Matt, the backs of dial indicators are kent to be swapped out depending in their application. You could put the back of the imperial indicator on the metric one to fit in your old holder. Every plunge dial indicator I have and have seen have this capability.
Considering the material properties of wood, why would we want to cut pieces with this kind of tolerance? Isn't the moisture level of the wood going to change these values after the piece is cut? EDIT: I'm not saying Matthias's method is not useful. There are certainly other things you can cut on a table saw where you would want this kind of accuracy, I was just wondering why you would do this with wood.
Bought a digital one that does both metric and inches for $23.48 (Inclusive of international shipping!!!) from deal extreme. Comes with a flat backside and a backside with the "eye" on it. The flat backside is metal, just a piece of magnet from an old hard drive and it stick to any thing metal very well. www.dx.com/p/zndiy-bry-z-086-1-6-lcd-inch-metric-digital-indicator-black-0-25-4mm-277077#.VIaYPzGUdcg
Overwatch I believe Matthias has talked about that in the past. I agree with you, it's quite possible that this level of tolerance is not reasonable for most applications.
I don't have the space in my garage for a regular table saw, so I use a portable contractor saw. I love the saw, but the down side is its got an aluminum top. Your comment at the end regarding rubber feet has me intrigued. I'm going to look into what types would be best/easiest to use. Thanks for that. For me, if you can be more precise and accurate, then why not ? I guess it's a matter of choice.
I wish I had this guy's genius -- not necessarily for this tool, but check out his other videos. He can come for dinner at our house any time and share some of his math-meets-woodworking intuition.
I've been doing this for a while now, but with a DeWalt jobsite saw which has an aluminum table. I've only gone to this extreme with things like tenons, so my required range of movement is always similar. All the same, I think my current arrangement using a bracket that wedges in the T Slot is both clunky and overkill, so I think I might revisit and borrow your idea of using weight and friction. As you said, you really don't anything too serious to stop a DTI spring moving the bracket. I was looking at a nice fence arrangement on Stumpy Nubs channel this week. He uses an Incra TS LS fence system. It's crazy expensive, but allows micro adjustment via a large thumb wheel, and it would fit perfectly with using a DTI to measure relative movement of the fence. I wouldn't pay $500 on a saw fence, but I might try and make one. Fortunately, I am a retired toolmaker with access to a machine shop, which makes all the difference with a project like that.
Re all the comments about precision being unnecessary. I found out quite early on that slop can multiply on some projects to give pretty glaring errors - at least to my eye. People laughed at me when they saw me using digital calipers with wood, when they used a tape measure. If it is easy to be precise (and these days it is), why would you want anything less?
10 лет назад+3
This dial indicator are awesome but more awesome is that our hand is so precise that you can set every value you want (only in your hand, of course) Give it a try.
I am thinking you were seeing was the result of blade flex. Machinists take a "spring cut" after making a final pass on a work piece. It helps mitigate tool flex that is almost always involved with tooling. Nice piece. Fred
I have a compound miter saw that the arbor shifts the blade a fraction of a millimeter when engaged (run out). It is enough for me to notice, and adjust for that minute action each time. It is an automatic adjustment for me, though I should have taken the saw back for a replacement or refund. It is a great tool for training, because it shows a level of tolerance.
You could also get a standard magnetic back for your dial indicators. Most should use the same 4 bolt pattern on the back (at least most that I've seen do), and I was able to find a magnetic back for a dial indicator for about $5 online. It's not quite as easy as the fridge magnet, but it's a more professional looking, and probably more durable solution.
They also make adhesive-backed vinyl magnet material that you can get at Joanne's, Michael's or any craft shop. It's great for adding a magnetic backing to almost anything - especially charts, that you want to keep easily accessible.
Very nice solution for the times when you DO want accuracy of that degree! As noted below not always needed but when you do this would seem to me to be an excellent way to go about it. Efficient!
