150mm orbital sander disc alignment helpers and CAD drawings - SCHTAER, YOKIJI, METAHO

150mm sander platforms, sacrificial velcro pads and discs all have funky and mismatching hole placements, so it might be difficult to align the air holes. Also there's plenty of 125mm-related models, but not many for 150mm aside from festool and mirka-specific ones. 125mm hole placement is usually similar, but 150mm are all over the place, both generic and branded

These are models and drawings for 3 styles of 150mm sanding pads i have. I'm using a SCHTAER SCH-150 sander with the original plate, but the same machine is sold under different brand names like red&black YOKIJI and green&black METAHO. Look at the pictures to determine if it looks the same as what you have

STEP 2mm disc samples and DXF drawings are provided for 3 disc styles, as well as an alignment helper:

Style A - 21 holes total, 18x8mm, 3x10mm. Modeled after decent bang-for-buck sanding discs i have in use (purple ones)
Style B - 15 holes total, 6x9mm, 8x11mm, cental is 19mm. Modeled after cheap generic discs i used to have, but they were rather crappy
Style C - pattern created based on the original platform that came with my sander. I've seen platforms and sacrificial pads with this pattern, but i guess it's meant more for abrasive mesh discs rather than sandpaper, as the hole pattern barely aligns with those, and the platform itself has internal cavities for directing airflow.

An alignment helper STEP is provided, 1 combining A and C patterns, and 2 with just outer-most pins, as they seem to fit most hole patterns. If you want to change anything or make your own, just import the DXFs into CAD of your liking as a base sketch and continue from that. Onshape was used to create everything
Print the helper with whatever settings and material, but make sure to print the pins solid, and probably tune down/disable cooling for best layer adhesion so that they don't snap off as easily. PETG works fine

There are versions with 8 and 12mm long pins. Use 12mm with thick velcro pads, or 8mm otherwise. If unsure - cut the model so that there is just 1 base layer and do a ~15min test print.

***Please keep in mind that all models are created based on manual measurements with good digital calipers, but i cannot guarantee sub-mm accuracy, and there is room for human error. I did test prints and everything seems to fit ok, though