[dkochan]

After owning my machine for a couple of years, I finally got tired of the buzziness and vibration. I had read that some folks had glued/stuck damping pads on the underside of the chip trays to damp resonance, so I found some PSA-backed 1/8” thick neoprene on ebay for a steal. (That place has gone to the dogs, but every once in a while you hit gold.) While I was waiting on that, I started poking around the mill. I’d feed the table around at various rates, trying to get a loud buzz. Then I’d run around putting my hand on parts of the machine trying to see what was buzzing before I ran out of travel. It was a sight to behold, I’m sure. Tip: Write a little NC program to feed the table around whilst you do your hands-on investigation. Wish I’d thought of that out in the shop, and not as I was writing this.

The biggest sources of vibration noise, and their cures:

The spindle/motor door: Even with the latch fully tightened, it vibrated against the head. I put some weather-strip-like molding along the bottom edge of the door. It stopped the vibration and also helps hold the latch snug. Note that the spindle lockout switch will buzz HORRIBLY if the door is open, but it’s quiet with the door closed. I left it alone – it’s the plunger that vibrates and fixing it would not be worth the effort, IMO.

The axis coupling cover panels: All three buzzed to some extent. I pulled them and put thin rubber strips under them, just tacked on to the panels with Goop. The rubber was leftover from *something* years ago. Anything about ¼-3/8” wide by 1/32-1/16” thick should be plenty. Try to get it right up close to the holes (I decided when I was about through that I should have punched holes) – otherwise the panels will deform a bit around them when the screws are snugged down. While I had them open, I put witness dots on the couplings and nuts with a paint marker. If I ever suspect axis slippage, I’ll be able to know right away without further testing.

The access panels in the chip guards (top section of chip tray): They buzzed. These were actually the first buzz I tried to fix – I used electrical tape as a buffer but it wasn’t quite thick enough. I went back and used the same rubber strips that I used on the coupling covers and it worked great.

The access panels in the lower cabinet: I was only using one of them, and the rest buzzed. I pulled the covers, found out the little screws were held on with little nuts that become invisible in the presence of chips on the floor. Heh. I was out of my mystery rubber strip, so I put silicone caulk around the edges, then reattached. It’s not likely that I’ll remove any of these, but if I do they’ll clean up with minimal effort.

The doors in the lower cabinet: The fit/alignment is, well, not the best. The front door is the only one I ever close all the way. I used a strip of the same molding I used on the head and it snugged it right up. Since I leave the other doors open, I had to quiet the latches – they rattle like mad if they’re just hanging free. I used the uber-high-tech electrical tape on them – just taped them to the edge of the door with the tape stretched to give tension– no worries.

The access door for the lube pump: The fit on that one is pretty wacky. Electrical tape along the bottom edge of the door itself killed the buzz. I need to figure something else out, though, as I don’t think it’s going to stick for long with the coolant splash. Maybe a few dots of silicone, allowed to cure before closing it.

I finally got the neoprene sheet and installed that under the chip trays. It didn’t do a whole lot – it’s pretty subtle. The improvements above did far more, and were cheaper to boot.

There’s still one access panel on the back of the mill, but I’d have to pull the upper chip guards to get to it. It’s not too noisy, and I’ll probably do something neanderthal like tape over it before I pull those guards. They were a major pain to get into place.

Thinking about putting more of that neoprene sheet inside the head to damp some motor noise. The machine is so much better now that I have given up my witch hunt for now and am back to making scrap and the occasional part.

Hope this helps someone!

Dave

[zephyr9900]

Dave, thank you for posting this. I'm gonna need to print it out and study it to do it justice. I'm on the verge of redoing the head door, to replace the hinge with cabinet slides to move it vertically instead. (With my full enclosure, I currently need to set M998 position at 0.5 inches below Z homing for the head door to clear the enclosure.)

For me, the biggest reduction in noise was to install Mach3.042.029 (just installed 3.042.030 this evening) which has a much smoother motion on conturing moves. I see that Tormach has just posted their own implementation of 3.042.029, but only for Series II users (and Series I with upgraded spindle VFD)...

Randy

[dkochan]

I was pleased to see that the version of software included in my spindle upgrade, which arrived Thursday, was the newest one!

Too bad the upgrade rendered my machine unusable.

[zephyr9900]

Dave, after reading your post I guess I've never had bad noise issues with my machine. I didn't like the axis coupler covers, so I replaced them with stainless covers. For unribbed flat covers, I always bow them a little (roll with a cylinder while on a phonebook typically) so the middle touches the frame first when I tighten the mounting screws. I've removed the left and front base doors (well, to be precise one of the front base door hinge welds broke...) but I don't have any problem with the PC compartment door.

Sure, there are specific diagonal moves that will excite a resonance in the chip pans, but that has never bothered me enough to check into damping material.

Randy

[MichaelHenry]

My 3-year old Series I mill had some sheet metal rattle at certain speeds and especially with combined X/Y moves and it appears that the noise was coming from the sheet metal cover on the head. I pulled the upper half of the motor cover (the hinged door) and then removed the 6 screws on the lower half so that the bottom was free of the head casting. I then cut up a set of three, 3" tall pieces of Dynamat trunk insulation to fit between the left hand side, back, and right hand side of the cover and the head casting. The insulation was applied to the inside of the bottom half of the cover and everything was re-assembled. The rattle is now essentially gone.

Mike

[TMashino]

For what it's worth, I just stripped my mill down to the stand only. I then started to put it back together piece by piece and added weather stripping between all sheet metal to sheet metal surfaces. After each piece I put back on, I would move the table around to see when my vibration got worse. Which seems to be at about 8 ipm. This helped to quite the mill down a little. I then bought some Dupli-Color Professional Unercoat and Sound Eliminator. This comes in a 17 oz aerosol can that I bought from O'reily Autoparts. I sparyed this on the inside of my base. I was amazed at how well this quieted the machine. There still is some vibration, but it is significantly reduced. I am considering spraying the outside of the base as well.

Tom

[dkochan]

I then bought some Dupli-Color Professional Unercoat and Sound Eliminator. This comes in a 17 oz aerosol can that I bought from O'reily Autoparts. I sparyed this on the inside of my base. I was amazed at how well this quieted the machine. There still is some vibration, but it is significantly reduced. I am considering spraying the outside of the base as well.

Tom

I was looking at that stuff a few months ago and thinking it might work. I was also looking for a deadener for the bashplate on my little WR250R - it's a resonator and noise reflector as-is. Chickened out on both counts, thinking about what a mess it would be if it didn't work out.

Now I think I might give it a try. Thanks for the info!

Dave