Looking for strategies you all use to get your end-mill set to exactly the same Z as the top of a work surface. I've used the paper sheet trick, and I've seen folks just tap the work surface with rotating end-mill, but these are both +- a few thou techniques and the latter mars the work surface. I'm wondering if folks have a method for getting less than a thou setting of the end-mill in relation to work surface. I guess some technique that uses an indicator and the table as a reference? What other approaches?
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Largest Manufacturing Technology Community on the Web
Stay Connected:
Best way to set tool height to work surface on manual mill
- Thread starter drcoelho
- Start date
- Replies 54
- Views 6,079
Mark Rand
Diamond
- Joined
- Jul 9, 2007
- Location
- UK Rugby Warwickshire
I must admit that I bring the stationary tool down to touch the surface, then lock the quill. All Z movements are then done with the knee.
That's what I've been doing, sometimes with a sliver of paper to make detection of contact more definitive. BUT, I'm wondering whether there is a more accurate technique that gets the Z height detected with less than a thou tolerance.
Richard King
Diamond
- Joined
- Jul 12, 2005
- Location
- Cottage Grove, MN 55016
You can leave the spindle turned off and move the quill so the tool touches and turn the spindle by hand moving up the slightest until its off the surface. With modern day digital readouts you can zero at that spot. I use the paper trick on mills and surface grinders too. As mark said...lock quill and raise the knee. Move the knee dial to zero too. I have never done this but use a feeler gage, say .005" on the turned off spindle and zero everything.
Conrad Hoffman
Diamond
- Joined
- May 10, 2009
- Location
- Canandaigua, NY, USA
I sometimes use a planer gage to whatever the part is resting on, since it's total height I'm after. Stationary tool and just bring it down to touch, so the planer gage just slides. Not sure this is any better than 0.001" and I usually just touch the surface with the running end mill, since I'm going to clean up that surface anyway.
Trboatworks
Diamond
- Joined
- Oct 23, 2010
- Location
- Maryland- USA
I scuff and run- drop the quill and lock or bring the table up and lock then run up the table with the DRO till I get a scuff.
Zero the scale and start cutting.
If careful that scuff is less than the repeatability of setting up the workpiece in the vise.
Maybe if you really need it the work could be set in card stock in the vise and a electric contact setup used.
I don't know- it just seems working in with running cutter works- same on lathe- I can bring the tooling to spinning work and have less than a thou cut if I were to run with it.
I think I am listening for the touch more than watching for it..
Someone will start in with it so it might as well be me- I try to stage work so I am not trapped by these blind alleys where I need to hit some tolerance with no setup room- part is left with some meat if staging in and out of vise, bores left a bit over, bearing seats on shafts a bit big etc.
But... I am hacking one off parts out of billet for space ships so others might approach work differently.
Zero the scale and start cutting.
If careful that scuff is less than the repeatability of setting up the workpiece in the vise.
Maybe if you really need it the work could be set in card stock in the vise and a electric contact setup used.
I don't know- it just seems working in with running cutter works- same on lathe- I can bring the tooling to spinning work and have less than a thou cut if I were to run with it.
I think I am listening for the touch more than watching for it..
Someone will start in with it so it might as well be me- I try to stage work so I am not trapped by these blind alleys where I need to hit some tolerance with no setup room- part is left with some meat if staging in and out of vise, bores left a bit over, bearing seats on shafts a bit big etc.
But... I am hacking one off parts out of billet for space ships so others might approach work differently.
MilGunsmith
Stainless
- Joined
- Mar 6, 2006
- Location
- Sandyston, NJ
I have one of those 1" thick electronic blocks that they make for CNC users. Put it on the work surface and then bring the cutter down until the light comes on. Now you zero, move 1" and zero again.
kb0thn
Stainless
- Joined
- May 15, 2008
- Location
- Winona, MN, USA
Mitutoya z-setter gauge. Dial indicator with button on it that lets you get your tool exactly 1" above the surface the gauge is sitting on.
Buy Dial Indicators - Sign In: Free Shipping $50+ | Zoro.com
I have one of those and use it sometimes. But what I actually use every day is a 1-2-3 block on my machines without a probe. I jog z to somewhat less than 2". Then I try to slide 2" of 1-2-3 block under tool while I bring z up on biggest increment. Once 1-2-3 slides under, I pull it out and incrementally jog down one step. Then switch to next finer increment and repeat. In about 10 seconds I know where z surface + 2" is. I also use this on the CNC lathe with broken tool setter.
But seriously, on my knee mill? I just bring tool down with quill until it touches the surface of the work. Then use the knee for z-axis. In 16 years of doing that I don't recall ever getting a tool mark. When working with soft materials I do try to zero in a spot that is going to get machined off anyhow.
Buy Dial Indicators - Sign In: Free Shipping $50+ | Zoro.com
I have one of those and use it sometimes. But what I actually use every day is a 1-2-3 block on my machines without a probe. I jog z to somewhat less than 2". Then I try to slide 2" of 1-2-3 block under tool while I bring z up on biggest increment. Once 1-2-3 slides under, I pull it out and incrementally jog down one step. Then switch to next finer increment and repeat. In about 10 seconds I know where z surface + 2" is. I also use this on the CNC lathe with broken tool setter.
