DIY Rotary for Snapmaker 2.0

This DIY attachment was created for Snapmaker 2.0 A350, but may work on the A250 with modifications to linear rod length. This build is a DIY alternative to the official Snapmaker Rotary Module when using the laser module on cylindrical objects. It is not designed to be used with the 3D or CNC modules. Even using the laser module, this custom rotary tool option has limitations on the type of objects you can laser on the Snapmaker.

I am making the assumption that the tolerances between one A350 to another is fairly small, and that this DIY rotary should work for your machine. However, you may have to tweak the design slightly. Your results may vary.

Basically, you create rotation on this attachment by using friction on the CNC waste board**. As the bed moves front to back, the rubber bearings are turned, thus rotating the object that is laying on top of the bearings. It is a very simple design that utilizes brackets that screw into threaded holes on the existing towers and a few rubber bearings that slide onto 10mm linear rods stretching across the bed. The side brackets I made were acrylic, but you could also have them cut via CNC, or 3D printed. I used multiple layers of 1/4" Acrylic to get to a thickness wide enough to create the rigidity you need. I have included the STL file for 3D printing the bracket as an alternative to laser cutting the side brackets. It has only been tested using a cylindrical thermos that did not have a taper. I will be testing using a sleeve for tapered objects in the future.

**Using the 3D heated bed or the metal laser bed has not been tested. Modifications to the rod hole height could possibly be made to test this. The CNC waste board is what worked well for me.

• 2 x 10mm x 500mm Linear Rail Rod
• 4 x 10x35x11mm Polyurethane Rubber Bearing
• 6 x M4 x 20mm Threaded Knurled Thumb Screw Grip Knobs
• 4 x 10mm Bore Carbon Steel Shaft Collars (optional?)

Rail Brackets will need to be created, and there are multiple options using Acrylic, Wood, or 3D Printed Filament.

The DIY Rotary attaches to the existing vertical posts using the M4-sized threaded holes on the sides of the vertical stanchions. The first step is to decide how you want to create the rail brackets. Considering you have a Snapmaker 2.0, you have 3 options: Laser Cut, CNC or 3D Printed.

Please note that for my workflow, I use the CNC waste board during this operation. If you plan on using the heated 3D bed or laser tray, the parts for those are in the next step.

Laser Cut

Please note that I laser cut my brackets on a Glowforge. Snapmaker owners will understand that changing back and forth between modules is tedious, so I just used a different tool in my workshop. I also used multiple layers of 1/4" Acrylic for each bracket. I have not tested laser cutting acrylic on the Snapmaker. I don't think the Snapmaker laser is powerful enough to cut through 1/4" acrylic, but would guess you could use 1/8" material, and just use more layers to get to the desired thickness and rigidity of of bracket. You'll need .75" worth of layers to work with the 20mm M4 knurled threaded screws.

The SVG files needed for this project are included for you to import into Luban.** I have included the Adobe Illustrator and PDF versions of the files if you need to make adjustments in your vector program.

**At the time of writing this Instructable, there was a bug in Luban that resized SVG files when importing. You'll have to set the size manually and confirm that the height and width are correct. Also note that Luban rounds the numbers. The dimensions list below are the exact numbers from Illustrator, but Luban will round up to 2 decimal places.

Rail Bracket Dimensions:

Width: 163.407mm

Height: 75.952mm

3D Printed

The STL file for the side bracket has been included, but I did not test this method. The holes may need to be drilled out depending on the filament and 3D printing method.

CNC

I did not test this method either, but the included SVG should be able to be imported into Luban and used to cut the side brackets. Again, you will need to verify dimensions in Luban due to resizing of the SVG.

Rail Guide Dimensions

Width: 66.463mm

Height:68.642mm

Although using the CNC waste board works best for my workflow, others may want to try the 3D or laser beds. I've modified the bracket so you can slide it up and down until the bearings rest on your build surface. I have not tried or tested this option, but attached the files needed for you to test this. If you're successful using this bracket, please leave a comment below!

Sliding Rail Bracket Dimensions:
Width: 163.407mm

Height: 88.399mm

The M4 threaded knobs I selected makes it easy to uninstall this when not in use. You could use regular M4 screws. When properly installed, there should be a little pressure holding the rubber bearings down against the bottom plate.

• Attach the side brackets to the vertical posts, but do not tighten the screws. Keep them a bit loose until all the parts have been added.
• Slide 2 rubber bearings onto each 10mm linear rod. I had to add a little bit of lubricant to the rod to get the bearing to slide without resistance.
• Slide a guide onto each side. They should move when perfectly vertical, but have some resistance when angled slightly. The guides are optional, but may help prevent creeping of the object.
• Insert each rod into the holes on the side bracket. The slide into holes on the other bracket.
• Push down on the bracket slightly to ensure each bearing is on the bed, and tighten the screws. After all screws are tight, verify the each bearing does not rotate freely.
• Load a file into the interface and run through the manual alignment to verify the the bed can still move back and forth and that the bearings move
• The shaft collars are listed as optional, as I found I didn't need them to keep everything secure. They can be installed on the linear rod outside the rail bracket to prevent the rods sliding.

Modifications

This design uses very robust 10mm linear rods. You could modify the design to use 7mm rods so you could use standard bearings. The larger 35mm rubber bearings work well, but are pricey.

Using the manual adjustment to set the work origin point, I set the laser a couple millimeters above the object. I also run the laser head side to side to ensure it doesn't hit the object anywhere along the length in case there are any discrepancies in the diameter. Test the ability for the object to roll evenly by moving the bed front to back. Then go ahead and start your job!

Tapered Mugs

To ensure that an object rolls evenly, I created a sleeve to go on the skinny end of a tapered thermos mug. I measured the largest diameter of the mug with a calipers, where the mug would roll on the bearings. Then measured the bottom diameter, and then laser cut a sleeve using multiple lasers of 1/4" plywood glued together.