Setting Tool Height

[Mosey]

I made this little gage for setting my cutting tools at the proper height on the lathe. It needs a little bling to make nice, but it works. I bought a spirit level from China for $1.00, and popped it in the groove.
You set the vee side against your lathe center or spindle and rest the flat on the tool tip. When the bubble level is centered, your cutter is at the same height as the lathe center.

[stevehuckss396]

Thats a good Idea Mosey

[DavidF]

Good idea... Hmm that lathe looks very familiar...southbend 10k??

[mklotz]

How did you set the level parallel to the lathe CL to tool top plane?

[Arbalest]

If you fancy a nice red one, $15 at the moment.

http://www.edgetechnologyproducts.com/speedy-lathe-gage.html

[Goldstar31]

I have a far more exotic tool. It's called a bit 'er broke hacksaw blade. It goes between the work and the lathe tool or centres. If it stands vertically it is spot on , if it tilts one adjusts the packing until it does.
It is useful on centres to find out their alignment in the other plane.

If you get really worked up, it can go on a vertical mill or drill and sometimes one really becomes a 'two tool operative' and has another bit of broken blade.

In one of my really wild moments, I made a bit of round rod- and halved it exactly -- as a certain finder.

I'm sure I'd like one of these new fancy gadgets- I could love it and cuddle it-- and maybe call it George!

[Mosey]

Good idea... Hmm that lathe looks very familiar...southbend 10k??

Yes, observant one, 10K, and a sweet one with hardened bed and no wear.

[Mosey]

How did you set the level parallel to the lathe CL to tool top plane?

Marv,
I hope I didn't miss the subtle meaning of your question, but the level is parallel to the axis of the side vee and the bottom of the rectangular notch. Therefore, when the bottom notch is on top of the tool tip, and the vee is up against the circular spindle, they are all lined up.

AS for the old pocket scale or hacksaw blade method, I wonder if that is good enough to get your cutoff tool aligned with the center of a 1/8" diameter workpiece you are parting off? It isn't when I do it.

Mosey

[mklotz]

Yes, you understood my question.  The line formed by the bottom of the 'V' and the line formed by the bottom of the rectangular notch determine a plane that will pass through the lathe axis when the tool bit is properly aligned.

To work properly, the plane determined by the level must be parallel to the above plane.  My question boils down to - When you cemented the level into the tool, how did you ensure that its plane was indeed parallel to the plane of the above paragraph?

I've never tried the rule trick on small (eg, 1/8") stock but I have to agree with you that it sounds problematic.  My approach was to mill a small block to a dimension such that, sat on the top of the compound the flat top of the block was exactly at lathe center height.  The tool is brought close to it and adjusted such that a thumbnail dragged from tool to block feels no edge.  The human finger is exceedingly sensitive to this sort of thing.

[Mosey]

Marv,
The spirit level is only parallel with the axis through the other 2  points, not on that axis. So, a level line through the lathe axis finds the tool top only when it is the same height as the tool. Phew, I hope I'm clear enough for you.
Mosey

[mklotz]

I think we're having a communication problem.  Perhaps it can be resolved with a little gedankenexperiment.

Imagine that the level vial is tilted upward by, say, 15 degrees relative to the top of your instrument.  Clearly, in that condition your instrument would not align the lathe tool with the lathe CL.

One could see 15 degrees but a tilt of, say, 2 or 3 degrees, might not be obvious yet it would still affect the accuracy of the instrument.

So, how did you guarantee that the level vial isn't tilted relative to the plane from the bottom of the 'V' to the flat that sits on the top of the lathe tool?

[Mosey]

Easy.
I milled the slot for the vial parallel to the bottom of the device, which is the exact same dimension as the apex of the vee. Elementary, Dr. Watson (She's on tonight).

Mosey

[Maryak]

Stupid question but what happens if your lathe is not level?

Best Regards
Bob

[Chris J]

Stupid question but what happens if your lathe is not level?

Best Regards
Bob

That strikes me as a fundamental problem if you use a level.
I seem to recall that Arbalest had a neat solution to tool height that sat on the lathe bed.
I think that would eliminate that problem. ?

[Goldstar31]

In an earlier bit of a reply, I gave two solutions- both very elementary ones. The first was the blade held at a tangent in a vertical position whilst the second one was to create - or find the centre. I simply said half any bit of round - no more, no less and there is exactly the point where the lathe tool is planned to be.
It doesn't require bubbles or any thing fancy- it is what MAN has done since time immoral.

