Basic Keyway/Slot Cutting

[RaisedByWolves]

Don't disagree with any of your flex points. IMO, once you start the full cut it tends to pull all that flex and then continues the cut at the width of the cutter. The reason you want to cut the key in one pass full depth to get all that flex the same for the full pass. I had to recenter the 3/8" most likely because I centered the ¼" before taking a heavy cut. Once it cut the ¼" key it likely did shift over the backlash on the bed and I adjusted to that on the 3/8". No comparison of this machine to heavier or more rigid machines, just trying to help someone who asked see what it could do.

I get where you're coming from, but the round column machines have some unique issues that differ from other style machine issues.

Note I didn't say only "This or that" style machine has issues, they all have limitations. Knowing these will make your end result better and prevent tolerance stacking and such. I don't like using the term tolerance stacking as it has become a buzzword, but it does work nicely as a catchall.

I also have a round column mill and they have a unique issue in that they not only flex in all the normal places, but the column twists in reference to the head, sometimes winding up in a new location to your X/Y, and also laterally as well as deflecting, especially under heavy loads. First few times I used a round column it was a bit curious coming from learning on and using B-ports daily.

Your job has whatever needs it has, that have to be met, and if you are the end user or will be fitting the parts what you're doing is Ok.

If you plan on sending that part out to a customer, they may expect more.

Just food for thought.

 

[BladesIIB]

I get where you're coming from, but the round column machines have some unique issues that differ from other style machine issues.

Note I didn't say only "This or that" style machine has issues, they all have limitations. Knowing these will make your end result better and prevent tolerance stacking and such. I don't like using the term tolerance stacking as it has become a buzzword, but it does work nicely as a catchall.

I also have a round column mill and they have a unique issue in that they not only flex in all the normal places, but the column twists in reference to the head, sometimes winding up in a new location to your X/Y, and also laterally as well as deflecting, especially under heavy loads. First few times I used a round column it was a bit curious coming from learning on and using B-ports daily.

Your job has whatever needs it has, that have to be met, and if you are the end user or will be fitting the parts what you're doing is Ok.

If you plan on sending that part out to a customer, they may expect more.

Just food for thought.

Fair enough. For the job at hand you do need to be within the tolerance outlined for that job. Checking the Machinery's Handbook the tolerance for a class 1 keyway for the 3/8" slot is +.002" and -.000" and for the 1/2" is +.003" and -.000". From what I can measure, I was within tolerance on this demo. If this were a customer job, I likely would use an edge finder to get the center of the shaft, vs the eyeball method. Make a test cut at depth, let the machine flex, and verify I was still on center. I briefly mention using an edge finder for center in the video but since this was not an actual project, I think I missed some detail that could have been there. Always good feedback to help me on the next one. Thanks!