Finding a freezer
Writing about what to look for in a freezer.
| Key-points |
Status |
Size |
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Modularity (No cooling rods in-between levels) |
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Supercooling function (to reach lower temps) |
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When we were looking for a freezer, there were three main requirements it had to meet.
Firstly, it had to be big enough for us to be able to fit a CNC and our other hardware into, but not so big that it would be unpractical to have stationed at a lab. Utdyp
Secondly, the freezer had to be modular. To ensure a maximized use of space, the freezer could not have cooling rods in-between the different freezer drawers. This would make it impossible to find a big enough CNC. Vis med bilder
Thirdly, the freezer had to be able to reach low temperatures. Since freezers are made for storing food, not drilling prostates, they usually did not go below -18*C. However, more modern freezers often come with a super cooling function, meant for cooling the freezer more than usual after if had been opened, to help protect the food. This can often take them down to -30*C. Vis
Finding a CNC
Writing about what to look for in a CNC.
| Key-points |
Status |
Size |
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Modifiability (How easy is it to change/alter components) |
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Temperature resistance (Can it withstand -30*C) |
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When we were looking for a CNC we had several requirements it had to meet.
Firstly, it had to be big enough, but not too big. Milling prostate slices would require a minimum bed size of approximately ... mm X ... mm. But the CNC also has to fit inside the freezer. Here you have two options. Measure the size of your freezer and order a CNC that fits within the specifications, or buy a CNC that is modifiable and can be cut down to fit in the freezer. Utdyp om hva som gjør at den kan bli kuttet ned
Secondly, since the components are to be operating in a -30*C environment, it is important that they can withstand it. How can this be checked/What components are most important to check
Modifying the CNC
Writing about what changes must be made for the CNC to be compatible with the freezer.
| Key-points |
Status |
Measuring |
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Cutting to size |
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Double-checking the fit |
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Incorporating our own components
- New Base-plate
- Use Baseplate.dxf file to create component. The baseplate used made for this CNC was made using a platecutter and an 5mm aluminium plate. After the plate was cut, the 4 mounting holes showed in the DXF-file was drilled out using a pillar drilling machine, and a 5mm drillbit. Lastly, the rough edges around the hole was removed using a 6.3mm countersink bit.
- The plate was mounted to the CNC machine using soe existing threaded holes in the bottom of the y-axis beams. They were mounted through the rubber feet that came with the CNC kit, and four M5x25mm bolts were used.
- New support beam at the back
- To make the back support beam, start with a 20mm x 20mm aluminium extrusion profile. We used the rear crossmember beam from the CNC building kit. This is then cut to a length of 320mm using a band saw (or metal hand saw). The edges are then sanded lightly to remove rough edges. If liquid coolant was used during the cutting process, make sure to wash the beam.
- Next, some mounting holes needs to be drilled into the beam. This was done using a pillar drilling machine and a 5mm drillbit. Using a caliper, mark two lines 10mm and 30mm from each end, and at the centre of the beam (10mm from the edge). Then, line up the drillbit, and drill the 4 holes through the beam. Lastly, use a 6.3mm countersink drill bit to remove the rough edges around the hole.
- To mount the beam, slide it into place, and use 4 M5x30mm screws to hold the beam in place. '
- New mount for the z-axis
- Clamping attachment
- Camera Mount
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Tips and tricks for making the modifying process easier. (Marking the axes with colors) |
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The CNC needed some modifying in order to fit into the freezer, and to mill in the way we want it to mill.
The first thing we did was cut the profiles and leadscrews so that the CNC would fit together.
Since the axes came pre-built with stepper motors and end-plates, we first had to dismantle it. To ensure that the right motors would be assembled with the right profiles, all pieces were marked with tape. Every piece from the first y-axis was marked with white tape, every piece from the second y-axis was marked with white tape, and every piece from the x-axis was marked with blue tape.
We measured the freezer and found that the freezer was ... cm wide and ... cm deep. We then measured up that distance on the x-axes, starting from the end of the stepper motors. We added an extra 0,5 cm for the end plate and and extra 0,5 as a safety margin.
We marked the distance with several rulers, and a square tool, and the areas to be removed were marked with tape.
We then measured how much material was to be removed from each of the profiles and marked the same length of material on the leadscrews.
The components were then sent to the workshop to be cut. The profiles were cut with a ... (Kappsag?) and the leadscrews were cut with a (vinkelsliper?).
Next the newly cut edges on the leadscrews and profiles had to be made similar to their other ends.
