rewolff
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Posts posted by rewolff
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A bearing is a device that makes movement in a certain direction really easy.
So inserted into the plywood are bearings that allow the left axis to turn really easily. And that's the movement that it needs. It does not need to move sideways (front-to-back in fact). So the bearing doesn't help in that direction. And if it does move, the caps prevent it from sliding all the way out.
Now there is another bearing: the extrusion head is using a sleeve bearing to move over the left axis when there is Y-movement, and it allows the axis to turn when there is X-movement. It is this Y-movement that apparently has more friction on the sleeve bearing than in the inside holes of the bearings in the front and back panels.
Mine started making noises again, and I oiled it again. Either it requires quite constant oiling or it requires oiling a few times. I don't know yet. I just have the oil next to the machine and when the ticking annoys me I give it a few drops....
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If it's your own shop, it would be appreciated if you disclose that fact in your post.
Even when Amazon KNOWS I'm located in the Netherlands (when I'm logged in) it keeps saying: Free shipping available. Only at the last moment does it tell me: Only in USA.
So, because they are knowingly trying to mislead me into thinking that shipping will be free, and then they hope that I've invested enough in assembling the order that I'll go ahead and pay for the shipping too. Sorry. I'm not falling for that one again. I'm not buying at amazon unless I have to.
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So far, screws that come loose have not hindered the running print. Three times so far. :-)
On a serious note, yes, what you're saying makes sense.
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[for the record... Someone asked a question about laserprinters. That post has been removed. ]
Yes you may....
... Somewhere else. This is about 3D printing. Nothing to do with laserprinters. Good luck!
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What I've done to get the bed level is to have it print a big skirt, and then watch for consistency around the circle. If you position the skirt/object a bit smart you can even adjust the screws as it is printing the skirt.
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In my case (yesterday) oiling the axes helped.
Apparently it's always the left axes that does this.
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Dazzan, the M113 g-code is not really important. The replicator program doesn't recognize it, but IIRC the firmware in the machine will.
On the other hand, I had big troubles with the slicers in replicatorg. They would generate extrusion parameter commands that did not correspond to what my machine wanted.
Experienced people can then go in and tweak a simple command in the startup-g-code. But this is too difficult for a "first time print".
Try cura. Once you have some experience you could go back to replicator. (but you won't).
Don't throw replicatorg from your computer just yet. You must be able to start it when you request help from ultimaker....
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In my experience when my extrusion stops midway during a print, and you can push filament out by hand, there are two options. Or maybe both.
* First the screw on the material feed may need adjustment. Too tight or too weak and the material slips.
* Second: the actual extrusion might be requiring too much force. This could be because you're trying to go too fast, or you might be running it not hot enough.
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OK. The bearings I have are 8 mm wide. This would require cutting away part of the plywood that you've left "in place".
I'll wait for the smaller bearings to arrive.
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Ok Joergen, if you can describe the sound, I'm not the only one to have had this effect. :-)
I'm taking the "sewingmachine oil" home now... :-)
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When the head moves in the Y direction the intention is that the assembly moves on the brass "bearing" that slide over the left and right axes. These axes turn to provide X movement, and are therefore put in a bearing on the front and back side of the machine.
Now, instead of the brass bearing sliding over the axes, the whole axes moves with the head until it hits the laser-cut cap that is put over the bearing.
Question 1: Has anybody else seen this?
Question 2: Should we lubricate the XY axes?
(After assembly with just a few of those caps to go, we thought: "they're not really necessary, so lets leave them off. Let's print! If this had started happening then, the machine would've come apart! But in the meanwhile we got bored and put them on anyway. :-) )
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Just a FYI...
I see that the pressure (from the feed mechanism) on the extruder changes a bit in relation to the position of the extruder on the bed. This is caused by the PLA being able to move about a bit inside the bowden tube. So when the bowden is bent more because the extruder is near [200,200] the effective length of the bowden tube is maybe a mm shorter or longer than when the extruder is near the origin. This effect will be stronger if you have a larger ID tube.
So the 4mm ID bowden tube will affect print quality a bit, whatever way you look at it.
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I love good news. does this mean we will have the option to set different speeds for perimeter/loop/infill sometime in the future?
I'm from the future. We can do this now. :-)
(Get the latest cura from github and it's included. Daid wrote something about him not having tested it, but I have.)
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Also, you want your plastic to cool and become solid before the next layer.
I wrote a program to output G-code yesterday and forgot to put in an "enable fan". So my build started, and things got sloppy after a few layers. Apparently things heat up/don't cool enough that it isn't solid enough for the next layer.
And I had already put it "too" slow. I put in 30mm/sec for the first layer and then forgot to change speeds. So it rpinted the whole thing at 30mm/s instead of faster for the higher layers. A similar object printed just fine at a higher speed, but with the fan on.
