Hexapod

Just testing the limit on how many components you can include in a 3D preview from Autodesk 360. Quite a few apearently. The explode view function is intresting.

Recycling PLA from 3D prints

Jens Dyvik and Jon Nordby did some research and experimenting on recycling 3D print waste, aswell as combining plastic and wood waste.

Upper plate: Grinded PLA.

Left plate: PLA and valchromat combined.

Rigth box: the burnt and failed results of valchromat combined with PLA.

The plastic was grinded using a household mixmaster.

This block is pure PLA casted in a box, then put under pressure by the means of vices.

This however, is the result of a failed batch of PLA and valchromat: 

Evacuating the oven from TorbjørnNordvik on Vimeo.

oven made from a trashcan!

Our casting oven is now operational! 

Made from a trashcan, it is not pretty, but is does wok very well!

Bronze casting oven from TorbjørnNordvik on Vimeo.

Milling steel on the shopbot

The OCD tingler! As we were doing some exeriments with cutting steel on the shopbot, we made this:

A binary dice made of steel, with some brass gears put inside before welded shut. The dice measures 50 x 50 x 50, and weighs in at 320 G. We cut the steel with casemaker pattern at 10mm/sek with a three flute 6mm bit, 1,5 mm at each pass.

The pieces where welded together at 50 amp with our TIG welder.

PP plastic

I milled som PP plastic with the shopbot today, ran a 6mm singleflute at 18000 RPM 35mm/sek with 8mm pass depth.

The chip formation was good, and the surface quality turned out great!

More welding with jigs!

After learning to make jigs with the CNC, this artist then welded his piece together in the jig.

Welding large, but acurate structures becomes easy when you use a jig.

This jig was made from scrap materials.

It is important to ensure that your workpiece is properly grounded when welding. This connection is done wia this clamp, wich is connected to the welding machine.

Antenna for drone

Made the mounting ring for this antenna for a client today, as we milled it from a soft alloy of aluminium, we churned this out at 12mm/sek 4mm cut depth with a 6mm bit.

Making A wax seal

Christina lewis came up with the idea of making her logo into a wax seal. Challenge accepted! So today, i milled the logo itself from a block of aluminium, going slow at 6mm/sek with a 2mm singleflute bit @ 18000 RPM, the handle will be made later from some wood.

we started out with a simplified vector file, wich we then made toolpaths from in Vcarve, the program which writes code to the CNC machine.

The machining process is loud, and draws attention!

The finnished seal:

The end result:

Wrenches

Tired of the cheap looking steel wrences that came with the shopbot?

Just download these awesome tools!

DXF, SVG, STEP and STL files for this project is downloadable for free through this thingiverse site.

You can download the Fusion files Including toolpaths through the 3D preview by clicing on the autodesk logo in the left lower corner. The toolpaths is currently not up to date, some of them is also missing.

replicating viking jewelry

This piece were found hundreds of years ago, but made long before that, in year 900. The piece were digitized using a 3D scanner. The scan where then split in rhino, and the respective sides where then milled in wax, and fitting boxes for the sand mold where made.

The first step of a sand cast is to make the sand fine, you want no lumps in your mold! Here Jens Dyvik from Fellesverkstedet is preparing the mold.

This is one of the sides of the mold, together with the tools we will use to pack it with sand.

We left the tabs from the milling process of the mold frames, so that the sand will hold the mold better.

The first layer of sand is the most critical, so we powder the sand realy fine to catch all the details.

The sand must be packet realy hard. The blunt end of a hammer works just fine.

The two sides of a sand mold, complete with inlett and air wents.

for registration, we use 6mm dowels, normaly used in carpentry. We use a triangle pattern for registration, so there is no option to mount the molds together wrong.

Once the molds where ready, it was time to prepeare the metal, in this case salvaged from old harddrive cases.

We used the electric furnace to the rigth to heat the metal to 700 degres celcius.

here the metal has been poured. the sand contains quite a bit of oil to make it hold the pattern. This oil lets of some nasty fumes, so we use our fume extractor until the part has cooled, and is ready to be removed from the mould.

