Hi IRobertI
Thanks for the quick reply.
Have powered down and manually moved the print head.......the X Axis (Moving left to right as I stand in front of print)....moves freely......feels tight-ish....but it does move ok with moderate hand pressure......
Y Axis......stiff as hell........and when I manually move it, I can hear the squeek....and it SEEMS as if the squeek is coming from the upper back left of the machine, with the POV being again me in front of machine...........
The head should move freely with moderate pressure so something is not right. The first step I would take is to measure and see if things are square. Move the head to the middle of the machine and then slide it a little bit to the left. Measure the distance between the rod on the left of the machine and the rod that runs through the print head. Measure at the front of the machine as well as the back of the machine. The distances should be as close to the same as possible. Rinse and repeat for the other rods to see if things are off somewhere.
If you find that it isn't square we can go through the steps to rectify that next.
Oh, and another thing. Maybe it would be worthwhile to check that the rods haven't been bent during shipping. Did the shipping box look ok when you got it?
Hello Again.
Got a set of Mitutoyo digital verniers here, and this is as near as I can measure it......Have spent a decade on mills and lathes, this seems pretty parallel to me.........not perfect but "ok".......???
Hi IRobert
Yep everything looked fine in the box.
Just had another play with the power off.....the "stickyness" of the axis seems pretty consistent no matter where the printer head is in the Y Axis.......if it was bent I might expect it to be free in some places but get tight in others....maybe.......?
The measurements in the image seem ok to you? Drift of a couple 100ths of a mm does'nt seem too bad to me.
Yeah those look fine to me. It's difficult to diagnose when you can't feel it yourself. If you listen closely are you able to locate where the sound is coming from at all? I'm thinking that something around the motors is rubbing against the case perhaps? My poor brain is starting to shut down as it's nearing midnight 
I'm sure the night shift (from my point of view) will be along shortly to offer advice.
In the mean time I'd check the other axes as well, just in case.
Hi Carl - I'd focus on the back left corner, yes. Looking on your video, I see that there's the wire there going to one of the limit switches - that looks quite taut, although we only got a quick view. Is that catching/rubbing on anything?
Look at the short belt coming from the motor, and see if that is catching on anything that you can tell. You might also try removing the metal cover over the motors in that corner, and see if anything becomes apparent. Possibly the pulley attached to the motor has shifted position, and is now rubbing on the side panel of the printer, for instance?
Thank you both for your kind help.
Must say I am loving this so far. 
Astonishing technology.......
I was going to take some more footage and make some notes on a few more images, then both my cameras died. I will charge them up overnight, get another print going in the morning (like I need an excuse....would run all night now if it wouldnt keep us awake sqeeking at us...lol.)......
I will report back here in the morning.
As I was sticking my nose in for a look and listen, I did get the feeling, hunch, it is something to do witth the motor belt.....
Yes there is a wire rubbing against the belt in the corner, but it is not tight/cutting in....yet..........have moved it out the way with tip of finger and noise is still bad...so I moved on...but yes I need to get that wire secured....What do you recommend? will tape glue take the heat in there?
The belt coming out of the motor ....looking through the front of the UM2........the bottom wheel of the belt, the belt is to the far right of the wheel, rubbing up against the retaining wall of the wheel............the top wheel on that belt, is rubbing on the other side.........the wheels driving the belt maybe out of X alignment.......???
Will take pics in the morning. And thanks again for your help.
The belts all go around pulleys. The pulleys each have a set screw to hold them firmly to the rod they are on. You can loosen a pulley and then slide it to the correct position. I'm not quite sure what you mean but the short belt from the stepper motor to the pulley above - that black belt should not touch anything on the way. If it does you will get problems.
Also be aware that if the long belts are too tight you can get too much friction on a given axis. Inside the side blocks are belt tighteners. I've never opened mine though. I have no idea what they look like.
Hello all
The shot below shows the belt coming out of the motor.........the belt at the top pulley seems all the way to the left.......the belt on the bottom pulley wheel seems all the way to the right........
