Some may be wondering about the recent focus on machining related topics. The pure model railroading has been on a bit of a hiatus as I get geared up for some model engineering. The latest project, and it is indeed a project, is a new milling machine! I am not changing direction just adding more of them or at least the distances I can travel.
Why Get One?
After my initial experimentation with milling on the lathe, I concluded that I needed more capability to accomplish my long term goals. Getting set up was an involved process and once there, the milling “envelope” was small and speeds available were limiting. An end mill smaller than 3/8″ would require spindle speeds in excess of the Myfords ~1000 RPM top speed.
Why This One?
My model engineering aspirations date back more than 40 years so it definitely not an impulse buy! I essentially compromised on the biggest bench mill I could imagine safely fitting down the basement stairs and onto a stand in beneath my 7 foot ceiling. I suppose if I eventually end up with a ground floor shop I might add a full sized Bridgeport type mill but this ought to do and I am proceeding on that assumption.
Based on the assumption that the mill acquired would it for the rest of my life, I set out to find as good a mill of not more than about 400lbs with as many bells and whistles on it as I could manage. And that I could bring myself to pay for.
The pay for part meant either a used mill of North American or European origins or a new one of Asian manufacture. While I wouldn’t say no to a Schaublin, Deckel or Fehlmann, the new ones are way more than I could justify. A multiyear search for used bench mills turned up effectively no candidates. Lots of big manual knee mills but not bench mills. They are out there in Canada because I have seen Tom Senior mills in other people shops but nobody was selling one where I was looking. It looked like buying new was the way forward.
After considerable research, I landed on the Precision Matthews PM-728V-T. It is made in Taiwan to claimed higher standards than most modern imports. Here are the features that I considered important:
- square column: two axis to tram is enough
- pre-installed 3-axis digital readout(DRO): counting turns of the handwheels and allowing for backlash got old quick on the Myford
- power x-axis feed: x is the side-to-side direction and the usual one involving a lot of cranking, at .100 per crank, 20 inches is a long way
- 370lbs: I could imagine managing that
- R8 spindle: this is what Bridgeport’s have and tooling is abundantly and locally available.
- 120VAC power: three phase is not somewhere I want to go.
Getting the thing out of the driveway, down the stairs and on to the stand was an incremental production of about 5 days, mostly spent in preparation: building a ramp, a gantry, removing doors and handrails, etc. (Moving 400lb lumps of iron is not the time to be lackadaisical)
After the mill was in place, various infrastructure and assembly tasks were needed before any actual work could start. Assorted tooling was required as well which was a challenge in the current lockdown in Ontario.
All that being said, chips are being made and I expect everything to settle back into balance with layout construction in the near future.