Author Topic: Growling while Facing  (Read 4432 times)

ddickey

Growling while Facing
« on: August 20, 2018, 02:22:39 PM »
I've noticed my lathe is starting to growl when I face a part.
Last night I faced a 7 1/2" diameter piece and it started out fine, as I got closer to center it started to moan. First thing that came to mind is wear and gib adjustment. My machine has little wear although it does have some of course. I just had the cross slide off recently and did a gib adjustment so don't think it is that. When I flipped the part and did the other side I clamped down slightly on the cross slide lock when the growl started no change in sound at all.
Any ideas?

woodchucker

Re: Growling while Facing
« Reply #1 on: August 20, 2018, 02:39:47 PM »
Feed it before it bites you...  :P

try tighening the gib, sounds like it might be a harmonic or something.. tight = mo better.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder
For pics: https://imgur.com/user/woodchucker/posts

Remember measure once cut twice, or was the measure twice cut once...

4GSR

Re: Growling while Facing
« Reply #2 on: August 20, 2018, 02:40:01 PM »
I always thought that was normal.  Sometimes it will do that, sometimes it won't.  Especially notice taking a rapid face off on a part.

Ken

chips and more

Re: Growling while Facing
« Reply #3 on: August 20, 2018, 03:09:58 PM »
In my experience with chatter on a lathe. I have noticed that it’s mostly caused from poorly adjusted end shake (pre-load) in the main spindle bearings. Or from a flexing tool bit or something else in that area. Not to say jib adjustment is out of the question but I have not seen too much of that. A crack in the casting on a cross slide once. Of course this depends on the size of lathe, lathe design, material being cut, type of tool profile and a gamut of other excuses…Dave

If you do not have chatter but a funny tool cut pattern? Then that could be from harmonics within the power train being transmitted to the work finish. Like motor noise, whining gears, belt(s) too tight, etc.
« Last Edit: August 20, 2018, 03:17:39 PM by chips and more »

4GSR

Re: Growling while Facing
« Reply #4 on: August 20, 2018, 03:23:23 PM »
Go to remember, as you get closer to the center, you SFM slows way down. And if you are hand feeding, it will growl if feeding heavy towards the center.  Also, insert tooling may cause it too. 
What size lathe do you have?
Ken

ddickey

Re: Growling while Facing
« Reply #5 on: August 20, 2018, 03:41:40 PM »
It's a 13x40.

ddickey

Re: Growling while Facing
« Reply #6 on: August 25, 2018, 12:32:49 PM »
I don't remember this before.
I think it started when I changed from an aluminum solid post to steel.
I got rid of the t-slot set up I had with the aluminum and went with two dowel pins and might bites. The post is incredibly rigid but I wonder if that is causing the howl somehow.
Guess I can pull it off and try facing with the compound to eliminate that possibility.

Carpenter84

Re: Growling while Facing
« Reply #7 on: August 25, 2018, 12:37:34 PM »
With the rigidity, it could be better transfering the force/chatter further down the cross slide to a weaker point below?
Shawn

ddickey

Re: Growling while Facing
« Reply #8 on: August 25, 2018, 02:54:04 PM »
Makes sense.
We'll see when I put the compound back on. Won't be for a while though.