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Lathe – toolholding – quick change four way toolpost
The quick change toolpost can be bought or can be made.
fig homemade quick change four way toolpost
This might seem to be a good idea but there are some odd problems with it.
Firstly, with most toolholders the back of the toolholder stick out. This does not matter where there is just one toolholder but where there are more they might clash.
Secondly, the cutting edge has to project further out at the front than it would have to do otherwise because of the toolholder to its right. In the case of a parting tool the tool becomes useless.
Thirdly, as the toolpost rotates the last cutter used could well clash with the workpiece.
The only advantage is that up to four tools are immediately available but then it does not take much longer to change quick change tools anyhow.