I would like to print a larger shelled part that would not require supports if printed with the top facing down. After it is printed, I want to flip it over and print raised letters on top of it in a different filament color. Doing it this way will eliminate the need for multiple color changes and the need for supports.
I plan to print an alignment jig on the printing table that stays on while removing the object that needs to flip over to ensure the part goes back into the correct location.
A sample model of what I’m trying to do is in the image below.
You are asking a lot of the printer because what you are trying to do is far outside the design intent. But when has that ever stopped us?
Here is how I might approach this. This is based on the fact that you are designing a jig and presumably that jig will be printed in place otherwise this suggestion does not work.
Create two models. one in one orientation the other 180 degrees in the X or Y axis.
Make sure your jig is part of the Assembly but before you go to print, deselect the jig. This will allows you to position the model inside the virtual screen before printing.
Note the models X-Y position and for the second model with the lettering, dial in that X-Y coordinate manually to match the previous model.
This can all be simplified to a small degree by using a small 1x1mm cube that is part of the assembly and serves as the anchor when slicing and positioning the model.
What is a shelled part?
I’d accept the color changes. I don’t thing there would be as many as you might envision.
Flipped over you a re still going to have color changes because the red is inset into the grey.
The text at the top is a single color change when it transitions from the red square’s top to the white text.
The only way you can really ditch the color changes at least at my level of printing knowledge would be to make two parts Part one being the red cube with text as one part and the base as a second part.
Like I say though, that is my solution at my skill level. Other folks way more skilled than me may offer better solutions.
The problem is that the printer can only print a single line level on the Z-Axis at a time. one level is completed, the bed drops one line level on the Z-axis. Any Z-axis containing multiple colors gets a color swap and filament purge until, in your case, you clear the two color line zone. That is why flipping it over won’t help. You still have multiple line levels that are two color. You can count how many color changes there are by scrolling from line 1 up through line X in the Preview tab in Studio.
@Wsquared58 A shelled part is a hollow part. In this case, it would be a hollow cube with 5 sides. Like a box with no lid. If I printed the cube in the orientation as shown, I would need a whole lot of support structures (more material/more print time). Imagine printing the cube shell upside down so no support was needed, then pause the print, flip the cube upside down, and then the final couple of layers would be the white letters on top. Only one material swap required and no support structures. The grey fixture in the picture can be made of the same material of the box. Its the jig that stays on the table when I flip the part to make sure the cube goes back into the exact location as before.
Rather than leaving the jig on the build plate and risking it getting hit when you try doing the 2nd part of the print I think I would do the following.
Print the first part
Arrange the second print as follows
a. A print of the alignment jig
b. A pause - to allow you to insert the first part into the jig
c. Resume and then print the final part
I think as a previous poster said you could design all 3 parts as one assembly, but then selectively hide and show the parts needed for the two prints.
This model isn’t quite what you are asking to do - but does have the 2 stage process with the pause and insert you would need.
The grey part is the alignment jig and would be made out of the same material as the cube and printed simultaneously. There is a .5mm gap between it and the cube. It’s chamfered on the inside to allow me to rock the cube out of place with out disturbing the jig, then it serves as a centering mechanism when the cube is flipped and placed back on the table.
When I try to make the cube not printable, it sends the text to the print table…
Always worth a try once. I’m already making it with flush text. But I’ve been asked to make it as raised text. The part I’m making already takes forever to print, and I don’t want to sacrifice the surface finish I get from the print table when printing with the top side down. I may just have to play around and dig into the g-code.
This is the sort of thing that the Prusa core / XL were bragging about “print on any flat surface” etc.
Bambu’s homing and startup are gonna be very problematic. I’d throw away the entire startup sequence and rely on manual gcode here.
You say you want a relief, I would recommend to make 2 copies of the text: One that you position on your larger part, that is a NEGATIVE part, and is sitting as a 0.4mm (or however much you like) deep cutout. Position this like you see the Benchy text on it’s underside. Then you can print the text seperately, at whatever appropriate height, and epoxy it into it’s cutout home.
