[qet]

Can these benchtop mills be used to mill stainless. The parts we are going to be working with are small, but I would be concerned that it would take days to mill a single piece. What would people who mill stainless parts recommend for a small prototyping mill? We would be making relatively few parts, but most need to be done on CNC because they are highly symmetric and small, and our other big mill has about and inch of slop in it (I know it should be fixed but its easier to buy something new than to fix something when you are at a university).

Thanks

[ihavenofish]

theres a post somewhere showing a sieg kx1 mill cutting a stainless (304?) 3" model train wheel. i think it was cut at 4ipm, and seemed to do a nice enough job of it.

so id say yes, some of these little mills can handle stainless, though whether its fast enough for your needs, i dont know.

[sansbury]

Can these benchtop mills be used to mill stainless. The parts we are going to be working with are small, but I would be concerned that it would take days to mill a single piece. What would people who mill stainless parts recommend for a small prototyping mill? We would be making relatively few parts, but most need to be done on CNC because they are highly symmetric and small, and our other big mill has about and inch of slop in it (I know it should be fixed but its easier to buy something new than to fix something when you are at a university).

Thanks

Yes. Depending on the application you may be able to use a so-called free machining stainless steel such as 303, which trade some strength/corrosion resistance for easier cutting. There was a fellow here a while back making decent-sized stainless gun parts for sale on a Sherline mill, which is small even by bench mill standards. But it was slooooow going.

Also, I'm sure I'm not the only person here who shudders at your last sentence.

[Jeff Simkins]

Small mills will cut stainless, but you should consider fixing the slop in the larger mill. Small mills have slop too. If you don't know how to control, compensate, or improve on this condition, then you will eventually have one large mill and one small mill with slop.

And he is correct! It is easier to write a grant for a new $600K tool, than it is to maintain a $60K contract to keep an old $600K tool working. It is because they are in different funding categories. The only catch is that the new tool purchase can't have the same function as any tool that is already on the asset list. It depends on the direction of research too.

Fix the big mill! Learn something valuable today.

[qet]

The big mill is a standard bridgeport mill of unknown age. I downloaded a manual and figured out how to fix the slop. It is pretty good now, still a little slop but before it was like 0.1 inches in both leftright and frontback. The mill that we are looking at getting is from sherline. I hear differing opinions on how good these are. One thing is that it has to be built in the USA (my advisor insists).

[sansbury]

Get a Taig then. Still US-made, very good quality, low cost to CNC, but much more capable than a Sherline. The Sherlines are very good quality too, but are really best for plastic or very small parts. Both machines are good for small work because they have a good high-speed spindle which the Chinese machines lack.

[LongRat]

I've cut both 303 and 416 stainless on my X2. 10mm 2-flute carbide tool, 0.5mm depth of cut, 150mm/min. Dry!
Here is a ring I made out of 303.

[ViperTX]

Longrat,

What did you use to create the model?

I'm struggling with modeling software...have been trying MOI.

So, my X3-CNC has been sitting motionless in the garage for over a month now...because I'm struggling with software.

Paul

[LongRat]

Just checked out MOI. Never heard of it before.
This was done from a very simple 2D DXF, tool paths created in SheetCam. Literally a 2 minute CAD job. The corners were all rounded using a 1.5mm radius cutter.

[sansbury]

For simple 2.5D work, you can use eMachineShop's free CAD software and export to DXF, and import that into CamBam's free version for CAM. This is the simplest good freeware I've found.

[project5k]

you know, i've allways wondered how you hold a stone in like that.. is it inserted from the bottom and then has tabs under it, or is it glued in place?

[Crevice Reamer]

The Novakon NM-135 can certainly do stainless--And they give an educational discount!

http://novakon.net/3.html

CR.

[ihavenofish]

you know, i've allways wondered how you hold a stone in like that.. is it inserted from the bottom and then has tabs under it, or is it glued in place?

could heat the ring to expand the hole then set the stone and let it cool. only need a fraction of a mm expension to get an interference fit on the jem.


thats how id do it anyway :P

[project5k]

hadn't thought about that. makes sence, i do it when i wanna press fit a bearing onto something.. i warm the bearing gentley with a big hot light, and i freeze the part and they just slip together, but once they both get back to room temp, you cant budge em.