CN milled catapult

Ever since seeing this little 3D-printed catapult, i knew i had to build a better one. so i designed a bigger and more powerfull one in aluminium.

i used Fusion 360's adaptive clearing to remove the bulk of material, then fiunished of the pieces with contouring rounds.

Here, the parts are laid out for the assembly:

The spring assembly was constructed by layers of 1mm plywood, later knitted around, so that they are still able to slide, but not separate

Of course, i had to use a 3D-printed wrench to assemble it:

The arm was riveted to the main axle:

And here it is, in all it's glory besides the smaller 3D- printed catapult, and the printer who printed the small one.

Producing the first part for my hydroponic setup

So, today i decided to produce the first part for my hydroponic setup. The part in question was the Left mounting bracket for the tubes, here marked in red.

Since this part will need to handle both twisting and downwards pressure, i did FEA analysis of the part, and changed the design until i was happy with the result:

immediately after machining the part, i had to play with it to see if it was rigid enough. Needless to say, the part snapped. The problem was that i had not taken in acount the direction of which the grain in the wood is orientated.

Disapointed with todays result, i gave up any further work, and instead pimped my office-cactus with some ultrabrigth LED's and ate chocolate.

Engraving aluminium stamps

I have been experimenting quite alot with engraving the past days, and these are the latest results in aluminium, the intention is to use my new knowledge to make custom wax stamps. The flat knurling where produced by running the pattern over the part again, but in the reverse direction.

Later, i made a case to fit the big pokemon symbol, lined with royal blue velvet. For this box, i choose to embed a M5 nut in a triangle pocket, making the hinge for pivoting lid type box.

Visible in this picture, is the velvet pad before and after covering. Notice the leftover tabs on the side of the part, used for keeping the part stuck to the material from which it has been cut, these where cleaned of with a router before covering.

The box assembled, ready to accept the velvet pad. The box where treated to achieve the old finish, first with oil, then it was torched, before it was oiled, sanded and then again torched. As a last touch, finishing oil where applied.

The pokemon token laying in it's case. visible to the front of the case is the embeded magnet which mates with another magnet in the lid, keeping the box shut.

CNC milled suitcase base

A frind of mine was tired of hauling her heavy suitcase around town, with the small wheels getting stuck everywhere. I made her the solution: a big, thick aluminium plate with huge wheels! 

I used the shell function in Autodesk Fusion 360, together with the web function to remove as much material as possible without compromising on rigidity.

Progressing with the screwdriver case

Here is the latest progression on the screwdriver set. Now that i had made one functional prototype of the drawer, the time had come to produce five of the new improved versions.

After generating toolpaths, the parts where milled from plywood and aluminium. The plywood parts where to be milled from both sides, so three wooden dowels where used to ensure that the material lined up from both sides.

Then, once i had five aluminium frames, and five wooden trays, i had to begin drilling the holes for the small brass screws that hold the frame in place. As much as i enjoy operating the CNC machines, there are something special about forming material by hand. Therefore, grabbed my toolbox, and began the process of marking, drilling and countersinking the holes.

After ensuring that the screws did infact fit in the aluminium frames, i mounted the frames to the wood. Using one of my favourite tools, a brass hammer i made my self some time ago, i hammered the frames onto the wooden trays.

Then using another of my selfmade tools, the small parallel clamp, i secured the two pieces together while i predrilled the hole for the screws. Then, i mounted the piece on a small board with a welding clamp, and inserted the threee screws.

As i had not used Bitrafs lasercutter for quite a while, i decided to produce a temporary rack to store the drawers in when i am not working on them. After some thinking, i came up with a quick design in Fusion 360. I took roughly half an hour to cut.

Thats it for now, the next thing i will have to do to finish this project, is to lasercut the wooden inserts for the aluminium frames. Then i will need to cut the final wood cabinet in wich the drawers will sit.

Wooden screwdriver set

Even tho i am a big fan of mass production, the tray that my screw drivers came in was poorly moulded from crappy plastic. I decided to remake the tray in oak plywood and aluminium.