Matthias, for best results,just be sure to keep the rod absolutely perpendicular to the fence, or the measurement might be skewed, since you are going for that kind of precision you are awesome!!! =D
Nelson Baietti The effect for small angles is very moderate. Being 5 degrees off would be glaringly obvious, but only throw measurements off by 0.4%. And because I'm only measuring small increments, it would make a negligible difference. And if it's 2.5 degrees off (still quite obvious), the error is only 0.1%
uhhhmmm... wow, yeah, actually now that you've mentioned that and I stopped to think a little better about it, I even feel kinda silly! You are absolutely correct, and the calculation of those numbers is quite impressive! Yeah, Matthias, for that and so others we're such a big fan! Thank you very much for the reply! Take care!!! =)
From watching your videos I've always been interested in dial indicators (or dowell indicator, which Ive thought it was cause of the way you say it). I really like small-scale measurement devices. I couldn't justify buying one having not demonstrated any utility for it, but today I saw good condition one at the re-store for $1 and picked it up. I'm wondering if the spring return action changes the accuracy of the reading. For example, if you began a measurement with a dial indicator starting at already 50% depression (due to space constraints), would that reading be different than if you did it just at default position? Because as the spring gets compressed, it's pushing back with more force against the surface of what it's measuring, so the force required to move from 0 to 2 than if there were no resisting force is greater. Sorry long question but I think it's pretty straightforward
You are talking more about the softness of wood than you are accuracy of an indicator at it's position where measured. Quality indicators manufactured have a newton force accuracy statement.
Matthias, Thank you, thank you, thank you for this vid. Dial indicators for woodworking... it's.. it's... so bloody seductive. It has me in its hooks. It makes me irrational sometimes, gosh. I just bought four Mitutoyo dial indicators, 5 mm, 10 mm, 20 mm and 50 mm. The resolution of the 5 mm one is 0.001 mm, the rest are 0.01 mm. Yes, currently I have more money than sense, but... but... dial indicators! Gosh.
Matthias not sure if you would see this, but would love to see if you have done something similar for your Dewalt saw, the one with the ferrous top, magnets are no use for those.
You should play those against each other-use one to see how much the other moves when you plunge the probe. Could be interesting. I would, but I don't have a workshop in this city yet.
It's great that you ended up so close to 20x20 mm in the end, but what I don't understand is why, after the first cut, there was a 0.1 mm difference between the two sides (21.24 vs 21.13), although cut with the same fence setting.Why was that?
I may be missing some space constraint or other valid reason, but maybe not cutting the "fridge magnet" to the round shape of the micrometer could have helped with its stickyness to the metal surface of the table saw.
In another video of yours you talk about blade deflection when cutting to final dimension, Is that .005" deflection throwing your workpiece out of square by the amount of deflection? In your opinion would it be more accurate to get the workpiece to just over size (final dimension + at least half the kerf of the blade) and then make final cut, to avoid any blade deflection? The arbor and shaft driving the saw blade are rigid in that respect so we know the blade is cutting at a slight angle if you can measure deflection, right? Or am I thinking about this wrong? Also beyond staring at it with a square, do you have a specific method for testing a sled for accuracy? I've seen the 5 cut method but was wondering if you had any other approach.
One problem is that the probe needs to be at a right angle with the fence otherwise you are actually moving the fence by a bit less than what it indicates (requiring multiple iterations)
What kind of precision do you need to have on your rip fence to make that kind of cut? I bought a new aluminum fence which, to my dismay, is bent approximately 0.2 mm. I guess you need something better than that.
I'm still trying to figure out why anyone needs to be closer then .010 on wood. Depending on the species the humidity in the air can change it that much from morning to night. I could see this as a great tool to square up your saw.
David Harris You rarely need that sort of precision. But if, for example, I'm making a bar to ride in the saw's slot, it's handy to be able to work that precisely.
Just using digital calipers and dial indicators will easily get you a lot more precision than your crappy eyeball. You can buy these tools for cheap now days. It's not like you need machinist quality gear.
why not just glue some non-slip mat on the back but then I thought about how that stuff works and it has a tiny bit of give before it becomes "non-slip" so it would be inaccurate. I guess the magnet is the best way to go.
They're available with a lug back, doing a google search yields a bunch of them out there. For Mattias' idea though, I think having one without the lug makes it a lot more sense, no need to over come the lug against a flat surface.
acousticguitarpeter Ok, first of all, i am just asking. I am not an expert, but i remember from highschool something about the magnet screwing up the watches, so there is my question. Maybe a more powerfull magnet can cause some miss reading or something. Again, i am just asking, this guy sure knows the answer.
.010" is a lot. Lay three sheets of printer paper on your desk and run your finger over the edge. Then you'll see how big .010" really is and how much it could effect a joint going together. A dowel that is .010" bigger than a hole will require you to pound it in with a lot of force. (hard wood) A dowel that is .010" smaller than a hole will drop right in. Even the thickness of one sheet of paper, .003" can be a big deal. The difference between a tight fitting joint and a sloppy one can easily be .003". I am a machinist and have spent 20 years making precision parts.
