Help me choose a mill

[tomelectro]

Sorry for yet another "what mill should I buy" thread, but I'm a rank newbie and could sure use some advice! I want to fabricate and mill cutouts, etc on 19" rack panels for custom electronic gear. Panels are typically 3/16" thick aluminum, 19" wide and up to 5 - 7" deep. Most holes/cutouts would only require a couple of inches movement in x and y directions, but would it be nice to be able to run the whole panel without moving and re-clamping the work. Also, I would like to be able to take a rough-cut panel and square it and trim to size on the mill (or is there a better tool/method for this?)

My budget's around $1200 (not including tooling), and I'm waffling between an X3 and a Grizzly 3358 (RF-30 clone?). How much bigger does the table have to be than the workpiece? An X3 has a table a little wider than a rack panel, but not very deep (21.625" x 6.25"), and the t-slots don't run to the end of the table. Also, the total x travel is only around 16". Can I still clamp a 19" panel to this? Or should I go with the larger 3358 (table 28.75" x 8.25"). I'm would be doing mostly flat panels, so I'm not too worried about the alignment issues of the round column of the 3358. At 600lbs though, it's maybe starting to get a little heavy for a home workshop.

The pros and cons as I see it: X3 pro - less expensive, dovetail column, a little easier to move, much support and info available. Con - smaller table and x & y travel. Grizzly 3358 pro - more powerful, bigger table, greater x & y movement. con - round column.

What am I missing?

Any advice is greatly appreciated

[ataxy]

unless you intend on doing alot of z movement the rf30 clone would be a good choice for you as for the x3 you could easly get a workplate that will permit you to install longer part but it would not give you more travel

[tomelectro]

Thanks- I think you're right. It's funny how much writing the post helped sort things out in my head. By the time I finished it, I had pretty much come to the same conclusion to get the Griz 3358, though i'd still like to get opinions. I'll watch the used market as well, to see what turns up.

As for the X3 table workplate, where would I get one, or is it something I would need to make?

[ataxy]

well its not hard to make as its simply a flate plate with threaded hole

also you may want to look for a miil like the bf20 there are two version of it the standard one and the L version that offers around 18" in x travel

[pzzamakr1980]

If you plan on doing cnc, buy yourself a mill that has a dovetail column. There are a number of threads dealing with exactly this topic and why a round column mill is not appropriate for cnc'ing. While that statement is an opinion and while some people are very happy with their choice, the majority all point to the dovetail mills.

[ataxy]

yes this would be true but in is case he mostly want x and y travel, but its true that a square collumn is more a mill then a round column one wich is more of a press drill with mill capacity

[pzzamakr1980]

The reason I dont like the round column mills is rigidity. As you said, they are great drills but the forces acting on it from movement of the x and y axis tend to cause deflection and movement. While I realize that it is not much it is there, especially with deep cuts and such. I have an x3 myself and its fitted with a large fixture plate that allows me to hold much larger pieces. This works great.

[philbur]

I think you will find that and RF30 clone has the necessary 19" + travel whereas the X3 doesn't. Round column should be fine for the work you describe, rigidity will not be an issue. If everything is to be aluminium, with relatively small cutters, go for the RF30 with the highest spindle speed. 3,000 rpm would be good. 1,500 rpm would be a disaster. Belt drives are relatively easy to increase spindle speed. geared head drives not so.

Phil

Originally Posted by tomelectro Sorry for yet another "what mill should I buy" thread, but I'm a rank newbie and could sure use some advice! I want to fabricate and mill cutouts, etc on 19" rack panels for custom electronic gear. Panels are typically 3/16" thick aluminum, 19" wide and up to 5 - 7" deep. Most holes/cutouts would only require a couple of inches movement in x and y directions, but would it be nice to be able to run the whole panel without moving and re-clamping the work. Also, I would like to be able to take a rough-cut panel and square it and trim to size on the mill (or is there a better tool/method for this?) My budget's around $1200 (not including tooling), and I'm waffling between an X3 and a Grizzly 3358 (RF-30 clone?). How much bigger does the table have to be than the workpiece? An X3 has a table a little wider than a rack panel, but not very deep (21.625" x 6.25"), and the t-slots don't run to the end of the table. Also, the total x travel is only around 16". Can I still clamp a 19" panel to this? Or should I go with the larger 3358 (table 28.75" x 8.25"). I'm would be doing mostly flat panels, so I'm not too worried about the alignment issues of the round column of the 3358. At 600lbs though, it's maybe starting to get a little heavy for a home workshop. The pros and cons as I see it: X3 pro - less expensive, dovetail column, a little easier to move, much support and info available. Con - smaller table and x & y travel. Grizzly 3358 pro - more powerful, bigger table, greater x & y movement. con - round column. What am I missing? Any advice is greatly appreciated

[tomelectro]

Thanks for all the replies. I think that most of the time my work envelope would be well within the X and Y travel of the X3, so with a larger fixture plate I would probably be OK when working with pre-cut blank 19" rack panels, which are readily available. So it would just be an issue of if I wanted to rough-cut the panels myself and clean them up and square them on the mill, which would require the full X and Y travel of the RF30, unless there's a way to do this with the X3?

I think what I really need is to get a good beginner's book. I have The Home Machinist's Handbook by Briney, which is a great introduction, but now I'd like to find a book with more emphasis on milling techniques. Any suggestions?

Thanks

[ataxy]

see this is the thing there is no technique per say there is a basis wich you probably learn in the book you bought and then there is how you apply it and this in my point of view is pretty blurry as this will depend on alot of factor such as the machine you use, the material you are working on, the tool you are using (hss vs carbide vs no of flute vs coated or non coated vs quality) and the part you are doing, in the end it all boil down on how you plan on executing your part abd by that i mean the type of fixture you will use to do your job and the sequence of operation (like will you drill befor you mill and ounce you mill the part will you still be able to place the part for the next operation) these are all thing that a book cannot teach you and come from experience and previous error

[pzzamakr1980]

I agree with ataxy, there are will be a thousand right ways to do this and a thousand wrong ways, all depending on who you ask. If you would like some ideas that are free, keep checking out the site. There is always an old machinist who has years of experience making something and showing how he did it. For a perfect example, check out the posts by widgitmaster, he is an artist when it comes to metal. His minirouter thread and his lathe turret thread are perfect examples. He also shows how he sets everything up, and what speeds and feeds hes using. I also dont think anyone could dispute how he does it.

P.S. I am not implying that widgitmaster is old, or only old people know how to do things. Figure of speech.