johnse

Check the Support Horizontal Expansion. for both of these I suspect you can set it to zero.

I don’t know if you figured this out, but it seems the easiest thing to do would be to create one file. Add a pause-at-z command (I think you do that with a gcode post processing script) at the layer where the jig finishes (assuming the top of the jig is flush with the top of the plate. At the pause, add the plate, change the filament, and continue.

I would add to what @Smithy says: when you print the test parts with holes/slots in them, make sure they are 2-4mm thick. If there’s any elephants foot going on, the first layer or two will be significantly smaller than the rest of the hole. This can be easily remedied with a craft knife after printing,

The UM3 moves print core 2 up and down so that only the core currently being used is at the level of the layer being printed. When core 1 is printing, core 2 is retracted. When core 2 is printing it is lower than core 1, effectively retracting core 1. so, no, dual material printing doesn’t need the z-hop.

The slice you’ve shown is going to have problems with the bottom curve. It looks like you have generate support touching buildplate instead of everywhere. The upper arch may build ok with bridging, but the bottom of the circle will be literally printing on air generating spaghetti.

That looks to me like the support is not creating an interface layer. Try the setting: Enable Support Interface. A description I found on Reddit: "Generate a dense interface between the model and the support. This will create a skin at the top of the support on which the model is printed and at the bottom of the support, where it rests on the model." This will greatly improve the quality of the part's surface.

Your choice of the Black Widow, having the direct extruder is a good one. I found a video showing the assembly instructions for the Black Widow Extruder. It looks like the filament path is pretty well constrained in that there appears to be a wedge snugged up to the gear and follower wheel. It looks like the extruder is completely different in style from the Tarantula, so the mods above wouldn't work at all. Good luck experimenting. I can recommend the Flexion extruder.

In Fusion 360, that would be a "Combine" operation. I expect FreeCAD has a similar operation. Looks like it is the "Part Union" command: https://www.freecadweb.org/wiki/Part_Union

I think you are experiencing a common problem with soft filaments. The filament path from the extruder gear to the hot end needs to be fully constrained or the filament will tend to buckle and jam. When you increased layer height, it’s needing to feed material faster, at higher pressure...increasing likelihood of a jam. you may be able to modify your extrude similar to this mod https://www.thingiverse.com/thing:2668711 That's for the tarantula, you’d need to modify it for your printer. you could also upgrade your extruder. I have the Flexion extruder, and there are plans online for both single and dual versions. Single is here: https://www.thingiverse.com/thing:2060966 I have heard good things about the bondtech BMG, but have no experience with it.

I haven’t tried printing TPU with support. I modified my other printer to print ashore 60A TPE, but it’s a single extruder. I’ve been using PVA and Breakaway with PLA and Tough PLA. Are you letting the PVA fully dissolve? Or are you being impatient (like me) and trying to remove it early? I see four kinds of interfaces: the underside of the angled pieces, the tops of the lower angled pieces, the bottom of the top, and the top of the base. Is the support material providing interface floors an ceilings? Or is the TPU bridging across sparse support? Which of these are giving you problems? Perhaps some pictures of the finished part may help? You may be able to minimize the affected areas by designing your own support. For example, you could eliminate top-surface contact by building columns from the base plate on either side of the lower angled parts and then bridging to provide the support for the upper ones. Similar for the top part. Also, where you have room, you can use slopes to connect the support columns where you have enough vertical space. you may also only need to support the angles for a few mm on either side of each hinge.

I have found the easiest way to move objects is by using the arrows. Move the mouse until the arrow becomes a lighter color and then click and drag. It doesn’t always seem like you’re clicking right on the arrow, but if it’s highlighted, it will work. Also works the same with rotation and scaling.

You could also model it as a solid cylinder and then tell it to use a single wall, 0% infill, and 0 top layers (and 0 bottom if that is open too.

You might have better luck using either PVA (dissolves in water) or Breakaway. Then again, the angles look like you may only need support to keep things from sagging at the hinges. You may be able to design minimal supports into your model and thus minimize the contact areas.

Do a search in the forums for Sketchup and watertight. STL files are just a bunch of triangles...there’s no concept of shapes, cylinders, spheres, etc. Apparently the STL files generated by Sketchup are not watertight and/or have other problems. you may be able to fix them with the MeshTools, but it would be worth your while to learn a better tool to create models.

Others here have said that Sketchup tends to cause problems. Blender should be useful, and there is a thread here Fusion 360 (free for student or “startup” use...startup license can be renewed every year) can also be used. To load an STL in Fusion, first upload it via the Data Panel.

Monoprice doesn’t make the printers they sell. My Monoprice Ultimate is really a Wanhao Duplicator 6. It looks like the mini is a Malayan M200 which has a printer definition in (later versions of) Cura. There’s a pretty extensive Wiki for your printer at https://www.mpselectmini.com/slicers/cura Welcome to the community, have fun, and listen to @gr5 😊

The red on the rop of the ring shows at least part of the problem. cura is thinking it needs to support the top of the arch. Normally support should only show on bottom surfaces. I suspect this means the normals of the mesh are reversed. look in the marketplace for Mesh Tools. Others can likely give give more explicit directions.

The bed heats more slowly than the hot end, so it heats first...can take several minutes. if you mean the bed gets up to temp bit the head never heats...I don’t know.

I’ll echo what @gr5 said: design inner holes with a diameter approximately 0.4mm larger. For example, I am attaching PLA and/or Tough PLA to acrylic sheet cut on my Glowforge with M3 screws. I design in Fusion 360 with diameter 2.8 to account for 0.2mm kerf from the laser and 3.4mm in the PLA part. This is usually a snug fit. I could probably go to 3.5 if I wanted the bolt to slide easily. In general, if I want a printed part to slide inside another, I will design about 0.2mm clearance for a smooth sliding join. If I want a tight fit I might use 0.15mm. most of these parts are under 40mm in longest dimension. Many much smaller. All of these dimensions came from trial and error. Also, first layer squish will make the hole smaller there. Do test measurements on a hole opening further from the bed. It’s easy to open the first layer up to match the rest with a small knife. I’m using 0.4mm nozzle with 0.1 layer height. i do notice that horizontal holes in vertical walls tend to be about 0.1 mm larger than the vertical holes.

Congratulations!! I am glad you got it figured out.

Hi @rich080487, those aren’t strings, they are “antennae”. Whereas strings are material sticking to the just-printed object as the head travels to the next, these are formed as the head completes travel to the new part. A small drop is hanging from the nozzle and attaches to the outside of the prior layer. Next layer, the drop hits that previous drop, and so on. This is why they grow up and away from the part. Temperature doesn’t affect these much. I think retraction may be the thing to focus on.

This video talks about a kind of similar sound, maybe, of an Ultimaker clone. I don’t know if it might apply here.

If you can post a .3mf Cura project file it will be easier to help.

As @gr5 mentioned earlier in the thread, you may want to turn off combing. This is what leaves lines during the fast travels between the circles because it doesn’t retract during those moves. There’s also a minimum travel distance before retract

I print a lot of 3mm holes on my UM3. 0.4 mm nozzle and line width, typically 0.1 mm layer height. In Fusion 360 I specify these as 3.4mm holes. This has worked well for me with PLA, Tough PLA and Ultimaker Nylon. In nylon the holes are just slightly smaller. The holes adhere just fine.