I have a very large print (at literally the max my width my printer can do). The side towards the front is pulling upwards apparently hard enough to pick up the tape off of the bed.
Two questions.
1) Any idea why this is happening and what I can do to fix it? My first guess at this is that because I have a very large, open frame printer (IdeaPrinter F100L), that the part towards the front is getting too much draft, causing the plastic to dry too quickly and create an upward force on the tape. (Perhaps next time I print something this large I can put something in front of the printer?)
2) How should we handle large prints that have defects in them for customers? This print is only half of the entire object and takes a day per piece. This same problem happened to the other print in the same spot on it (towards the front of the printer).
Just been dealing with a difficult large print for several days ourselves. Basically, youâre right, itâs caused by uneven cooling. The lower layers stay heated from the build plate while the upper layers cool, causing contracting forces in the print. Now on small pieces, these forces are usually not enough to lift the print, but are actually still present inside the finished piece. In big pieces the effect is much worse, and the outer corners/edges will lift.
The best way to fix this would be an enclosure with temp. control⊠but thereâs a few other things you can try that will help.
1. More solid bottom layers. This will simply help strengthen the structure to lessen warping.
2. Use a tall and close-proximity skirt - This helps trap hot air around the outside of the print to keep it evenly warm
3. Check that your build plate has consistent heating - many plates have dead zones where the wiring is, or where there is no insulation (usually around the edges) Use an infrared thermometer to find out. If thereâs a big difference in some areas, position the print in an area where thereâs minimal variation.
4. Lower the bed temp after the first layer to as low as possible before you start losing adhesion. This will help create a less extreme temperature gradient in the piece.
5. Reduce fan cooling as low as possible without letting the layer quality suffer.
The worst part about these prints is it takes forever to retry them! Good luck.
For prints like that I usually use a brim, it helps spread the pressure out and prevents warping of the parts. Unless you have a closed build area and a heated bed, that might be your best choice.
The fix I have not seen suggested yet is washable glue stick. Put a thick layer over the tape, primarily in the corners. Also, just to make sure, you are printing with PLA right?
Hi, I kind of disagree with your comment on #1. I too have a large printer with an open frame. I have a Fusion3 F306 thatâs 306x306x306 and I donât have any issue with curling, even when printing at the edge of itâs capacity. The problem is most likely the design of the printer. I bet the heater isnât going all the way to the edge making the edge cooler than the middle. I used to have a MakerGear M2 and that was the problem with that printer⊠the edges of the platform wasnât being heated.
You didnât mention what kind of plastic you are using either. I print in PLA and donât use tape at all. I print directly on the glass with the bed set to 59 degrees C.
As for #2⊠you canât give a customer a print that is defective. Just donât accept orders that you donât have the proper equipment for. Stay with smaller prints and turn down the larger ones.
I highly recommend Elmers Glue Stick. My prints on an ultimaker stuck down so much I ruined the bed.
I also have a robo 3d printer that had a problem like this. I didnât want to use any adhesive as the bed isnât removable and therefor difficult to clean. Painters tape worked ok but then it did the same as you. My solution was to
(1) better insulate the back of my bed with thicker cork board and print with a thinwall like isometros said,
(2) Wipe down the bed with alcohol before every single print, no exceptions.
(3) adjust heat settings to minimum allowable conditions and
(4) Create some fan shrouds.
Now I print directly on the glass bed.
Reasoning behind these solutionsâŠ
(1) walls on the side and more insulation makes sure heat can only go up evenly from bed level. It also has the knock-on effect of insulating your electronics from your heat so they dont overheat.
(2) anything on the bed will reduce contact surface between the part and the bed. It doesnât sound like much but its a huge deal. You will be surprised at how much this increases bed adhesion.
(3) This is finicky. My recommendation is to be as close as possible to perfect but always on the side of too much heat. Too hot might mean a warped part but too cold means a jammed nozzle or possible loss of bed adhesion
(4) If your talking about uneven cooling your talking about airflow and You have a monster fan right next to your hotend is modifying the airflow around the part with every pass. Make sure air is going where you want it and isnât going where you dont.
Itâs not a defect of the printer, itâs a design flaw, as itâs missing a critical piece thatâs required⊠a properly heated bed. As I say, my M2 had a heated bed but it wasnât designed properly. My F306 has the heated bed but itâs properly designed, providing even heat across the entire bed surface, even at the edges. If your printer had a properly heated bed, you wouldnât need to use tape and the print wouldnât be lifing off the print surface. Itâs as simple as that. Of course, a well built printer costs more, the F306 being about $4000 and my dual head at $5000, but you can print commercial quality, no headaches. Just the fact that you are experiencing this and ask for solutions just shows the limitation of the printer itself.
PS. I stopped using alcohol and started using just water at the suggestion of my printer manufacturer. The alcohol leaves a residue on the glass. Switch to water⊠maybe it will help.
A heated bed will help a lot, as will using LĂłreal elnett hairspray (warning - you may have to immerse the build platform in water/alcohol mix for it to come off, so for most things I use âthe big red canâ from Big Lots) â I use binder clips and print on a removable glass plate instead of the Robo3D R1 bed so I can chuck it in a bucket if it doesnât want to budge (glass from Lowes since Home Depot wonât cut it). For tall prints, I print a shroud (brim of 999 layers) - the shroud destroys itself, but keeps the part intact.
The other thing that will help a lot is dialing the temperature as low as possible â my âbest resultsâ temp setting is 205 for PLA, but if Iâm printing something that tends to warp, I print at 200 (but that can make thick->thin not adhere as well â fix with superglue).
If you have a heated bed, the elnett works even better â heat the bed to 40c, print, then after printing, squirt it with âcanned air upside downâ and the thermal shock will make it pop right off (but will make your prints taste bitter!).
I have successfully printed 200mm width parts without any raising of the edges by disabling the fan for the first 3 solid layers.
I am using a heated bed and I also reduce the temperature after the first layer, so the first 3 layers have a lot of time to cool down and become rigid enough to counter any warping further up.
Also materiel can be a huge influence, for large Parts I like to use Colorfabb Ngen.
3d-eez (http://3d-eez.com/ 1) if you can get hold of some. Requires a heated bed, provides a reusable surface (30 prints an counting for me). Other than that make a box for your printer (if it has a heated bed this helps) to stop the rapid cool of your printed objects.
The only thing is My first print bonded so tightly I thought I was going to bend the build plate trying to remove, so I highly recommend covering with a thin layer of Elmerâs disappearing purple(havenât tried others).
Also I used to use ABS juice, but prefer the build plate 3m âglue plateâ
This company also sells an acrylic enclosure for like 7 bucks!