Anyway of course I put in the "enable fan" but forgot about the speed and it printed great in twice as long as the other (similar) object.
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I have loads of larger bearings. I'll see if I can adapt it for my bearings....
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Don't worry about the belt tension for now. It prints quite reasonable with QUITE a lot less tension on the belts than the video recommends as "perfect".
In the video you hear a "ploing". Mine vibrates just below hearing range. Quite acceptable prints. Nothing hints at "belt tension too low" for me.
[update] after writing this, I later went to the machine and found that NOW the tension on the belts is quite a lot more than when we had just assembled it. So it changes after a few prints. Don't worry about it in the beginning.
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FYI, I saw you get popups about unknown G-codes.
THis is just that the software in the computer doesn't know about them, the printer does. ANd if it doesn't it isn't that imporant. Don't worry about it. Just click continue.
(I at the moment I have to go, so sorry I might have missed something in your last post).
Anyway.... if you're having any trouble, try slic3r. The other one didn't work for me. It's all fixable, but not easy before you've got something printed.
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In theory, when the extruder is commanded to extrude, plastic comes out. When the extruder is commanded to stop extruding, plastic stops coming out. That's the theory. In practise, plastic continues a bit after the extruder is commanded to stop. The blobs arise when plastic comes out while the extruder is told to stop.
For example, when building a "cup", the "old fashioned" way of doing things is to do a loop around the cup, stop, increase Z by the layer-height, and then do the next layer. All good, but the plastic continues to come out for a little while when the extruder is stopped. So you get a blob. And possibly holes on the next part where not the expected amount of plastic comes out.
With an object like a "cup" or the pink panther woman, there is no reason to stop moving. With "joris" enabled the Z-movement is spread out over the whole outerloop. Therefore there need never be a stop, move Z, start. And after a short while, the plastic flow will have stabilized and be perfectly smooth. So you get a nice smooth object.
This morning I designed an interesting object. Specifically designed to NOT be disjunct: The head should be able to keep on moving. No jumps required. This resulted in a beautiful print. Only on the first layer of the top-fill, the head hit the object and bumped it off the bed. And it burned a hole in the last few mm of the object. Oh well.
Openscad however had rendered this quite coarse. So I figured out how to make that more smooth, and I went for it again. Same object, slight change in aspect ratio, but still a simple closed contour on EVERY level. However this time when cura slices it, I see a blue "travel" line in the gcode-preview. I'm not going to waste filament on this: this is not going to come out as I want.
I'm still reading cura-code to see if I can find the offending code....
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I've been practicing on
http://www.thingiverse.com/thing:1216
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Without 'joris' I get a big fat blob along a side. Not my picture but shows what it looks like:
or
So: How can I get rid of the remaining blobs?
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That will happen if you try to extrude too much plastic. Too much plastic can be printing at a high speed. So: How fast are you printing? How hot?
(I'm not that experienced yet...)
At the moment I like printing at 210, and 150mm/s is close to the extrusion limit at 0.2 mm layer height. Hmm. at 0.1 mm you have a factor of two margin there...
Maybe you're extruding too cold?
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I have now. I'm NEVER going back. Never!
:-)
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Hi,
How do you guys purge ABS after going back to PLA?
I've warmed the extruder to 250, and then purged some filament until the ABS stopped coming out.
Now several hours of printing later, the occasional ABS blob comes out and ruins a print.....
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Aaargh... We've fixed it. I don't remember what we changed to get it this way, but this hasn't happened for a few days now. Grrr. Sorry guys.
I think switching to cura and printing a skirt has helped....
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However getting M3 threaded rod can be difficult in the US, I guess... It's just smaller than 1/8th of an inch, so that won't fit. If you cant get metric get the largest size smaller than 1/8th.
If all else fails, just run with the three of those screws. You will need the three that are closest to the extruder. Hmm. The fan might dangle a bit.. Hold it up with the screw you have hold the other side in place with the one that's broken. Or just anything that's straight and fits.
What's stopping us from using Servo Motors?
in Coffee corner
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As far as I know, there are two technical thingies that people call "servos". You could consider it "homonyms". Two things that share the same word.
First there are the remote controlled airplanes and trucks servos. Those have a potmeter that provides feedback to the controller in the servo to where the hand is. Due to this potmeter, the travel is limited to about 270 degrees. (Some don't go farther than 180 degrees).
On the other hand, there are industrial servos. Those have an encoder that "counts" (as mm_build puts it) the position of the rotor.
On a different level of course these two things are the same: They both have a motor and a position sensing device.
But when you say the positioning is inaccurate and that they do not offer full rotation, then you're thinking about the hobbyservos with the potmeter, while you should be thinking about the ones with an encoder.