Atlas 3995 Chattering

[stupoty]

Have you checked the spindle preload is enough ?

Stu

 

[gedkins]

Have you checked the spindle preload is enough ?

Stu

I set it according to Atlas manual.

 

[markba633csi]

This thread: https://www.hobby-machinist.com/threads/models-for-grinding-hss-lathe-tools.62111/
Page 4, Post #36
also:
I often skip the honing on mine, but it helps

 

[JPMacG]

I have no problem parting 12L14 steel, 6061 aluminum, brass and cast iron on my Craftsman (Atlas) 12". I get a nice finish on the parted surface. I'm not bragging - I'm just offering this to let you know that it can be done.

Is your cross slide gib properly adjusted? Did you lock down your compound and carriage? Is the parting blade perpendicular to your work? Are you using plenty of cutting oil ( I like kerosene for parting). For parting I keep the speed very slow - less than half normal. And I hand feed, backing out to clear the chips occasionally. I use a very sharp HSS parting blade.

Sorry if I have stated the obvious. I'm just trying to remember all the ways that I have gone wrong.

 

[SouthernChap]

For parting I keep the speed very slow - less than half normal

Yep, this is probably one of the more impactful changes I've found that makes parting mild steels pretty drama free.

Recently had to part off some stainless and that was a little noisy and slightly tense (keeping the workpiece/parting off tool lubricated and also keeping up enough of a steady feed to avoid any potential work hardening was a bit of a challenge) but it was okay in the end.

 

[stupoty]

I set it according to Atlas manual.

Nice , just thought I would mention it as I had some weird chatter / tool issues once that ended up being the pre-load set too low

Stu

 

[gedkins]

Received brand new very sharp HSS cutters today. Set cutter hgt to dead center of work piece. Added cutting fluid. Tried three different speeds. Results the same. Compound is tightened at gibs so it cannot move. Slightly tightened spindle preload, Re-indicated precision bar in chuck. TIR is dead on .005. At this point this lathe is heading to the bottom of the lake as my new anchor. This piece is free machining steel,

 

[markba633csi]

Let's see that cutting tool
Who is your supplier? No one named Babin I hope

None of the tools you showed earlier in your first post were HSS as far as I could tell- they were all variations of carbide
and not suitable for your machine

Have you experimented with grinding any?

 

[gedkins]

Little Machine Shop. Looks to be made in India. I don't believe its cutters at this point, every cutter I have used has the same result - they can't all be bad to the same level.

 

[4WHLDRFTN]

Yeah. That bit is not helping