But seriously, on my knee mill? I just bring tool down with quill until it touches the surface of the work. Then use the knee for z-axis. In 16 years of doing that I don't recall ever getting a tool mark. When working with soft materials I do try to zero in a spot that is going to get machined off anyhow.
upthebikes
Cast Iron
- Joined
- Aug 23, 2007
- Location
- Great Lakes USA
If you really, really need to reference the work surface and can’t just touch off with a tool and cut the actual part out of your material as said above ...
Use a wide / broad tip sharpie magnum. Dot the piece, let it dry. Repeat 3 or 4 times on the same spot. Then use your paper to get within .003.” Then remove the paper and creep up on the dot until the tool just whispers on the dot. With practice, you can reliably take off marker and not touch the material. It is a real pain in the ass, but will get you within your .001” You can do the same with dykem, but it will be more like 5-7 coats.
Use a wide / broad tip sharpie magnum. Dot the piece, let it dry. Repeat 3 or 4 times on the same spot. Then use your paper to get within .003.” Then remove the paper and creep up on the dot until the tool just whispers on the dot. With practice, you can reliably take off marker and not touch the material. It is a real pain in the ass, but will get you within your .001” You can do the same with dykem, but it will be more like 5-7 coats.
Limy Sami
Diamond
- Joined
- Jan 7, 2007
- Location
- Norfolk, UK
Something or nothing.
Machining a lot of plastic which gives false readings (cos the cutter tip goes in ??) many moons ago I came up with a fix - use a strip of brass shim of known thickness (usually 0.015) and cover it with black sharpie.
When the tool only just marks the ink I call it good and deduct the shim T
N.B Use brass shim as it doesn't damage the tool tips !!! .IME steel shimstock can be quite hard.
YMMV but it's served me for nigh on 50 years.
Machining a lot of plastic which gives false readings (cos the cutter tip goes in ??) many moons ago I came up with a fix - use a strip of brass shim of known thickness (usually 0.015) and cover it with black sharpie.
When the tool only just marks the ink I call it good and deduct the shim T
N.B Use brass shim as it doesn't damage the tool tips !!! .IME steel shimstock can be quite hard.
YMMV but it's served me for nigh on 50 years.
I run the quill down until I see chips flying. Then, I go a little more just to be sure I really saw chips flying. That's zero. If I go too far, I back off a little and ponder just how much a goo-goo mark will matter to the finished product, and I pre-plan what I will tell anyone who asks.
SIP6A
Titanium
- Joined
- May 29, 2003
- Location
- Temperance, Michigan
If your "Z" dimension is less than a .001 your going to need to measure it at some point, so how you touch off doesn't make any difference.
Limy Sami
Diamond
- Joined
- Jan 7, 2007
- Location
- Norfolk, UK
Exactly, or as I was told many many years back, ''it's a milling machine boy, not a surface grinder''
rickseeman
Cast Iron
- Joined
- Oct 7, 2014
I don't know if you can get sub-thou accuracy in that op on a manual mill.
Forestgnome
Stainless
- Joined
- Aug 2, 2008
- Location
- Californeeeah
I'll usually touch off the cutter on part of the work surface that's going to be cut, but if I'm concerned about marring the surface I'll use a feeler gauge, feeling for a slight drag.
CarbideBob
Diamond
- Joined
- Jan 14, 2007
- Location
- Flushing/Flint, Michigan
One of my early mentors reached in Gerstner box and pulled out a pack of Zigzags.
I was surprised knowing other uses and knowing him.
He told me wet it and stick it, you do not have to scar the part and do not chip the cutting tool.
Since then I have learned that different pieces of regular paper or even rolling type used as shims have a different thickness offset.
Have and do the feller gauge method but do not like it. As a maker of cutting tools this is how to chip the tip in carbide.
Goodly honed tools as in lathe not a a problem. Milling tools different.
Manual mill and what way, way under a thou in Z......???
Bob
I was surprised knowing other uses and knowing him.
He told me wet it and stick it, you do not have to scar the part and do not chip the cutting tool.
Since then I have learned that different pieces of regular paper or even rolling type used as shims have a different thickness offset.
Have and do the feller gauge method but do not like it. As a maker of cutting tools this is how to chip the tip in carbide.
Goodly honed tools as in lathe not a a problem. Milling tools different.
Manual mill and what way, way under a thou in Z......???
Bob
thermite
Diamond
- Joined
- Sep 21, 2011
Person could have a lot of effort invested in a high-precision part, go for the last surface or complex feature that actually could be make or BREAK "get paid" ELSE "scrap and start-over" - wasting all the prior investment in it.
Slab it into a sandwich.
Same alloy, either side.
Mill away adjacent.
Don't even touch the "money."
Adjust with depth mic. Even gage blocks.
The scrap doesn't get to "vote". The money-piece rules the day.
Your mill will not HOLD across that modest span?
Pilgrim?
You are bidding the wrong sort of work for a wore-out manual mill, aintcha?
Just grip yer own guts in yer front teeth, bite down HARD, and do the best you can.
Know the many helpfuls. Use the bestest fit, any given tasking.
No ONE PERFECTLY MAGICAL WAY to it!
Any mill-hand walking has used MANY methods to git 'er done.
It's a mill. Go figure they can do more than just the one thing?
T'was ever thus..
Last edited:
