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Stainless 304 MRR on a Brother Speedio 16k spindle

mutiny

Cast Iron
Joined
Jan 27, 2019
Location
Raleigh
Hi friends,

We have a set of parts with about 30 cubic inches of stainless 304 to remove. Max cut depth is a bit under .5 in. From simulations I've done, high feed milling with something like Helical's solid carbide high feed tools will have around 2.5 cubic in/min with their .5in tool but I'm not yet sure how the 16k spindle is going to handle it.

So I have a few questions for Speedio owners:

1) What sort of MRR should I expect in 304 from this spindle?
2) What's your best strategy for removing material? I've seen mixed reviews on this. HEM is obviously great if you have the cut depth to make it efficient, but I'm not sure I do. I've also seen at least one member say that their high feed tools offered much better tool life and process reliability.
3) What might I expect with the 10k high torque spindle? We'll have enough parts like this in our future that I'm considering the F600X1 essentially for this (and similar) tasks.

Looking forward to hearing from everyone!
 
If I’m not mistaken, MMR will be determined by the material and the cutters. The only difference the machine will make is if it has higher rapid rates, quicker tool change and more rigid construction. Once you are in the cut, you are limited by how the material wants to be machined.
 
Here is a standard Brother spindle machining 304 with a 20mm high feed mill.

BT30 helical SUS304 brother tc s2c - YouTube

MRR looks like in the 2.5 to 3 cubic inches/min range. Your part geometry and workholding will determine which type of machining, HSM or HFM, will be most efficient. If you can keep the cutter engaged more with a spiral in or spiral out or helical toolpath that will improve efficiency. Less air cutting. A High Torque Big Plus machine will be able to remove two to three times what a standard spindle can. They can handle larger Diameter tools and heavier chip loads so more MRR. Of course depending on what your part geometry allows and part and workholding rigidity... For instance, High Feed machining puts a lot of downward force on the workpiece, so if you have a large, relatively thin plate unsupported underneath, that will not be a good set up for high feed machining. With a very efficient (low air cutting) HSM tool path you should be able to get to 4 or 5 cu"/min I think, .025" Radial x .5" Axial x 350-400 IPM. I have had the best success with 5 flute end mills for hsm in Stainless in a Brother.
 
Thanks for chiming in, Frank!

With a very efficient (low air cutting) HSM tool path you should be able to get to 4 or 5 cu"/min I think, .025" Radial x .5" Axial x 350-400 IPM. I have had the best success with 5 flute end mills for hsm in Stainless in a Brother.

Can you point to a specific tool that you'd drive with those parameters? I'd love to run something like that I've not been able to find an end mill that can handle the SFM necessary to maintain appropriate chipload at those feeds.
 
I have several clients that are partial to IMCO end mills. They have a nice 5 flute. M525 series. I have had good success with Iscar 5 flute, Ultra Tool 5 Flute, OSG and others. I am sure some people here can chime in with their recommendations as well. Because of the relatively shallow depth of cut, you can definitely have success with smaller diameter 3/8 or possibly 5/16 end mills. Less costly. Smaller diameter will take less stepover but can spin faster... Try calling tech support at some of the end mill companies for their recommendations too.
 
OP's approach sounds reasonable. I'd probably go after it with a 0.75-1.25" Seco or Sandvik high feed to up the MRR. I like the Seco stuff but the old shop I was running switched to Sandvik's stuff for better insert life in 304/316. I was just using one of the Seco/Niagara solid carbide 1/2" high feeds in 4140 and it wasn't even showing anything on the spindle load meter (granted this is a 30hp machine not a Speedio). There is just not a lot of cutting pressure with high feed milling since you're making such a tiny chip.

I would routinely get after it on 4140PH in a standard 16k spindle in a R700X1 with one of those Seco 1" tools and like 6" of stickout. Get a stubby and you'll have no issues. It's still sound like an angry goose is trapped in the machine but it does that on my Okuma, too LOL.
 
Hi friends,

We have a set of parts with about 30 cubic inches of stainless 304 to remove. Max cut depth is a bit under .5 in. From simulations I've done, high feed milling with something like Helical's solid carbide high feed tools will have around 2.5 cubic in/min with their .5in tool but I'm not yet sure how the 16k spindle is going to handle it.

So I have a few questions for Speedio owners:

1) What sort of MRR should I expect in 304 from this spindle?
2) What's your best strategy for removing material? I've seen mixed reviews on this. HEM is obviously great if you have the cut depth to make it efficient, but I'm not sure I do. I've also seen at least one member say that their high feed tools offered much better tool life and process reliability.
3) What might I expect with the 10k high torque spindle? We'll have enough parts like this in our future that I'm considering the F600X1 essentially for this (and similar) tasks.

I haven't been running much stainless lately but I looked back through some old parts. The last parameters I used in 316 were:

Machine: Speedio S500X1 16K BT30 spindle
Tool: Helical 59402 (3/8" 5-flute with chipbreakers), Weldon flat
Toolholder: Maritool stub-length set screw
Parameters: DOC 0.900" WOC 0.025"

Helical's tool calculator suggested 600 SFM and 0.0052 IPT, 3.975 in3 MRR. I backed off 10% for process reliability (maybe unnecessary) to 530 SFM and 0.0046 IPT, 3.125 in3 MRR. I remember it running very well.
 








 
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