blobby prints on TAZ6

The angle of support does exactly what you thought it did sorry for misunderstanding the issue on that! There are a few things you could try for your support that might help, if the trouble is just that it is only supporting the space underneath the model you can check to see if your “Support Placement” is currently set to “Touching Build Plate” and if it is try switching it to “Everywhere”. If, in addition to the supports not being present everywhere you need them, you are also concerned about the overall support structure not providing as much support as you need you can try changing the “Support Pattern”. The most reliable way to pick the best type of support for your model is going to be to open the model in Layer View in Cura so that you can see the adjustments you are making without having to fire off a print each time.

So it looks like Z-alignment “random” was actually a bad idea. It caused little blobs to appear randomly across the model. I think the solution to the problem is to try to locate the “seam” at the middle of the model where the cylinders intersect. I’m not sure how exactly to do that.

Regarding support, I tried using concentric instead of zig-zag. I think overall the result is worse.

You can select a specific area for the z seam by using the same set of options only choosing the “User Specified” option and calculating where you want it placed or you could try the “Seam Corner Preference” and select “Hide Seam” theoretically this will make it so the seam will be tucked in a less visible area as long as that is feasible for your model. For the support style I might give the grid option a shot. The best way to check if the supports are going to be effective in my opinion is to check them in layer view and see how they are sitting on the model before trying a test print. Usually if you can get a good adjustment of those supports in the layer view it will come out pretty well in the real world when printed.

It occurred to me that there’s no reason for there to be any seam in this model. The model is made from 6 semi-circles. Each one can be completed by starting at one end and finishing at the other one. Is there some way to force this behavior? Maybe “hide seams” would do it.

Regarding support, the support looked to me like it would work. I think I don’t really know what to look for. I suppose a potential issue with the concentric support is that it will work OK if the extrusion is perpendicular to the support lines, but it’s possible to get extrusion that runs parallel to the support. It looks like maybe the failed extrusions were actually curving along the edge of the model, so they would have missed the support. Is it possible to get support that extends a bit beyond the model?

In terms of forcing Cura to start each layer at a certain point there is an option in the travel settings for “Layer Start X” and “Layer Start Y” that say they will set a coordinate that your print will try to start each new layer near. That could theoretically help with that but it isn’t a setting I have personally used so I can’t offer much for assistance past that in terms of what you would want to set those numbers to, it would be kind of trial and error I think.
I might try a grid pattern for your support. I find this to be the most reliable in terms of a good solid surface to support more difficult to print items. In regards to having the support extend out past the model I haven’t found a settings that automatically cause the support to extend past the model. You may be able to find a way but it would involve adjusting support settings and seeing how things came out in layer view until you got something that looked like what you wanted.

I did another trial of the print. This one was slightly different as I also iterated the design a bit. The grid support was fantastic at producing a clean underside. But it was quite difficult to remove. I guess that’s a trade-off. The pictures of this color of PLA are harder to see:

Here’s the picture from the front. The finish is nice all around the outside and there seem to be seams on the inside on each cylinder. (In addition to being hard to see in photos it’s hard to see in person.) I saw the option for specifying the seam position, but there was no obvious way to figure out the X and Y positions of a location in the model, so I just put it back to the default (shortest distance, I think). I couldn’t find “Seam Corner Preference” in the menus anywhere. Where is it?


Overall I’d say this is a pretty successful result.

I have to say that one thing definitely bugs me about this: if you have to use the sdcard to print successfully then if you have the Lulzbot Mini you’re screwed—no sdcard slot. I have been pondering buying a printer for home use and my budget wouldn’t go beyond the Mini. (Maybe not even that far.)

I did notice a problem: I apparently weakened the attachment of part of the bottom rail when wrangling with the support structure, so it’s going to break off.

The Seam Corner Preference setting is directly below Z Seam Alignment in Cura 3.2.21.
Screenshot_2018-06-25_11-24-24.png
In regards to the SD card concern. I haven’t found that it is necessary to print using the SD card to avoid printing issues in most situation, usually only if the computer is in heavy use while printing or has not great computing power. The major benefit to the LCD screen in my mind is for especially long prints where you don’t want to worry about the computers sleep function or an automatic update interfering. With that being said I did want to let you know that we do have a LCD screen that can be added to our Mini printers and if you purchase a Mini 2 which we just released it comes with the LCD screen stock. Just as some stuff to keep in mind when you do have the money saved up.

We seem to have a pretty old Cura version: 2.6.52 is what I wrote down. I’ll have to see if I can get them to upgrade.

With the existing configuration, using a computer that is dedicated to the 3d printer and not doing anything else, I have found (as noted above) that it is essential to use the sdcard slot for a reliable print. But maybe upgrading Cura will help?

Using 2.6.52 could certainly have something to do with your difficulties. I know that one of the major changes in Cura 3.2.21 was that it processes and opens faster than Cura 2.6.69 which was the last stable version before 3.2.21. If possible I would definitely recommend updating to the most current version of Cura and see if that helps resolve your issues with buffering during the print. If you are able to update, one thing I want to mention is that you will want to make sure to completely remove Cura 2.6.52 as we have found that the Cura 2.x string of software can’t run concurrently with 3.2.21 on your computer. You will also want to make sure that you clear your computers cache to prevent those old files from causing confusion with the new software.