End Mill isssue

[Todd_71]

Just a quick thought. Is that rough edge you're cleaning up a result of being flame cut or plasma cut? If so that will eat up your cutter pretty fast. JR49

Yes. Probably flame cut.

 

[jlsmithseven]

5C is the taper of the collet I believe. It could be R8 though. Anyways someone will help you with that. You might have had the wrong collet and that could definitely be your problem if the 1/4" worked fine in the drill chuck. It sounds like the combination of not using a roughing end mill, maybe having the wrong collet type, and the edge being too hard is your issue here. With machining, it's rarely just one thing . Have fun, glad to help out.

 

[JR49]

Yes. Probably flame cut.

You should hit that flame cut edge with a grinder first to save your cutters. Also, see my first post, as I just edited it with more info. JR49

 

[Todd_71]

You should hit that flame cut edge with a grinder first to save your cutters. Also, see my first post, as I just edited it with more info. JR49

Thanks, I'll hit it with the grinder and take another go at it. The cut was very uneven and I could have just taken a small slice off it with the band saw but I was just playing with and learning as this machine is only a couple weeks old.
The edge I was trying to side mill you can see on the left size of the attached picture (this was taken after using the face mill but before side milling). Not the best picture but you can see it was very uneven.

 

[willthedancer]

A little chalk on the end mill shank will help stop the slippage. No globs, but a thin dusting. I rub it on and wipe the excess off.

Sent from my Moto G Play using Tapatalk

 

[mikey]

Thanks for answering my questions. The guys have given you some good info. I should add that you should never hold an end mill in your drill chuck; it is not accurate or rigid enough for that.

An R8 collet will hold most end mills quite solidly. It only requires about 30-35# of torque to lock solidly. It will be more accurate than an end mill holder.

I'm wondering if the issue isn't a combination of the wrong speed, feed rate or depth of cut. You have a good machine that should have handled a profiling cut with no problem but you need to get the speed, feed and depth of cut right and it is best to conventional mill this one. Yes, a rougher would be the best tool here but even a finishing end mill should have handled this easily. Take a look at those tables I linked to and check your cutting conditions.

JR raises a good point. Flame cut steel can harden the surface layers, making a clean cut difficult. Grinding it back is a good option, as is sawing it off. However, a good rougher and a decent depth of cut will also get past it.

 

[jlsmithseven]

Based on the photo you showed, I have a question. Is your machine trammed correctly? How about the vice itself? If you're cutting even .007 deeper on one side than the other, that could easily create the chatter you're receiving.

 

[Todd_71]

It's trammed within .002 across the table. The vise is within < .0005

 

[jlsmithseven]

That answers that . Good job. Did you get everything Fixed?

 

[Todd_71]

No not yet, but haven't had time to work on it yet and I am going to order a roughing end mill to see how/if that helps.
That and Bob is going to come by this week and help me out. When I figure it out I'll post what the issue(s) were.
Thanks again for all the great feedback!!!