basic lathe tooling questions for new lathe

[TOM REED]

(04-03-2012, 01:54 PM)candiamel Wrote: First of all, I’m not very experienced at machining, so I’m looking for really basic guidance to purchase some tooling for my Vectrax 14x40 lathe.

I was thinking about 5/8” tool holders as those will more-or-less line up the carbides with the center of the turning. Though maybe not exactly. I know, I know, I really should get one of those fancy dovetail tool posts but I’m running out of cash!


So, here are my questions:

1. Is there much difference in rigidity or quality of cut from stepping down from a ¾” tool holders to 5/8” due to vibration or flexing?

2. I’m told that CCMT or CCGT bits are the ones of choice for hobbyists like me. Given that, is there any difference in cut quality or should I have any different expectations than the mediocre results that I’m getting from my “TT” triangular cutters?

3. IF there is no difference in cut between a CCMT and a TT, does it make more sense to keep using the TT because of better economy? (you get three cutting surfaces instead of two)

4. What do you suggest for a carbide insert cutoff tool?

5. Can anybody point me to a simple chart that shows approximate turning speeds, feed rates, and cut depth for different materials?
Thanks!
Bob

oN MY LATHE 12x40 advertised size I dont see any real difference in cut quality. I have a QCTP wedge style I bought from CEDCO and am happy with that, I have bought
some 1.5 inch shank larger toolholders that I have now cut dovetails on to use for the QCTP and use the large carbides I have and am also happy with these. I have been using HSS cutoff toolholder but recently bought a carbide cutoff tool 9/16 that was made in Korea with 10 inserts for about $80.00. That was a waste of money, I guess I should have sprung for a Sandvic as they say they are the best. I have lots of HSS tooling for a rocker toolpost so will have to make a lantern toolpost for my lathe. I almost think that the old rocker and HSS tools are the best for most of the thing I do other than the heavy cuts which mine does extremely well with carbides. tom

My experience level I would say is quite amateur with most of it 30 yrs ago in the gunsmithing end, back then I would have died to have a lathe the quality of my new import made by SIEG.

check out chathamtool.com he has a very nice set of plans for a turret toolpost that looks excellent, I am going to make one of these which will also improve my skill level. These plans are selling on e-bay for under $15.00 funny I just checked to see if I could get to the website for this and his does not come up so you will have to search e-bay to find them. tom