Hi all.
I have designed this and 3d printed it.
But the upright part is sitting on top of the base and so is a very weak joint.
How do I design the model so that the printer starts printing the up rights inside the base for a stronger fix.
I have designed this and 3d printed it.
But the upright part is sitting on top of the base and so is a very weak joint.
How do I design the model so that the printer starts printing the up rights inside the base for a stronger fix.
It’s so dark it’s hard to see what you’ve got going on. It would help if you share the .skp file. I suspect this isn’t really a SketchUp thing anyway. SketchUp doesn’t control the way the printer adds features. Maybe you need to rotate the part for printing.
Sounds like an interesting design problem but, as @DaveR mentioned, your picture makes it impossible to tell what is happening.
Should the thing be modelled in two parts, the base with holes and the upright with pegs that fit in?
3D printing is inherently weak in areas like this. It is only as strong as the adhesion between the smallest of layers. Even as a solid block this joint would be weak. A hole and pin might work a bit better as it would print some wall thickness to create both parts, but still as weak as the weakest layer in the pin. Changing the print direction so the layers don’t run horizontally through the joint would help, but may be impossible for the shape.
Personally I would either completely redesign the thing, but not being able to see it properly limits the suggests there, or print it as two parts both with a corresponding hole and insert a wooden dowel or other appropriate strengthener.
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Boat Stand.skp (2.5 MB)
HI guys,
Sorry about delay in replying. Been busy, Thanks for replying.
Im no expert on Sketch up, but love using it to make things for my models. Im not printing the sign at the same time as rest of the stand, so please ignore that.
The issue I`m having is the 2 upright bits. They are rather fragile as they are only sitting on top of the base unit. I thought I have seen in the training videos, in the past, on here where you can mould 2 parts together to get a strong fix.
I have drag down the base of the uprights, so that they are inside base unit. But when printing it does not look like like its printing as a solid object.
Really hard to explained. Sorry
Anssi the part was design to be 2 parts to start with, but I thought I would get a better fix if it was one peace. Could make it two parts no problem but would like to learn if I could make a strong join using sketchup.
If I was to make the parts inside the base unit a different shape would that make the 3d print start printing inside the base unit?
If all else fails then I will make then as 2 parts and use dowels to put in together.
Thanks again for replying. 
That won’t change the printing unless you print the parts separately and then you’ll need to provide some sort of joints to connect the parts.
How about something along these lines. I haven’t added the posts on top yet. The holes in the bottom of the uprights are to receive barbed threaded inserts. The holes are centered on the rounded bit at the ends of the base but they could be moved toward the center a bit to give a thicker wall on the upright.
You’ll probably want to rework the base anyway. There’s some weird geometry there.
Edited to add:
Here’s a different view. I moved the holes inward a bit and fillets added.
I’d also consider doing something more than the name plate to tie the uprights together at the top.
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Thinking about your boat stand when I should be doing real work. 
Maybe brass rod spreaders between the uprights? Knurl the ends and use cyanoacrylate to secure them into the uprights. The name plate could be mounted on the front spreader.
I think the upright could be refined further. How much does the model flat top weigh?
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More play while I eat my lunch. Uprights in two halves glued together. The ends of the horizontal arms need something.
Probably drifting away from what you want, though.
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Hi Dave,
Thank you so much for your in put and time you took re doing the design. Hope you did not get in trouble.
Was not really expecting such help so I have superglued the broken bits back together.
Really like your end result will look good into doing that one when it breaks again.
Attached is a photo of the model that sits on it. The one that came with the kit was boring. 
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Hi Box,
Thanks for you reply.
I have superglued the broken bits back together for now, but will remake the stand in 2 parts and use dowels as anchors next time it breaks.
Will need to do some research on the 3d printing side. There must be a command somewhere that tells the printer that that join needs to be solid.
@DaveR has kindly not mentioned what a mess your model is. Your model is all raw geometry with multiple internal faces. You need to get a handle on that and understand what solids are.
Burying the upright down into the base is really just confusing things, even for the printer.
The whole shape, or at least the individual parts, need to be continuous ‘skins’. A manifold solid, a watertight shape. You have all these internal faces that are not helping in any way.
If the stand was modeled as one single ‘solid’ then the printer would print that joint as part of the whole solid. But you must remember that the very nature of 3d printing still makes that a weak point, because the layer at that point has a small surface area. If the object was printed at a 45 deg angle that point would be stronger because the layers would be running diagonally though the joint.
3d printing, at least the home version, isn’t the be all and end all that people think. It takes quite some understanding to put together the right design, print angle, printer settings, material etc to get a good strong object.
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Dave’s given you some great options, I’ll just throw this in as another thought.
You can use a threaded fixing quite well with 3d printing. If you print a hole smaller than the screw/bolt you can screw it in and it will tap its own thread. The hole also gets walls so it is stronger than a plain honeycomb. It also doesn’t need a nut on the end and it can be undone if you want to disassemble it or replace just one part. You can see in this vid how I have created a section that fits into the other section, this could be a simple friction fit, might take a bit of trial and error to get right, or a bit of sanding. All of these extra faces add strength to the connection and the threaded fastener reduces the risk of it snapping at the weakest point.
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Out of curiosity I sliced your model in CURA and seems like it interpreted the model as having a void in that area, hence why is not printing as a solid or adding infill, if you added supports then you have some filament there but not really strong.
Yes, but they need to be independent with a small gap between them (not touching in any way) and you’ll likely need to enable supports in the slicer so the floating upright has a base to print on, I won’t do it for this design, though.
For this specific model you are creating, is best to follow the advise already given.
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Thanks again for advice.
Still learning how to use Sketchup and any advice I`m getting is helping me learn more.
All the little bits I have done in the past have been flat peaces and had no trouble printing. First time trying out a more detailed object.
Yes I know now there are lots wrong with the design. But I would not know what they are if I had not asked you guys.
To me the idea looked good. And the end printed result was what I wanted. Putting a side the weak joints.
Nobody is commenting on the look of it, simply pointing out modelling issues. The design itself is irrelevant in the this case.
If you posted asking for a critique of the aesthetics of the design then that would be something else.
Zitat : " Im not printing the sign at the same time as rest of the stand, so please ignore that.
But when printing it does not look like like its printing as a solid object.
Really hard to explained.
Sorry "
Ja , wirklich schade, denn bezüglich Schild wäre ziemlich klar was falsch ist: die Schrift ist mit der Platte nicht verschnitten und kann so auch nicht richtig verschnitten werden, weil sie nicht weit genug in die Grundplatte hineinragt.
Sorry. Did not mean to make that sound like a negative comment. Thanks for your asvice.
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