. Since this is an industrial model, these plastic housings are designed to be replaced as modular units. Recommended Replacement Parts
If you cannot source a replacement piece immediately, community experts recommend these methods for a "solid" repair of the existing plastic: Plastic-Specific Epoxy
for the PS-300B there to identify the exact diagram number for your cracked piece. Industrial Sewing Machine | Brother Temporary Repair Alternatives Brother Ps-300b Crack
Because industrial machines have many small plates and covers, the best way to ensure a perfect fit is to use Brother's official Online Parts Navigation tool. You can download the specific Parts-Book
The Brother PS-300B is a programmable electronic pattern sewer. Depending on where your crack is located, one of these genuine Brother assemblies will provide a clean, "solid" fix: Top Cover Assembly (Light Gray) Part #LM4973001 Stop-Drilling
For a cracked Brother PS-300B industrial sewing machine case, the "solid piece" covering you likely need is the Top Cover Assembly or a specific
: Avoid standard superglue; use a two-step plastic bonder like Loctite Plastic Bonder Brother Ps-300b Crack
which is designed to withstand the machine's high vibrations. Stop-Drilling