Who can enlighten me how to process ultra-hard material?
I am a beginner for machine processing. My foucs is RF/Microwave components, just wanna set up a small lab for precision housing. Who can enlighten me how to process ultra-hard material, like stainless steel, titanium on benchtop milling machine. Are there have some CNC machine can help me? or just have good method and do it on common machine.
Like any machine, you have to take it easier than aluminum or another softer material. Use carbide to cut that stuff. On a benchtop mill, keep slow feeds and speeds. You might even try insert end mills. SPeaking of, you probably won't have the horse power to use large cutters. At work when we mill tougher materials we use carbide inserts with coatings, usually from Iscar. We mill pure tungsten, thats tough stuff.
If it's REALLY hard, I'd just grind. Patience is going to be necessary if you want to mill those materials on a benchtop...
Thank you so much. Do you know where can find the function among feed, speed, load power...? If keep surface roughness around 0.8, how to do it? Sometimes, tolerance is critical, +/-0.01mm,like dowels position. But process must stop to change inserts, how can I go back to zero point at this critical tolerance?
Grinding need enough patience, I can have a cup of tea... :-)
There is not really a perfect function for finding feed, speed, load, etc. There are some basic formulas you can use to find RPMs. If this were a production job like I run at work, I would say work it all out. BUt the thing is, your benchtop mill probably won't be able to go by what a calculator would say, you will almost always to have to feed slower. Not sure how experienced you are with milling, but you will get quickly get a feel for what you should have your speeds and feeds set at with your machine. The speeds and feeds on a Mazak or Haas will always be larger #'s than a Sieg X3.
GOod inserts like those made by Iscar are very consistent on all dimensions. THe insert will have a threaded "shank", male acme thread I believe. That will thread right into a tool holder (which will fit in a collet). So that insert will thread into the female theads of the tool holder. The good part is that the lengths of the "shanks" on the inserts is very consistent. So you can thread in an insert, use it, wear it out, thread in a new one, and it will be right where it used to be.
A lot of this makes use of the power drawbar though, which you likely will not have. So you will simply need to touch off your tool. Get a 246 block, set it on the surface of the mill and touch off your tool. Correct your zero's and you are good to go.
I change a lot of ball insert cutters for one job. What I do is just place the block on the clean table. Bring the spindle down (off of course). Bring the spindle down so that the cutter is below the surface of the block a little bit. In increments of .001", move the spindle up closer to the surface of the block. Try to push the block against the cutter lightly. Obviously if a cutter is in the way, you wont be able to move the block. When you are getting close, change the increments to .0001" moving up in your Z axis. Apply a gentle but steady push on that block. As soon as the block begins to slide, you've got your zero.