Squealing/squeaking and Ticking from Right Hand Z Threaded Rod

After homing and during the descent from the top to begin a print, the right X end makes a steady squealing or squeaking noise combed with a regular repeating 'tick-tick-tick ...' sound. The ticks are spaced roughly .5 seconds apart. I have applied sufficient machine oil to the threaded rod and some to the smooth rod. The sounds do not present when the carriage is moving up during the homing procedure (only when the carriage moves down).

I suspect the brass nut might not be sitting perfectly level against the underside of the inside of the top of the X end. Does this sound likely? Or something else?

I thought maybe to lift the carriage and try spinning the nuts on either X end to a new position either higher or lower and then resettle the carriage on them. This will likely throw off the Z setting.

I'd sure appreciate comments. Thank you ..

Hi Garry,

Yep, experiencing a high pitched squeak/squeal coming from the right z axes here too. Indeed only when it's moving downward. Had this since the beginning even though sufficiently oiled. Seems to be a little less after oiling but soon returns. I decided not to worry about it but the idea that this maybe due to some high friction or something isn't too soothing I must admit. Can't say I'm experiencing any ticking sounds. Sorry I'm no further help, but at least you know you're not the only one experiencing this so it will probably be nothing too serious. Few other posts on weird mendel90 sounds the last couple of days but all related to insignificant causes.

Edited 2 time(s). Last edit at 11/13/2013 05:44PM by Nilez.

Watch the top of the threaded rod and see if it is hitting the bar clamp. That may be the clicking sound.

Fl0yd

Hi Nilez,

Glad not to be the only one. Hmmm? Mine too right from the start. I suspect the nut is falling with each tick and hitting the thread below. Doesn't occur on the way up because of the constant weight of the X carriage. The squeal would be because the nut threads are binding on the rod thread. I suspect again that the nut is somehow un-level. Those are my guesses. Would like to hear other ideas. I bet lots of people don't have this issue and I'd like to know why ..

Makes sense indeed, so no amount of oil will ever fix that then.

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Fl0yd
Watch the top of the threaded rod and see if it is hitting the bar clamp. That may be the clicking sound.

Thanks, but there is plenty of space. And the rod is spinning perfectly true as far as I can see.

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Nilez
Makes sense indeed, so no amount of oil will ever fix that then.

Hoping to possibly hear from Chris on this. I should have checked the inside of the X end carefully before building but I didn't so can't say what it looked like. If there was a small nub or tiny imperfection in the surface it would cause the nut to sit un-level and thus the noise. How to fix this without disabling the machine? Oh! How about put the carriage to the bottom, lift it manually to the top and hold it somehow, the spin the brass nut up half way, heat it somehow, and lower the carriage onto it to melt any imperfection on the plastic that sits on it? Then the nut is more level? Crazy idea?

Or maybe I am barking up the wrong tree all together.

The nut should be a tight fit in its trap. If it isn't for some reason you could wrap selotape round it.

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[www.hydraraptor.blogspot.com]

We re-seated the nuts in the X ends and the ticking is completely gone and the squealing almost gone. The squealing that remains is coming from the left rod when it just begins to descend from the top. I will put the carriage to the top, loosen the Z coupling and re-tighten it to ensure the threaded rod is perfectly aligned with the motor shaft.

Hi Garry,

That's great! How do you re-seat the brass nut?

I just raised the X assembly and lowered it again onto the nuts being sure they went in all the way. Someone was helping me do this so I didn't see the orientation of the right nut before lifting the X carriage. But the ticking is back this AM but only when I lower the X carriage to make a print. If I jog it down with the Pronterface buttons 10mm at a time it doesn't tick. It is difficult to see but the right nut might not be seated as deeply as the left so when I can get some help I will try to seat it further. Are you having any luck correcting your squeaks?

Ok thanks Garry, I'll try that as soon as possible. I think that after seating the nut, you have to recalibrate the printer?

Yes, I had to. I assume you will need to recalibrate too. Mine wasn't changed by much but enough to require a new Z home number.

I still could not eliminate the squeal so tested a small upper section of one threaded rod with Lithium grease and it helped immensely. I had used 3-in-1 oil initially but it dries up to fast. I don't have motor oil in the house so that is why I used the 3-in-1. Would it be OK just to use Lithium grease? I know the manual could have called for it but it didn't, thus I hesitate to put it on the entire rods. Maybe it gums things up eventually? And if lithium grease is OK, is there a preference between the white or brownish grease?

