by: Yun-Han Lin
This article introduces the process of using laser cutting to manufacture and package assembly parts. The steps are as follows:
- Preparing wooden board/ Other parts and material
- Planning junctions on parts
- Labeling parts with numbers in sequence
- Reducing friction among parts
- Packaging based on size of parts
0. Preparing Wooden Board
Most wooden boards on the market are basswood, while some are Medium Density Fiber (MDF). These two kinds are more eco-friendly, less likely to cut your fingers, and they are more easily colored.
1. Planning Junctions
This is the most important step. It is suggested to fix the part on a wooden board (similar to the model part). The width of the joint is 0.5mm. If the parts are cut with little precision, it is recommended to increase the width to 1mm, and usually there are only 1 to 2 junctions on one part. If the part’s overall length is over 15cm, there should be more junctions.
Junctions are the key to a well-designed model. Examples here are just the basic rules, while there are so much more for you to find out and try.
A. Easy to disassemble: Parts can be easily removed.
(1) Rounded Shape: With diameter less than 20mm; only one junction is required. If over 20mm, junctions are needed on both sides of the circle throughout the diameter.
(2) Rectangle: Junctions are put on the longer sides, making it easier for users to remove parts by rotation.
(3) If there are many small parts, you can fix them on the working board, so you can always find them when needed.
B. Increasing friction can facilitate assembly.
(1) Gear: The junction should be placed at dedendum rather than the addendum.
(2) The junction can be placed on the surface in contact to increase friction.
2. Labeling Parts with Number
The size of most wooden board is limited to A4, which makes it easier or delivery and can prevent breaking if boards are stacked.
E.g. The Moon Rabbit assembly kit contains 33 parts in total, which I split into 2 parts, each at the size of 145*120mm.
There are two ways of numbering. One based on where the parts go during assembly, and the other on the placement in the package. I personally prefer the latter, because it suits the sequence for assembly and can be less confusing.
3. Reducing Friction
Burn marks from laser cutting can cause great friction on the parts. Here are some methods to reduce the friction when it comes to gear set or machine components:
A. Sandpaper: Smoothing out bumps at junctions or the burn marks.
B. Beeswax: A layer of soft wax used on any surface for lubrication.
C. Wood Wax Oil: Same effect of beeswax, but it the cost is higher.
D. Spindle oil/Lubricant Oil: Great effect but it could leave oil stains on the surface.
The basic rule is to prevent parts from bending due to shaking during delivery. The standard method is using a heat shrinkable film to wrap the boards to prevent parts from loosening and to keep out moisture. Self-adhesive bags are also good options.
To be honest, as long as you are familiar with the procedure, these steps can be completed in half a day to one day. I look forward to seeing more individuals or studios in the future that present various laser cutting works!