I also took another video:
If you pause at 30 Seconds you can see the two wheels (bottom one not so well)
I have measured the inner edge of the belt, top and bottom.....with the internal left wall of the printer.........bottom inner edge of belt is 8.35mm from wall..........inner edge of belt top is 8.80mm from wall...............so if the measurements are correct.......when viewed from the front, the belt top is slanted to the right, the bottom to the left............which is backwards to the how it appears in the images......belt seems all the way to the left on the top pulley.........but measurements say Belt is actually leaning toward the inside of the machine, to the right........???
The above image is from your video near the end. The red arrow points to the gap between the pulley and the motor. That is huge on your machine compared to mine. That gap should be as small as possible without touching the motor. It's about 1/2 mm on mine. I suggest you remove the left back metal cover (just one screw to remove that screws directly into a threaded nut like piece welded to the cover), remove the motor, loosen the pulley on the motor and slide it closer to the motor without touching it, tighten it back up (very very tight) and then put it all back together.
Hi gr5
Thanks for the tip I will give it a try.....
Is there a tutorial or dummies guide to taking one of these things apart in order to do this sort of thing?
Decided to bumble through....always my favourted option.
I have removed the large white vertical cover by taking out the single screw in the side wall....
I have removed the motor and its 4screw and black plastic wall mount...........and I am ready to move the pulley wheel along its shaft, closer to the motor......
But how do I move the pulley wheel along the shaft?....I see a hole in the side that looks like it would take a grub screw.....but I cant see anything in there to attach a tool too.........so am I doing this wrong or as the grub screw head sheered off somehow.....? Or have my old eyes let me down........
I was going to hit it with a hammer.....but as the motor is still wired to the machine, I couldnt get a good hold on it.....which is probably a good thing....LOL.
Cheers
don't hit it with a hammer! You will probably damage the stepper.
There is a "set screw" or "grub screw" or whatever you want to call it in the pulley. Try shining a bright light in there. It should be the same hex size (or torx) as all the other screws all over the UM2 (except the fan screws).
It will take a huge force to loosen that tiny screw. Tighten with similar torque.
Sorry..was my old eyes.....there is a grub in there........DOH!......
Ok....will now stick it all back together and have another go.....
Thanks all/Gr5........thought I am sure...I will be back.
Make sure that you press down firmly on the stepper when you're tightening the four screws that hold it to the case. A loose short belt (which is what we call the belt that the motor drives directly) will make circles come out ugly and make infill lines not touch the external shell of the models.
Many thanks gr5.
All back together now, nice and tight......all axis move freely, and with simlar pressure needed to move each.....and NO SQUEEEK>!!!!!.
Easy when you know how, and you, know how....thanks again.
Will run off some prints now and see how things go. Will keep the thread posted.
Quiet as a Mouse........ Thanks again.......
I do sometimes hear a quiet clicking noise that seems to be coming from the back of the machine (I can live with it), where the fillament gets fed in to the long tube........anything to worry about? The print it was doing at the time came out fine. Light click, every 8th of second-ish......last about 20-30 seconds.....went away...came back a bit....went away.........on this new print, a much bigger print, so far, no clicking from the back.........
And UM2 machine speeds........lots of different ideas out there, but you guys seem to really know what you are talking about......so I ask
50mm/s 150mm/s higher?...............what can you get away with without shaking the machine apart, I kind of like my new toy....
As a test, in "Cura" I made a 20x20x20cm block to calculate machine time based on what I thought I had learned....came out to 72 hours......does that sound about right?.........
Print speed is limited by several things. For a start, it depends on the volume of plastic that you can extrude per second; a well set-up UM2 with suitable filament at a high-enough temperature can print at least 10mm³/second - but some users have had problems reaching that speed in practice.
The volume per second is equal to the linear speed x the layer height x the extrusion width (which is usually the nozzle hole diameter - 0.4mm). So for instance, 10mm³/s is a 0.25mm layer printed at 100mm/s. Or it could be a 0.125mm layer printed at 200mm/s (since both 0.25 x 100 x 0.4 and 0.125 x 200 x 0.4 equal 10).