Not something I have every tried and am not really experienced in 3D printing inovation but could you print the text seperatly and then attach it (super glue maybe)? edit (maybe make a recess of the test in the shell that the text would fit in but still be higher then surounding shell surface when in place?
Or could you print it upside down with the raised text but something like the equivalent of a brim around the letters that the rest could print on but have a wide(er layer) seperation between the psudo-support and the actual shell print layers?
Okay so that is better visualized.
Why do you want to go through all that?
You talk about supports causing the print to run longer and wasting material which is true, BUT…
You need to apply those time concerns thinking to the printing the jig base. There is time involved in that print too. If time is a consideration you have to count the time to print the jig, time to print the box, time to flip the box over, time to print the text.
Then as far as wasted filament, that jig is wasted filament.
Maybe print with the text flush. You will have the filament changes but but you can print the cube upright and avoid the supports.
I am printing a test with text facing the build plate right now. I have a project I want to do that I need to learn this process for, but using .svg’s
Here is my first pass using Bambu Studio’s “Add Primative” and “Add Text” options. I learned a few things and certainly can improve but in regards to your question it would save you a lot of work to do the text flush. That was with the text reversed/mirrored and against the build plate.
The reason is that I’d like an embossed logo on top of a box,.I’m not wanting the logo to be flush. That’s an easy solution, but it doesn’t get the end product I’m looking for. When using supports and printing on top of those, you do not get the nice finish you get when printing directly onto the textured plate. Regarding the waste of time and material, my box is relatively deep and large and using supports while printing open top down would be a huge increase in print time and materials (I plan to print 100’s of these). Printing a simple location jig would be much more efficient.
Ultimately, for the sake of getting this project moving along, I’ve printed the embossed logo separately and just superglued it in the location it needs to be. It’s not my preference, and takes extra steps and materials to do (much longer than just simply flipping a part in the machine mid-print) but it will do for now.
There is another option which has been mentioned already which is to pint the text debossed say 1mm deep and print just the text as a model with a Z thickness of 2mm and fit them into the debossed text and secure them with a drop of glue.
By debossing you can be assured that it is aligned and avoids looking like it rests on top.
You might be able to get away with doing a woodwork style inlay? I.e. print a small hollow for the text, then print the text separately and insert into the negative space. Either friction-fit or glue the letters in place. You do need the cavity though for positioning if nothing else - laying down separate letters on a completely flat surface would be a nightmare.
You cannot bypass the homing process, which will fail if there is something already on the plate. So, run another new print job on existing print is a no go.
You can probably cheat it by let the printer probes on the empty plate then pause and swap for the plate with setup jig/fixture on it, but alignment (both XYZ) for this is another sh*t show.
If you ever operate or program for CNC milling a part that requires cutting on both top and bottom surface, you will understand how much time consuming just to create fixture just to hold the part upside down with top side now is done with cutting.
I have tricked bambulab to try to start printing in midair by adding the base part, then adding a negative part of the exact same height (i just copied that part and changed its type to negative part). That way the text on top doesn’t want to “fall down” onto the plate in bambu studio and wants to start printing in mid air.
Then I needed another copy of the box part in the exact same position as before, this time without the negative part (and without the text on top, of course).
Like that i have achieved that my part can be ironed in straight lines without leaving non-ironed places for the first text-layer, because bambulab doesn’t know about the text on top. (I dont’ know if adhesion is worse like that though.)
I guess, that you could print your box to the exact same height plus the alignment jig, then pause, turn it around and place it there to be printed on top of. I would probably use magnets inside the box to hold it down firmly enough. And i would make sure that the text only starts at the exact layer after the box was finished.
However, if the surface finish is of concern, then i guess the woodwork style inlay is a great choice. You could either do this flush (cutout same height as letters) or raised (cutout shallower than letters) and have the plate surface on both the box and the letters: Maybe, (i havent tried it) you could even press the finished box onto the letters while they are on the board, so you don’t have to mess around with dozens of tiny parts, like the dot on “i” which isn’t connected to anything else.
I’m already making it with flush text. But I’ve been asked to make it as raised text. The part I’m making already takes forever to print, and I don’t want to sacrifice the surface finish I get from the print table when printing with the top side down. I may just have to play around and dig into the g-code.
