Bed levelling (and also print surface discussion).
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In the interest of sanity, I have edited the first post to make it clear that there is no magic snake oil (3Dlac or anything else) that can be applied to a print surface that will compensate for a bad design. The only thing that can be applied to a printer that will negate the need for software compensation is good, sound, mechanical engineering principles that will ensure that the nozzle to print surface distance is maintained to an accuracy better than 0.1mm over the entire print area.
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Deck-
I, too, have had just an awful experience with printbite – to the point that it's really beginning to piss me off. It's as though I'm printing on black ice. It's hard to imagine that things are supposed to adhere well to this. I honestly don't know what I'm missing add far as making it work or if it's simply a waste of time completely.
Thanks,
JonathanHi Jonathan,
I thought it was just me! Various forums are scattered with posts from users who extol the virtues of the stuff so I was convinced that it must be something I'm doing wrong. I like you analogy to black ice - at best it's no better than plain glass. I've tried everything. I've measured the bed surface temperature with a thermocouple and I know that there is 13 deg C difference between plain glass on aluminium and glass with print bite so I've tried 13 degrees higher, 20 degrees higher and it's not until I go to 30 or 40 degrees higher that it starts to work but even the not well. Then I'm in the realms of using 90 to 100 degrees bed temperature for PLA ! I thought I'd got it working so (foolishly) walked away from a print. After about 45 minutes, it curled up, wrecked the mini height sensor and tore the mount off the bottom of the bed.
The guy that I bought it off (I'm sure you know who I mean) contacted me a few weeks ago to ask how I was getting on with it. I told him. He suggested various things like using big rafts (fine if the raft would actually stick) upping the hot end temperature (causes all sorts of problems with oozing), running the bed even hotter (I want to print on it - not fry my breakfast !), increase layer height, decrease layer height, use a print cooling fan and run the hot end even hotter (what!) etc. Finally he suggested that maybe a squirt of 3Dlac might help which makes it a bit bloody pointless.
I just wish I could find away to get the stuff off my (400mm square) glass so that I can use it again. Maybe I'll put it on Ebay - for sale, 400mm x 400 x 6mm float glass with PrintBite attached (I wouldn't want to inflict it on some poor unsuspecting soul though).
Anyway, this is way off topic but I feel better for the rant…....
Ian
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I'd agree with you Ian that a mechanically excellent printer doesn't need software compensation, but it takes time, money and patience to get to that machine and not everyone gets there.
As for surfaces, I've tried printing onto aluminium with hairspray and glass with hairspray, and printbite.
I don't get any problems printing with it, I mainly print abs. If I use 250 deg C nozzle and 120 deg C bed temp for layer 1 I get good adhesion, I can drop the temps quite a lot after that. I clean it with acetone between prints, I do not coat it with anything, I use a small brim but no rafts.
I'm just saying this in the interest of balance, as I've nothing but positive experiences with this surface. Perhaps I need to try some of the other surfaces out there for comparison, but prints stick and don't peel so I've stopped looking for a better surface.
I've printed Angus' warpinator 5000 in abs onto printbite with no lift at all. It's a real test.
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DJ,
Thanks for the feedback.
Ref the time, money and patience - fully agree which is why I made the comment in my OP that not everyone can get there.
Ref PrintBite - I know that lots of people get on well with PrintBite which is what is frustrating and other than this post, I haven't made any derogatory comments on any other forum. Maybe it just needs 120 bed temp but that's not something I'm prepared to do with PLA. The problem is that I "over specd" the aluminium tooling plate at 10mm thick, and coupled with 6mm glass, even with 12mm of insulation under the bed and an 800W, 240V heater, it takes long time to heat up. I'd be happy if I could go just a few degrees higher (say 60 to 65 or even 70 instead of 50) but 120 is 70 degrees higher than "normal" and is more than I'm wiling to go to. At that temperature, I'd have to start using a print cooling fan to stop the print "sagging" which would likely mean that I'd have to run the hot end higher, which would likely lead to oozing, which would mean higher retraction, etc….......
It's a shame because I'd really like to get away from using any sort "goo".
Ian
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I to would agree with both of you
I have no trouble with Printbite either and I normally set 115 on the Bed for ABS and 70 for PETG.
I would love to try PEI as that is supposed to be the ultimate but I can't find anywhere to get a piece big enough for any of my Printer's (Built or otherwise) I can get some specially made but the price is extortionate getting on for £1000 for a 8x4 foot sheet and that aint going to happen.
Doug
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I would love to try PEI as that is supposed to be the ultimate but I can't find anywhere to get a piece big enough for any of my Printer's…............
Doug
Me too. It seems to be available in US but not over here (at least in 400mmx 400mm). If you do find a source, give me a shout - maybe we can split the cost.
Ian
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I would love to try PEI as that is supposed to be the ultimate but I can't find anywhere to get a piece big enough for any of my Printer's…............
Doug
Me too. It seems to be available in US but not over here (at least in 400mmx 400mm). If you do find a source, give me a shout - maybe we can split the cost.
