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- Aug 12, 2013
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- 858
Just one note: since you have a thread dial and if you are cutting imperial threads, then you don't have to leave the half nuts engaged (as Jerry did because he has no thread dial).
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PM 1236 tool post issues
- Thread starter Blackhawk
- Start date
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- Aug 15, 2013
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- 2,109
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- May 4, 2015
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I left a comment on your YouTube trying to explain the steps to cutting threads on the lathe. Also I think your tool holders need remilling to get them flat. If it were warmer weather and my back wasn't causing so much pain I'd offer to mill them for you . Shouldn't take much about 15 thousands on the inside bottom. Question when you turn the hold down bolts how much force are you using. You may be bending them.
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- Dec 3, 2013
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Just to add a note about Shars. When ever buying from them always check to see if the same item is offered on ebay. If so it is usually (not always) less cost and less for shipping. As an example I just recently bought a BXA#1 tool holder to see how they compare to the CDCO tool holders. They list for $17.50 on the web site and shipping to me was going to be $15 (insane). The same item on ebay was $12 and shipping was $6, a $14.50 difference for the exact same item.
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- Feb 7, 2019
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darkzero, how do you like the cold gun? how often does your compressor cycle?
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- Oct 11, 2016
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There's a simple test to see if your QCTP holders/toolpost -end up- having a properly horizontal base for the tool...
Put a test indicator in either the chuck or on the ways and measure the bottom of your tool holder by moving the carriage back and forth (in the Z direction)... It should read less than a thou. Check all of your holders, and if they are consistent and it is not less than a thou there was a manufacture or mounting problem for your tool post. If your holders vary (are different from one another) then it could be the holders fault and you might need new ones. A last test is to check the same holder 4 or 5 times, taking it all the way off, and snugging it in place each time. If that measurement isn't exactly the same every time then there are serious problems with your tool post - for sure.
Although offshore tool holders and tool posts are more likely to have problems, even a big name top-of-the-line one will have problems the odd time. Please ensure that your tool post is properly mounted; there should be .010 to .020 between the top of the nut and the top of your compound slide, or nothing will hold down properly (and nothing will line up, either).
I once helped a guy that thought the two 'hold down' screws that are sometimes provided with the T nut were to hold everything down.... Of course that isn't the case and the tool holder didn't do its job. Removed the hold down bolts entirely, milled the top of his T nut and problem solved...
Put a test indicator in either the chuck or on the ways and measure the bottom of your tool holder by moving the carriage back and forth (in the Z direction)... It should read less than a thou. Check all of your holders, and if they are consistent and it is not less than a thou there was a manufacture or mounting problem for your tool post. If your holders vary (are different from one another) then it could be the holders fault and you might need new ones. A last test is to check the same holder 4 or 5 times, taking it all the way off, and snugging it in place each time. If that measurement isn't exactly the same every time then there are serious problems with your tool post - for sure.
Although offshore tool holders and tool posts are more likely to have problems, even a big name top-of-the-line one will have problems the odd time. Please ensure that your tool post is properly mounted; there should be .010 to .020 between the top of the nut and the top of your compound slide, or nothing will hold down properly (and nothing will line up, either).
I once helped a guy that thought the two 'hold down' screws that are sometimes provided with the T nut were to hold everything down.... Of course that isn't the case and the tool holder didn't do its job. Removed the hold down bolts entirely, milled the top of his T nut and problem solved...
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- Nov 27, 2012
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I wouldn't recommend them especially for what they cost (the Exair ones anyway). They use a lot of air & I only run them at 50-60 psi. I got 2 of them for cheap (at different times) years ago. On the lathe I only use it when drilling titanium to help cool things down in addition to spraying on coolant manually. Sometimes I use it when knurling depending on what I'm knurling. Other than that I really don't use it much. They do actually blow pretty cold air though. The one for my lathe is stuck the back of the stand most of the time for storage (magnetic mount).
A few months ago I finally hooked up the other one on my mill. I wanted to hook up an air line to blow chips away & figured I might as well just use the second one rather than sell it.
https://www.hobby-machinist.com/threads/my-misc-quickie-projects.76777/#post-661372
I bought them when I was looking for an alternative to flood coolant or a mister as I didn't want to run flood coolant at home. I wouldn't buy them again that's for sure but they're there & I'll keep using them when needed. I think I may buy a fogbuster some day or stop being a wuss & finally hook up the flood coolant on both my lathe or mill.