This is the part straigth out of the mold:

This clip shows me revealing the cast piece:

jon Nordby noticed that the dents left in the surface of the cast, coresponded with these dark marks in the sand. We beieve these are made by gas trapped in the mold, and that the issue can be corrected by making more went holes.

The finnished piece. Now, the process will be repeated, with silver instead of aluminium, to complete the job.

Manual work

We love our fancy computer controlled machines at our fablabs. But, sometimes we have to dust of the old manual mills and lathes to either produce an entire part, or do finishing operations on a Previously CNC´ ed part.

yesterday i used bitraf´s machinery to do finishing operations on parts for my hexapod. also, i tried fusion 360´s adaptive clearing strategy on aluminium for the first time. i am happy with the results.

Always start with a clean machine! Even a tiny chip clamped between the vice and part will mar the surface of your part, and throw it out of alignment!

This machine needed a good round of brushing, vacuuming and oil before the work could start.

Having machined these two parts from one side on our shopbot, i had to manualy machine and thread the holes and mill recesess for screwholes.

The `affected` areas is marked in red on this screenshot:

As the parts where odly shaped, i used parralel blocks to be sure they where properl clamped in the vice, and at the rigth heigth.

Having measured and marked my parts, i put in centerholes to aling the drillhead.

Here i put in a 2,5 MM hole, prepearing the part to take a M3 thread.

I ran this bit @ 2500 RPM without coolant.

It was necesary to drill through the first feature with the 2,5bit, to reach down into the part.

To alow an M3 capscrew to enter into the part, i milled a recess with a 5,5mm endmill, then bored it with a 6mm drillbit. Following that, i knocked of the edge using a countersink.

This one has three flutes, and are typicaly best used at RPM´s not exeeding 500.

Here the parts has been flipped in the vice.

Left to the drillbit, the holes from the previous operations is visible.

To rigth, near the end of the parts, there is wisible remains of the tabs from the CNC operation. They where a bit execesive, but they will not be visible, so i will not remove them.

This milling machine is very easy to operate, with only a few switches to operate. it also doubles as a drillpress, leaving more space for other machines in the worksop. with simple mahines like this, it is advised to not change gear while it is running, as that will ruin the gearbox.

Milling a recess with a two-flute endmil. This one measured 5mm. I had to run this slow at 400 RPM, to keep vibrations down.

Tapping a hole for M3. The oversized hole i am sticking the threading tool throgh, will let the screwhead sit flush in the part.

Here is the finished part, ready to be installed into the robot.

The tools used for these operations. The next pictures shows operations on another part.

Had to turn down some M4 screws to atach the freshly manufactured parts to the robot. Having a small metal lathe in the lab is very usefull!

This is the sensor assebly for my hexapod. it will move just like a animatronic eye, alowing the operator of the machine to navigate independent of the direction of the main body.

Yesterday i milled the yellow big ring on the shopbot, it requires CNC machinig from four sides, so this is a proper test of the shopbot.

The first test of fusion code in aluminium.

1mm each pass at 8mm/sek with a singleflute 6mm carbide endmill.

Here the part has been machined from both sides, cut loose and ready for turning.

when cutting the outher diameter of the ring on the shopbot, i ran it at 8mm/sek, an a depth of 5mm with the same bit as previous operations.

This was way to deep, and so it resulted in chatter and chip weldig. therefore, i touched up the surface in the lathe.

Our lathe is very precise, and capable of high speeds, leaving almost a mirror finnish.

Here the surface finish of the 3D milling is visible. i ran a 3.175 mm two flute ballmill when doing the finishing pass.

i ran it at 8mm/sek, altough i do believe that this was to slow for this bit, due to it having two flutes.

I put a buffing wheel in the lathe, finishing of this test piece.

As the results where good, i will go ahead, and mll the finshed one in brass, and produce the jig for carring out the two last operations, miling the recesses in the sides.