With the 6040 becoming operational and the Grizzly being rebuilt, we don’t have much use for a 3rd mill, the Sherline won’t make a good mill without significant investment, and its current limitations shouldn’t necessarily make it a bad lathe. It was originally a lathe so I plan to turn it back into a lathe.
- The Sherline was set up as a mill with a vertical axis.
- There’s a lot of backlash in the X axis (to avoid confusion, the axis that goes left/right when looking at the machine, or to/from the lathe spindle)
- There is only one spindle belt, there was a prior harvesting of the lathe belt to replace the broken mill spindle belt
- The Y axis (forward/backward when looking at the machine) has a little bit of backlash, but far less than the X axis.
- The Potentiometer for the lathe spindle is missing. Ideally this should instead be controlled by the controller
- The Y axis motor has a broken pin
- We actually have lots of tooling and accessories (such as boring bars, etc)
Problems to overcome
- Spindle speed control should be controlled by the controller so dynamic speeds can be utilized.
- Tool holding, there’s only one tool holder, a future improvement would be to make an automated tool turret, the Y axis bed is quite large so right now a lot of tools could be mounted in individual tool holders.
- Work holding, there’s no chuck I could find, determine if we have collets that could work
- Swing over Y axis bed is quite short. Tools probably will need to hang over the edge, probably not that bad, but make sure there’s nothing else to be done.
- Coolant (seems the machine is fairly well set up for coolant, might be nice to set it up at least as an option.
- Shield – Before getting it working as a lathe, it seems prudent to build an enclosure to prevent accidental flying objects.
Questions to anyone who knows
- What’s the state of the computer and controller? Would it be better to use a GRBL board or use the current setup?
- Anyone know of any concerns that I’m missing?
Work I’ve done at the time of this post
- Opened headstock cover to assess spindle
- Swapped mill spindle belt back to lathe spindle belt
- Obtained new drawbar for boring bar (though it requires some fudging so I’ll seek a better one still)
- Removed milling UHMW plastic milling attachment to assess bed.
Next work I’ll do
- Determine how the missing spindle potentiometer could be controlled via a controller
- Clean the machine (lots of swarf and dust bunnies)
- Remove mill Z axis
- Relabel axis to be the more common lathe coordinates
- Take measurements and photos
Lots of to those who have traveled before me on this machine. If this runs contrary to anyone’s desire for this machine, please let me know and I’ll stop and/or undo any work I’ve done.