Does anyone have a good explainer on the at least three different and incompatible styles of Glock rails (FMDA, P80, and something else), and perhaps even information on where to find dimensional drawings and how-to-make-at-home tutorials?  I've read that rails are something you CAN make at home even though most people don't want to, but I can't find anything online beyond some years-old half-completed projects.

Same for the "locking blocks", are there dimensional drawings anywhere?

PY2A has the files for their rails on their web site, under the "files" section.

FMDA based projects usually includes the CAD for their rails in the download, or you can download the original FMDA 1x.2 package to get the rail CAD.

Not sure about the P80 diy type.  I thought P80 you had to get their commercial rail/locking block combo

Thanks, found 'em!

FMDA front rails are machined so you're not going to be making them at home without a mill. They are the most common design and you will not have trouble finding frames for them. There is supposed to be a 3rd gen coming out soon if not already.

PY2A front rails are bent sheet metal and you could cut them and bend them at home if you wanted to avoid being on a list as having bought "ghost gun" parts. Frames for them are less common but they release their own on their website and they are good quality.

P80 rails are not specifically designed for 3D printing but 3D print community has adapter their designs to use them.

For the first two you will need to buy an OEM or equivalent locking block for the model you want to build. For P80 the locking block and front rail are a single piece.

Thanks.  Damn, I was hoping to be able to make everything at home, except of course for the trigger assembly and slide parts.  I haven't found a source for locking blocks other than mail-order.  Tried asking at a gun show recently and got the look.