ecolometrics
Plastic
- Joined
- Aug 12, 2019
I run a machine shop at the local maker space where I also train basic manual machining on the mill and lathe.
I have a new to me Summit SC EVS-550B (probably Taiwanese) CNC machine with #40 spindle, a Fagor 8040 controller and a power drawbar. I have been buying NMTB40 tool holders for it. Some used, some new. Most of the tool holders have threads that are cut 1.3 to 1.4 inches deep. Those work fine. But some of the tool holders have only 1.2 in or less of usable thread. Those do not sit securely in the machine. I have a few questions:
1) Bad luck? While I returned the first tool holder, I picked up three more (Three Chinese and one US) with the same issue.
2) Can I extend the tool holder thread by tapping it? I would assume I’m dealing with heat treated tool steel. What Rockwell rating are these tool holders? Do I need to anneal? I have tried doing this by hand with a three flute gun tap, and the tap chipped almost instantly.
3) How dumb would it be to put a spacer between the tool holder and the spindle?
Other items of note: The machine has a manual but it’s useless. Also, CAT40 tool holders don't fit. I'm not brave enough to mess with the drawbar.
I have a new to me Summit SC EVS-550B (probably Taiwanese) CNC machine with #40 spindle, a Fagor 8040 controller and a power drawbar. I have been buying NMTB40 tool holders for it. Some used, some new. Most of the tool holders have threads that are cut 1.3 to 1.4 inches deep. Those work fine. But some of the tool holders have only 1.2 in or less of usable thread. Those do not sit securely in the machine. I have a few questions:
1) Bad luck? While I returned the first tool holder, I picked up three more (Three Chinese and one US) with the same issue.
2) Can I extend the tool holder thread by tapping it? I would assume I’m dealing with heat treated tool steel. What Rockwell rating are these tool holders? Do I need to anneal? I have tried doing this by hand with a three flute gun tap, and the tap chipped almost instantly.
3) How dumb would it be to put a spacer between the tool holder and the spindle?
Other items of note: The machine has a manual but it’s useless. Also, CAT40 tool holders don't fit. I'm not brave enough to mess with the drawbar.