Not sure if this is the correct category, but I couldn’t find a better one. Anyway, a little background first. One of the offshoots of my 3d printing hobby is 1/250 scale RC models of famous ships. I have only had one complete success, a model of the Edmund Fitzgerald, but I have another model in progress, and a few past ones that I call learning experiences. So obviously, the ships that I want to do are pretty long, ranging from approx 60cm on the very bottom end, to over 130cm on the top end. Most are in the 80-120cm range. As I print the entire hull and superstructure, I have had to print in segments up till now. This works, but creates a LOT of extra assembly work and frustration, as well as being weaker than a single segment hull. So enter my idea of a quite specialised FDM printer. A quick note, I am aware of the Creality CR-30, but don’t want to go that route for detail and strength reasons primarily. I am not 100% sure I will go ahead with this build but I am seriously considering it, and figured I couldn’t go wrong asking for feedback from you all.
So my basic idea is this. A 1400mm long by 200-235mm wide bed. The Z axis will probably be 130mm, give or take. The idea would be to do aluminum extrusions along both sides of the bed (I haven’t settled on an exact configuration yet, but it will probably consist of two extrusions bolted together to get the desired profile. I would have v-slot wheel carriages running on the extrusions and a classic ender 3 style gantry would be mounted on these carriages to travel along the length of the bed. I would probably use 4 carriages, 2 on each extrusion, spaced aprox 10 cm apart to provide better stability. I realize this configuration will have a pretty high moving mass, which will limit print speeds, but that is allright with me, I am not aiming for a high performance printer. Doing a long h-bot style configuration might work and would probably be higher performance, but it would limit side access somewhat, which I need, as there won’t be any top access where I would put it if I build this thing.
For the print bed, I am thinking probably 7 rows of screws/bolts 3 bolts across to mount the print bed to the printer, with silicone heat mats in between the rows. This calculator https://jscalc.io/calc/mVSHnXdt0sjpeUFM if it is accurate, tells me 250 watts would take about 7-8 minutes to heat the bed; that is a while, but the prints will be around the week long mark a lot of the time, so that doesn’t seem to be a big deal to me, just as long as it can attain 60°C. So I have a couple questions maybe some here can answer, and I would love feedback, constructive criticism, and suggestions too.
Question #1: could a mosfet be added to any off the shelf mainboard go supply the power to the bed so 250+ watts doesn’t need to go through the board? Likely would be a BTT SKR Mini E3 V3.
Question #2: Regarding auto bed leveling, can Marlin firmware be configured to have a rectangular probe grid of 4 by 23 instead of a square grid? That would be ideal.
Question #3: Any preferred places to buy v-slot aluminum extrusions? Maker parts.ca has extrusions up to 150cm, but I would prefer 160cm. Thanks for reading this long speil, and I am looking forward to seeing your replies!
Edit, added paragraph spacings.