Designing a Aluminium X/Y/Z Printer
February 17, 2016 06:58PM
Howdy All,

I currently have a nice little xyz printer made by a local company, but I would like to scale it up, its print bed while 250x250x370 is nice (in reality its more like 220x220x300, usable) I am looking at making a custom print bed (with resistors for heating etc) of around 400x400, I am curious, what are the design considerations that I would need to take in consideration, could I take the current measurements and simply scale it up? Do you start with the Size of the build area, and then figure the percentage difference between the current design and the larger design build area, and then simply scale everything else up from there?

I've attached a quick quick mock up of the basic design

I've color coded it to make it a bit easier

1. The Red 30x30 is 410mm
2. The Blue 30x30 is 380mm
3. The Green 30x30 is 470mm
4. The Build Plate is 250x250 (Dark Blue)
5. The Runners for the Y Plate is 20x20 410mm Long

Any and all consideration and thought is greatly appreciated... I have seen 300x300 plates available and wouldnt mind scaling up to that, and would really like to get the 400x400/500x500 project started... just want to get the basics down before I start cutting up 30x30

Thanks Allen

Mark
Attachments:
open | download - Bot.jpg (32.1 KB)
Re: Designing a Aluminium X/Y/Z Printer
February 18, 2016 03:31AM
There are lots of threads on these forums about the problems you will encounter if you try to scale up a printer design, so I suggest you find and read them. I will limit my comments to the bed heating. Forget PCB bed heaters and resistors, what you need is a cast aluminium tool plate (which will be flat enough) with a silicone heater underneath (slightly smaller to leave room for fixings around the edge). If you want to be able to remove the bed + print then clip a sheet of 4mm float glass on top of the aluminium.

Use either a 24V bed heater and 24V-capable electronics (preferably one of the modern 32-bit boards), or a mains voltage bed heater driven by a DC-AC SSR (in which case you need to implement a number of safety precautions, especially if the printer has a moving bed). These people [www.aliexpress.com] will make a silicone heater to your size, voltage and power specifications.



Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Re: Designing a Aluminium X/Y/Z Printer
March 10, 2016 04:10PM
Hi guys,

+1 for the silicon heatbed. An aluminium plate flat enough should be thicker, that means more weight.
You can find AC powered silicon heatbeds, which heats faster than 24v ones, and saves on the Power Supply Unit expenses.

Briefly about large machines.
1/ A moving bed in X or Y is not a good idea because big means heavy. Prefer designs with still beds, like Deltas or mecanics with bed moving only in Z direction.
If you scale up a design, you scale up errors and problems too. It's not easy.
Most of the time, anything should be checked (calculated) and upscaled if needed. From the first nut to the last cable.
You need to bring as much precision and build care as possible. That means quality components and materials.
Because as distance increase, gap, play, vibrations will increase too.

Maybe the easiest design to build a big printer is the Delta.

++JM

Edited 1 time(s). Last edit at 03/10/2016 04:11PM by J-Max.


^ Things I said. My thingiverse here. My website there (in french).
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