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hi,

I am new to 3d printers, for past couple of months I’ve been looking at several diy projects and decided to make printer of my own. So, I started looking for some specific details, for now, my frame is of 1000*900*900 mm size and print bed is of 900*900 mm size. I have 5 nema 23 stepper motors(1 for X-axis, 2 for Y and Z-axis)with 2phase, mk8 direct drive extruder with nema 17 motor, 6 end stops and arduino mega 2560 R3 with 54 I/O pins(do you think its sufficient?). I have easy access to a4988 stepper drives(do you think i can use them?), I have absolutely no idea about current and potentiometer related things(should i be concerned?). And finally how many heatbeds should I use?

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Hi @navyatejadir I love the idea of building my own printer, especially a large volume one (and your dims are huge), but it’s a daunting task. Unless you get everything right, you’ll end up with something that doesn’t produce a decent enough quality to use and you’ll have spent quite a lot of money on it. If I were in the position to attempt this I’d probably start with something smaller and cheaper, maybe a kit Prusa clone that can be upgraded, then adapt that for a larger size and move on from there. Things like current to the motors are really important and building a ready-made kit would allow you some experimentation to get an understanding before you moved on to a bigger project.

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Hello!

I’ve built a printer about the size of yours, and have experience from designing several smaller ones, but with the same mechanical layout. There are a few things that you have to consider when building this big. First and foremost does the frame have to be rigid. I used MISUMI T-slot 25*50 mm in my machine, and while it is sufficient I could easily have used bigger profiles and if I were to do it again I would use 50*50 mm as a minimum.

Second thing to think about is motion system. Don’t even think about linear rods! do yourself a favour and get quality linear rails like these http://www.tpa-us.com/images/miniature-linear-guides.jpg for every axis. For movement I would also recommend either a core-xy arrangement to utilise the strength better from the motors (both motors are used for xy movement). For Z, if you are planing on a moving bed (mine is stationary) I would suggest using three ballscrews like these http://www.hiwin.com/images/roller_screw_ballscrew_large.jpg, moved by a single stepper, to keep them in sync. Otherwise you will end up with all sorts of weird and wonderful problems, but no useful prints.

For hotends, have you seen the e3d volcano? If not have a look at it. I’m using two of them to produce 0,2mm layers for perimeters and 1,1 mm layers for infill. Saves quite a lot of time. Also, if you can, don’t go down the route of 8-bit electronics, you will regret it. Get yourself an Arduino DUE with a RADDS-shield instead. To this setup you will need some external stepper drivers like the m542 from lead shine. Your nema23 steppers will probably just melt the a4988 drivers, especially if they are of the standard stepstick model with insufficient cooling and a tiny heatsink on top.

Lastly, for a printbed you would get yourself a thick piece of cast aluminium tool plate, which is completely flat. This will also stay flat when heated so you will not face the problem with a wired printed, that many have. For heating this plate, get yourself a custom made silicone heater from china. I have one 90*90 cm, powered by 220V drawing 2200W at full power, which heats my bed to 120°C in less than 20 minutes. Also, if you are planning on using the full volume of your printer, you will need to enclose your printer and actively heat it. I’m using 2 resistive heaters powered by mains power, each drawing 400W.

Hope that something of this makes sense, I am currently in hospital with my blood filled with morphine.

If you have any other questions please contact me either here or on email bo.oscar.svensson(at)gmail.com