[GrievousAngel]

Hello All,

What machine tool(s) would better suit manufacturing of projects like the example attached below?

• Would a xyz CNC table with a Bosch Colt router handle it or would I need a table-top vertical mill?
• If using a mill, how automated (CNC control or power feed) could expect if on a modest budget?
• Which approach would be more cost effective?
• Please don't consider the minor lathe requirements.

Thanks,

Billy

[fizzissist]

Some old Afghan with a file and a hacksaw in a garage on a dirt floor could make this assemblage.

Take that as a dose of humility (as I often remind myself to do) and consider that with anything more advanced you're talking rhetorically.

[The Blight]

Fizzissist, you missed the "better suit" part of his question. If you think that a file and hacksaw is the best way of going at it, then you must be truly skilled.

[Bob La Londe]

I could certainly make the 3 plates on a mill or on a gantry router. In general a small mill will be more rigid, but its not going to be rigid enough to take hogging huge cuts. Personally I have gone to a hybrid setup for this type of part. I've got a small Taig with a Porter Cable router mounted on it for high speed cutting. (I also have a gantry router with a Bosch Colt) Then I plug the numbers into ME Consultant and see what cut will get me where I want to go the fastest.

If I were to make THAT assembly I might cut out the plates on the Taig, use it to spot for the obvious drilled holes with a small ball mill (the router is too fast for a drill bit), then drill and tap on the drill press allowing it to self center on the spot marks.

If I had to be as accurate as I could be I might do everything on the Hurco, but initial milling might be much slower because of its maximum spindle speed. I'ld have to plug in the numbers for heavier cuts and bigger cutters and compare.

Is this a one off project, production run project, or just a piece of machinery you selected at random as an example to ask your question? The answer to this question would affect how I tackled the job.

For exampe: For production I might throw multiple setups on the table of the Hurco once, and do everything for each tool on all work pieces. Then change tools. Tool changes would be faster also since I could premeasure them all and have them in individual tool holders ready to snap in. While some of the cuts might have to be slower than the Taig with its 28K spindle the overall production rate might be higher with no manual finish work, one tool change per tool for multiple parts, and fast tool changes.

For a single one off part I'ld do it on the Taig because of its potential for material removal rates with the smaller cutters and reduced setup time inspite of slower tool changes with the ER collet chuck I have mounted in the router.

I could do it on the gantry, and in theory the 34000 rpm Bosch Colt could have higher material removal rates, but that has not shown to be true in practice. In addition I would probably have to go as slow as the Taig or slower to get similar accuracy due to flex in the machine under heavier cuts. If it was all super light cuts I could go screaming fast for feedrates though. I have it "turned down" to a max 300IPM and I tested it as high as 600. Also, for a job that required lots of rapids it might be faster even if the cuts were slower because of its high rapid speed.

"I want to know which machine is the best," is not an easy query to answer. Not even for one type of part. There are different ways to approach a project. I can see that and now after learning CNC machining for several years I can see how much I don't know.

I bet some of the guys here who really "know" what they are doing just roll there eyes and think, "where do I start?"

NOTE: Precise Bits, who makes the best collets to use directly in many routers, has noted that the spindle bore of the Bosch Colt has changed in the last couple years, and is no longer as good as it once was. See their website for more information.