However, at faster print speeds, the nozzle pressure is much higher, so you may be more likely to get oozing from the nozzle when slowing for corners, or changing layers, or moving between parts of the print. So for more complicated shapes, or where the highest fidelity is needed in the output, you will probably want to print at much slower speeds - more like a half or a quarter of those sorts of throughputs.
Total print time may also need to be increased when printing smaller parts, in order to allow for one layer to cool before the next is laid down. Generally you want the minimum time per layer to be somewhere between 3 seconds for thin layers, and 7-10 seconds for thick ones.
Another consideration affecting print time is the amount of infill printed inside the shape; you can often print with surprisingly little infill, unless it is needed for mechanical strength, and not having to print infill on every layer makes a huge difference to total print times.
And regarding that soft ticking noise. Yes, that seems to be normal, I have the same noise on mine. I think illuminarti mentioned he had heard it as well. I believe it's simply the sound of the stepper when it's running very slowly.
Super feedback gentlemen, thank you very much......
I will need to go over the numbers to understand them better but thanks, a great starting point......
Machine speeds, I think I am ok with......in fact maybe I should slow them down a bit? (See below).......Though the infill idea sounds interesting as the models I am making so far are just decorative...so they dont need to be bomb proof........Cura currently has infill settings of 20%......what could I get away with within reason for the objects below?
The ticking noise, yep, it seemed to change if I wiggled the plastic as it headed in to the tube....ie, straighten it out a touch as it enters machine and the ticking "changed" so I assumed it was a feeder issue.......and as it is printing fine, then no worries.
On to my first prints. (No laughing at the back...I know there are better ways to lay out a model like this, but I am just in the "have fun and play" stage at the moment....so wanted to test overhang and other issues)
So I have knocked up a model of Drone 02 from "Silent Running"< using 3DSMax.........export as .obj to Cura..........and this is what I get. the large model is 70mm tall-ish.............
1. Overhang....I get the dribble ripple effect on the underside...no probs I know it cant print in thin air.....but what is max angle of "overhang" slope it can print.
2. The two lower images show the finish on the print.......the back face of the model is very nice indeed. Very close to smooth in the XY axis.....and I can feel the tiny "record grooves" in the Z Axis........
However the front of the print has lots of artifacting in the plastic......mainly presenting itself as vertical striations. Giving an almost un-sanded wood grain look to the front of the model.........
My first thoughts were maybe one of the axis was damaged........but then the back face of it is so smooth.......which lead me to think it was in some way to do with how the tool path is done on the front faces........ie, instead of making a front face with a single move along the front face........it seems to have done several 90deg to face moves to "build up" the front face" resulting in this lumps and bumps??....
Is this a toolpath issue? a limitation of the tech?
Top shot is just a WIP render of the Max model.....
Many thanks again.
Those ridges you are seeing is caused by what we call "ringing", it's a mechanical effect. As the print head changes directions quickly there's some inertia to overcome which basically causes the head to vibrate.
Some tests done by a member a little while back suggests that lowering acceleration a bit helps reduce this effect without causing to much of an effect to the overall print time. You can read the test here:
In some cases it can also be the infill showing through and in those cases it can help to increase the width of the outer wall a little bit.
Slowing down the print will probably help a lot the ringing and the the overhang quality I suspect. Where I want absolute best quality, I've been printing at 30mm/s, with 0.1mm layers. (See examples http://www.extrudable.me/2013/12/17/highqualityultimaker2/ and http://www.extrudable.me/2014/01/02/the-guy-with-the-dragon-part-2/).
If you have a sufficiently thick top/bottom thickness set in Cura - I'd say at least 6 times the layer height - then you can probably print that shape with zero infill. The only possible issue might be getting the top to close in - but even then, it's not a huge surface area, and I can't tell if it's flat or sloped. If it has a bit of a slope on it, then it shouldn't be a problem at all.
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IRobertI 520
I would try powering the machine off and then manually pushing the head around to see if you can locate where the noise is coming from. Maybe something is rubbing or you need to put a little drop of oil (such as sewing machine oil) on the rods.
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