How often are you guys having to do recalibration?

Hi!

I am having alignment issues again. So, I was trying to make some stuff on PG Black Acrylic, and the alignment was terrible. So, lately, I am having to factor in for maybe a half-inch alignment off to the right of the area that the app shows. I am trying recalibration again right now. However, I am wondering if I should be constantly running into this issue. The last time, it made it reasonably better, but it was not perfect. How often do you guys realign your machines? I always do the “Set Focus” prior to each print, even if I am working with the same materials or designs. I have also only had this for like a month and have made probably 1,200 ear savers and that’s it. So, it shouldn’t be crapping out already.

With the ear savers, it hasn’t really been an issue because the prints aren’t really specific. However, I plan to start making stuff that requires exact precision. So, I am hoping that someone or support can assist. I don’t want to be ruining my materials every other time. Sometimes, oddly, part of the print will be fine with alignment than it will wig out and mis-align and cut into my previous prints, which were in the same design during the same cutting (see photo). I stopped the print, as you can see, because it was just going to mess up what I had already done. I didn’t touch anything during the process. It has even marred part of the side of the honeycomb because the alignment was so off, even if it wasn’t supposed to in the app. It hasn’t affected the height of the honeycomb at all. Truthfully, it may have only ever printed with exact precision a few times. However, I thought laser was supposed to be consistently precise.

My GF is situated by a window, so I have natural daylight shining through. Or, at night, I have the fan light on. Does that matter? Should I be in a completely dark dungeon? I am trying calibration with the glass covered. So, no light should be affecting the calibration.

Does it matter that I am using a PC tablet as my means of accessing the app and printing? Could it be something with my computer’s software?

Can I not do other stuff in the GF app while it is simultaneously also working on a print? Not doing anything to the design being printed, but sometimes I’ll open a new tab and work in another design file while waiting for the print to be completed. Alignment seems to be off, even if I am not touching the computer and staring at the specs on the wall. But, just thinking of possibilities.

Would bumping the plastic table that it’s on affect the alignment? Is it that sensitive? And, by bump, I mean, my beer belly is touching the edge of the table when I take out the material… not actual bump. I’ve been very careful to not bump the machine. Does it matter if the plastic table is on carpet?

Thanks in advanced!!

This is odd, I only did this once around when they released the feature. Only now I notice the calibration is out but it’s only 1 mm and that was when I accidentally bumped the machine a little harder then I was happy with. My machine is by a window and didn’t do anything like you suggest

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I don’t know what is going on with your machine but, if you are not moving your machine (or picking it up or shifting it around a lot) and, it is on a sturdy surface, you shouldn’t need to run the calibration frequently.

I have run the calibration exactly once and, my machine has stayed pretty close to spot-on since then.

Having the alignment change in the middle of the print sounds like a different issue. Belt slipping? Maybe someone else will have suggestions. Otherwise, you’ll hear from support (give them a business day or so).

Edit: Like @cindyhodesigns, my machine is near a big window that gets lots of sun. It doesn’t seem to cause any problems.

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Once, when they gave us that ability.

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Once.

The accuracy is only expected to be about 1/4", although for many people, it’s much tighter. It doesn’t change over time.

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So, I think I saw this test being recommended by the support. So, here’s some screenshots after this latest calibration. It’s still off. Or, is this just normal??

Before and after photos of the medium draft board print of the Gift of Good Measure. It also didn’t actually cut through it (see last two photos).


Tried again with the same design in the center of the draft board. It worked a bit better as far as accuracy. However, is this acceptable variance? I don’t understand the inconsistency. Also, it still didn’t cut correctly, as I think the circles are supposed to be cut.

I want to say that maybe it’s an internal software issue? It isn’t reading the QR code for the PG material. And, it will say “Cooling Down” in the app while it is still cutting the material. And, it gave me an error message saying that the machine has been bumped when I definitively know nothing touched it. Sorry, a lot of different messages.

I had a machine that did something like this, and it ended up being replaced. The weirdness only happened in the right-most few inches of the bed; as long as I avoided that area, it worked just fine; but once the head went over into that right-most few inches it would go wonky and start cutting over things instead of where it was supposed to.

They had me test it by cutting a Gift of Good measure as far to the right as possible, then posting (I believe) a screen shot of the cuts vs. design after it was cut.