Matthias Wandel There really needs to be a magnet that's stronger than your typical fridge magnet, but less than the rare earth magnets you could pick up a car with. How about it, science?
Dude--apparently, you have total confidence that your fence lock is setting your fence *perfectly parallel* to the saw blade/miter slot each time you release and reset it! Dollars to doughnuts that ain't the case!
yes, of course I can put it on non-square if I'm not careful. The key is to put it on square. And your point is? And if it was some typical microadjust contraption, the effect would be much worse becasue it's further from the blade.
My point is you're shooting for a level of precision that is outside of the very tools (saw, fence) that you're using. Btw you put it best when you said "Much more accurate than you really need for wood". Imo a better application of that dial indicator would be when you're setting joiner or planer knives, or checking for runout on a saw blade, etc.
Matt, the backs of dial indicators are kent to be swapped out depending in their application. You could put the back of the imperial indicator on the metric one to fit in your old holder. Every plunge dial indicator I have and have seen have this capability.
Ferrous table saw tops make life so much more fun and accurate
A simpler table saw fence micro adjuster (simpler than the one I made a few years ago)
My table saw has an aluminum surface, so I might follow your suggestion of using rubber feet.
Considering the material properties of wood, why would we want to cut pieces with this kind of tolerance? Isn't the moisture level of the wood going to change these values after the piece is cut?
EDIT: I'm not saying Matthias's method is not useful. There are certainly other things you can cut on a table saw where you would want this kind of accuracy, I was just wondering why you would do this with wood.
Bought a digital one that does both metric and inches for $23.48 (Inclusive of international shipping!!!) from deal extreme. Comes with a flat backside and a backside with the "eye" on it. The flat backside is metal, just a piece of magnet from an old hard drive and it stick to any thing metal very well.
www.dx.com/p/zndiy-bry-z-086-1-6-lcd-inch-metric-digital-indicator-black-0-25-4mm-277077#.VIaYPzGUdcg
Overwatch I believe Matthias has talked about that in the past. I agree with you, it's quite possible that this level of tolerance is not reasonable for most applications.
MaximusPayne Why does it matter so much if it's "reasonable?" The point is it's possible.
.01mm precision. With wood. By table saw. Man, you're really cool.
3:05 This man is in a league of his own .
I don't have the space in my garage for a regular table saw, so I use a portable contractor saw. I love the saw, but the down side is its got an aluminum top. Your comment at the end regarding rubber feet has me intrigued. I'm going to look into what types would be best/easiest to use. Thanks for that. For me, if you can be more precise and accurate, then why not ? I guess it's a matter of choice.
This is a great idea. I made one and found it has improved my accuracy greatly. Thanks!
I wish I had this guy's genius -- not necessarily for this tool, but check out his other videos. He can come for dinner at our house any time and share some of his math-meets-woodworking intuition.
I've been doing this for a while now, but with a DeWalt jobsite saw which has an aluminum table. I've only gone to this extreme with things like tenons, so my required range of movement is always similar. All the same, I think my current arrangement using a bracket that wedges in the T Slot is both clunky and overkill, so I think I might revisit and borrow your idea of using weight and friction. As you said, you really don't anything too serious to stop a DTI spring moving the bracket. I was looking at a nice fence arrangement on Stumpy Nubs channel this week. He uses an Incra TS LS fence system. It's crazy expensive, but allows micro adjustment via a large thumb wheel, and it would fit perfectly with using a DTI to measure relative movement of the fence. I wouldn't pay $500 on a saw fence, but I might try and make one. Fortunately, I am a retired toolmaker with access to a machine shop, which makes all the difference with a project like that.
Re all the comments about precision being unnecessary. I found out quite early on that slop can multiply on some projects to give pretty glaring errors - at least to my eye. People laughed at me when they saw me using digital calipers with wood, when they used a tape measure. If it is easy to be precise (and these days it is), why would you want anything less?
This dial indicator are awesome but more awesome is that our hand is so precise that you can set every value you want (only in your hand, of course) Give it a try.
wat
I am thinking you were seeing was the result of blade flex. Machinists take a "spring cut" after making a final pass on a work piece. It helps mitigate tool flex that is almost always involved with tooling. Nice piece. Fred
I have a compound miter saw that the arbor shifts the blade a fraction of a millimeter when engaged (run out). It is enough for me to notice, and adjust for that minute action each time. It is an automatic adjustment for me, though I should have taken the saw back for a replacement or refund. It is a great tool for training, because it shows a level of tolerance.
