MadModder
Gallery, Projects and General => Project Logs => Topic started by: John Hill on August 25, 2017, 05:21:34 PM
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I thought I had mastered this years ago..... :bang:
I am using the top slide set over method and have produced a pile of metal shavings and still no accurate taper!!!!
I clamp the cross slide and lock the carriage travel, the top slide gibs are on the snug side and the tool seems to be perfectly on centre (tested by end facing) :coffee:
The top slide angle is set by mounting a DTI on the tool post and indicating against a plain bar in the lathe. Taper angle is not the problem, what is the problem is that the tapers are barrel shaped. :scratch:
I cannot get the tailstock up to support the end of the workpiece without fouling the the top slide handle, neither can I manage to get a good finish turning the top slide by hand! :bang:
Today will be a busy day but maybe this evening I will get to have another try paying particular attention to tool height.
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Tool height is critical - needs to be bang on centre
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Any chance you can turn your top slide the other way - without fouling the chuck? If possible you could then use a centre in the tail stock for added support. Probably not feasible but, hey, I'm thinking outside the circle (Don't like the box. circles suit lathes better anyway) :ddb:
Of course, the solution a few of the members in my club would use would be to CNC the thing. Tapers are dead easy and no tailstock fouling. Alas, we mostly turn handles.
John B
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I have to have considerable overhang on the tool to clear the tailstock , I use a D shaped insert set to 60 degrees
same as the cetntre , gets in right to the end , finish cuts 4 or 5 passes without infeed just taking dust off works for me .
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If you have a sine bar and sine blocks, here is a cool trick I did that makes cutting a taper a walk in the park.
A part I machined
(http://i210.photobucket.com/albums/bb270/rodweb/Lathe/Collet%20Chuck/DSC_5109_zpsaf81cd79.jpg)
And the cute little sine bar I bought from ctctools. Its magnetic so it sits in position on its own accord
(http://i210.photobucket.com/albums/bb270/rodweb/Lathe/Collet%20Chuck/DSC_5114_zps3af99236.jpg)
Putting it all together. The lower lip aligns it with the compound
(http://i210.photobucket.com/albums/bb270/rodweb/Lathe/Collet%20Chuck/DSC_5116_zps0d99d8e4.jpg)
And setting the compound angle against the tailstock. (You have aligned your tailstock haven't you?)
(http://i210.photobucket.com/albums/bb270/rodweb/Lathe/Collet%20Chuck/DSC_5117_zpsbcabe684.jpg)
And the final result which is a perfect fit!
(http://i210.photobucket.com/albums/bb270/rodweb/Lathe/Collet%20Chuck/DSC_5120_zpscb73d212.jpg)