- The leadscrews were rounded using a drill and a (Båndsliper).
- The profiles were filed using had files
- New holes were tapped in the profiles using M5x0.8 tapping tools.
The y-profiles were then reassembled with their end-plates and stepper motors.
Next the x- axis was attached to the y axes and its stepper motor too.
After all the axes had been connected, the CNC was placed inside the freezer to double check if it would fit.
- New Base-plate
- Use Baseplate.dxf file to create component. The baseplate used made for this CNC was made using a platecutter and an 5mm aluminium plate. After the plate was cut, the 4 mounting holes showed in the DXF-file was drilled out using a pillar drilling machine, and a 5mm drillbit. Lastly, the rough edges around the hole was removed using a 6.3mm countersink bit.
- The plate was mounted to the CNC machine using soe existing threaded holes in the bottom of the y-axis beams. They were mounted through the rubber feet that came with the CNC kit, and four M5x25mm bolts were used.
After the axes had been assembled, some components from the original design needed replacing. The original design contained a base plate and a frame to stiffen the machine. The designs of these components were slightly changed to better fit our purpose.
The first component to be made was the base plate.
This component can be created by downloading the "Baseplate.dxf" file
Building the CNC
Writing about how the instructions were followed to assemble the CNC.
| Key-points |
Status |
Following the instructions (Say which instructions we follow, and which we don't) |
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Attach the endstops |
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Plug in the wires |
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Here we will begin writing...
The clamping mechanism
Writing about how to produce and attach the clamping mechanism
| Key-points |
Status |
| Explaining the concept
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How to acquire the parts |
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How to attach the parts |
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Here we will begin writing...
The z-axis
Writing about how to produce and attach the z-axis with the spindle
| Key-points |
Status |
| Explaining the concept
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How to acquire the parts |
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How to attach the parts |
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Here we will begin writing...
The Z-axis part of the CNC, containing the spindle motor, will have it's own frame and setup. The development process of this is described here.
The frame of the Z-axis is made from leftover material from the downsizing of the CNC, as well as beams meant for use in the frame. This was done so that as much material and parts as possible comes from the CNC building kit.
The main beam was cut from what remained of the X-axis beam from the downsizing process. It was then cut to a length of 242mm using a kappsag. After that, the holes on the edges were threaded with an M5x0.80mm threading tool. The rough edges from the cut was also lightly filed to remove the sharpest edges.
Bilde
The next part of the frame is the legs. This was made from the bottom crossbeam 1 in the CNC building kit. To make them sequal in apperance, they were cut from each end of the crossbeam. They were cut to a length of L=154mm using the Kappsag. Next, the rough edges from the cut was filed down. The next part was to drill holes for the mounting screws. 4 holes were drilled out in each beam, at the center of each slots: 10mm and 70mm from the top of each leg. See the picture below. The drillbit used was Ø5mm thick.
bilde
With the holes drilled out, the legs were connected to the main beam using 8 M5x30mm bolts. The picture below shows this assembly.
Bilde
The Next part is to assemble the spindle to the Z-axis assembly. For this, follow the guide in the instruction manual page 23. When finished, it should look like this:
Bilde
The camera
Writing about how to produce the mount and attach the camera
The camera will be attached on the left side, above the x and y axis. This will maximize the how much of the bed we will see. It will be attached to the z axis frame, pointing first to the left, and then another beam pointing backwards (Like an L).
| Key-points |
Status |
| Explaining the concept
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How to acquire the parts |
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How to attach the parts |
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Figuring out the requirements (camera angle) |
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Here we will begin writing...
The Lightburn tutorial
Writing about how to boot and connect with Lightburn
| Key-points |
Status |
| Explaining the concept
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How to acquire the parts |
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How to attach the parts |
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Figuring out the requirements (camera angle) |
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Setting up Lightburn
Start by connecting your computer to the CNC by using the cable.
When you first open the program, it will display as shown in this image:
To add the machine to Lightburn, start by pressing "Devices":
Next press "Find my Laser" to let the computer automatically detect what you have connected to your computer.
Once it is done scanning it should display a GRBL. Select it and choose "Add Device".
Name the device after your choosing and select axes of length (X=100mm, Y=100mm) and press "Next"
Next select "Rear Right" as the origin of your laser, and turn off "Auto home your laser on startup".
Click Next.
Your CNC is now added to Lightburn and the front page should look like this.
Next the CNC device has to be calibrated against Lightburn so that the machine will run effectively and safely.
Calibrating Lightburn
Controlling the CNC
Creating and Running a Program