Engineering

CNC

Lathe

Mill

Engraving

Centec Mill

Sieg SX3

Taig Mill


Here's the Taig mill with it's WC pan adapter motor cooling shroud :) The mill was purchased from Peatol Machine Tools. It's now been sold on after a few years of reliable working and is being replaced with a Sieg SX3 which is being converted to CNC now.

The tray and limit switches are now sorted out, I've still got the sides and back of the enclosure to do, but it's getting there. I need to tidy up the cabling but I can't do that until I make the back.

 

Here are the details of the limit switches - since taking these photos I've modified the Y axis limit as the rubber guard at the rear kept tripping it! There's also a picture of the motor mount adjustment, this has been modified twice as drive motors changed.

Here's a recent picture of the Taig doing an Engraving job on an MDF sub-bed - cutter is a solid carbide single point 0.006" tip running at 7500 rpm, feed was 20 ipm - no problems run dry in Engravers Brass. There's another Engraving job shown on my Engineering Page. I've made a bed plate that gets used for engraving now, the MDF still gets used if I'm drilling or milling through.

 

Stop Press!

I've now finished my 4th axis  - it's simple and it works fine. Made from a spare spindle, and a few bits of aluminium I had lying around. The ratio is 72:1 and even with a little 0.7A stepper motor it's virtually unstoppable. Using 5 microsteps gives a resolution of 1/200th of a degree. Backlash is adjustable by moving the motor on it's mount. The worm and pinion were run for half an hour with Solvol Autosol metal polish to bed them in and then the backlash was re-adjusted - it's nil :) The test piece was just to prove engraving/milling was possible wrapping A axis. See my Engraving page for further information.

 

Recommended Modification!!

I had a problem with the X axis gib screws. The design is flawed in my opinion, it relies purely on grub screws staying put, with no locking device. The motor side one was slack from new, and on a recent job decided to come loose. This has a really nasty side effect, it allows the carriage to move freely to the right and jam to the left!!

The cure is simple, throw away the grub screws and replace with longer bolts and a locking nut as per the Y axis.

10-32 bolts are not easy to come by in the UK, so I re-tapped 5mm and used those.

 

ER-16 Spindle conversion.

I finally got around to making an ER16 spindle, It took about an hour. I used a spare head assembly and pulley.

Spindle is a Straight shank Extension mini collet chuck from J&L Industrial Supply

ER16 EXT/MINI/COLL/CH 16DIx160 MM LONG
J&L part No HHV-76014D

16mm id bearings came from my local supplier. They are rated at 10,000 rpm with grease 18,000 with oil.

All it needed was 2 collars making, one fits below the bearings and has spanner flats, it's held onto the shank by setscrews into ground flats & loctite. The top bush is held with three setscrews. The pulley needed just a tiny amount boring out to make it fit. I used the existing centre spacer and mount. I had to shorten the shaft to get the pulley down against the top bush. The shaft was case hardened, but once through that it cut easily. It was assembled in the vice with a bit of pressure to get some pre load then all tightened up.

I ran it for couple of hours to set the loctite and did some test cuts, seems very good.

Nice touch is it is hollow with a threaded section that has a screw. It makes it easy to get a repeatable height offset when changing tools.

Here's a few pictures that show the top and bottom bushes and the completed head.

 


Return to the main index page or to my Engineering page.

Links


Stepper Motor Drives, Stepping Motors and Motion Control Equipment from Alzanti

Hans Wedemeyer's CNC page

Peatol Machine Tools

Nick & Felice Carters Taig pages

Tony Jeffree's Model Engineering pages

 J&L Industrial Supply


Steve Blackmore

steve@pilotltd.net

Copyright 2004 Steve Blackmore