19 May 2021

Fall Back And Punt

As predicted by Ratus...

The test print got tippy and fell over about as soon as the head started the warhead portion.

So I've redrawn it in segments and we're going to try again as soon as JT wakes up in the morning...

OK, maybe not that early, but as soon as he can get around to it.


  1. It wasn't that risky of a prediction, when you are printing on a FDM machine you have to take into account how you part oriented and the surface area that is in contact with the print surface.

    With supports enabled it might have actually finished, but would probably have taken a lot longer to print.

    I'd suggest that you install the same slicer, most are free and open source, as JT and see what it looks like in the layer preview.

    Also, if you have any questions, let me know and I'll try to answer/help like I'm doing with SiG.

    1. We're so very new at this and all my previous experience is removing not adding material.

      I've broken it into more parts now, which will allow us to make them with the widest part down.

      We learn by doing.

      JT says it's fine until it starts the rear cone then the drag of the material pulls it over, but the entire tail is stable enough until then, so we should be OK.

    2. Just had a look at the new split model.

      I'd say you should have the fins at the top with a 3-6mm outside brim should be fine, maybe a bit of PVA gluestick on the bed for insurance.

      Otherwise, I think the other large parts should be fine with a 2-3mm outside brim.

      I look forward to seeing the complete print.

      I'd love to have a copy of the stl files.

  2. I've seen one guy at the Hacker Space (coop builder space) print some parts with sort of like sprues to hold it up that he then cut off the part once it was finished. Uses more material, but maybe an easy way to make a part more stable while printing. I've found 3D printing fascinating, but haven't gotten into it yet. Another cool thing I've seen people do is printing a part in a beeswax kind of material and then using that for lost wax casting with aluminum or brass. I love these kinds of DIY projects.

    1. Those "sprues" are called support material. There's a bunch of different types of supports, as you understood, they do use a bit of material depending on settings. But the biggest thing that they do is add a lot of time to your print, anywhere from 30-50% more than without supports and post-processing time needed to remove and sand where the support was.

      Also, there are some special casting filaments, do a search for "lostPLA casting" it's the same technique but with regular inexpensive PLA filament.

      As for getting into 3d printing, the main slicer softwares are free and open source, STL files are plentiful on Thingiverse and the Prusa equivalent site.

      Just install a slicer and use the preview mode to see how it would print, play with the settings see how it affects the estimated print time.

      If you want to do some basic 3d modeling, TinkekCAD is a free browser based app that you can export STL files from.

    2. Unfortunately it appears that TinkerCAD doesn't run on the right platform but it looks like there are a number of alternatives like FreeCAD. I haven't really done anything with CAD in years. Back in the 1990s I did a lot of development for AutoCAD R12 and R13.


You are a guest here when you comment. This is my soapbox, not yours. Be polite. Inappropriate comments will be deleted without mention. Amnesty period is expired.

Do not go off on a tangent, stay with the topic of the post. If I can't tell what your point is in the first couple of sentences I'm flushing it.

If you're trying to comment anonymously: Sign your work. Try this link for an explanation: https://mcthag.blogspot.com/2023/04/lots-of-new-readers.html

Anonymous comments must pass a higher bar than others. Repeat offenders must pass an even higher bar.

If you can't comprehend this, don't comment; because I'm going to moderate and mock you for wasting your time.