[Newbie] How To Adjust Tool Height On A Lathe?

BGHansen said:
Just chiming in a little late from some posts above. The 4-way is very rigid and I'm guessing yours has a detent ball so you can index to different positions and return to the original? Very handy when doing production jobs when you are using your cross feed/compound micrometer dials. Rotate your QCTP and your micrometer dials are off, have to align again.

Bruce
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My Dad bought a surplus Le Blond 18" swing production lathe from A.O. Smith (Milwaukee, WI) in the mid '50's. It had a turret that had detents for angular settings. When we used an angular position other than the detent options the tool height was higher. (A-pain). Interestingly enough, the lathe was probably a dedicated custom build since it had no compound or threading provisions. She could really HOG steel though. Bottom line, SHIMS !
 
Yes, I am brand new to doing metal working, other than very simple cut to length/drill holes/weld/bolt together stuff, and while I do happen to have a fair amount of scrap metal of varying types, sizes and shapes, from the perspective of a person brand new to this, and learning that tool height is very important if you want to do it, the "just wing it" approach, to me, isn't the kind of thing to do, to learn how to do something well, as it adds just another thing to the list of "things you have to do just right to do this successfully".

For doing something new, I try to minimize the ways to do the job poorly, and maximize the ways to do it well, and so that when something goes wrong, there are fewer reasons as to why it went wrong.

Anyway, from what I can tell, it would take about a 3/4" +- 1/8" or so cutter to line up to center, and those don't seem to be readily available [at least at the BusyBee and other online shops]. And the QuickChange at the BB also requires some milling to make it work, so I'll go to shimming the tools on the 4-way.

As well, my 4-way doesn't have have any detents for assisting in rotating the 4-way to a repeatable position. It's not a huge thing for me.

Thanks everybody for your help.
 
As others have said, shims are what you will need. There's been a lot of evolution in the equipment over the years and in the past, a 4-way would be considered the ultimate to have. The old rocker style were fun and you had to use shims as well. I think you might have a Busy Bee where you are but you could also mail order. They sell a shim pack with assorted sizes for just this purpose.

Also, you're using a cemented carbide tool where the 4-ways are more suited to indexed tool holders which have a taller profile and come closer to the centre line of the lathe.
 
Oh, just to add, in the machining world, shims and grinding are the most common "adjustment" technique. When you see things that need to be tweaked a bit, a solid stack of metal is the best and strongest approach. Any sort of fine adjustment (with screws, threads, etc. is usually for the measuring instruments.
 
I also have a lamppost-style holder with a couple of toolbit holders which can hold 1/4" [I think, I haven't measured, maybe also 3/8"] that I probably will figure out how to use down the road, when I get more experience and it seems as if the job needs a different kind of hold [for clearance maybe].

I've also got a set of 4 1/2" tools with replaceable carbide tips at various angles for 'general' cutting, and the tool pictured was suggested to use specifically for doing threading. they are all pretty close to the same height, but I still have to see how close...

Down the road, I may also make a larger shim to go underneath the 4-way, so that baseline for the tools are closer to the centerline, so I would have to use fewer/smaller shims with each tool.
 
For our information, some manufacturers fused some ideas from the lantern Toolpost and the four way, with a tilting key (as from the lantern) in each of the four positions. South Bend was one company that did. I have one somewhere, and I will find the part number
 
pineyfolks said:
Pick up a cheap set of feeler gauges. You can take them apart and have a complete set of shims on hand.
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I bought three sets of feeler gauges at an use store (it was all that they had) for a buck apiece. They are very handy for all sorts of things in machining besides setting your lathe bit.
 
Hi Dave,
I'll add my voice to "shims". They are not a whacky work around, that is the intended approach. After a while, you'll end up with quite a little assortment of shims. I use "machinery shims". You can get them in kits with many different thicknesses or packs with a bunch all the same thicknesses. There are available in various sizes ("A" is pretty small, "B" larger, . . . . etc). They are used when setting alignment of equipment (i.e. a motor & pump alignment). You can also purchase shim stock in a role.

On my bigger lathe I used a 4 way turret for nearly 30 years, finally got around to buying, setting up, installing a QCPT - I prefer the QCTP. But a 4 way turret is a good tool post.

I recently got a smaller lathe which came to me without a tool post. So I bought another QCPT (different brand from the first one - much smaller machine). I set up the tool post / holders so they sit right down on the top of the compound. I only do this on the holders in which I keep the same tool all the time (i.e. the common tooling). To adjust the center height I have glued a shim to the bottom of the tool holder (I get some of the rigidity back and the little adjusting screw never comes loose, because it isn't there). In otherwords, even with the adjustment of a QCPT, a person may choose to switch back to using shims (they work fine).
 
Just to add some more as the thoughts appear. Centre line adjustment isn't that critical. Get it within 10-15 thou (of centre or lower) and you should be fine. If you are facing, you'll have a nib left but it's not a big deal unless that's a big deal for you. The slight difference from centre for regular turning just changes the cutting angle slightly... very slightly.

This becomes less critical in larger turning and more important as you get to small diameter turning.
 
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