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Is your machine sitting on a flat surface? Not necessarily level, but flat - free from twist. Is it sitting on a solid surface?

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If I swivel mine on the table to access the exhaust, I will check for a calibration difference. I have a shim on the right side, so there is potential for things to shift.
So far, only once since the first time calibrations were given to us.
My test is a simple design that is scored once, then the board is moved.
I then zoom in and try to place it exactly over the first cut.
If it looks like below (a slightly fat score), I count it as a success.

image

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I did a calibration the first time but as I was flipping things over, I needed real precision and it wandered a bit from expectations I ran it again on paper glued to the original.

Now however I use the numbers at the bottom as no matter what, if the numbers are the same, the location is the same, When it gets really critical I do a score (3 power top speed) first and use round numbers I can remember for the location. and go back to those or if off I can use the numbers to move it very precisely. Many times I end up under a millimeter from the edge.

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I have to get into the habit of using the precision placement box more. Do you find that the camera based machine homing method repeats with very high accuracy? Makes me want to do some testing now.
If the “homing” does repeat say within .015" then one could do very reliable positioning after a cold start. One item to consider is the fact that the crumb tray has some X-Y free play (mine does anyway). Maybe it can be registered more accurately than the location the dimples provide. Probably pretty simple actually. I’ve drilled a few holes into the base of my machine already. :innocent:

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I think @timjedwards put up a design in the free area that narrows the range of movement of the tray. My main interest is over a consecutive engrave/cuts where that is not an issue.

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And actually, I have found that a level table is important. If the table surface isn’t level, sometimes the gantry moves after I square it up before turning the machine on. Make sure the table doesn’t rock, either.

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Yes, level is better. It is a machine tool; they are always leveled - it is part of the setup.

Regarding calibration, I would box mine up weekly (or even more often) , then unpack it and just start cutting and almost never recalibrated.

From what I can tell on the latest pictures, I’m on my phone so it’s tough, but it looks like it’s within 1/8”, which would be within spec.

One thing to note, the calibration is calibrating to a horizontal plane. Anything above or below that plane where set focus is used, will appear to be off. So if the material is warped at all, that will cause things to be at different horizontal planes, thus appearing off in the camera.

Set Focus measures at the specific place you tell it to. I would use Set Focus first always, rather than not doing so. It will still autofocus without using set focus, but you may notice that the design “jumps” a little bit when you go to hit print. This is because when it does the autofocus scan, it’s reading a different measurement than is expected (which can be a few different things) and is updating the bed image and how it’s dewarped for placement.

It seems you also have a few things going on, with the cooling down, head bumped, etc.

The cooling down - if it gets hot, it will pause the job and then pick back up when it’s cool enough, but this doesn’t stop the job timer in the app (or, if you hit pause, the timer will keep counting down).

The head bump could be a sensor issue, or it could be an actual obstruction somewhere it’s hitting causing the accelerometer to jostle unexpectedly.

If you are getting the head bump thing, it’s possible that it is hitting something, and the head is losing track of where it is, which will cause your alignment to be off. If the head is ever moved to a different position while the power is on, and it’s not told to move like that, it will lose track of the calibration/where the head is, until the next reboot. For example, if you move the head manually an inch by hand to clean it, your next cuts will be off that much (or could be worse, it goes to the boundaries and loses even more steps).

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May I ask, what is the purpose of reboxing it every week?

The latest pictures are definitely better alignment. However, with the prints, they were still not cutting properly. There are “cut” parts (e.g. the circles) that didn’t make it through the print. So, I think something is still wrong.

I always do Set Focus prior to printing, and thus far, all my prints have been on flat PG material.

I’m not sure if you saw the photos with the bat symbols. Do you know why the alignment would be good (well, reasonable) in some parts and then completely off in others? The cuts were definitely supposed to be separate entities. Yet, it cut into each other in multiple places. Could that be because I am importing different images into the app as opposed to having just one files from an external source? I mean, the software is still in beta, so could it be a glitch?

Oh, maybe that might be part of the problem? The table that it is sitting on is level, but it is a plastic folding table that one might use for picnics. I should perhaps get something more sturdy? It’s also on carpet… not sure if that makes a difference. It doesn’t visibly move or rock during the process, but maybe the stability is so sensitive that it’s affecting the alignment?

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