You could also get a standard magnetic back for your dial indicators. Most should use the same 4 bolt pattern on the back (at least most that I've seen do), and I was able to find a magnetic back for a dial indicator for about $5 online. It's not quite as easy as the fridge magnet, but it's a more professional looking, and probably more durable solution.
Now that's picking the fly shit out of the pepper, as my old boss would say! Nice setup you have there.
That's one I haven't heard, and I've been around long enough to hear most. Adding that to my vocabulary. :-)
They also make adhesive-backed vinyl magnet material that you can get at Joanne's, Michael's or any craft shop. It's great for adding a magnetic backing to almost anything - especially charts, that you want to keep easily accessible.
One word to describe that...perfection!
Very nice solution for the times when you DO want accuracy of that degree! As noted below not always needed but when you do this would seem to me to be an excellent way to go about it. Efficient!
Matthias,
for best results,just be sure to keep the rod absolutely perpendicular to the fence, or the measurement might be skewed, since you are going for that kind of precision
you are awesome!!! =D
Nelson Baietti The effect for small angles is very moderate. Being 5 degrees off would be glaringly obvious, but only throw measurements off by 0.4%. And because I'm only measuring small increments, it would make a negligible difference. And if it's 2.5 degrees off (still quite obvious), the error is only 0.1%
uhhhmmm... wow, yeah, actually now that you've mentioned that and I stopped to think a little better about it, I even feel kinda silly! You are absolutely correct, and the calculation of those numbers is quite impressive!
Yeah, Matthias, for that and so others we're such a big fan!
Thank you very much for the reply!
Take care!!! =)
From watching your videos I've always been interested in dial indicators (or dowell indicator, which Ive thought it was cause of the way you say it). I really like small-scale measurement devices. I couldn't justify buying one having not demonstrated any utility for it, but today I saw good condition one at the re-store for $1 and picked it up. I'm wondering if the spring return action changes the accuracy of the reading. For example, if you began a measurement with a dial indicator starting at already 50% depression (due to space constraints), would that reading be different than if you did it just at default position? Because as the spring gets compressed, it's pushing back with more force against the surface of what it's measuring, so the force required to move from 0 to 2 than if there were no resisting force is greater. Sorry long question but I think it's pretty straightforward
You are talking more about the softness of wood than you are accuracy of an indicator at it's position where measured. Quality indicators manufactured have a newton force accuracy statement.
Sugru would also work well for making some silicon rubber feet on the back, for the non-magnetic types.
Matthias,
Thank you, thank you, thank you for this vid.
Dial indicators for woodworking... it's.. it's... so bloody seductive. It has me in its hooks. It makes me irrational sometimes, gosh.
I just bought four Mitutoyo dial indicators, 5 mm, 10 mm, 20 mm and 50 mm. The resolution of the 5 mm one is 0.001 mm, the rest are 0.01 mm. Yes, currently I have more money than sense, but... but... dial indicators! Gosh.
Nice job. Very interesting. I guess it's to within a hundredth of a millimeter until the humidity either goes up or down...
Tearing apart an old hard drive is a good source of free magnets to glue on.
You can get a magnetic back from Shars for about 5 bucks. It just attaches to the back of the indicator and is extremely strong.
Yeah this guy thinks he "invented" something commonplace in machine shops, a mighty mag would also work for about $15
Brilliant idea with the magnet! Thanks muchly, its gonna solve a major problem for me :)
Would you recommend maybe even gluing a few small neodymium magnets on the back, or would that be overkill, so to speak?
Very accurate Have the time a 32nd of an inch is great. Good video
neat, as always good job Mathias!
Very good! But have you done a simple test to check how close you would have got just setting the fence to 20mm in the first place?
Steve SteveS Yes, could have got lucky, but more likely, not.
A quest for you, Matthias --
How does one build one of those "off and on" magnetic switches that's on your original base?
Matthias not sure if you would see this, but would love to see if you have done something similar for your Dewalt saw, the one with the ferrous top, magnets are no use for those.
Helpful as always Matthias THANKS
You should play those against each other-use one to see how much the other moves when you plunge the probe. Could be interesting. I would, but I don't have a workshop in this city yet.
Metric for the win!
My saw only has an aluminium [sic] top so cant use this beautiful idea unfortunately.
