You should not need to change anything, so just click through, choosing number of PCB you’d like, choose Lead free if in Europe etc., otherwise leave as default.
I uploaded the gerber size shows 0 * 0.
If you get a gerber size of 0*0 your files probably didn’t upload correctly. Try downloading a fresh copy of the repo and then try uploading the zipped gerber again.
Tried again still comes up as a 0*0 can you email me the correct file so I can try that way? bennieschmith@gmail.com
had the same problem, downloaded file, uploaded to jlcpcb and got pcb size not defined
Can You fix the zip file on the github?
Which size of board are you trying? I just tested the Micro & Standard, both work. I suspect you’re uploading the main zip file which has more then just the Gerbers. Either extract the three JLCPCB production files and upload those accordingly or just download the three production files individually. You start with the Gerber.zip, then later the BOM & CPL.
The main zip, needs extracting on computer first
The three production files, no extra extracting/unzipping needed
To download an individual file, click on the file, you may see text or not depending on the file and if you click on “View raw”. Then click the “download raw file” link.
Micro v4.5 - Gerber_AIO_V4_5_Micro.zip uploaded
Standard v4.5 - Gerber_AiO_v4_5_Std.zip
tested STD, from main folder.
I will check this one from subfolder You mentioned
See the zip files on the main/first post.
You’re uploading the Gerber zip? Try a different browser?
I have only Google Chrome on my PC
In google Chrome you do get this dimension. But you must find the gerber deep in the folder, as you see in my folder after “Unpacking All”, there is still an unpacked zip file in the last folder.
You are right.
I had to download main zip, unpack it on the disk, and send zip file from the main zip.
When I collect zip file ready for jlcpcb downloaded directly from the github it does not work - dimmension is empty - crazy for me
All the files work perfectly on Chrome and Firefox.
Works fine downloading directly “Gerber_AiO_v4_5_Std.zip” from Github too 
PCB ordered, files work perfectly
Does it no longer need a relay external to operate the lock valve? Which is the smd that has to have a heavier one to handle more load? Replace with what part number?
The lock traces and MOSFET “should” be able to take the heat. Around 4 Amp on micro and 5 Amp on Std easily continuously.
I don’t think there is an SMD that fit directly.
YOU MUST PUT A BIGGER TROUGH HOLE DIODE to do so, the SMD one is 3 Amp max for the whole board, so maybe 1.5 Amp for the lock circuit.
This as not been tested, it’s there if someone want to use it, anyway this project is for educational purpose, not intended for real machine use! 
The holes are there
On STD it’s D12 on top,
On micro it’s D6 on top (no labeled, in the red circle), D2 at bottom
jlcpcb “C22456” not available any alternative?
C347289 or C3795
Is it possible / advised to run higher copper weights without it messing with any traces? really wanting it to be bulletproof.