Shapeoko 2 stepper motor skips

I have a shapeoko 2 with some upgrades. I acquired this machine from a friend and im trying to get it working. Currently my main issue seems to be with x and y axis loosing steps.
Ive done most or all the possible culprit fixes but still have the problem.
When i run a simple jog i can easily prevent the movement by hand. When it skips i can see that the motor itself is not turning so this confirms to me its not the belt slipping nor the pully.
I upgraded to a new adjustable power supply thinking that would fix. (Old one was only 12v)
My gshield V5b indicates 30v input so i have tried different levels of voltage with no noticeable increas in stepper motor torque. Ive tried adjusting the pot screws on all the outouts and it seems even turned right up to max it doesnt change nor does it go into any thermal shutdown.
Are my nema 17 motors possibly just not powerful enough? Should i just get nema 23?
I keep reading other people say 17’s can even do aluminium but i cant even get anything cut in soft wood.
Any help pleaee?

12V PSU = severely underpowered system.
Nema17 are marginal to begin with.

Also realize that steppers available torque drop at speed (shaft RPM).
So with low PSU voltage (12V) / small stepper (Nema17) you really cant go too fast before it will stall out, even without any load.

Upgrading the PSU to 24V will in theory increase the system capacity with 200% so that is one way to go. If you are inclined to upgrade further, skip getting a 24V PSU and upgrade stepper drivers to minimum TB6600 and a 36V PSU. Further down the road I’d also take a look at upgrading to Nema23’s as they are abour $20/piece.

Thank you for your reply, this newbie really appreciates it.
I put a volt tester on my variable psu and apparenty the led display it has was incorrect. It was indicating 30 volt but in actual was only putting out 20 ish. So i carefull turned it up to 35 and im now putting 28 volts to the board.
This gave me better results in the torque but still seems week imo.
I haven’t tried any carving just yet but im working on it.
You indicated that upgrading to tb6600 would be beneficial. I actually have 3 of these drivers but were purchased for a larger cnc build im doing. Im far more capable of the building part than i am at the electrical stuff fyi.
Nema 34 motors are in the larger cnc build based off of lnternal bearing linear tracks driven by heavy belts. These tracks were salvaged from a comercial paint booth where i work and i sourced them to have cost over $2000 for each track (7feet long). I have 5 of them…lol apparently they are rated to have 0 tolerance in all directions.
Back to my topic at hand, i wonder if maybe i should utilize these tb6600’s on my shapeoko 2 and consider better options when i get to the bigger cnc build? Also get some nema 23’s and 9mm belts.
Also I haven’t seen any clear procedures on how to convert over to these new drivers.
Should i consider learning the mach 3 also?