Ian
Ian
You could check out the Filafarm products they do What i suspect is a epoxy substrate with a very thin PEI coat sprayed on to it
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Proper pei must be worth trying but large pieces are clearly hard to get affordably.
Ian for pla I'm only using 70 deg C on printbite. But yes I accept I have to use fan even with abs and that the high bed temp can cause some softening of the lowest layers of a print.
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…..........Ian for pla I'm only using 70 deg C on printbite. But yes I accept I have to use fan even with abs and that the high bed temp can cause some softening of the lowest layers of a print.
I'll try it again some time. I can't see why it doesn't work for me but does for others. I was just wondering about the heat cycle that is recommended. Maybe that didn't work as it should because my bed took ages to cool down due to it's high thermal mass. I'll try it again but this time remove the glass/PrintBite after it has heated so that it cools down quicker. When I consider what it cost me, plus the cost of the 400mm x 400mm x 6mm float glass, it'll be a shame to give up on it. It's just the episode of the print lifting which resulted in a destroyed IR probe and X carriage has made me a bit reluctant. Next time I try it, I'll sit there with my finger hovering over the emergency stop button:)….......
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Ian
You could check out the Filafarm products they do What i suspect is a epoxy substrate with a very thin PEI coat sprayed on to it
Cheers for that Doug. At 129 Euros I'd have to be sure it'd work though. Tell you what - you buy it then lend it to me to try:) (only joking).
Joking aside, I'd really like to get away from using any sort of goo. Although 3DLac does work very - parts stick like the proverbial but just fall off when it cools down (as evidenced here https://www.youtube.com/watch?v=vG1WqijJ634)) it does upset the IR probe due I suspect, to it changing the reflectivity of the glass. I went to the expensive of having the glass sandblasted because I had seen someone having success with that - didn't work me though. Then I tried having it sandblasted and treated with something called (Brite Guard) - a "glass man" told me it was the dog's danglies - that didn't work either. Kapton tape works a treat for me but it's such a pain to apply and tears easily when removing prints.
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Two other print surfaces that may be worth trying:
1. PEI-coated aluminium from clever3d.de. The black version should work very well with the IR probe. I'll do some detailed measurements when I have time.
2. This http://www.lokbuild.com/ has recently appeared. I have no idea how much it costs or whether it is any good.
I print PLA on plain glass on one of my printers, and usually on PEI on the other. Some PLA filaments stick to the PEI too well and the print is difficult to remove.
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Just had a look at LokBuild and the stockists that I have checked it seems it is available in only 2 sizes 203x203 or 305x305 not big enough for any of us in this thread
I did Email Clever3d to enquire if they could do me one for my 650 diam bed and got the reply that the max size they could do was 550 IIRC but they do do one that will fit my CoreXY at 450x450x8 at €195 plus carriage or €155 for a 410x410x8 tho not cheap it may be worth a go?
Doug
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That's quite a lot for the Clever3D bed. I guess whether it is worth it or not depends on how durable the PEI coating is, and how flat they guarantee the plate to be.
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yeah I know it isn't cheap but I believe Lykle has one and rates it highly
I think they must disolve the PEI Granules in a solvent ant spray it onto the Alloy bed which they claim is machined flat and has 4mm holes in each corner for mounting?
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If it's machined flat, then in a new printer build it would save the cost of an aluminium tool plate for the bed, which makes it better value.
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Indeed
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If it's machined flat, then in a new printer build it would save the cost of an aluminium tool plate for the bed, which makes it better value.
Good point. I have it on my todo list to replace the 10mm thick plate with something thinner - hmmm…........
Edit. ..........but then it is handy to have a removable surface such as glass, in order to rapidly print multiple parts without having to wait for the bed to cool.
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If it's machined flat, then in a new printer build it would save the cost of an aluminium tool plate for the bed, which makes it better value.
Good point. I have it on my todo list to replace the 10mm thick plate with something thinner - hmmm…........
Edit. ..........but then it is handy to have a removable surface such as glass, in order to rapidly print multiple parts without having to wait for the bed to cool.
I like that facility too. On a printer with a non-removable bed, I would want a fan below the bed to cool it faster when the print is finished.
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I got a good price for 3mm PEI sheet from a Chinese distributor. I haven't ordered it yet because I read that material thickness is hard to keep flat using adhesives. I originally though to mount it to the tool plate with stainless flat head screws but now I'm unsure, I'm afraid that method will produce bulging around the screw heads . Has anyone used a thick sheet of PEI? Thanks…
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I have never tried PEI that thick but I think it will be sub optimal for a number of reasons
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loads more PEI than you need. PEI is useful as an adhesion surface, other than that it is an insulator which does not help your heated bed.
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As you mentioned: difficult to keep flat. I have used thinner ~1mm PEI and an issue is the adhesive coming debonded over time. The 3mm will have the same problem but probably earlier as you will be pumping more heat into to maintain the same surface temp.
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PEI is pricy why pay for what you don't need.
Regarding screwing it down. You will probably get a air gap in the middle which will mess with the effectiveness of the heated bed. It won't be flat around the screw heads either
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