QIDI Q1 Pro Build Plate Alignment Guide for BIQU Plates

I wanted to run a BIQU plate on my Q1 Pro as the blue plate QIDI provides is in my opinion not worth using - PETG sticks HARD to it and you can't lower the plate temp much and still get adhesion.

It uses a 250x250 build plate and there was one on AliExpress and on Amazon but both are actually 257x257mm and do not fit because there's a shroud around the hot plate to guide build plate placement.  You can take off the shroud, though on my version I had to take off the electrical connections from the mother board and grounding to the platform to do so.  There are evidently different versions of the Q1 and some advice I got on Reddit ended up not being correct that the shroud came off with 4 screws and it's easy to align the BIQU plate after.

However, once the shroud is removed the BIQU (love these things, use on 3 different brands) plate fits on there and doesn't hit anything else in full travel.  However there's no reference point to anchor the thing and I use my fingers at the back and sides to position it as square as I could.

Getting motivated, I created this from scratch in TinkerCad (took me 4 iterations) and it does the job fairly well.  There's only one hole in reasonable proximity to the rear left corner (right is used by the grounding screw - could work around that but chose not to) so I needed a pretty tight fit to be useful with only one screw holding it down.  It still wants to rotate slightly, but is 'usable'.  There's a cutout on the platform a bit farther left that I should, when I get motivated, increase the horizontal size of this jig to utilize that for additional stabilization - next update will have it.

I printed this in PETG, glass transition is 75-85 so printing PLA or PETG is no issue, chamber (doors open )only gets to about 32 C at the highest. I also print ASA at times and this will still be fine (chamber temp to 55 C and no load) but the build plate temp at 80 will touch it in a thin line.  I will re-print this in ASA soon just to have my bases covered.

Print this standing up (only flat side down) - not ideal for layer line strength but this doesn't bear weight so shouldn't be an issue.  I used a .4 bi-metallic nozzle and .24 layers - normal .24 strength profile and speeds.

Let me know if you try it and it works for you.  I'm willing to modify it a bit more as above and based on recommendations. Happy printing all!