New to metalwork

Machine Shop
#1

Hi - new guy here.

I’ve got a project I’ve been kicking around for a long time involving machining some unusual oblong aluminum tube I have. Problems: I’ve never operated metal working equipment (other than a drill press) before and the machining might be a tad ambitious for a first project.

Other than going through the materials on the machine shop committee wiki, how might I get started with the project once I’ve got some workable plans for my first attempts? I will need to use a mill for the bulk of this work and will probably need a means of rotating the stock against the bit - I want to say I need a rotary vice, but I’m not sure if that’s the correct term.

Will there be a bridgeport course in the future or can I meet someone at the space for some guidance?

Thanks.

#2

I have offered a Bridgeport class in the past, but it’s just me imparting the information freely available on the Machine Shop wiki. We do not have a rotary table. I’m keeping my eye out, but they’re pretty pricy, not to mention heavy. 200#-300# heavy. What is it you’re trying to do?

#3

I’m trying to mill male and female joints into 1/8" wall tube. It’s oblong, so it can’t be turned on a lathe.

Perhaps I’m describing the wrong thing. What I’ve seen looks manageable by one person and should slot into the X-Y table like an ordinary milling vice. I’ve seen them for a few hundred dollars.

#4

You’ll have to send pictures. The best price I’ve ever seen for our plain stationary vice is over $500. And I’m not envisioning anything that can be done to oval tube with a rotary table that would require one.

#5

Tubing is 1.5" x 1.0" w/ 0.125" wall. Here’s a 3-view sketch of the general concept (with channels for spline locks):

Here’s the raw material itself (hinting at my intended purpose):

While I could foresee milling the female joint with, say, a 7/8" bit making a plunge then a horizontal cut, the male joint seems like it would either require some sort of rotation or more playing with the X-Y wheels than even a determined person could do consistently.

But I’m decidedly new at this, and perhaps there are simpler ways. Or it’s simply too ambitious.

Bridgeport issues
#6

You wouldn’t get any precision out of trying to mill the slot w/ a full width bit. Ideally, I think you’d use a CNC lathe for something like this. Depending on how long the tube is, you could do it on a manual mill with a cross-slide rotary table (which we don’t have yet), or on a CNC mill. The first thing to think about is how you’re going to hold it. How long is the tube?

#7

I haven’t finished the design yet, but I’m thinking ~6" would be the maximum length of any piece.

A lathe with a secondary 1- or 2-axis powered cutting tool is what your’re thinking by CNC lathe?

#8

I’ve actually never seen or looked into CNC lathes, so I’m not sure exactly what it would take. Seems to me any lathe with an encoder ought to be able to move the x axis in time with the chuck.

For 6" I think you could do it on a CNC mill.