Print your own Microspringer
So now you want your own Microspringer ? Files were uploaded on YouMagine.
YouMagine lets you preview parts in 3D although scale is off.
You can also download the source Sketchup file for the Microspringer. Source SKP file might be easier to work with than STL files.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Choice of material : ABS
The Ultimaker II is designed to print mostly PLA or ABS. I've decided to use ABS because it can be "melted" with acetone.
I made the hull waterproof by brushing it with acetone. Some assembly (ABS on ABS) was also done that way.
PLA is a bit easier to print than ABS (less retraction/warping) but would probably require some sealer to make it watertight. Some RC boat designs on YouMagine or Thingiverse suggest liquid polyester filler for PLA. But I can't vouch for this.
Toughen up, buttercup. You'll have to make your own choice ! :)
Files - Overview
Parts overview
Everything was designed in SketchUp. The hull itself is actually multiple components which means there's some "processing" to be done before exporting everything.
Typically it involves "merging" multiple components (using the binary operation tool "outer shell") into a single solid.
The keel/stuffing box for example is separate part (which I find easier to modifiy/move/adjust) from the hull. Same with the motor mount although in the end they are merge into the hull.
Models need to be scaled down 1:10 as SketchUp isn't good at handling small objects (extrusions can leave you with holes in your model). I suggest you do the scaling down in your slicer.
I tend to shy away from "complex prints" and choose to split complex parts into sub-assemblies which are assembled once printed. You may want to go a different way.
Everything was designed around the components (motor, servo ...) I intended to use (see the bill of materials). If you choose to go with different components, make sure they will fit or make the required tweaks.
Files - Printing and assembly notes
First take a look at the build log to get an overall view.
Before assembling parts you may want to sand them to get a better surface finish. Sanding individual parts is usually easier than when everything is glued together.
hull - 100% infill
Cura generated a lot of support which was a pain in the a** to remove. Lots of cleaunup and sanding.
Stuffing tube (a simple piece of OD 3mm/ID 2.1mm brass tubing) was sanded, brushed with acetone and then "hammered" in the hull. The melted ABS acted as glue on the sanded brass and no extra glue was required.
deck - 100% infill
There are holes for three double bollards. They're easy to move around if you want to have the bollards elsewere. I suggested you also print an extra piece of ABS to strengthen the deck around the bollards especially if you intend to actually use them for towing/pushing.
I suggest you install the motor and everything before gluing the deck to the hull. While everything is still reachable once model is complete, it is easier to work on the "open" hull.
I used methyl-methacrylate adhesive to bond the deck onto the hull. It also acts as filler. But you have to be quite quick as pot life is around 5 minutes. I then brushed the hull/deck seam with acetone to melt/weld everything.
push_knee - 10-20% infill
You need to print two of these. Infill can be on the lower side.
Sand them before you bond them to the hull/deck. I "acetone-welded" them in place.
rudder - 100% infill
A simple rectangular cuboid with a channel to fit a 2mm rod. Part is sanded to a streamlined profile after printing.
Stick a piece of 2mm steel rod in the hole/channel with CA and you're done.
rudder_horn - 100% infill
This part is to be seated/glued to a 6mm/2.1mm collar. You might have to tweak it or design your own.
superstructure_base, rear_cover, wheelhouse - 100% infill
I've decided to break down the "superstructure" into multiple parts as I didn't want to get into a complex single print.
Look at the general schematics above to understand how everything fits together.
When modding stuff, make everything as light as possible.
wheelhouse_roof - 100% infill
Roof is removable on mine so that I can access the wire salad for the nav lights.
exhaust - infill 10-20%
Could probably be printed with rear_cover. I "acetone-welded" it in place.
double_bollard - 100% infill
I printed them (x3) laying flat. Legs are hollow. I cleaned them up with a 1mm drill bit and then CAed small pieces of 1mm piano wire to stiffen them. I then used methyl-methacrylate glue to secure them on to the deck.
Not shown : extra transverse beam
I printed and added an extra beam under the deck, see build log entry 2014-12-13. Not really needed though.
Non-3D printed stuff
Handrails were made from brass (1mm or 1.5mm) and are held in place either with CA or methyl-methacrylate adhesive.