General 3D Printing Thread


 
I am using (as Bryan called it ) wonky aluminum plate. Are you guys taking the ultem sheet and just attaching it to your build plate, or replacing the build plate completely? From the previous posts it sounds like you are just attaching to the build plate.
 
I've used Ultem on top of my glass cause I have a regular circuit board like heater... Lately I've backed off the Ultem and gone back to Kapton cause the last piece of Ultem I got was a bit too thin and ABS could actaully pull it up a bit on the edges of the print and cause layer adhesion problems. When I use that thin Ultem I stick it to the glass with hairspray to prevent it from pulling up (I didn't have this problem with the thicker Ultem sheet I bought the first time). The thin Ultem hairsprayed to glass ended up to be a bigger PITA than the Kapton tape, and since I got the borosilicate glass my Kapton has been sticking down much better, lasting for many more prints, so it turns out to be easier than the thin Ultem for me...
 
I used silicone adhesive to secure my thin piece of Ultem to the aluminum plate, but this plate is pretty flat.

I'm not getting great results though. The first layer sticks about as well as any other method, but I'm getting a ton of warping on my prints. I've gone from 90C to 105C in 5C increments and I'm pretty much maxing out my bed. Measured with an IR thermometer I was seeing over 100C on the build surface so the numbers seem right. Tonight I am going to build a cardboard box to put over the whole thing to trap some heat in and see if that fixes it.

I tried spraying it with hairspray to make the print stick better and I ended up making a warped print I couldn't remove once the bed was fully cooled. How does that happen?!
 
Bryan Mayland said:
I used silicone adhesive to secure my thin piece of Ultem to the aluminum plate, but this plate is pretty flat.

I'm not getting great results though. The first layer sticks about as well as any other method, but I'm getting a ton of warping on my prints. I've gone from 90C to 105C in 5C increments and I'm pretty much maxing out my bed. Measured with an IR thermometer I was seeing over 100C on the build surface so the numbers seem right. Tonight I am going to build a cardboard box to put over the whole thing to trap some heat in and see if that fixes it.

I tried spraying it with hairspray to make the print stick better and I ended up making a warped print I couldn't remove once the bed was fully cooled. How does that happen?!
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Yah, if you've got a lot of first layer squish ABS prints can be tough to remove when fully cooled, add in hairspray and " fuggedaboutit"! LOL Heating the bed back up a bit can make it release easier, and some sideways taps (as opposed to just pulling upward) can be helpful too. It's kinda crazy how an object can be stuck down so solid and then suddenly pop off as if it wasn't stuck down at all...

The cardboard box will definately help reduce curl on ABS, I tried one long ago to see if it would help and it did. Then I ran into some plexiglass I had sitting around and cut some holes in the box and put in plexiglass windows, the front one flips up (just held on by tape). It worked great, planned to build a real wooden box with sliding plexiglass doors (like a display case) but months later I'm still running the cardboard box. It works great so I have no urgency.

I've been running the bed at 110C for ABS and the hotend at 230C, and try to pull the parts off as the bed cools off, between about 50C-70C seems to be the range where parts release easiest.. One of the nice features of Ultem SHOULD be that you can pull the sheet off the bed, flex the sheet and the part pops right off. Unfortunately, if you've got thin Ultem and need to stick it down somehow you no longer have this option, which makes it just about as convenient as Kapton at that point. I had good luck with my 1/16" Ultem sheet without securing it down to the bed/glass, the 0.04" Ultem sheet wont even sit flat on its own, and curls very easily under ABS prints. I would not buy any Ultem thinner than 1/16" again. I have run into problems with adhesion on some parts of an Ultem sheet, I'm thinking either a drop of lubricant made it onto the bed when I oiled the smooth rods, or perhaps I wiped the Ultem with a rag that had a tiny bit of oil or something on it. I cleaned with Alcohol, Acetone, Windex, dish soap, no matter what I tried I couldn't get ABS to stick to that area. I eventually tried cleaning with one of those 3M scouring pads, which removed the surface from the Ultem leaving it kinda white rather than glossy. It did the same to the prints, no longer coming out glossy smooth, and requiring hairspray to get really good adhesion.... basically I ruined that (expensive) sheet... so don't do that... lol
 
There is a lot of good reading here. Now I need to decide on which one to get. I'd like to get one with a good size print area, but don't know which one to get.
 
I'm not sure if I've seen it mentioned here, but I've heard a lot of people are happy with the Printrbot Simple Metal as well. It's only 6x6x6 and doesn't have a heated bed (so PLA-only) but it is sturdy and compact.

I've been having all sorts of "fun" with my Makerfarm i3. From my prints it seems like the bed isn't flat, because some areas the extrusion is being over-smooshed, and some areas it's not making good contact at all. It is consistent where it occurs which is nice in that I can tell it isn't just being sloppy, but it happens in pockets rather than linearly which would indicate a planar misalignment. I've printed on glass, the bare aluminum bed, aluminum with PEI attached with silicone and pressed under weights. It's infuriating because we're talking about 0.5mm here so it's really hard to figure out.
 
