OK I'm still new to lathes & machining, but I have spent the last 12-18mths
really frustrated with my Myford 7
I bought it 2nd hand, and it is only a small lathe, but I have seen othere
peoples work & that looks OK.
So I have persisted tring to solve my cutting problems, with no lucks so
far. I purchased several books & have search the net
but can't seem to find an answer. I don't have time for tech courses ( I
barely have time to get into the workshop) which are a
fair way away, and charge a lot anyhow.
In a nut shell, I can't seem to get a smooth cut, on Aliminium or on Mild
Steel. I'm not being picky here, the best I've done has ridges in it.
But a 'normal' cut is just so rough. It looks like the metal is being
'pulled' from the surface rather than cut or sliced.
I've tried HSS & cobalt & carbide tools. I've tried fast & slow, manual and
auto feeds. I've spent ages grinding tool bits
being careful not to over heat, and NOT water cooling so I create cracks.
Then only to see them 'burred' when used.
sort of like they are made of cheese. None of my efforts has given me a
smoothly cut surface (forget mirror finished here,
just smooth enogh not to cut your hand will do!!) I don't get any bad noises
when I cut, and while I'm cutting it looks OK,
but when I turn machine off, I see a really rough (not as bad as a golf
ball, but one the way visually) surface
So could someone write me a checklist or something, in order that could lead
me to the cause?
Should I buy indexable tips?
Am I setting the tool to low? or high? (I'm trying real hard for centre)
Should I use positve rack or negative? (I'm using positive)
Faster or slower? (tried both, slower seems worse however)
Different material? (tried Aliminium & mild steel)
Heavier / lighter cuts? I probably tend to light to very light cuts. 1/4
turn on crossslide would be a big one for me
or maybe just junk the myford & buy a 'real' lathe? will that fix the
Any help appreciated. I would just like to be able top cut a nice
smooth(ish) surface on a piece of metal (any colour or type will do!)
Thanks in advance
- posted 16 years ago