Cryogenic Machining: Custom Rubber Parts

Cryogenic Machining Custom Rubber Parts

Fashioning a custom, one-off rubber part for your project isn’t usually an option, but [Ben Krasnow] has an alternative to injection molding and casting: machining frozen rubber.

As [Ben] points out, you can’t exactly pop a sheet of rubber on your mill and CNC the needed shape; the bit will push the material around rather than cut it. Freezing the rubber first, however, allows you to carve into the now-hardened material.

His initial setup consisted of a sheet of aluminum with water drizzled on top, a square of neoprene placed on the water, and a steady stream of -60 to -80C alcohol flowing directly onto the rubber. The water underneath freezes, holding the neoprene in place. This proved problematic as the ice-clamp gives way before the milling is complete. [Ben] later adds some bolts to clamp the pieces down, allowing the milling process finish as planned.

A small plastic tray sits underneath this assembly to capture the alcohol as it runs off, feeding it back with some tubing. [Ben] recommends against a submersible aquarium pump—his initial choice—because the pump stopped working after a few minutes immersed in the chilly alcohol. An external, magnetically-driven pump solved the problem although it does require manual priming.

Stick around after the jump for the video and check out some of [Ben's] other projects, like his quest for the perfect cookie, or CT scanning a turkey.

[Read more...]

USB to DB25 Adapter Uses GRBL For Parallel Port CNC Communication

USB-Parallel-GRBL

With the continuing manufacture of new computers, there is a clear and obvious trend of the parallel port becoming less and less common. For our younger readers; the parallel port is an interface standard used for bi-directional communication between a computer and a variety of peripherals. The parallel port’s demise is partially due to the invention of the USB standard.

If tinkering with CNC Machines is one of your hobbies then you are familiar with the parallel port interface being fairly popular for CNC control board connections. So what do you do if your new fancy computer doesn’t have a parallel port but you still want to run your CNC Machine? Well, you are certainly not stuck as [Bray] has come up with a USB to Parallel Port Adapter solution specifically for CNC use.

A cheap off-the-shelf USB to DB25 adapter may look like a good idea at first glance but they won’t work for a CNC application. [Bray's] adapter is Arduino-based and runs GRBL. The GRBL code is responsible for taking the g-code commands sent from the computer, storing them in a buffer until they are ready to be converted to step and direction signals and sent to the CNC controller by way of the parallel port DB25 connector. This is a great solution for people needing to control a CNC Machine but do not have a parallel port available.

[Bray] is using a Raspberry Pi running GRBLweb to control his adapter board. However, there are other programs you can use to communicate with GRBL such as Universal G-Code Sender and GRBL Controller.

The board has been created in Eagle PCB Software and milled out using [Bray's] CNC Router. The design is single-sided which is great for home-brew PCBs. He’s even made a daughter board for Start, Hold and Reset input buttons. As all great DIYers, [Bray] has made his board and schematic files available for others to download.

DIY CNC Dust Collection

A DIY CNC dust collector

CNC machines are great at churning out custom parts, but they tend to make a mess in the process. [Darcy] has built up his own CNC dust collection rig to collect the dust and keep his workspace clean.

To capture the dust, a custom dust skirt encloses the cutting tool and directs the vacuum. This was made by gluing acrylic parts together, creating a box that contains the dust and provides a connection for the vacuum system.

For $1, [Darcy] built a cyclone dust extractor. This spins air around in circles, causing the dust to fall to the bottom of a container. The result is less dust reaching the vacuum, and much less money spent on vacuum bags.

Since the vacuum makes quite a bit of noise, a muffler was needed. This is just a simple wood box to contain the machine. It can also be used to vent the exhaust outside to further prevent polluting the workspace.

While we’ve seen some similar builds in the past, [Darcy]‘s design could be helpful for those looking to build their own system. He also gives us a video which shows the effectiveness of the dust skirt, which you can find after the break.

[Read more...]

A Tale of Two Ring Boxes

ringboxes

This is a tale of two hearts, two engagements, and two ring boxes. About a couple of years ago, [curtisabrina] proposed to his girlfriend. Rather than just hand her the ring, he placed it in a locking ring box [imgur link] he custom-made. The box seems normal at first glance, but lifting up the first drawer reveals a complex and ornate gear system. The gears can only be turned by a pair of interlocking heart-shaped keys – a gift [curtisabrina] had given her months earlier. The mechanism is nothing short of stunning – planetary reductions drive a spring-loaded iris which opens to reveal an engagement ring.

[curtisabrina] built his ring box after hours at his signmaking job. The job gave him access to some incredible tools, such as the MultiCam 3000 series CNC. The box turned out great, and he showed his work off in a Reddit thread.

