Create an internal hole within a wall for nut inserts


18650 x 10.skp (396.0 KB)

I am making up a battery holder for 18650 cells to run with a battery tester to check cells before use in another project. I have tried to do this in tinkerCAD and that was relatively easy, just create a shape and click the ‘Hole’ button and the shape becomes a hole which can then be embedded and grouped within the wall. See the box end example file , after I have exported from tinkerCAD and imported in to SU.

Box end example with holes.skp (152.9 KB)

The idea is to solder two nuts together with a 2mm conductor, to make the bridge for the battery connection. Pause the print half way through, drop the assembled nuts and conductors in to the half finished print, and then continue the print. This method does work, I have already tried it making plastic 'enclosure ’ for Vero Board plugs with PCB riser headers.

Just wondering how to achieve thee internal holes with SU

I have '‘push/pulled’ the round holes through the walls, but can’t work out how to embed the hexagon slot and the interconnecting channel.

is there a simple ‘Make solid object a hole’ command as in tinkerCAD? I can’t find it…have been reading lots of threads about making holes using push/pull, but can’t work out how to embed the hole within a wall. Tried to push a hole in to the wall, then re create the wall, but can’t get that to work either.

I’ll keep reading around this and see what else i can find, but after two days of ‘tinkering with this’ not come up with anything myself.

My experience with ANY CAD is:
None up until 2 weeks ago,
Played with TinkerCAD on line, Fusion360 (Could not even draw a solid box! ) and now SU.


It looks to me as if you’re almost there.

You can draw a line across the top face of the box where the hex nut is to go and then use the Move tool to move the corners down.

There are staggered faces in the model. Are they supposed to be that way?


Ahh , no , I see what you are thinking, but no…the flat tops are intentional.

This is for a 3D Print, so the tops there need to be flat. when the print is stopped half way through the nuts need to be dropped inside the 'slots NOT protruding . If they protrude then they will interfere with the extruder head. Probably need to actually make the interconnecting channel taller in fact, maybe up to the top of the flat tops.

I was hoping someone could tell me how to do this all from within SU as opposed to doing it from tinkerCAD


Staggered faces…, If I understand you correctly, then yes. The round ‘tube’ hole is the hole for the bolt sticking through the sides of the box, Two nuts connected to each other by a piece of drilled and soldered 2mm copper wire.


I was busy drawing up what I thought you were after and got the tops wrong. Easy fix, though. Otherwise, is this kind of what you’re after?

I redrew the thing from scratch, which I was going to suggest anyway. I made the bit in green to put in the walls of the box and then deleted the skinning over the holes. Obviously you’d leave the tops flat instead.

Flat tops:

Does this look right? Maybe you don’t need the holes on the outside, though.


Hi yes,
so you are creating the green linking ‘hole’ and then 'placing it within the box?
How to you make the object a 'hole"

Yes, this is about right.

I have since done another one in tinkerCAD, attached.

Yes the holes do need to go through to the outside. These 18650 cells, are protected or un protected, the protected types have small PCB built in into the end of the cell, So 18650 cells can range from 65mm long, all the way up to about 70 mm long.
So these inserts in the box will have short setscrews in from the outside, to screw in to make contact with the cell.

18650x10.skp (647.2 KB)

There will also be a wire from each tab going to a voltage monitor PCB, so while discharging the 10 cells all wired in series, the PCB sends data to a data logger monitoring the voltage of each cell.

Previous boxes I have bought like this , have cheap and nasty springs and never take the current levels I discharge the cells at. I have a wooden construction at the moment, just fancied making it a bit neater


How do you get the X-Ray style view?
Cant find it in the menu system, what is it called


Yes. I drew it with the back faces out. The green is my style’s back face. I made the “hole” a component to make it easier to handle. The ends of the cylinders on either side coincide with the inner and outer surfaces of the box. After placing them inside the box walls, I exploded them and then deleted the faces skinning the holes.

