try sawing again and see what happens. Nope, I'm looking at it right now. It gives the pulley selection and lists them as largest, middle and smallest and says that agates, japsers etc, should be on the largest pulley (which it was until earlier today). Additionally, that was the way it was delivered to my house and set up by the HP guys after they asked me what I would be cutting most. In the morning I'll move the pulley to the smallest (slowest) pulley, make a few cuts into my grinding wheel and report back the results. I just took another look at the manual and while it does say "largest, middle, and smallest" and it gives the type of rocks to cut using these settings, it doesn't list which is fast and which is slow. I'm assuming that the smallest is the slowest because of the MOHS number it suggests cutting. Does that make sense? To be honest, I couldn't tell by ear when I switched from largest to middle if the RPM changed. It sounded the same to me although it took longer to cut a slab than normal.
|
|
|
Post by sheltie on Jun 13, 2013 18:52:42 GMT -5
I get that tab on a lot of my slabs, just one more thing that my tile saw is good for fixing. I just use my cabbing machine to grind them off. But, at this rate I'll have to get new wheels pretty quickly.
|
|
|
Post by jakesrocks on Jun 13, 2013 19:13:52 GMT -5
Smallest motor pulley and largest power feed pulley to slow down the feed. The smaller the power feed pulley, the faster it will feed.
|
|
QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,640
|
Post by QuailRiver on Jun 13, 2013 20:39:02 GMT -5
Sheltie, My response was to your earlier post when you stated that the largest pulley was your fastest one when you wrote: "... I changed the speed by putting the belt in the MOHS hardness 6 slot (slower) rather than the 7 I had before. Based on only two slabs, it may be better. Too early to tell. The instructions for my saw specify, agate, quartz, topaz and jasper the belt should be in the largest pulley (the fastest one), MOHS 7; the middle pulley is for Orthoclase, Feldspar and Onyx, MOHS 6, and that's the one I'm using now. The slowest pulley is 5 MOHS or below and is meant for Apatite, Fluorite, and Calcite." In that post you seem confused as to the speed as it relates to pulley size. The largest pulley on your POWER FEED ARBOR is your SLOWEST feed rate pulley, not the FASTEST speed rate as you stated. The SLOWEST SPEED (Largest pulley)IS the correct one for agates. However, I think it's time for me to surrender the field! Good Luck!
|
|
|
Post by jakesrocks on Jun 13, 2013 21:12:04 GMT -5
Either your instructions were printed in China,or you're reading them wrong. If the step pulley is on the power feed shaft, the largest pulley should give you the slowest feed speed. If the step pulley is on the motor, the largest pulley will give the fastest feed speed. With the smaller pulley on the motor, the belt will only move a short distance per RPM. If that belt then goes to the largest pulley on the power feed shaft, the motor will have to make several complete turns to turn the power feed shaft one revolution. Small at the power source (motor), and large at the shaft being driven will always slow things down.
|
|
|
Post by deb193redux on Jun 13, 2013 22:28:37 GMT -5
I agree you go slower for harder material.
depending on where the step pulley is, larger can be slower, i.e. it is in the driven position
|
|
|
Post by Rockoonz on Jun 14, 2013 2:06:07 GMT -5
Big pulley is slowest, for hardest material. Small pulley is fastest for soft, only I never change mine, no need to. leave it on the slow setting.