Bryan, are you printing on regular glass or borosilicate glass? When I was printing on regular glass I found the thickness varied a bit and there were areas on the surface that were high and low, the borosilicate glass is much flatter. You said your problems occur in pockets so I am guessing it has to do with your print surface having dips and humps, if the print is squished on one side and not the other then I would say the bed wasn't level, or your z-carriage isn't horizontal. Also, I found the wooden base on the MakerFarm bed to be too flexible, if you are still running the wooden bed then I would suggest perhaps you upgrade that to aluminum. A while back I switched over to pillow block bearing instead of linear bearings on my (aluminum) bed and I've been really happy with it so far...
 
I believe it is because none of the build surfaces I've used are flat. I was originally using a piece of glass then thought it had too much variation so I went to just printing on the bare aluminum but had a hard time getting stuff to stick to it. I then adhered a piece of Ultem on top of that, which was pressed between some glass with 40lbs on it, and it seems to have this issue pretty badly. Then I put a piece of glass on top of that and it is better but still has spots where the print head contacts the glass (again, non-linearly so it isn't that there's a height problem in z-axes or the bed not being level enough). I rotated the glass 180 degrees and the problem spots moved so the glass is definitely garbage. Flexibility of the support structure isn't an issue at the 10mm/s I'm testing at. I think the problem with the ultem+adhesive was that the piece of glass I used to compress it was one that ended up being non-flat so it basically left its impression in the bed.

I'm weary of spending even more money on trying to fix it. I've already spent over well over $100 between switching to pillow blocks, two different aluminum build platforms (the first was from China and absolutely horrible), two sets of glass, a sheet of ultem, a roll of giant kapton tape, adhesives... I think that's all. Where did you get your boro and was it the right size or did you have to cut it?
 
I ended up getting my boro through Ebay, though I had found it on Amazon as well (can't remember why I went ebay, might have been just because they accept PayPal). At any rate, I've been very happy with it. Since the heated bed we have is very common there are lots of options for boro glass, the 200mm X 214mm glass I got fits perfectly. Since I purchased a while ago my Ebay history is no longer showing an active link, but I am pretty sure this is the same product I got (same seller, same price, same specs, ships from USA). The ground edges surely are a plus compared to window glass, and the surface is much flatter.
I have had similar frustration with ULTEM, the first sheet I got was thicker and worked great until I wore it out (or perhaps accidentally got some oil on it from my smooth rods or a rag), the next ULTEM I got was thinner and wont lay flat. Since I got the boro glass I have moved back to Kapton and it is working nicely for me. I too have a wide roll of Kapton, so that cost is already absorbed, and I have gotten very good at laying down smooth kapton layers, so for me this is the best (and cheapest) way to go right now.
 
Have you considered a simple piece of mirror tile from Home Depot? Very cheap, very flat, very rigid. Just clamp on top of your aluminum bed and then put kapton or Ultem on top.
 
I haven't tried the mirror tile, but all I see they have is 12" so I'd need it cut. I'm going to try the borosilicate that Ralph linked which hopefully will make all my dreams come true without any fuss. Either that or I'll find something else to complain about. Thanks guys!
 
Bryan Mayland said:
I haven't tried the mirror tile, but all I see they have is 12" so I'd need it cut. I'm going to try the borosilicate that Ralph linked which hopefully will make all my dreams come true without any fuss. Either that or I'll find something else to complain about. Thanks guys!
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If you are going to do borosilicate glass, I recommend you check out Mcmaster. You can can thicker sheets for around the same price and all of mcmasters products are guaranteed to be within spec or you can return.
 
For what it's worth, I find the 3mm sheet to be plenty thick and rigid, so going thicker would just be adding more weight the way I see it. After looking at multiple sources (including Mcmaster) this sheet seemed to have all the specs and features I require so at the best price (while shipping from the USA) so I took a stab in the dark with this seller (based on positive ebay feedback for this seller on this item). It worked out well, I have no complaints, my hills and valleys are gone!
I have about a dozen different sheets of glass I've printed on, and you know it's bad when you start to learn each piece of glass.... this one has a bump in the middle, this one has a valley on the side.... Wherever you get your boro glass, it's nice to finally have a sheet that is FLAT!
 
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Jeff Baker said:
I like the Taz but the price. Still no release info on the kit. I also ran across the Iron 3D by http://diytechshop.com/. It has a print area of 12x12x14. Gues I can start making my list of needed materials to see if I can get it cheaper.
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That Iron 3D kit looks pretty solid, I'll have to read more about it. Whatever you do, go with something that has a metal frame. Aluminum extrusions are very popular for printer frames due to their strength, light weight, and the fact that they are easily customized.
 
The Taz can be built pretty economically if you source the parts yourself - one of my officemates built his. You can get the extrusions cut to size from a couple of companies (pm me if you need a source). I built one of these: http://www.thingiverse.com/thing:41967 but would to the taz next time.The other advantage of the taz is they have complete instructions on site which is pretty helpful.
 
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