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Spindle shakes at 3,000RPM Mori Seiki SL-25
- Thread starter meowkat
- Start date
- Replies 37
- Views 3,293
RJT
Titanium
- Joined
- Aug 24, 2006
- Location
- greensboro,northcarolina
Level the ways of the machine, spindle is parallel to them. Shaking sounds like the machine is not resting on all its feet. Need to have equal pressure on all feet when it is level.
Dan from Oakland
Titanium
- Joined
- Sep 15, 2005
- Location
- Oakland, CA
Earlier SL series lathes had a leveling block that mounted on the turret for leveling the machine. Not sure if the SL-25 was the same or not.
Yeah I have a few of those that came with the machine. So if I just level the machine properly with all the feet making contact the spindle shouldn't shake at 3,000 RPM? I was watching something on youtube and a guy mentioned there is usually a place on the casting that you can place a level to level just the headstock 4 feet.
Booze Daily
Titanium
- Joined
- Sep 18, 2015
- Location
- Ohio
That's where the back of the draw tube is. Take that sheet metal cover off and check in there.
Might be some gunk loaded up throwing it off balance.
Might be some gunk loaded up throwing it off balance.
GENERALDISARRAY
Hot Rolled
- Joined
- Jan 3, 2019
The chuck actuator/ extension piece/ spindle tube, is bent. No amount of leveling is going to fix it.
It will have to be disassembled, cleaned and inspected to find where it is bent or otherwise knocked out of concentricity.
Like the post earlier, it is leveled by attaching a plate to one of the tool stations on the turret. On the newer NL series that station will need to be at 12:00.
It will have to be disassembled, cleaned and inspected to find where it is bent or otherwise knocked out of concentricity.
Like the post earlier, it is leveled by attaching a plate to one of the tool stations on the turret. On the newer NL series that station will need to be at 12:00.
Lots of chips in there, and looks like someone jammed a roughly hewn (sawed) piece of plastic in the bore that will need to be extracted with like a slide hammer or something. I ran the spindle up to 3k again and it really seems like that box is the only thing vibrating, it can't be felt through the spindle housing which is probably a 1-ton+ cast iron tube clamped to the bed of the machine.
I worry about that box getting messed up from the vibrations.
Alright I'll look into that.
vmipacman
Cast Iron
- Joined
- Nov 21, 2014
- Location
- Virginia, USA
That is basically the rotary hydraulic cylinder that pull the drawbar in and out (opens/closes chuck jaws). It should be dead concentric with the main spindle tube. The drawbar “floats” inside the spindle tube and moves an inch or two back and forth. What you are seeing is a concentricity/runout issue between the spindle and that section of the drawtube. Could be bent, or could have been reassembled wrong after trying to replace the o-rings inside.
After removing the cover, Put a mag base indicator on some stationary part of the machine and touch off on the back of the drawbar where it exits the aluminum housing. Outside preferred since inside is prob dirty and banged up. Turn spindle by hand. You should see significant runnout, .02-.03?
After removing the cover, Put a mag base indicator on some stationary part of the machine and touch off on the back of the drawbar where it exits the aluminum housing. Outside preferred since inside is prob dirty and banged up. Turn spindle by hand. You should see significant runnout, .02-.03?
cnctoolcat
Diamond
- Joined
- Sep 18, 2006
- Location
- Abingdon, VA
Yes, your rotary hydraulic draw cylinder is running-out excessively.
On Mazaks, you can adjust the concentricity of the cylinder by varying the torque on the mounting-flange bolts.
See what you can do with the bolts and flange to true everything up. If you can't, then you could have a bent draw-tube.
With all the mounting flange bolts removed, the draw cylinder and draw tube should slide right out together.
ToolCat
On Mazaks, you can adjust the concentricity of the cylinder by varying the torque on the mounting-flange bolts.
See what you can do with the bolts and flange to true everything up. If you can't, then you could have a bent draw-tube.
With all the mounting flange bolts removed, the draw cylinder and draw tube should slide right out together.
ToolCat
Scruffy887
Titanium
- Joined
- Dec 17, 2012
- Location
- Se Ma USA
Asking that question tells us a bit about your knowledge of a CNC lathe. All good as everybody has to start somewhere. Lots of good answers above and I would suggest you proceed with caution. Post pics and ask questions here as you step along. Piece of plastic inside draw tube most likely has a through hole and is a spindle liner. Not sure I would use a slide hammer. Some type of penetrating lube first. Dried/oxidized coolant may have "glued" it in place if it was used as a long term single part production lathe.
Pretty sure it isn't a spindle liner, more likely just a plug so they didn't have to keep cleaning the chips out of the hydraulic draw cylinder (they had built up there pretty excessively already). It has a 1/2-13 tapped hole and a hex-head bolt in it, ostensibly for easier removal.
Some good suggestions in here, I'll try to get to work.
Dan from Oakland
Titanium
- Joined
- Sep 15, 2005
- Location
- Oakland, CA
With your setup, you are measuring the runout between the actuator housing and your spindle- you need to mount the indicator on the frame of the machine and measure the runout of the actuator itself.
On edit- I see now where your base is mounted- its ok. Is the actuator housing wobbling? can you indicate it between the spindle and the aluminuun housing on the headstock side?
On edit- I see now where your base is mounted- its ok. Is the actuator housing wobbling? can you indicate it between the spindle and the aluminuun housing on the headstock side?
Last edited:
I'm not sure I follow, "runout of the actuator itself" should mean the bore of the actuator right? The sheet metal bracket the indicator is mounted on isn't connected rigidly to the actuator.
How should I position the indicator or otherwise change my measurement setup?
vmipacman
Cast Iron
- Joined
- Nov 21, 2014
- Location
- Virginia, USA
I don’t think 5 thou would cause what you are reporting. Your measuring inside the bore, not on the face right?
So run it at various speeds working up to the 3k where you see the issue. The rattling/wobbling should be happening at 1000 rpm too, just not as violent. If it happens when you get to 3k only maybe you have some harmonic thing. Just putting your hand on it would prob change it enough to quite it down.
So run it at various speeds working up to the 3k where you see the issue. The rattling/wobbling should be happening at 1000 rpm too, just not as violent. If it happens when you get to 3k only maybe you have some harmonic thing. Just putting your hand on it would prob change it enough to quite it down.
No I don't think it's a harmonic it shakes a little bit above 1,000.
Booze Daily
Titanium
- Joined
- Sep 18, 2015
- Location
- Ohio
What's mounted on the spindle? Chuck, collet nose?
Scruffy887
Titanium
- Joined
- Dec 17, 2012
- Location
- Se Ma USA
There are a lot of chips back there. Could a chip buildup be throwing it out of balance?