This was a good exercise in Autodesk Fusion 360 toolpath generation.

The brass screws where made from 8mm rod, and the slits where cut with a jewelers hacksaw. Then they where turned in the lathe so that they sit flush with the aluminium frame.

This is the toolpaths for the aluminium frame. it has roughing offsets, to make space for evacuating the chips from the cut.

This is where things gets complicated. The wooden tray is 3D milled. That means that the CNC machine is moving with all axises at the same time, to produce smooth edges with a round cutter.

Holddown

I prefer to use lasercut wood washers to mount the material on the CNC, aswell as keeping the piece from moving under cutting.

This part were cut from 5mm polyethylene, a very soft material. Therefor, it had to be secured well before cutting.

The washer are cut to spec, so that they fit exactly in the slot.

This part needed to be chamfered around the outer perimeter. To allow this, it had to be secured with a number of washers and screws. Itwas not possible to avoid collision with the washers on the thin parts, so these where hold down with wood washers, while the rest of the part where secured with steel washers.

In this example, i was making a table, and the legs where to be chamfered from both sides. To acomplish this, i cut a jig for the part from some scrap wood. As this jig where cut by the machine itself, i can now position the part perfectly in the machine each time.

Rigid FDM delta printer

Altough we have a few FDM printers at Bitraf, i now see the need for having my own at my office. i started to develop a small scale delta printer last week.

The printer is constructed from a plates milled from sheet of 10mm 6082 t651 aluminium.

Movement is performed by NEMA17 steppermotors, and HIWIN linear bearing rails.

This is what i have modeled so far:

As the ultimakers, this design also equips the captured nut concept, in this case M6 nuts, as seen in this cutaway:

In this cutaway, the belt tenison system can been seen in the lower left corner. Notice the stiffening bracket in the middle of the linear rail assembly, and the milled weigth reducing pockets.

These are the main components of the printer, here laid out, ready for toolpath generation.

I decided to use this project as a testcase for Fusion 360`CAM strategies, in this case adaptive clearing.

The milling bits normaly break When peak loads is achived when running into a corner. Therefore, the feedrate must be reduced for the entirety of the toolpath when using normal CAM strategies for avoiding milling bit failure:

What adaptive clearing does, is to slowly dig the milling bit into the material, before performing a series of deep cuts at maximum depth, with optimal chipload. In this way, the tool will not experience peeks in loads, as the tool will have constand load. This reduces the runtime with a suposed 40%

I will spend the next weeks experimenting further with Fusion CAM. This is my first result with adaptive clearing:

Pulsejet sled update

Finaly got the time to do some welding on the Pulsejet powered sled. i added the reinforcement bars at the back, and prepared the aluminium bracket for welding. The jet sled is currently being exhibited at NDC oslo 2016 together with my hexapod.

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.

Milling aluminium with

When milling difficult parts, installing them in a jig is the way to go. Normaly i would use valchromat, but we had problems with it cracking when holding small aluminium parts. Therefore, Christian Anker decided to use PP plastic, which is a nicely machinable material, with more hold than valchromat.

The CNC machine produces a smaller CNC

I produced the parts for a friends smaller CNC, on Bitraf's huge CNC. How cool is that?

The cutting has begun!

The baby CNC! The banana is for scale. NOTE: This is an imperial banana, not a metric one!

Here, the brackets is installed. 

This is the machine with the bridge installed, waiting for the spindle.

The tools used for the roughing and finnishing. The bigger 8mm bit has two flutes, and provides exelent chip removal rates, while the smaller singleflute 6mm leaves a great finish, at the cost of efficience.

For more info on the CNC, follow this link.

Aluminium bracket

This was milled on the shopbot, As the bit started to show wear, you can notice the stepdown increments of 3mm on the second picture. 

The resulting surface finnish is good, but not as good as desired

CNC milled 3D printer display bezel

 Made the bezel and knob for my friend christian's 3D printer with the shopbot today. This was a 30. min job @20mm/sek with my favourite 6mm singleflute bit.

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: