In the Beginning, there was Dark…

(i.e. What I started with)

By Chris Krstanovic

 

 

After a lot of research, I decided on buying a Smithy machine. It is bigger and heavier than its Chinese made siblings. It is also more expensive, hovering around $2400 mark, 2 or 3 times the HF model. I selected the LTD model, as it has a longer mill arm, not necessitating lathe chuck tear down, when switching between mill and lathe. I was not wrong - it is very discouraging to have to spend 20 minutes to switch around, to do a 2-minute job, and then switch back. You end up not doing it at all. They don't tell you this when you buy it. The smaller machines like Taig and similar, will be even easier and cheaper to convert, but I wanted something with more power, and rigidity. Although, the Taig looks like a toy to me (sorry guys, no disrespect intended), I am sure one can still make nice stiff on it.

 

      

As it arrived, with few add-ons (click on the pics to see the larger version)

 

Smithy Lathe end is pretty good, but I feel that the mill is a bit underpowered, and not as rigid as mill only models. You do not want to take 0.250" deep cuts in 4130 steel. Not bad though. Quality was surprisingly good considering its origin of manufacture. Not to say that there were no problems, but Smithy support is excellent (you will not get that with HF), and everything was resolved fast.

 

Still, there are couple things that you need to know:

 

q       Backlash was bad, particularly on long (X) axis. I measured 0.030" out of the box - and it is not adjustable. I managed to get it down to 0.016" by using a shim under the half-nut. Y-axis was better - just 0.016", ending up at 0.002" after tightening the nut. Z-axis is preloaded, so there is effectively no backlash. If you are using this manually, it is a nightmare. Evan with CNC software compensation, the backlash meant that even moderately heavy cut would bounce the carriage between the backlash limits. Although, going shallow in CNC will work, I recommend you spend ~$350, and convert to cheap ball screws. Now, my lash is better than 0.003", and with SW compensation, non-existent.

q       Ways were in generally poor condition. You will need to polish them. Do not go crazy about it: a bit of polishing will do the job. This enables you to tighten the carriages better, and still be able to move them (thus better accuracy). Y-axis was not that bad, but when you facing on the lathe, there would be light rings due to this. After polishing, and ball-screws, all is well now.

 

      

More add-ons: DROs with covers and ways/screw covers

 

Immediately after the installation, I added DROs (digital readouts) to all three axes, and never looked at crude dials on the machine. Remembering the chips and the crud that will be forthcoming, I added a Lexan shield above the Y-DRO. It is easily removable, and held in place with two cabinet door magnet latches. I use these a lot, as they are great for this kind of application. The ways cover, protecting the ways and more importantly screw threads from the chips, is held in the same way. Opt for double magnet latch - holding power is 4X better, and they will not tilt due to much larger footprint. The way covers were made from plastic tablemats from Wal-Mart. This arrangement works great.