Getting a New PM-1054 Going

[erikmannie]

Here is the surface finish that I got before I was able to deploy your collective advice:

The last DOC was .020”. The RPMs were 800.

 

[erikmannie]

My cutter traveled 10” in 4 minutes, so is the feed speed 150 IPM?

For this project, I obviously don’t need a nice surface finish, but in general I would like to get a better finish than in the photos.

Now that it is too late to work in the shop, I can read and think about what changes I will try.

When I was face milling at a .020” DOC, I could not detect any vibration in the knee mill. Earlier, when I was taking off .130”, there was a little rock ‘n’ roll.

It will be interesting to see what the dial indicator shows for a head trammed with a machinist square!

I don’t have an air compressor. I really don’t feel like I have money or room for one, either. I would also guess that canned air would be uneconomical.

 

[xr650rRider]

inches per min. So 10" in 4 mins would be 2.5 IPM.

 

[davidpbest]

10" travel in 4 minutes is a feed rate of 2.5 IPM. If I were running my 2" 4-insert face mill, it would be feeding at 10-14 IPM. The leadscrew on your 1054 is threaded 5 TPI. So if your feed handle is rotating at 1 revolution per second, that's a feed rate of 12 IPM. Intuitively, one rev per second seems about right to me for the 2" cutter at the 0.020" DOC.

 

[davidpbest]

I just did a test run with my 2" Haas HRNP face mill - different insert type (see attached). At 0.020" DOC, into CRS, what felt and looked right to me was 750 RPM at 12 IPM feed rate. Chips were coming off straw color, the work piece wasn't absorbing tons of heat. The surface finish was smooth to the touch (finger nail test) but had the same kind of tool marks yours is showing which is characteristic of CRS. Later this week, I'll try it again with my octagon style HOP insert face mill (waiting for steel graded inserts at the moment).

 

[erikmannie]

I know that I have a long ways to go in order to get a near-mirror finish, but let’s remember that 1018 does not lend itself well to easily getting a beautiful finish. The rare times that I machine aluminum, brass or 12L14, I am reminded how nicely these materials machine.

I machine 1018 about 90% of the time because it is so easy to weld, affordable, and I am so lazy that I *plan* to be able to use a magnet to help me clean the machines.

You guys are really nice to take the time to help me; you can bet that I will pay it forward!

I have had a hard time getting time to study because of working such long hours for at least the last 3 years. I did so in order to stock up on welding & machining equipment. That phase ended yesterday when I resigned from my Saturday job. This one development *almost doubles* my free time, and almost all of my free time is spent metalworking and studying. The point is that I will be able to pay it forward almost immediately.

 

[davidpbest]

About the only way I have obtained “mirror finish” on 1018 is with an angle grinder and several passes with abrasive wheels followed by scotch-brite pad. LOL I hate the stuff except for structural fabrications. In my experience, on the mill, the best surface finish for 1018 is with either very sharp HSS tooling or an insert that has a honed edge and deep chip breaker that’s intended for use on aluminum. Everything else I’ve tried leaves toolmarks. I much prefer working with 12L14 or 4140.

 

[erikmannie]

Now I recall that most of the steel that I buy from the local steel yard is specifically A36 hot rolled. Compared to 1018, A36HR is less expensive, more ductile, and more difficult to machine to a mirror finish.

A little Googling reveals that abrasives or a surface grinder are usually more practical (faster and easier) in order to achieve a mirror finish on A36HR.

I imagine that many an entry level machinists have been humbled by A36, not realizing that their choice of material set them up for this frustration.

As with any material, a more rigid machine and workholding setup, improved trammel, fine tuned feeds and speeds, clearing out chips (particularly if using an insert with a wiper), oil, and cutting tool selection (material, nose radius, quality) can optimize the surface finish.

Compared with most other steels, choose A36 for affordability and weldability at the expense of machinability (with regard to maximizing surface finish) reduced tensile strength.

A36 scratches easily and can be porous.

 

[erikmannie]

Here is the surface finish on this 1” wide A36HR with 12 IPM feed, 1200 RPM, plenty of dark screw cutting oil. This milling machine is still working with a machinist level + 1-2-3 block trammel. Ignore the bevel, as that was done with a single angle cutter.

 

[erikmannie]

There is one last shot of a face milling job with a .0022” DOC, 1200 RPM on a 2” indexable face mill, 11 IPM feed & dark screw cutting oil. I see now that I need compressed air.