As for working from a known base ie Arbalest's way, perfectly correct to know exactly what size your lathe or mill is. What system is adopted thereafter is up to the operative to adopt.  I have a very high tech solution to lathe height. I have a 'Murphy- twer that size bit of metal' - he made pies and pasties as well. I scratched a centre height on it by putting a centre in headstock and - drawing a line. Oh, brother I've got a nice set of 'Jo blocks' and dial mikes and tenth thous things-- and Good Old Murphy with his bit of half round, me bit o' hack saw blade and me bit of block.- with a line on it.

Let's be simple. EH?

[Jo]

In an earlier bit of a reply, I gave two solutions- both very elementary ones. The first was the blade held at a tangent in a vertical position

I use a 300mm long "blade" to adjust my tools to the centre and as I have a QCTP and have a holder dedicated to each tool so rarely have to set tools up from scratch. The size of the work is irrelevant when using this method as you set the tool up on something of a reasonable size in the first place .

These tool vendors seem to be trying to make up gadgets left, right and centre for use in the workshop. Personally I have given up buying/making them because if I don't use them every day the workshop gnome has a habit of hiding them from me when I do want them again .

Jo

[bp]

I use a centering scope that I got from ENCO a year or two ago.  Stick it in the tailstock chuck and you can see tool height.  They are not only good for centering!!
cheers
Bill

[Jo]

I use a centering scope that I got from ENCO a year or two ago.  Stick it in the tailstock chuck and you can see tool height.  They are not only good for centering!!
cheers
Bill

Now there is another gadget that I keep forgetting to use 

Jo

[Bogstandard]

Here is a little article I did a while back showing a few methods

http://start-model-engineering.co.uk/begin-with-bogs/top-tips-from-bogs-setting-cutter-height/


John

[Goldstar31]

Thanks John! Now comes the interesting bit of how height actually changes the tool cutter geometry perhaps to a point where there is no cutting whatsoever-- and if it is carbide-- no tool.

Sadly, most  of these manufacturers of exhibits for a Museum for Redundant White Elephants seem to disappear when the  people who have got their wallet spanners out- bought the stuff, shout Help- from somewhere in the wilderness.

 

[Arbalest]

That strikes me as a fundamental problem if you use a level.
I seem to recall that Arbalest had a neat solution to tool height that sat on the lathe bed.
I think that would eliminate that problem. ?

Yes Chris, this is mine. It also shows how quick a Tangential tool is to set up if you only have a four way tool post.

[Rayanth]

I'm still a little stuck up on how to make the actual adjustment... my limited (for now) resources give me the 'best' option I can think of as being "shim stock" from feeler gauges to shim up the tool until it's on center, but that can only get as accurate as the smallest feeler gauge in the set... is there something else others use?

-- Rayanth

[Arbalest]

I use all kinds of stuff but drinks cans and old feeler gauges spring to mind.

[Chris J]

That strikes me as a fundamental problem if you use a level.
I seem to recall that Arbalest had a neat solution to tool height that sat on the lathe bed.
I think that would eliminate that problem. ?

Yes Chris, this is mine. It also shows how quick a Tangential tool is to set up if you only have a four way tool post.

Thanks
I can see the way it works to set the center height, under the lip as it were.
Is there any significance to the lower shelf ?

[Arbalest]

No Chris, just an arbitrary gap for clearance.

[Bogstandard]

If you look at my tool diversion post, you can glean why I went for the scribed line set up method.

There are times, especially now with tipped tooling becoming so abundant, where zero or negative top rake is starting to be used more and more, so making the normal height setting gauges redundant, as if they are used with this type of tool, the tool tip height could be well below where it should be.

Maybe you will need to make a range of height setting tools to cope with the various types.


John

[Arbalest]

I only have an 8 x 14 lathe John which does'nt like negative rake tooling. The hobby inserts sold by Chronos and RDG etc work well though and are easily set with my height jig.

[Mosey]

Make an adjustable or variable height gage. Or, a whole set of them. Now you guys have something to do in your shops.
Mosey

[AussieJimG]

I made my tangential tool holders so the top of the holder is exactly at centre height. So I just have to put the holder upside down on something suitable (like brass) and press the tool down until it hits the surface and the job is done. Works for me.

Jim

[PeterE]

Jumping right in with my version of a tool height setter. I found a suitable sketch in GHT´s MEWM and it turned out as below:

Compared with the book, I made the setting arms as pins instead, that way I could slant the end and make a good scriber that followed the underside of the pin which of course also acts as the setting gauge.

There two pins are set as one for height from bed to center and the other from cross slide to center, whichever is the most convinient at the time.

BR

/Peter

[Arbalest]

I made my tangential tool holders so the top of the holder is exactly at centre height. So I just have to put the holder upside down on something suitable (like brass) and press the tool down until it hits the surface and the job is done. Works for me.

Jim

Clever idea Jim!

I was lucky with my insert tool, it needed a single piece of shim so I super glued it to the tool holder - it's always on centre height now!