[gwk]

has anyone who uses a 440 tormach actually used a 770 and compared the results of these 2 mills? is the surface finish the same running the same machining job in each? did you encounter a lot more tool chatter with the 440? were you able to adjust the feed and speeds to work out the tool chatter etc. ?

[MichaelHenry]

That would be a good question for John Saunders (NYCNC on YouTube). He owns several Tormach products.

[dlm3]

John has two 1100 and two 440 mills. The 1100 mills can do more material removal and have a large work envelope. The 440 mills are slower and have a much smaller, but still useful work envelope. Surface finish is the same on both if you use the right tools and correct feeds & speeds for the tool and material.

There are times when the 440 actually has advantages with its 10krpm spindle (e.g., engraving, small end mills & tiny detail work). The 770 also has a 10krpm spindle.

Graduate of John Saunders' Basic CNC Machining course. Highly recommended if you can get to Zanesville, OH for a weekend, particularly if you're starting from zero experience as I was.


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[petethered]

It's more tooling and F&S, but I had a buddy with a 770 look at some of the stuff I've done on my 440 and tell me that it looked the same.

[sansbury]

I have an 1100 so I can't comment too much on the 440, other than to say it's a nice-looking machine. When I bought the 1100 I considered the 770, but it wasn't "smaller enough," in either cost or size, to make sense for me. The 440 on the other hand is quite a bit smaller and cheaper and had it been an option I might well have gone for it.

The size of the 1100 does allow for more setups to make more parts (I've made fixtures to hold 10+ parts to do runs of a few dozen) and allow for having multiple setups on the table at the same time. most of the time I have mine set up with a vise and a small fixture plate I made which can hold a small vise, a 3-jaw chuck, or other fixture plates, and there's room for the rotary on the other side without pulling the vise off for parts under 10" or so. That's nice. But, aside from the larger fixture plates, everything I've made in the past 3 years would have fit on the 440 as far as I can tell.

Before I got the 1100, I had worked my way up through a Sieg X1 micro-mill and an X2 mini-mill, both of which I CNC'd. The X2 is quite a bit less of a machine than the 1100, but the X2 made real parts. Moving to the 1100, there were two huge differences: speed (in terms of MRR, material removal rate), and reliability. Since the 440 is a Tormach, I'd say you'd get the reliability. If you need to remove a lot of material, then it's kind of a case of "there's no replacement for displacement," in this case with rigidity and horsepower being the factor. I have a some parts that start as a piece of 6061 weighing 27 ounces and end as a part and 24 ounces of chips. I could have made those on the X2 but I think I'd have died of old age before finishing too many. Of course, a low-end Haas mill could smoke the 1100, and so on, so it's all relative. If you're a hobbyist making the occasional part or a commercial user who doesn't need to make a ton of chips, the 440 might be fine.

In terms of how nice the finishes on parts are, there are a TON of variables. Tool choice, fixturing rigidity, types of toolpaths, use of spring and finish passes, speeds and feeds all play an important role. Machine rigidity, in my experience, makes it much easier to achieve a certain level of finish quality. On the X2, I might need to do multiple .005" passes or use a fly cutter to get a finish as "nice" as I can get with a .025" finish pass on the 1100 using the same .500" EM used to rough the part. To a point, skill and patience can compensate for cash and iron.

A lot also depends on what a good surface finish means for you. If you're working in 6061 mostly and want the part to look and feel nice, like it wasn't hacked out of a block of metal with a chisel, then you are definitely in the ballpark with the 440. If you are looking for a mirror-smooth finish that will look slick after anodizing, then you are probably going to need additional finishing with a tumbler or wheel even if you're running on a Mori Seiki.