|
Page 1 of 6  Finally I have had some time to finish the CNC conversion (actually CNC mill conversion) of my Sherline lathe. It is based upon a Sherline 4000 lathe, a Sherline CNC conversion kit and an old milling column from a SpectraLIGHT mill.
Sherline have good descriptions delivered with their kits, but usually a bit sparse on the illustrations. This description is much like the Sherline description, but I have added several pictures to aid you if you are thinking of doing the same conversion of your Sherline lathe. Also during my work I fell into a (in retrospect, obvious) pitfall, and hopefully by describing it here you will not do the same error.
The following items are needed
- Sherline lathe (should be obvious), e.g. the 4000 type
- Sherline CNC upgrade kit (E.g. 6270 for the 4000 lathe)
- Milling column (Sherline type, e.g. s SpectraLIGHT column like mine)
- 8-32 tap with corresponding .136" (#29) drill. Alternatively a M4 tap with corresponding 3,5mm drill
- Three Nema23 stepper motors (two for the Lathe, one for the Milling Column)
- lternatively a new axle coupling for the milling column
Sherlines description for the lathe CNC upgrade kit can be found here. I recommend that you read this before or while going trough my description, as my steps are more or less just short-versions of the sherline text. Originally I planned making my own stepper motor mounts, but to save time and probably a lot of problems I ended up buying a discounted Sherline CNC conversion kit from eBay. Now after completing the project I am convinced this was a smart decision. If not for anything else than the reduced backlash/increased tightness of the included CNC kit lead screw. The backlash of the original Lead screw was one of my biggest concerns for the final machine prescision. Dismantling the lathe 1. Move the cross slide as far from you, and the saddle as far to the right as possible. 2. Loosen the 5-40 screw in the center of the cross slide lead screw, holding the leadscrew by the hand wheel. 3. Remove the two handwheels by loosening its set screw. 4. Remove the crosslide thrust from the crosslide table, by removing the single 5-40 screw at the top. 5. Turn the lathe over and separate the bed and leadscrew from the base by removing the socket head cap screws at each end of the base, holding the thrusts to the base. 6. Remove the head cap screw that holds the saddle nut to the saddle. 7. Remove the screws that hold the leadscrew thrusts to the bed.
The next page shows the modification needed to the lathe before mounting the CNC upgrade kit components.
|
