Building a larger Prusa Mendel

Hi -
I have built and currently use a Prusa Mendel i2 for all my 3D prints. I am starting to print parts for a second Prusa, and was wondering why I couldn't increase the scale of the second Prusa Mendel. I think I would just use the same printed plastic parts, but I could get longer threaded rods, smooth rods, and a larger bed.

Am I missing something, or can this be done? It sure would be nice to have a larger print volume going forward. If this won't work, how can I make a larger format 3D printer?

Thanks,
Rob

Within limits. As you scale up, you start to need thicker bars - 10mm instead of 8mm for example.

Also, as your print bed increases in size, so do your issues with temperature control, curling, adhesion, etc.

8mm rods are about at their maximum on the Prusa, if you were going to go half as wide and deep more I would go up to 10mm rods for all the axes. The prusa is fairly wobbly too so increasing the size will only exacerbate this. If you went up to 10 or 12mm threaded rod it might make up for that but you would probably want to add some lateral triangulation to steady the ship.

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Richmond, New Zealand
Thingiverse ~ YouTube

I've been considering a 12x12 Prusa for my first 3d printer. Looks like these have 8mm rods.

[www.ebay.com]

Krythis Wrote:
-------------------------------------------------------
> I've been considering a 12x12 Prusa for my first
> 3d printer. Looks like these have 8mm rods.
>
> [www.ebay.com]
> 2-3D-Printer-Kit-/321079205641?pt=LH_DefaultDomain
> _0&hash=item4ac1cfdf09


While that might be a 12x12 bed it does not look like they have increased the height at all so you are still limited to a 7" or so tall print. With that said just because it is being sold on Ebay with 8mm rods does not mean it will work properly. With that hotend and extruder drive sitting on those rods, I would bet they tend to sag once you get to the middle of the print. It certainly won't hurt ot go with 10 or even 12mm rods for stability. I mean why not they are not that much more expensive.

Edited 1 time(s). Last edit at 03/19/2013 03:42PM by rbc1225.