ok today the tooling for my new lathe arrived so I thought I would make some chips the lathe has a 4 way tool post when I put in a tool bit which is 3/8 x 5/16 x 3 1/4 it is too low how do I correct this? go easy on me please I am new at this I bought some books but this issue is not covered in them from what I have seen.
Shims of various thickness until the toolbit is at the correct height.
Having bought only second hand tool bits, I've ended up using all sorts of shims - feeler gauges for fine adjustments, some scrap steel, etc etc. Dont use a soft metal as you'll end up with a variable height shim.
You need to shim the tool up. Generally the holders are designed so that a tool that's the size the holder's designed for will be a bit low, you'll need to shim it up 20-60 thou. If the holder's designed for 1/2 and you're putting in a 3/8 tool obviously you'll need an extra 1/8 shim.
Use something rigid (i.e. metal), and make sure the tool is tight in the holder. I have the ugliest collection of shims in the world: brass shim stock from the local hobby shop, various bits of 28-gauge aluminum, some
1/8 sticks, basically whatever it takes to make _that_ fit in _there_.
I would like to add something to Tim's answer, just a tip. I like to store the tool holders or tools separately with the proper shims. I'll store the tool and shims pertaining to that tool together in a small container. When I need the tool, the shims are right with it. I may have got this tip from Ted Edwards some years ago.
As the other replies suggest, shimming is a common way to set the cutter edge to the correct height. Another method is to make some of the ramp/wedge gizmos shown on this page
With a few of these hickies of slightly different angles, you can quickly choose one that will allow you to adjust for the correct height for all of your cutting tools/BITS (I was told in a shop class many years ago that a BIT is something that goes into a horse's mouth).
I made my first set of these ramp gizmos on a lathe with a turret type toolpost, using an endmill to cut the trough. You'll likely be surprised how well they work after you've shimmed your cutting tools for a while.
Not a dumb question.. you just experienced the reason why the Aloris type quick change tool holders (QCTH) are so popular -- NO SHIMMING REQUIRED!
Shims are a hassle, and the Chinese knockoffs of the Aloris found in Enco, MSC, Rutland, et all are worth every penny -- particularly when they are on sales As AXA sized piston type holder, good for any lathe up to 12" swing, goes for as low as $89-99.00. The wedge type is supposedly a little more rigid and have better repeatabilty, and more expensive, but most of us hobbyists will never notice the differenece.
Get on the mailing lists of Enco, MSC, Airgas Rutland, JandL and you will learn a lot from the catalogs. Buy one as soon as you can and without meaning to be mean, throw your current one in the drawer to be used only in special circumstances. (I have two 4 way tool posts-- came with my lathes-- and have not used a one EVER!!)
If you do a google search on this newsgroup about AXA, or BXA QCTP, you will get a ton of old posts. Good info.
If all of your tool bits are too low, you might make one shim to shim up the entire 4 way tool post. Might be easier than shims for each tool bit.
I bought some holders for carbide inserts with 1 inch by 1 inch shanks so they were too high. I then machined metal off the botom until they were the right height without any shims. Only recommended if you find the holders very cheap.
You have to use shims. A possible source for shims is the steel shipping strapping that is used for tying stuff down onto wooden pellets. Cutting up a soup can provides thinner shims. Careful, don't cut yourself, cut only the steel. HTH.
thanks for the tips I made some shims from scrap steel and some hack saw blades (I ground off the teeth) I will look into the piston type tool post in the future I like the idea of the square shim that goes around the whole post will make one tomorrow thanks again
Yup..the famous Cigar Box full of shims is quite common in many shops.
Its been my somewhat simple experience, that most tool holders will need a 1/8" shim to bring the tool to centerling..but thats a big big big generalization and based on only a few years working around chuckers etc etc. Which is why all my lathes are equipped with KDK tooling.
Some may decry the impeachment of William Jefferson Clinton as a national trauma, but not humorist P.J. O'Rourke, who thinks the proceedings are a win-win situation
-- and grand entertainment to boot. Mr. O'Rourke, writing in the latest issue of the Weekly Standard, acknowledges that "some earnest souls have gone so far as to aver that impeachment has distracted President Clinton from ... raising taxes, destroying health care, appointing 1960s bakeheads to high political office, soliciting felonious campaign contributions, hanging friends out to dry for Arkansas real estate frauds, giving missile secrets to the Chinese, taking credit for the benefits of a free market about which he knows little and cares less, using U.S. military forces as fig leaves for domestic scandals and au pairs for the U.N., leading foreign policy back into the flea circus of Jimmy Carterism, having phone sex, groping patronage seekers, and snapping the elastic on the underpants of psychologically disturbed school-age White House interns entrusted with the task of delivering high-level government pizza." Ouch. Tell us what you really think, P.J. "No matter what, Bill," Mr.O'Rourke concludes, "your girlfriend's ugly, your wife hates you, and your dog can't hunt."
A city wide blackout at Fri, 16 Apr 2004 16:36:06 -0500 did not prevent "James Schenck" from posting to rec.crafts.metalworking the following:
Simple. Make a new tool holder.
However, as is normal, before you can do A, you must do B. (And thus B becomes the new A, and you repeat ... )
You'll need to shim your tooling to be the right height in the current tool holder. Use metal stock for the big gap, then what ever is thin enough to fill the remaining space. If you're faced with "too low" (just a bit under the centerline) or "too high" - go with "too low."