This is one of my test pieces straight from the lathe, it was mostly cut with a standard straight cut tool as shown in the second picture.
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-------- Original Message --------
Subject: [Unimat] First attempts - finish on brass (all?)
From: William Ayerst
To:
[email protected]CC:
Hello there chaps,
After the kind advice to try out a cannon and the location of the Edenstaal plans on the files part of this group, I thought I¡¯d test out the lathe again after a period of hibernation.
I am using a Unimat SL. The tool that came with the lathe was 1/4¡± HSS, so I have replaced this with a 6mm set from RDGTools (and after some experimentation, a 0.31mm shim underneath the tool, to return it to the height of a 1/4¡± tool). Now, using a left-handed cutting/facing tool I can cut across the diameter of a rod and get no ¡®pip¡¯. If I use a parting off fool, I get chips and very small curls of brass appearing, instead of chatter/etc.
I wanted to experiment with getting a good surface finish, so I am using a straight turning tool, as I understand it:
(Type-3 ST Turning)
This is the result:
The leftmost section has been polished with some emery paper while in the lathe, the right hand side is au naturel
If this is as good as I can expect, then that¡¯s fine - but I¡¯m going with as fine a cut as I can (the smallest subdivision on the cross slide) and as slow as seems reasonable (1-2mm per second longitudinally.
If anyone could give me some guidance as to what I¡¯m doing wrong - or what I need to do differently, I would greatly appreciate it.
Many thanks,
