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Dial indicator

Posted: Mon Oct 19, 2009 2:14 pm
by heathicus
Dusty (and maybe others?), I want to say thanks for posting your procedures on alignment using a dial indicator. I've always doubted my alignments using the tools that I had in my shop. So I picked up a dial indicator from Horrible Freight yesterday and it is really nice now knowing for absolute certain how accurate (or not) my alignments are. Sure, maybe I was close enough to begin with. Maybe I don't HAVE to be accurate to within .001", but the confidence in my alignments now is really nice. So thanks!

Now I just need to get a digital angle gauge...

Posted: Mon Oct 19, 2009 2:51 pm
by JPG
Have you been reading THIS thread??????;) https://forum.shopsmith.com/viewtopic.php?t=4409

Posted: Mon Oct 19, 2009 3:09 pm
by heathicus
JPG40504 wrote:Have you been reading THIS thread??????]https://forum.shopsmith.com/viewtopic.php?t=4409[/url]
I have. And I've found it educational and entertaining. But I don't have a piece of aluminum that will do the job. Any "square" piece of wood I have was cut with my previously untrusted alignments and checked with cheap instruments, so the squareness is untrusted. I'm still quite the newbie, inexperienced woodworker wannabe. So the dial indicator gives me a lot of confidence in my settings that I didn't have before. It's well worth it to me just for that. With confidence in my initial alignments using the dial indicator, I can eventually make an alignment jig that I trust like the one Dusty posted in that thread.

Posted: Mon Oct 19, 2009 4:03 pm
by JPG
heathicus wrote:I have. And I've found it educational and entertaining. But I don't have a piece of aluminum that will do the job. Any "square" piece of wood I have was cut with my previously untrusted alignments and checked with cheap instruments, so the squareness is untrusted. I'm still quite the newbie, inexperienced woodworker wannabe. So the dial indicator gives me a lot of confidence in my settings that I didn't have before. It's well worth it to me just for that. With confidence in my initial alignments using the dial indicator, I can eventually make an alignment jig that I trust like the one Dusty posted in that thread.
As I have previously posted, IMHO the best(most difficuly to achieve) test of squareness is to cut all the way around a board placing the just cut edge against the miter gauge each time . After the fourth cut rotate it 90 degrees further and check how the first cut edge aligns to the blade. If it aligns, repeat using a disk sander. All four corners should be very 'square'.

This involves a trial and error method, in that it most likely will NOT be good the first time. Adjust the miter gauge by 1/4 of the total error between the first and fourth edge and repeat.

Repeat until you are successful or are committed to a mental facility.

This WILL give you your square reference board or if committed, it becomes unnecessary. :rolleyes:

BUT What if the table is NOT square to the blade???? You know this any time you use it! If the workpiece is further away from the back end of the blade you can see it! If the workpiece is closer to the blade at the back, you can feel it and see the blade nibbling it. The work piece may rub against the side of the blade if too far out of alignment. Assuming the fence IS properly aligned to the TABLE, a similar situation will occur when ripping. These binding conditions become quite apparent when using a hollow ground blade(no set).

IF the table is NOT square to the blade, you still can get a square reference board, but it MUST be in error so as to provide CLEARANCE at the BACK edge of the blade otherwise the workpiece will either be nibbled or pushed back by the side of the blade.

Dial Indicator

Posted: Mon Oct 19, 2009 4:31 pm
by dusty
another way to do without.

This is basically the same as what JPG just posted but I finally found it and I'm going to post it anyway.

http://benchmark.20m.com/articles/TheFiveSidedCut/TheFiveSidedCut.html

It was interesting to me, the first time I did this test, because I had just gotten through doing the alignment and was pretty satisfied with it.

A word of warning if you are going to indulge in this game of improved accuracy - there are members of this forum who will tell you you are wasting your time because the wood will swell or shrink right after you are done cutting it.