Fast forward two years. [joetemus] was getting ready to propose to his girlfriend, and wanted to do something similar. He didn’t have access to high-end shop tools, but he did have a Shapeoko 2. Using the original box as inspiration, [joetemus] started designing. Over time, trial, and error, a second ring box emerged [imgur link]. Like the original box, [joetemus] started with a rough cut board. Nearly every part, including the aluminum gears, was cut on the Shapeoko 2. [joetemus] also celebrated his accomplishment with a Reddit thread.

[joetemus's] ring box isn’t quite as complex or polished as [curtisabrina's], but he was working with a machine that cost much less than the equipment [curtisabrina] was using. We think both of them are great, and are happy to report that both of their girlfriends said, “Yes!”

[Read more...]

A Little Lubricant Goes A Long Way…. With Your CNC Machine

CNC3020 Linear Rail and Lead Screw Lubrication

[Peter] has been having some positional repeatability problems with his CNC3020 Router recently. The problem was mostly in the Z axis and was measured to be up to 0.3mm off position after 10cm of travel. This may not seem like a lot but it was enough to break a few 1mm diameter end mills. The X and Y axes generally seemed OK. Surfing the ‘net reveled that the control board’s power rails did not have any filtering capacitors and that may have been the cause of the problems. Unfortunately, the positioning problem still persisted even after the cap’s were added. Frustrated, [Peter] then started a full-blown investigation to figure out why his Z axis wasn’t cutting the mustard.

In a CNC system there are 2 major components, the electronics and the physical machine. Since it was unknown which portion of the system contained the problem, [Peter] decided to quickly swap the X and Z channels, running the Z axis with the X axis electronics. The problem was still evident on the Z axis which means that there is something wrong in the mechanics of the machine. The Z electronics were put back on the Z axis and the testing continued by lowering the acceleration and the maximum speed. The positioning error was still there. Since it is possible that the Z motor could be the problem, it was decided to swap the X and Z motors but midway through the process the problem became evident. When trying to rotate the Z axis lead screw by hand there was a noticeable lack of smoothness and the axis seemed to jump around a bunch!

[Read more...]

Baby’s Room Gets a Palace with this CNC Castle Decoration

castle decoration

[Vegard] and his wife were expecting a baby girl, and decided to build a castle for their new daughter. As a prototyping geek with his own CNC machine in his apartment, he decided to take to Google Sketchup to design this well-crafted castle decoration for his daughter’s room.

The first challenge was figuring out what the castle would look like. [Vegard] had never been to Disney Land or World, and so had never actually seen any of the fairy-tale castles in real life. After experimenting with some paper versions, he settled on a design which incorporates multiple layers and can house lights within them.

The next step was to cut the final version on the CNC machine, then sand and paint the parts. After figuring out a way to mount the castle to the wall, some LEDs were added for effect, driven by an Arduino. The final version looks pretty good!

Hacking your kids’ room is great fun, and you get to keep making new stuff to remain age appropriate. We bet [Vegard] can’t wait until she’s old enough to enjoy a marble-run that wraps the entire room. In the mean time he can work on a classic robot stroller.

Super Nice CNC Router Build Leaves Little To Be Desired

Aluminum CNC Router
[Enzo] wrote in to tell us about his recently completed CNC Router (translated). This is an excellent high-quality, all-aluminum build with no cut corners. The work envelope is a respectable 340 by 420 mm with 80 mm in the Z direction. Linear ball bearings make for smooth travel and lead screws with both axial and radial bearings give a solid foundation of accurate and repeatable movements.

Aluminum CNC Router

We’ve had a bunch of CNC Router projects on Hackaday in the past, including other nicely made aluminum ones, but [Enzo] is the only one who spent just as much effort on his computer and machine control system as he did on the CNC machine itself. The computer, which is running Windows and Mach3, is an all-in-one style build that starts out with an old LCD screen from a broken laptop. Along with the reused screen, a very small ETX form factor motherboard was stuffed inside a custom made plexiglass enclosure. A Compact Flash card handles the storage requirements.

Underneath the monitor is another great looking custom made enclosure which houses the stepper motor drivers. There are 3 switches on the front panel to send main’s power out to the PC, spindle and an AUX for future use. On the back panel there are D-sub connectors for each stepper motor, the limit switches and the PC connection. Oh yeah, by the way [Enzo] designed his own bipolar motor drivers (translated) and sent the design out for fabrication. These boards use an A4989 IC and mosfets to control the motors. The schematics are on his site in case you’d like to make some yourself.

[Read more...]

Follow

Get every new post delivered to your Inbox.

Join 96,577 other followers