Skyfire, located in China, have developed a great small CNC mill and is now beginning manufacture - no struggling with a conversion of a manual mill. They call the it SVM-0
Part One covered making the blanks for the casting moulds.
Part Three will cover painting, assembly and alignment
Part Four will cover the electronics.
Skyfire are presently working on their website - we'll be sure to post a link when they have it up and running.
They are also working on a range of larger machines, with extended capabilities such as automated tool changer (ATC), and looking at producing lathes.
This article covers machining of the cast iron and initial parts fitting
The table begins with a block of cast iron, machined to size. Multiple cutters are used in a horizontal mill setup to make this a quick operation. (Note the table being machined in these photos is not for the SVM-0, it's a bit bigger. Same principles and end result however).
After the basic slots have been made, a T slot cutter is used to make the slots into 'T slots' to allow clamping:
Slots roughed out, the SVM-0 table looks like this:
Then the bottom must be machined - precise mounting points for bearing blocks, and slots and mounting holes for linear rails:
Mock-up of rails on table
The saddle is the bit sandwiched between the base of the machine and the table. It's where the linear bearing blocks mount for the X and Y axes. It starts life as a rough cast block
The ball nut mounting area and the flats for linear bearing mounting are milled, and then holes drilled. This must be done on both sides for X and Y axes:
Machining proceeds much the same as for the table and saddle
Rails are fitted:
Then the ballscrew:
It's vital to get the stepper motor mounts precisely aligned with ball screws to ensure smooth motion and no binding. A alignment jig is made for this purpose. The silver rounded part below presses into the black drilling jig. The flat on the silver part avoids interfering with the base casting.The silver piece then presses on to the ballscrew, and the black jig is used to drill the mounting holes for the stepper mounting plate.
The spindle motor sits nicely out of the way inside the head, attached to a mounting plate, with slots that allow the belt to be tensioned.
Careful alignment is vital. This begins with precision granite squares and use of the dial test indicators First one rail is aligned to the table edge:
Then the second rail is aligned to the first
The same process is repeated for the Y axis (the base) and the Z axis (the column)
The saddle is installed on the table:
And then both are installed on the base:
The basic components of the mill are now together: