Bed level issue

Hi guys,

I'm struggling with levelling a FF Creator Pro bed and I would like your expertise on this matter. Here's what I did:

1. At first i've done a levelling operation that they recommended, the one with their blue card and it all went good for a while. However after trying to print some large objects with ABS (noticed that PLA isn't that picky) first layers had issues sticking to the bed (btw I'm using a BuildTak surface mat).
2. The next thing was to try and level the bed with a dial indicator and that's when I realised that even though I would end up with having the same readings on the corners as the carriage passes the center area it seems to be closer that the edges and that breaks the level procedure altogether. I've read on the forum that this might be caused by the fact that the carriage is stressing the X-axis and it's sagging a little. However, what's your recommendation in this case, is there a workaround for this issue?

Thanks in advance!

Hmm, could simply be that the bed's not totally level.

Also abs warps a lot and needs bloody good adhesion to stay level. having the build volume enclosed and heated helps - which you should have with the pro.

What temp do you have the build plate at ?

I'm heating it up to 110 celsius degrees for the ABS prints. I'll give it some more tries, but it bugs me how that central area of the build plate is higher than the side ones (which I got them to be the same value on the dial indicator). I've also tried levelling with the bed heat turned on and of as a side note.

If it's level at all corners but not the middle, your build plate is warped.

you could try some thick (1/4") glass on top to ensure flatness.

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Originally Posted by emanuellupu

Hi guys,

I'm struggling with levelling a FF Creator Pro bed and I would like your expertise on this matter. Here's what I did:

1. At first i've done a levelling operation that they recommended, the one with their blue card and it all went good for a while. However after trying to print some large objects with ABS (noticed that PLA isn't that picky) first layers had issues sticking to the bed (btw I'm using a BuildTak surface mat).
2. The next thing was to try and level the bed with a dial indicator and that's when I realised that even though I would end up with having the same readings on the corners as the carriage passes the center area it seems to be closer that the edges and that breaks the level procedure altogether. I've read on the forum that this might be caused by the fact that the carriage is stressing the X-axis and it's sagging a little. However, what's your recommendation in this case, is there a workaround for this issue?

Thanks in advance!

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Can you do a test print and possibly show us a photo?

@Geoff - Of course, I'll upload one after work tonight.

As another update, i tried levelling again but this time with a sheet of plane paper, not the blue business card size that FF provides in their package but because of the center being higher again the extruder stops extruding plastic and i think it gets clogged. I did however a test print of this http://www.thingiverse.com/thing:215386 with those settings and it came out well. I'll try levelling this evening a little lower so that I clear the center area.

Quote:

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Originally Posted by emanuellupu

@Geoff - Of course, I'll upload one after work tonight.

As another update, i tried levelling again but this time with a sheet of plane paper, not the blue business card size that FF provides in their package but because of the center being higher again the extruder stops extruding plastic and i think it gets clogged. I did however a test print of this http://www.thingiverse.com/thing:215386 with those settings and it came out well. I'll try levelling this evening a little lower so that I clear the center area.

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If it's printing too close to the bed, it will click click click also and cause a backlog. This will strip the filament in the drive gear, which shreds it into plastic dust and creates a cavity in the filament around the bearing, so it won't feed after that, there is nothing fat enough for the bearing to press against the gear to bite into it and feed it down, so it just sits there idle.. creating more plastic dust. If you push and feed it it should unclog tho. I would just get the bed down a fraction more. If you are printing at 0.2mm , just plain paper is fine.

if it stays clogged...


a good thing you can do (if you play guitar) is get a light E string (electric) preferably nickel, the high E is thin enough to poke up the nozzle and all the way through the top - good for really cleaning the gunk out.

(What I am about to describe involves taking your Extruder motor OUT first, you want just the nozzle open - you wont get the guitar string through the extruder gear!!! only the nozzle pipe. VERY easy to take an extruder motor off. 2 Hex screws and the fan and heatsink all come out in one. Disconnect the motor plug and pull it out to the back and then sideways out of the print head.)

Heat the nozzle to 230, poke the guitar string up and slid it up and down, it will feel like there is some small friction, thats the gunk you are dislodging. Keep going up and down till the sliding is smooth up the nozzle hole, then push all the way through to the top of the hole and pull the guitar string through - BUT make sure you do not bend it at any time or create a kink in the string. I have pulled out stuff from my extruder that had been in there months (like a colour I knew I had not used for AGES and i'm like.. why is this still in here??? turns out just eventually cooked itself and didn't melt properly .. causing bad extrusion, not uniform, curly crap coming out of it and not a nice - also run the filament through 2 fingers, feel if it's smooth or has little air bubbles or rough patches. A good extrusion should feel nice and silky between your fingers.

Bed levelling can be a pain, but I also use a piece of paper, just plain old 86gsm A4 photocopying paper. Here's the trick tho...

Instead of running through the bed levelling process and trying to slide the paper under the nozzle to see how close it is, have the paper there ALREADY before the nozzle goes down. It might be impossible to move back and forward sure, it might be pinned to the bed - but thats good. Now you adjust the bed UNTIL you can move the paper slightly, with good friction - you want to feel the nozzle rubbing between the paper and build plate. Not so hard it buckles the paper, but a consistent friction - thats when you will be good for 0.1mm prints.

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Originally Posted by djprinter

If it's level at all corners but not the middle, your build plate is warped.

you could try some thick (1/4") glass on top to ensure flatness.

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I am having the same problem that OP states, high in the center of the build plate. I thought my plate might be warped and switched to glass but that has not solved the issue. The extruder is still closer to the bed in the center. Any advice?

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Originally Posted by larrwill

I am having the same problem that OP states, high in the center of the build plate. I thought my plate might be warped and switched to glass but that has not solved the issue. The extruder is still closer to the bed in the center. Any advice?

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Glass should be perfectly flat, so if it's closer in the center the only explanation I can think of bent x or y rods.

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Originally Posted by djprinter

Glass should be perfectly flat, so if it's closer in the center the only explanation I can think of bent x or y rods.

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It's not bent rods, its bending rods.

The print head is heavy, when it hits the centre of the X axis it sags a little because there is nothing to support the middle of the axis, and because the head slides along the entire carriage, you cannot support them from above and keep them straight. The sag is small but enough that it will let the nozzle slide away on either side of centre.

Pull up in the X carriage when you are at centre plate and you will see there is about 1mm of play.

Hello again and sorry for the late (very late) reply. I want to follow up with the results I got after following Geoff's advice and the response I got back from FlashForge support. So I've sent them a video of me doing a measuring of the print bed with a dial indicator which you can find here https://drive.google.com/open?id=0B8...zRZRjlZNnJFNnc , and they said:

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We notice the dial indicator is not fixed well. It move a little when carriage move. Even if you measure a difference of 0.2mm, it may be caused by plate, because the rod guide and bearings straightness tolerance is +_0.1-0.2mm.
>
> If you think it affact printing, we suggest you to print a first layer at 0.2-0.3mm, or add a raft as you already did.

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Adding a raft for models with a small surface finger print would compensate for the tolerante thay are talking about, at least for me it did.