Best posts made by GTech

My suggestion would be the same as all the others.
Make sure the aluminium plate has been cast, not rolled. Cast plates have less internal stresses and will warp less when heated, you should also make sure that plate has been face milled so it is level and flat.
This type of plates is a commodity if you can tolerate to use a default size, they are of the shelf parts you can can get on eBay.
You can drill the mouting holes with a drillpress or even a cordless if need be, just start with a small size drill and low rpm.

Since we are talking 400x400 and up, your only practical option is mains powered silicone heater in the 1kW range. Keenovo is a commonly used brand, they publish the specs for the integrated thermistors, there are even a few config samples here in the forum you can copy paste.
You can get those of Ali but there are also a bunch of retailers in europe. ... please do not forget, to run a ground wire to the bed as the silicone heaters only have a 2 wire connection

Insulation, my prefered choice is mealamin foam, often sold under brand the name Basotect. It can be used up to 240C and is flame retartend. It is commonly used as sound and heat insulation in cars, offices, public buildings. You can get 20mm sheets on Amazon or eBay. Use some 3M-468MP, high temperature resistant double sided sticky tape, and put the foam under your bed.

Print surface, get a magnetic sheet with a spring steel sheet, you can get those as kits on eBay and Amazon. It is just so much more convinient ... seperating a large PETG print from a ridgit plate without damaging the build surface or the print can quickly become a challenge.
Build surface it selfe, personal choice, my favourite is FR-2.

It was always my fault with my macros not beeing resiliant enough.

Thanks for the script but my point was a different one,
With the BLTouch we have a sensor that is able to detect and report a malfunction, which i think is a good feature.

IMHO it would be good if RRF could make use of this and be enabled to recognize when a malfunction is reported and to respond..

There is already specialised code for the BLTouch so this would "complete" the current implementation and close the feedback loop.

@razrudy I normally use 8mm at the size we are talking it is already quite a chunck of metal. You might be able to get away with 6mm anything below that makes no sense in my mind.
10mm will work as well, its just heavier and has more thermal mass aka. needs longer to heat and cool. Depends on what you can get you hands on.

As others mentioned mounting that thing is the challange, at 400x400 you will need to somehow compensate for thermal expansion or it will warp no matter how thick the plate is.

Take a look at the HeVORT printer, the guy is on the forum here as well, I think he has a nice way of mounting the bed ... it is just bit overkill . Also take a look at the Jubilee nice bed mounting as well.

On eBay and some stores you can also find silicone blocks and spacers intended for moutng printer beds. They are flexible enough to allow the bed to expand and act as a heat break between the bed and the frame at the same time ... not my first choice but apparently people use them succesfully.

Couple of related notes; You can get silicone heaters with holes in them so you can do the mounting directly under the bed and maximize the print area.

Forget about the Cartisan, 8mm 400x400 should weight something in the 3-4kg range(?) accelerating and decelerating that quickly without loosing steps is a whole different discussion. If you want to go Cartisian your only option is a PCB heater ... Chinese clone of the Prusa Mk42 most likely?

FYI I am just dialing in my new build, bit smaller then yours (300x300 build plate on a 8mm cast aluminium tool plate ~380x350) and with propper mounting there is next to no warping.
I disabled mesh bed compensation, active leveling with three Z screws is enough and I can print right up to the edge with a nice and even first layer.