If you have a indicator with the mounting bracket on back you could make the wooden block and glue a few magnets to the bottom.
It's great that you ended up so close to 20x20 mm in the end, but what I don't understand is why, after the first cut, there was a 0.1 mm difference between the two sides (21.24 vs 21.13), although cut with the same fence setting.Why was that?
Gijs van Oort Not sure.
different grain structure on the different sides of wood made the blade flex abit different maybe? too many differents here...
Thanks for the great idea, I'm going to make one of those.
0:01 that hair
Like eddie munster and doc brown had a mad scientists wood working love child.
He's an engineer, not a fashion queen
I genuinely enjoy and appreciate how much he doesn't give a rip about that sort of thing.
Great tip, thanks for sharing this one.
You can do the same with the plunge end of the vernier.
Awesome. Making one today.
I have an aluminum top on a ridgid. What was the material you could glue to the back for this?
Nice tool Matthias. Tell me, where did you pick up inexpensive mag switch? Best I can find is $25 usd.
Would a more powerful magnet on the back of a dial indicator effect the readout?
I may be missing some space constraint or other valid reason, but maybe not cutting the "fridge magnet" to the round shape of the micrometer could have helped with its stickyness to the metal surface of the table saw.
Would this be strong enough to check and adjust your tablesaw blade for runout?
In another video of yours you talk about blade deflection when cutting to final dimension, Is that .005" deflection throwing your workpiece out of square by the amount of deflection? In your opinion would it be more accurate to get the workpiece to just over size (final dimension + at least half the kerf of the blade) and then make final cut, to avoid any blade deflection? The arbor and shaft driving the saw blade are rigid in that respect so we know the blade is cutting at a slight angle if you can measure deflection, right? Or am I thinking about this wrong?
Also beyond staring at it with a square, do you have a specific method for testing a sled for accuracy? I've seen the 5 cut method but was wondering if you had any other approach.
bigdmcc You can try that if you want.
Nice and simple. Thanks.
Great tip!
Measure with a micrometer, mark with chalk, and cut with an ax?
What sort of wood was that? It had an interesting texture!
looked like birch :)
Bjørnar Haugen Curly maple
Matthias, do you work with any other mediums? (metal, plastics)
После такого видео хочется спросить: как добиться точности от направляющей. Кокой должен быть механизм направляющей?
Cutting to ten-micron tolerances with a table saw? I think I need to pick up one of those dial indicators...
One problem is that the probe needs to be at a right angle with the fence otherwise you are actually moving the fence by a bit less than what it indicates (requiring multiple iterations)
ratchetfreak See my previous answer to that comment
I think I need a better table saw.
Another option for non-steel tops might be Sewell"s Direct AirStick Microsuction Tape...
What kind of precision do you need to have on your rip fence to make that kind of cut? I bought a new aluminum fence which, to my dismay, is bent approximately 0.2 mm. I guess you need something better than that.
fischkarn Mine is totally straight.
Matthias Wandel
Any idea what that would translate to in terms of metric accuracy? For example +-0.02 mm per 0.5 m.
Excellent !
In the next video you can adjust to one atomic monolayer.
can you post a link to the dial indicator?
I'm still trying to figure out why anyone needs to be closer then .010 on wood. Depending on the species the humidity in the air can change it that much from morning to night. I could see this as a great tool to square up your saw.
David Harris You rarely need that sort of precision. But if, for example, I'm making a bar to ride in the saw's slot, it's handy to be able to work that precisely.
+Matthias Wandel I did exactly that today and I surely missed this "jig". Thanks.
Hi Matthias .May i ask what you sugested for a aluminium table . that has rubber feet .please?
I think he means those rubber feet for cutting boards. They're used to keep the cutting board from moving on the countertop.
...and what is this online source of metric dial indicators?
www.aliexpress.com/item/High-Quality-Dial-Indicator-Measuring-Tool-Indicator-0-01mm-5301-10/959319615.html
Cool man!
Just using digital calipers and dial indicators will easily get you a lot more precision than your crappy eyeball. You can buy these tools for cheap now days. It's not like you need machinist quality gear.
why not just glue some non-slip mat on the back but then I thought about how that stuff works and it has a tiny bit of give before it becomes "non-slip" so it would be inaccurate. I guess the magnet is the best way to go.
It figures a metric dial indicator would be annoying as possible by not having the standard mount so it can be conveniently used.