I can't imagine why brass nuts on steel would ever squeal. They have always been silent for me even with no lubrication. I add car engine oil because I think that reduces wear. Always add it below the nuts and run it down towards the oil. If you add it above it gets into the plastic and discolours it.

I have used grease in the past and it it has gummed up threaded rods and linear rods such the machine would not work, so I now only use oil.

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[www.hydraraptor.blogspot.com]

Yes, I am not sure about the brass on steel rod squealing but it was quite bad. Maybe because we have a dry climate here? I found a bit of Mobil1 Synthetic oil in the garage and it has done wonders. No squealing for now (a little over ten trips up and down so far since oiling) and the ticking is gone too! I might put a few drops on the smooth rods for good measure.

FYI: I get this loud squeeling too. A light spray of dry PTFE normally stops it for a couple of days, but it always comes back. I've double triple checked alignment of all the axis. Weird

I recorded the sound when the X carriage is lowering. YouTube of Lowering SequenceThe threaded and smooth rods are well oiled with motor oil but the whining sounds can hurt the ears when lowering and while I can live with it (because it's my machine), I cringe when it happens because I hate bugging the rest of my family. If someone does play the video please turn up your speakers and you should get a good idea of the sound although it does seem worse in person. Is this the same as your machine?

The YouTube link will not play - it seems to have the "private" box ticked.

Alan

I am sorry. I had tried to make it private so only the people with the link could see it. I should have made it 'unlisted' as I have done now. It should work now.

I can't really hear any "squealing" on the video. Just the whine from the motors and a ticking sound. I think that means the nut is loose. Try putting a heavy weight on the X motor to ensure there is downwards pressure on the nut and see if it changes the sound.

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[www.hydraraptor.blogspot.com]

Thanks Chris. Yes, there is no squealing anymore (well, just once and a while). I pressed down on the X motor on the trip down and the ticking was gone. And the high pitched noise was lessened greatly. On the way up I put pressure on both X ends and that caused a nice smooth whine from the motors.

The stepper motors whine - and that sound is tolerable - but the sound worst of the sound comes from something else. I think there is slight vibration causing a sharp ringing and that might be because the nuts are slightly loose??

I think the Z bars must be slightly out of alignment so all the weight is taken by the left end and the right nut has no pressure on it. That allows the screw to rattle against it with the vibration from the motor.

Maybe loosening the screws on the Z bar clamps and the Z motor brackets would allow the bars to lean to the right a little to allow the motor end to drop onto the nut.

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[www.hydraraptor.blogspot.com]

That sounds very possible. When I can get some help I will try that. Thank you ..

Just thought I'd add another possible "gotcha" to the mix - it doesn't sound like this is what happened here, but something to watch out for: when peeling those thin wispy threads of plastic off the bed/nozzle, it has a tendency to statically cling to your fingers, right? Well be careful that you know EXACTLY where it goes when you flick it off...

I got an almost invisible wisp of the stuff wound around my left Z-screw without realising once. It started squeaking and no amount of oil would make it go away. It was only when I happened to look more closely that I realised the plastic had embedded itself into the thread and was causing the nut to bind slightly whenever the carriage moved low enough. Five minutes with a wire brush cleared it, but it was the source of much head scratching for several prints!

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nophead
I think the Z bars must be slightly out of alignment so all the weight is taken by the left end and the right nut has no pressure on it. That allows the screw to rattle against it with the vibration from the motor.

Maybe loosening the screws on the Z bar clamps and the Z motor brackets would allow the bars to lean to the right a little to allow the motor end to drop onto the nut.

Thank you Chris, you totally nailed it. A friend came over and we did as you said. Now the carriage moves up and down smoothly and quietly with only the pleasant motor hum. The ticking and squealing, droning sound is gone! And I'm betting gone for good. The machine has never sounded like this. It's wonderful.

If I were to build the M90 from the beginning again, I would press the right side Z motor bracket and smooth rod clamp hard to the right to ensure that the smooth rod and screw were perfectly vertical. Then I would tighten them (we did this now). I would leave the left side bracket and clamp loose. Then at some point when the machine was powered and the carriage could be moved up and down I would move the carriage to the bottom and tighten the left motor bracket. Then I would move the carriage to the top and tighten the left Z bar clamp. This would ensure the left rod and screw were perfectly parallel to the right and there was not improper pressure between the vertical bars at any point from bottom to top.

I can't wait to see the prints after fixing this. I think they will be better than before.