At 5,000 rpm the motor develops over 1hp which will be enough for my needs. Embedded in the spindle pulley is a magnet for a hall-effect speed sensor. The 3 step pulleys are Poly-vees giving ratios of 2:1, 1:0.8 and 1:3. The spindle is driven from a new 0.55kw 3,000rpm inverter class motor which runs from an inverter at up to 5,000 rpm. Sticky materials like CZ 108 brass still need lubricant but I apply that with a paint brush. The 'coolant' nozzle isn't connected to a coolant pump - it's connected to a fairly quiet diaphragm compressor to blow chips out of the way as well as cooling the tool. To get to my desired 10,000 rpm top speed the bottom bearings had to be oil lubricated and hence the drip feed lubricator. The bearings are precision preloaded double row angular contact at the bottom and at the top two deep groove shielded ball bearings which are preloaded together but can float relative to the bottom bearings to take care of thermal expansion.

I designed the spindle to take ER32 collets directly and wanted it to be capable of up to 10,000 rpm. From a distance the welding looks OK but it's only after milling off the lumps and filling in the holes with Plastic Padding! I could do with attending the Rob Wilson School of Welding! The face was machined square to the arm in the lathe.

The spindle is home made and is supported on an arm fabricated from 4' thick wall square tube with a piece of 4' x 1' mild steel welded to the end.

Unfortunately I didn't take any photos during the conversion but this is the finsished machine: (Keeping the y-axis screw protected from swarf was a major issue.) I spent a lot of time drawing out parts of the engraver and eventually found a convoluted way of using them. The mounting of the nuts wasn't conventional but they were too good not to use. Some time last year I decided to unsheet the machines which had been stored outside and drag the best one into my workshop.īefore I retired I managed to acquire a good assortment of very high accuracy ballscrews off redundant equipment. I replied and was offered £100! The spindle was despatched and thus the machines were free! The pantographs and copy tables were taking up too much space and went to the tip. They looked like a suitable basis for a CNC conversion and, at the price, I couldn't resist them.Įven better was that, a matter of weeks after acquiring them, I saw an ad on for a spindle for an Alexander engraver.

Some years ago I acquired 2 Alexander manual engraving machines for the princely sum of £100. Having been mainly an observer on the site for some months I have been coerced into doing a post of my own.

Vectric cut2d crackers