They're available with a lug back, doing a google search yields a bunch of them out there. For Mattias' idea though, I think having one without the lug makes it a lot more sense, no need to over come the lug against a flat surface.
I like the switchable magnet.
It is actually against the laws of nature to add a mount loop in a metric dial indicator. It just doesn't work that way.
Matthias, where'd you source the indicator from? Anywhere here domestic? Google is only bringing up suppliers in China.
Does anyone know where I can buy this Shahe dial indicator?
Where did you get the metric dial indicator?
¿Can't the magnet cause some problem to the dial indicator?
I doubt it.
You saw the measurment after the final cut, was there any problem?
acousticguitarpeter Ok, first of all, i am just asking. I am not an expert, but i remember from highschool something about the magnet screwing up the watches, so there is my question. Maybe a more powerfull magnet can cause some miss reading or something. Again, i am just asking, this guy sure knows the answer.
TheLaoruga
The dial indicator is not affected by magnetism. The pointer is attached to a gear, which is driven by teeth on the measuring spindle.
Cant beat metric
Next step, one atom precision.
For some reason dial indicators are hard to find in Sweden. One would think all woodworkers use them.
No they are not www.biltema.se/sv/Bil---MC/Verktyg-och-Verkstadsutrustning/Testinstrument-och-Elektronik/Indikatorklocka-191443/
***** Holy crap. Thanks! I've asked in all the stores that I go to for tools or wood. None even knew what I was talking about.
Also in Jula and Clas Ohlson. So not hard to find at all really :)
I asked at Jula and Clas. :(
And bauhaus, byggmax and a few other places.
.010" is a lot. Lay three sheets of printer paper on your desk and run your finger over the edge. Then you'll see how big .010" really is and how much it could effect a joint going together. A dowel that is .010" bigger than a hole will require you to pound it in with a lot of force. (hard wood) A dowel that is .010" smaller than a hole will drop right in. Even the thickness of one sheet of paper, .003" can be a big deal. The difference between a tight fitting joint and a sloppy one can easily be .003". I am a machinist and have spent 20 years making precision parts.
John Welden but this is wood. if it was metal I'm sure he would've been even more precise.
wait, but he was saying that he was within 1 thou, not 10 thou. 3:16
You can unscrew the back off with the 3 screws and buy another back, and re install it.
Oh yeah, they are called INCRA RULES.
is better use metric system ?
Nathaniel Kencke Does not compute. Thousandths of an inch are 10x10x10, so it's tens all the way.
ib9rt Until you use a tape measure, or use anything other than an inch.
Matthias Wandel fractions of an inch make sense if you work in binary instead of decimal :D
Yes, metric is better. Actually, my country as virtually all world uses metric, but recently I saw dial indicators in inches in the store :D
***** There is even no learning in metric system, if one can count to 10.
You could just leave the fridge magnet it's original size rather than cutting it in a circle, no? More magnet would give you more staying power.
precision within .01 millimeters! pretty awesome! But then I see the circle of magnet underneath isn't cut perfectly round, and it hurts me so much.
And you did not mentioned you can turn a dial and set zero as you wish.
How about epoxying three rare earth magnets to the back of the gauge.
***** That would suck. It would mean having to pry the thing off the saw every time.
Matthias Wandel There really needs to be a magnet that's stronger than your typical fridge magnet, but less than the rare earth magnets you could pick up a car with. How about it, science?
1:15 broken
use magnet from hard drive
My table saw has an aluminum table, so I'll have to do something with rubber or other sticky material son it doesn't slide.
you should get that no tip cup and remove the bottom from it at attach to the dial indicator
Actually, I've already made a simple base similar to Matthias' and it works fine already.
Millimeters are so much easier.
How?
Dude--apparently, you have total confidence that your fence lock is setting your fence *perfectly parallel* to the saw blade/miter slot each time you release and reset it! Dollars to doughnuts that ain't the case!
yes, of course I can put it on non-square if I'm not careful. The key is to put it on square. And your point is? And if it was some typical microadjust contraption, the effect would be much worse becasue it's further from the blade.
My point is you're shooting for a level of precision that is outside of the very tools (saw, fence) that you're using. Btw you put it best when you said "Much more accurate than you really need for wood". Imo a better application of that dial indicator would be when you're setting joiner or planer knives, or checking for runout on a saw blade, etc.
The strong magnet near a dial indicator is not good idea.
Unlike watches dial indicators are designed to be used around magnets and magnetic bases.
Why?