Lee
|
|
|
Post by sheltie on Jun 14, 2013 7:53:25 GMT -5
It appears then that I'm back to the beginning. As I'm learning nomenclature, my "step" pulley has three levels. Up until yesterday it was on the largest level then I changed it to the middle level. I had thought the recommendations were for me to put the belt on the slowest , i.e., smallest level, but now I'm reading that the largest level was correct. I'm really confused. Since I previously had the belt on the correct level (the largest) and the tap was getting worse, yet the pencil test showed the blade to be perfectly in balance, what other steps should I take to decrease the tap? Does it all come back - again - to the type of blade? I'm going to try a few more slabs in the middle to see what happens but I really need to figure this out with your help. Here is a link that shows my saw. Unfortunately it only shows it head on. Those of you who understand - which is everyone but me - knows the pulley system is to the left (in red) as you look at the picture. The step pulley is in the very front of the red cover of the pulley system. If you could look at it without the cover, the largest would be to the left, then the middle, then the smallest. Does that help? www.hplapidary.com/p/965/highland-park-style-121416-inch-rock-slab-saw-model-16
|
|
|
Post by deb193redux on Jun 14, 2013 8:27:35 GMT -5
it sounds like the blade s aligned, but ... ... ... the pencil test is not to draw a circle, but a line. I think you disengage the clutch and push the vise forward to make a line, then you reset the pencil at the rear, rotate the blade a bit, and pull the vise back to make another line. if either line is not all the way along, this is degree of misalignment or blade cupping.
|
|
|
Post by sheltie on Jun 14, 2013 8:45:40 GMT -5
Ah! Ok, as soon as I stop my current slab, I'll try that. I just dressed the blade and changed it back to the largest of the step pulleys, so we'll see how that goes as well.
|
|
|
Post by Rockoonz on Jun 14, 2013 11:20:40 GMT -5
A sharpie with a wedge shaped tip will work even better since the tip is soft and the line will get wider and narrower. When you check make sure that when you rotate the blade and check again that the marker crosses the same point on the blade front and rear, since a little runout on the blade can be confused with misalignment. I doubt you would have an alignment problem with a new saw, it takes a lot of cutting for them to drift off. Here's my old HP 12/14 inch workhorse. I assume your step pully is in the front like this one, if so lg pully=slowest speed. Lee
|
|
|
Post by sheltie on Jun 14, 2013 11:40:39 GMT -5
Now I'm getting somewhere. I did the pencil test again, this time using the vise to run it from back to front. I didn't even bother to rotate the blade after the first test because the difference from front to back is about 1/16 to 1/8 of an inch! I'm sure if I ran the same test after rotating the blade the result would be the same.
So it appears that I now have an alignment problem. But where? On the blade or on the vise? How can you tell and how can it be fixed?
|
|
|
Post by Rockoonz on Jun 14, 2013 11:42:03 GMT -5
Another consideration with saw cut "nubs" is the rock placement in the vice. If you place it so the cut ends with the blade finishing the cut pretty much lined up with the edge of the rock as your pic seems to indicate, you will get a wider nub. At any rate the nubs will occur and must be ground off with a hard wheel. they will tear sanding belts and ruin soft wheels.
Lee
|
|
|
Post by Rockoonz on Jun 14, 2013 11:46:23 GMT -5
It's a new saw, call HP. It should have been dialed in at the factory. Do you own feeler gauges or a machinists dial gauge, you will need these to properly adjust alignment. Alignment is always dialed in by moving the blade.
Lee
|
|
|
Post by Rockoonz on Jun 14, 2013 11:51:31 GMT -5
Also when sharpie or pencil testing be sure that when you use the crossfeed to bring the tip to the blade that you turn it towards the blade and don't back it off at all, and same when cutting. the crossfeed will have a little slop in it to prevent wearing out prematurely.
|
|
|
Post by deb193redux on Jun 14, 2013 12:56:23 GMT -5
I think 1/16 could be ignored. but if the 1/8 is real, that is your problem. Try to repeat the test a few time to be sure. The solution would be to get arbor perpendicular to vise path and thus blade face parallel to vise path. It sounds like the blade is bending a bit to accommodate this misalignment. It is possible this has been why 301 blades died. They are more rigid than 303 and where it bends, the 301 snaps.
all of this with a grain of salt that I am far away and not actually seeing/touching saw.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Jun 14, 2013 12:57:19 GMT -5
Slop = backlash is the threads.
Wouldn't a good saw have anti-backlash built in?
|
|