[Spartan1]

Doing just finish machining will take a fraction of the time. All the heavy material removal takes a lot of time, especially on these smaller, lower-power machines. Machining time is FAR more expensive than casting or extruding, and the tooling is also expensive.

If it can be made in short sections as you indicated, it can be cast or extruded in short sections as well. If the goal is cost reduction, doing everything by machining is almost certainly the MOST expensive, most time-consuming way to get it done. I've had parts fabricated and plated by outside shops for less than my cost for the raw materials alone.

You indicated the shop you had quote the machining estimated 20 hours machining time on a 10-foot commercial VMC. If it takes 20 hours on a machine like that, it will take easily 60-80 hours, possibly much more, on a Tormach. And, you'll probably go through at least several hundred $ in tooling. You could probably get rough castings done for the equivalent of a very few hours of machining time, then spend a fraction of that 60-80 hours doing the finish machining.

With an extrusion, you'll pay a few hundred $ in tooling cost to make the extruder, then a few $/foot for the actual extrusions, and no machining will be required.

Try going to mfg.com, and create an RFQ. Specify the material and the tolerances you require - don't specify the machining process. Within a few days, you'll have several quotes, and I'd be willing to bet most of them will be a fraction of the cost you're expecting. If you specify milled parts, the quotes will ALL be high.

Regards,
Ray L.

Hogging through the aluminum was not much of a problem on the knee mill. I put the mold face up and ran 3/4 ball mill through it until I was close enough to the final design then put them sideways and finished it off with the custom cutter. Obviously that would be a heck of a lot slower in steel. Plus the finishing on all sides.

On Monday, I will contact Novakon because they are local and I will also look into extruding plus mag.com site. The product is production ready and all that is left is getting the full size molds done plus another piece of equipment. It's 5 designs and even if I have to go out and pay through the nose to get ONE mold of each, at least I'm making money and buying a bit of time to take it to the next level.

One other thing I didn't ask but I don't see why I can't do it. On the knee mill, I have three vices lined up. I machined a section then moved it along to get to another section. I don't see why I can't do the same thing with 36" inch sections on the smaller machines. Sure, no matter how well I position the piece, I'll have a few thousand step. Nothing a bit of grinding/sanding won't take out.

Ray.....thank you and everyone else for the advice/opinion.




BTW....The Haas salesman told me that I'm "playing" with small machines and even the TM2 He suggested I spend $100k buy a "real" machine. Apparently, trees really do grow money.....*sigh*

[tmarks11]

I don't see why I can't do the same thing with 36" inch sections on the smaller machines.

If you look at the Novakon Torus Pro, I suspect that you will find it is not really much smaller than you knee mill with a table of 40x12".

?????? I'm not casting anything. I'm machining a 4 inch wide and 120 inch long profile INTO steel or aluminum.

The confusion comes from your calling this a steel mold. Generally you pour something into the mold and cast it. Most people assume that a mold is a one-off creation, and a majority of the production work is done with casting the product. It sounds in your case that machining the extrusion IS all of the production work.

Is this a one time production, or do you foresee making a lot of these? If you are making these over and over, than you should probably think seriously about the Haas TM2, since the increased horsepower and increased X-travel will help over time. Used TM2s sell for about $22-24k for mid-2000's models (without tool changer).

One real advantage to doing these on a open bed mill (like the Haas TM2 or Torus Pro or Tormach) instead of your existing knee mill is that you could set it up with roller tables on both side, and machine the entire 10' section in one go, with just sliding it and re-clamping it on the table as you finished machining each 18-24-40" section (depending on what machine you ended up with). A well built jig would be needed to make sure you keep alignment between cutting sections.

As long as we are pouring time and money down a rabbit hole: cnc X-Y table with 15k spindle mounted on a moving gantry that can cut the extrusion all in one setup. Make the table 12" wide and 10' long, and it should be plenty rigid enough for machining aluminum. Down-side: can only make one type of thing.

[Spartan1]

The confusion comes from your calling this a steel mold. Generally you pour something into the mold and cast it. Most people assume that a mold is a one-off creation, and a majority of the production work is done with casting the product. It sounds in your case that machining the extrusion IS all of the production work.

ONE mould will makes ONE specific product at time multiplied by many cycles . In the case of hardened and chromed 4130, Short of an accidental damage, it should make hundreds of thousand...if not a million cycles.

The catch is...the moulds cost is completely irrelevant in a mature product range....but a new product range AND the amount of moulds makes it the "what do I do" head scratcher.