Former Member
Guest
I use something similar off the cross slide because if how the lathe is configured. As long as the reference is consistent and stable it is good.
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Show us your Tool Height Standard
- Thread starter YYCHM
- Start date
Former Member
Guest
For the mill I use a 0.0005 shim stock to touch of cutters and depending on a axis (x&y or z) compensate to zero as required for the tool. Based on my machines play 0.005 is more than sufficient to be considered a zero value. If I really want to be specific I can even zero that number out as well. Since its steel and not paper it is thinner and more consistent.
I do that shim stock technique on my mill too. Mostly to protect the edge of carbide if contacting hard material. I can just see fracturing an edge with any inadvertent down force. Safer to place some 0.005" brass shim on the surface, contact the end mill, lock the spindle, enter DRO offset same 0.005" amount, away we go.
I loved @thestelster's advice for setting Z on the mill. Instead of shim stock, he uses thin paper. You can bring your endmill down to touch it without worrying about damaging or dulling the bit. 1 thou paper is prolly close enough as is, but you can always dial out the thickness if you need to like @PeterT does.
On the other hand, none of you is gunna convince me that your rulers, nib cutting, fixtures, and tailstock centers are even close to being as convenient or as easy to use as a standard.
On the other hand, none of you is gunna convince me that your rulers, nib cutting, fixtures, and tailstock centers are even close to being as convenient or as easy to use as a standard.
LOL! You do you, and don't mind the rest of us!
About only tool I have used a setting height gage on, was a Tool and Cutter Grinder, and even then, it was start point for setting the cutting edge relief after you did the math, or checked the charts, to see how much higher or lower the wheel needed to be than the finger rest, to get the needed clearance.
First thing a fella learns around carbide tools, is that you never touch off if the tool is not spinning (mill) or the work is not turning (lathe), else bad things happen to good edges! With a little practice, it's not that hard to shave off half a Sharpie Marker mark. When zeroing off the CNC mill, used a decent magnifying glass, a Sharpie mark, and kept the move per click of the hand wheel suitably low that I could approach the work surface and get within a couple tenths before watching for the marker to take the first hits.
One thing I've been meaning to do one day is put a tenths indicator on the tip of the cutter & do a few passes at different DOC & materials. My guess is its going to deflect under load. So you set it to center reference 0.000" by whatever means, proceed to cut & the tool moves under say 0.002". No problem, pre-set it to +0.002". Now take a light finishing cut, less deflection, now 0.001" too high.
And what is the right height? When I see magnified pictures of actual cutting, it looks like quite a bit is going on at that scale. Rather complex & unpredictable interactions of shear failure, stacking, sticking, releasing, tool load, chip sticking.. and we haven't even got to heat & lubrication. My own personal data point is some of my parting tools are just plain happier at up or down a couple thou, cant remember which way. Maybe its that chip width or speed, but when I like how its cutting & check on a face cut, it does not necessarily go exactly through the center pip (or register exact to a gage datum, take your pick). So my own view is get it close with whatever device suites the setup preference, but that may not be the absolute resting pace for different permutations of materials or cutters. I guess one check in favor of a scale is it gives you that dimensional feedback right then & there. But I wouldn't buy a height gage for this. Making your own tools is usually always more fun & rewarding.
And what is the right height? When I see magnified pictures of actual cutting, it looks like quite a bit is going on at that scale. Rather complex & unpredictable interactions of shear failure, stacking, sticking, releasing, tool load, chip sticking.. and we haven't even got to heat & lubrication. My own personal data point is some of my parting tools are just plain happier at up or down a couple thou, cant remember which way. Maybe its that chip width or speed, but when I like how its cutting & check on a face cut, it does not necessarily go exactly through the center pip (or register exact to a gage datum, take your pick). So my own view is get it close with whatever device suites the setup preference, but that may not be the absolute resting pace for different permutations of materials or cutters. I guess one check in favor of a scale is it gives you that dimensional feedback right then & there. But I wouldn't buy a height gage for this. Making your own tools is usually always more fun & rewarding.
Attachments
Dabbler
ersatz engineer
On mu little lathe, parting was terible until I started to set the tool .003 below the centre line. Then things worked as they should...
Yep. Changed cutting forces, changed materials, and a bunch of other variables make it so you pretty much have to know how to read, and react, to them, to get to a satisfactory end result.
Since I have not ever had any issues with getting close enough for a decent start, without having to resort to yet another tool, I'll stick to what works for me.
Yet another of the (many) things we emphasized to the trainees, was that if you want results that repeat, you have to keep the variables down to a bare minimum. Lots of measuring, as the finish dimension approaches, with some comparisons of the results, vs. the inputs, so that the final cut could be as 'same' as they could manage, and still hit dimension.
You are no fun!
Seriously, as usual, those are all very valid questions and answers you present. I like it.
But still, for most purposes we have to start somewhere or we are just blind lemmings. 99% of what I do is happy with a plain old simple standard setup.
For those few exceptions that don't work that way, I like the speed and simplicity of starting from a standard and then adjusting from there.
For a few seconds, your discussion about deflection of the tool under cutting pressure had me doing a face plant. It's a good point. But cutting a nib doesn't address that cuz the load goes away as the nib approaches. In reality, it's no different than a standard but much more time consuming to do.
I wonder if maybe the cutting load deflection can be more or less ignored because it really only very slightly increases the back relief and is proportional to the cutting radius? In other words, matters less as the cutting radius goes up?
Surely, some insert company has studied this...... If not, it sounds like a great project......
Proxule
Ultra Member
I was taught to use zigzags for this purpose.
so to be the devil's advocate for a sec...
how about the work piece deflecting -upward- under the tool cutting pressure!!
Of course! Everything moves! No matter how big or how strongly held, everything moves. It's not if, it's only how much!
You should have seen my bride's face when a package of those arrived in the mail! Each to their own of course, but she knew exactly what they were and I didn't! Talk about a face plant!
LOL!You should have seen my bride's face when a package of those arrived in the mail! Each to their own of course, but she knew exactly what they were and I didn't! Talk about a face plant!
Y'know, there were lots of us that grew up around people that used those for smoking actual tobacco!
Chicken lights
Forum Pony Express Driver
I used to know a guy that could hand roll them while driving, it was pretty impressiveLOL!
Y'know, there were lots of us that grew up around people that used those for smoking actual tobacco!
DPittman
Ultra Member
Telephone books are pretty rare around here but so are cigarette papers.
140mower
Don
I watched a fellow roll one while running a Case backhoe, with the four sticks and the swing on the foot pedals....... Quite the sight to see.
There's a bible in every Hotel room, though! Jes' sayin'!