X-ray is a face style. See View>Face Styles. I didn’t use X-ray, though, because I didn’t want my hole component to be transparent. I painted a transparent material onto the faces of the box.

I would suggest you abandon TinkerCAD if you’re going to work in SketchUp. Your model needs a lot of help before it’s even close to ready for printing. There’s a lot of garbage geometry that needs cleaning.

To be printable, you’ll need to make a component or group of the geometry and SketchUp needs to show the component or group as solid.

New to 3D printing and SU. why does this not work. MakerBot Rep2

Ah…I did not actually there was a style called "X-Ray’ that was just my terminology!

Paining a transparent material…ah…clever…

Yes, I am just in the process of deleting a lot of those extra lines TinkerCAD created.

Was just wondering how to ‘get inside’ to clear up the internal extras…

Yes. I drew it with the back faces out.

Not sure I get what you mean there, but will have another go…


I think it would be easier to make the model correctly if you just draw it from scratch in SketchUp.

SketchUp is a surface modeler. Faces have no thickness and they have a front and a back. In the style you’re using, the back face color is a blue-gray. It’s the color painted on the cylinders in the style thumbnails. You need to make sure all exposed faces including those you’re see if you were inside the voids you’re creating are white-front side out.


Umm, yes, this is why I went with TinkerCAD…it is all a lot more self explanatory, being that much simpler. A lot of these concepts are not really able to be expressed in text like this and even the on line tutorials I have found so far never quite get it across as well as one to one type learning …wher you can ask and exact question ,a and have it demonstrated…

I thing kI might have an glimmer of what you mean by 'Back Faces out…so create a model 'backwards…OK. yes, in typing this ,.a light has come on …cheers

will try now.

another coffee. … I suppose once you get the hang of this sort of stuff it is easy…but learning process…I could have made this box out of thin steel and tog’ed it up buy now…been login this for …2 -3 days !


Maybe a demonstration with your model would be useful. I can’t do it right now but maybe later today or tomorrow I could.


I’ll have a play now creating the ‘hole’ section and see if I can get it to turn out something like yours

Trying to work out how to create a hexagon of a specific dimension across the flats…at moment…it only shows the 'inscribed radius…where as I need the AF measurement 9mm or there about


Start drawing the hexagon and hit Option to switch to circumscribed. Pay attention to the bottom left of the screen. There’s information about modifier keys being presented as you use the tools.


Oh ■■■■ this is bloody difficult… can’t even create the cylinder and the hexagon “cylinder” and make them ‘join’ in to a single item

tried different methods, creating a flat surface with a circle on it and pushing / pulling the surfaces…but then you need to pull one side toward you and push the other side away…then end up with a hexagon with a hole one side and a tube sticking out the other.

creating two separate solid objects and Moving one on top of the other.
drawing circles on a solid 'hexagon, so many variations…some time I can get a reference to drag the items to infer, some times now…seems totally random as it 'grabs a reference "


suddenly came together
…I think

any issues with this?Box with ‘holes’.skp (148.7 KB)

Just cannot place the holes inside the box though. Tried various methods of dragging them around, adding guides etc but not getting anything to ‘stick’ and infer correctly to line up


I told you, I’d be happy to show you how to do this.


I’m not sure this is what you want but I thought I’d take a shot.

Box with ‘holes’ ss (1).skp (156.4 KB)



I know, and that is appreciated…but I am not one to give up , if there is any chance of getting my head around it myself.

I was considering trying with a Wacom tablet, but have seen your posts about it elsewhere, (another forum?)
I think I may be having mouse issues too, have a wireless Mac scroll ball type mouse, a Button Free (Magic Mouse, and a little portable laptop scroll wheel mouse with retractable cable… The cheap Belkin retractable cable type mouse is probably the best…
Always thought Mac was supposed to be a designer friendly computer…but so far…any Mac mice are useless for SU.


Thanks Shep, playing with your file now,…cheers

What are the 'extra ’ components you created with the vertical bars…are they ‘helpers’ to help with alignment ?