This is another version of the same thing. http://www.sawmillcreek.org/showthread.php?t=50736

Posted: Mon Oct 19, 2009 4:51 pm
by JPG
dusty wrote:another way to do without.

This is basically the same as what JPG just posted but I finally found it and I'm going to post it anyway.

http://benchmark.20m.com/articles/TheFiveSidedCut/TheFiveSidedCut.html

It was interesting to me, the first time I did this test, because I had just gotten through doing the alignment and was pretty satisfied with it.

A word of warning if you are going to indulge in this game of improved accuracy - there are members of this forum who will tell you you are wasting your time because the wood will swell or shrink right after you are done cutting it.

This is another version of the same thing. http://www.sawmillcreek.org/showthread.php?t=50736
YEAH! Did ya notice that to correct 1/8" runout at 24" you need to adjust the miter gauge 0.03" AT 24" from the pivot!:eek:

This IS as I said NOT an easily attained goal!

The two cut method is probably more practical(make a cut, flip the workpiece to the opposite 'side' of the miter gauge and cut again. Measure the difference in the width of the cutoff and adjust by 1/2 that amount(at the backside of the workpiece).

NOTE: This makes more sense with a sled. Moving the miter gauge to the slot on the other side of the blade and flopping the board will result in negligable difference regardless of the amount of 'error'. Instead of moving to other side of miter gauge you can flip the board and measure the width at front and back. Again this checks the miter gauge ONLY!

Ignore this! It ain't right!!!

Posted: Mon Oct 19, 2009 5:46 pm
by mickyd
JPG40504 wrote:YEAH! Did ya notice that to correct 1/8" runout at 24" you need to adjust the miter gauge 0.03" AT 24" from the pivot!:eek:
........
.03" adjustment!!! I knew that dial indicator was needed in the process!!! :D

Posted: Mon Oct 19, 2009 6:40 pm
by JPG
mickyd wrote:.03" adjustment!!! I knew that dial indicator was needed in the process!!! :D
Would 1/32" have been less demanding of a dial indicator????:rolleyes:

Posted: Tue Oct 20, 2009 11:14 am
by heathicus
dusty wrote:A word of warning if you are going to indulge in this game of improved accuracy - there are members of this forum who will tell you you are wasting your time because the wood will swell or shrink right after you are done cutting it.
I'm fine with that. :) And I realize the wood behaves that way, but poor cuts are due to a number of variables. If I can confidently eliminate one of those variables - that being alignment - with the dial indicator, then it's worth it to me. I can direct my focus on other variables like technique and user error.

I'm all on my own here learning woodworking. I don't have a mentor or anybody to show me things. And the equipment I'm using I have completely disassembled, restored, and reassembled. I feel that setting those machines back up with accurate alignments will make the learning process a lot easier for me. And, as my skills and confidence improve and I become more familiar with using the machines, if I can become less reliant on a dial indicator that's fine. But the dial indicator helps give me confidence in the machines to accurately do their job so I can focus on gaining the confidence in doing my job.

Posted: Tue Oct 20, 2009 2:36 pm
by JPG
heathicus wrote:I'm fine with that. :) And I realize the wood behaves that way, but poor cuts are due to a number of variables. If I can confidently eliminate one of those variables - that being alignment - with the dial indicator, then it's worth it to me. I can direct my focus on other variables like technique and user error.

I'm all on my own here learning woodworking. I don't have a mentor or anybody to show me things. And the equipment I'm using I have completely disassembled, restored, and reassembled. I feel that setting those machines back up with accurate alignments will make the learning process a lot easier for me. And, as my skills and confidence improve and I become more familiar with using the machines, if I can become less reliant on a dial indicator that's fine. But the dial indicator helps give me confidence in the machines to accurately do their job so I can focus on gaining the confidence in doing my job.
Do not let the 'confidence' you have in using the dial indicator obscure the importance of ALL the other factors relevant to 'doing it correctly'(technique/procedure).;)