DIY - Refrigerant Recovery Machine - help needed

Hello everyone.

I've been looking for a recovery machine in my part of the world, even a used machine is so expensive that I can't even think about buying one of those as of now.

So, I went about searching how can I build one myself

I have most of the things, including the compressor, condenser - piping is of course no issue...

but I need a general diagram of such a unit plus =
how to remove oil from the refrigerant?
what to use as sep tanks? - where to install the seperator tanks things like such

how to inject the recovering refrigerant into a cylinder

need general guidelines so I don't blow anything up :)

regards

We used to use old condensing units, one for 407c, another for 134a, might be easier than trying to work from scratch?

yes, but I work in the automotive industry, don't have access to such things as you guys do

I have the compressor, condenser and all the piping needed

just need a basic diagram or flow chart - plus where to install sep tanks ideal locations etc would be very helpful