This topic contains 8 replies, has 5 voices, and was last updated by paulsroom 1 week, 3 days ago.
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I seem to have mostly resolved the ‘filament not sticking’ problem that I had a little while ago. I can even print okay without cleaning the PEI bed with an IPA wipe on occasions, although I prefer to follow the Robox instructions. However I am still experiencing inconsistencies. I decided to send out a 3D printed small flat pack Christmas tree instead of a card. I successfully printed a batch continuously over a day - each part took 45 minutes to print. All the parts were consistently printed. But that was a few days ago and now I decided to print some more. I have no need to make any adjustments so I loaded the same file and started the printer off. It’s not the same print as I had done the other day and as can be seen from the printed part, one leg is wider than the other. Although the filament is sticking to the base this difference in leg width and this seems to be causing the thinner leg to lift off the base. I’d like to think that I can guarantee a consistently repeated print when no changes have been made, but it doesn’t seem to be the case.
Hi @paulsroom, welcome!
let me guess: you’re using Abs? This material tends to curl upwards on smaller sections that do not have enough surface area of attachment on the bed.
This is what Brim is used for, requiring some clean up.Now each time the print finishes, the bed violently hits the front of the machine to open the door. The shockwaves over a period of time are likely to alter the positions of the other axes. A good thing to bear in mind. I have noticed good reproducibility on printz conducted one after the other, and interestingly have observed and reported very reproducible slicing across 2 machines using the same settings. Reported bed and chamber temps are not homogenous as you might expect. Fluctuations in room temps will affect these values too. I have noticed that an unstable worktop and vibrations in the room also affect the travel and accuracy of the print head. Not a lot though… just in the blobby / lauer drifty sense.
Now the only other things i can think about are there is a bit of gunk on your x axis in the region where the leg spreads out, or it is poorly lubricated. Remember the top bar is always kept dry and without lube.
Happy printing
@jabberwocky “Remember the top bar is always kept dry and without lube”
I definitively missed that one. I was about to lube it soon anyway. Why not?
I thought this required lube ?
@clicky Apparently it was the cause of the dreaded B axis error. Ref: some previous thread.
Also, if you look carefully, there isnt a bearing guide for that bar.Oh. Good I spotted your comment here. So - top bar is not to be lubed! Thanks. I’ll dig out that thread and read it more carefully! Thanks!
@jabberwocky Yes I’m using ABS - that came with the printer. The place upon which the printer sits is quite solid and not subject to variations. There is no passing traffic outside the house so it doesn’t pick up any disturbances from there either. I don’t move anything when it’s printing and just leave it alone until its completed a print. Whether or not the temperatures displayed are correct, they are consistent and reach the stated target temperatures within +/- 2 degrees. My point about the inconsistency is that the print I showed earlier in this topic displays features lifting that did not happen on the previous batch printing. While I may not have cleaned the PEI bed each time, I do check it prior to printing. The ‘gunk’ that you point out may have come from the fact that the preliminary extrusion it performs immediately prior to printing sometimes gets stuck on the nozzle and not kicked off on the rubber stop. I check this and although it does seem to be out of the way of the nozzle opening, I pause the print and remove this extraneous filament before allowing it to continue. This is not a common fault, it has only recently happened but once cleared it’s okay. I haven’t lubricated anything yet.
I haven’t actually used the brim feature yet and it didn’t need this on the previous batch printing of this particular part. Nothing lifted and the legs were of equal width. My point is that it has produced a print that is different from the one of a couple of days past without me making any changes - that’s the puzzle. I’m going to turn the part through 90 degrees on the bed and see what the result is like. I would say that the prints I’ve achieved overall since I got the printer have been very good indeed. It’s these odd glitches that I can’t account for that throw me off.
Peeling edges are usually solved by-
- Cleaning the bed with IPA, give it a good scrub in the area you will print on.
- Making sure the bed surface is flat, it is clipped down on all sides and wont move when you press on it.
- Recalibrating nozzle height.
- Ensuring the lid is closed for printing, even a draft will effect the shrinkage
- Adding brim.
- Increasing Ambient temperature in the filament profile, I use 55°C with ABS.
- Printing on a different section of the bed is a quick solution if you cant be bothered to clean/adjust other things.
(Sorry about the rotten photo - I’m going to buy a camera I can handle better)
My latest print which is a repeat of that above. No lifting this time and all the conditions were unchanged. I did clean the bed, although it showed no instances of any marks or minute extraneous filament residue. The temperatures were still the same (I have started putting a room heater on a couple of hours before printing now - from quite recently). The door was closed for the whole print time. I’m happy with the result, it achieves exactly what I wanted. For this particular part, it isn’t a major problem that a lift occurred on one print making the leg slightly bent - it still goes together okay and stands up as required. My only concern is why things change without my input.
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