Here's a (probably dumb) question:

Here’s a (probably dumb) question: is there a technical reason why so many consumer grade 3d printers are limited to print volume of ~1 cubic foot? I’d like to see a 3d printer at a reasonable price that can print 1 cubic yard. Is it purely a cost of parts issue or are there technical barriers?

If you compare the Mendel-Parts Beluga printer to the Orca or Luna it seems that cost of parts increases due to increased length of rods etc and increased diameters. Otherwise the Beluga is not much different from the Orca. http://www.mendel-parts.com/index.php/catalog/3d-printers/beluga-v0-10/beluga-v0-10-complete-kit-unassembled.html

A yard? Seriously? What’s next, a furlong?

rolls eyes. Oh, it’s the terminology gestapo… cubic meter then, better?

I know of one very straightforward technical reason. All those X and Y rods need to be dead straight and rigid for the printer to faithfully reproduce X and Y dimensions.

The challenge and cost of those rods goes up the longer they are because of simple gravity. At a certain size, they’ll start to sag. It’ll be enough to upset a print.

@Miles_Wilford - I was figuring it would be something like that, but would simply making the rods beefier (larger cross-section) and/or adding supports below each rod alleviate that issue? I see large format plotters that use similar mechanisms are able to scale up quite large… Granted, they don’t have the same loads on them, but the “true-ing” (sp?) issue seems like it could be resolved with some careful design…?

It’s also harder to stabilize the temperature of the print over a larger volume. Thermal gradients or even uniform temperature changes can lead to severe warping.

Since they were mentioned, I recommend against buying from Mendel-Parts. Their customer service was historically poor and problematic, and they keep doing major redesigns of their printers every time I look, to the point where I don’t think they spent any time refining the design. It reminds me of their original Gen 6 electronics which were not really well thought out.

A little more on point is @Hoani_Cross recently built himself an extended-Z Printrbot and could probably speak to the design and cost considerations.

@Michael_Hohensee - that seems a bit harder to alleviate. Perhaps a pre-heated build box (like a large low-temp oven) with fans actively circulating the air to minimize temperature variance?

@Eric_Cha There are people who have done it. I’ve seen postings from some of the “huge” printers even around here like the “Tiny” http://www.youtube.com/watch?v=edQkatziQXc

But it brings the cost and complexity up.

Three times the build length will give you 9 times the surface area and 27 times the volume.

I reckon cost scales somewhere in between those two numbers.

@Jasper_Janssen - will cost actually scale like that? So, if I had a 3d printer that printed a 10cm X 10cm x 10cm base area, and then doubled that to 20cm x 20cm x 20cm, the cost would go up by somewhere between 4 and 16 times the original price? That seems… exaggerated… but I am just a noob so I admit I know very little about the costs (hence why I am asking these questions)…

I just can’t see a $1000 3d printer going up to $4000-$16,000 just to go from a 10x10x10cm print volume to 20x20x20cm…

@Tony_Olivo I’m going on a bit of a tangent here but, I wasn’t recommending him buy it and it’s good you pointed out those issues. I bought an Orca from them a couple years ago and it got to a point where I called every morning for a few days in a row after I had waited a month. They do inform you that there is a lead time as is common in the community.

Yes the design has drastically changed and improved since I bought mine (V0.2). I’ve upgraded mine and I plan to use it to print parts for a printer of my own design. I’m also jonesing for a RAMPS or RUMBA now because I have their Gen 6 without HBP control etc. Gen 6+ still doesn’t have support for multiple extruders either and supports 1 fan only.

TLDR; I can’t recommend a Mendel-Parts printer to anyone who will need customer support and is not willing to integrate self sourced electronics. Otherwise I like the frames…

@Eric_Cha There is no direct reasoning beside that that’s about what nicely fits on a desk to play arround. And nost follow ups stayed in the same region. Of course larger dimentions would need more rigid structure, but thats easy to come by. Temperature is not an issue once you got past a few centimeter in size it’s equaly bad :slight_smile:

It’s more about what you intend to do. Just extend the dimentions to wherever you want to have it. Take Rostock, a printer well made for tall objects. On the other hand, usually extending in one direction (X or Y will already give you the needed freedom. After all, you don’t want to make a massive 1m3 size object, so slice your design into simple (if possible rather flat) parts and glue it after printing.

@Eric_Cha It does not scale like that. But when you start getting up to the size of near 1m x 1m bed the supported linear bearing systems get expensive. http://vbx.com has some supported systems that you can check out. I know there’s open source systems available but I don’t know much about them.

I could build a meter cube printer for $500 easily. I however would not be able to talk myself into building such a beast because I would not be willing to risk $50+ of plastic that take a week or more to print.

You can make huge printers by using open linear bearings and rails like these: http://www.dhgate.com/2pcs-sbr12-200mm-linear-bearing-rails-4pcs/r-ff80808131bbc13d0131bbc61d5c005f.html?gl=1&catalogid=011014006001&keyword=linear+bearing+rail because then your way stiffness is not dependent on your rail diameter. You bolt the rail to as large a chunk of metal as you want.
The main problem is the exostratospheric cost of printing something that big, and how long it takes.

Thanks for the info everyone. I guess I should note that I wasn’t thinking about literally printing a solid 1mX1mX1m cube, but rather some larger objects that (for various reasons) don’t really lend themselves to being chopped into smaller sections and glued together. Oh, and it would be for prototyping, not production, as obviously, the material costs (not to mention time) would be prohibitive…

Here’s a follow on question for you - what do you folks think about using a CNC router table and putting a 3d printer extruder to the Z-axis mount? I have seen some YouTube videos of people who have done it, and it seems like a cool idea (large format subtractive & additive printing in one)… Granted, a CNC router table is expensive, but if one can add additive printing capability for not much more, it seems like it would be worth it to me (for my uses at least)…

Main reason is that printing 1 cubic meter item on FDM printer would take ages. Second is that 40cm axis (for 20cm workarea) made of 8mm smooth rods costs something like 20$, but 120 cm axis has to be made with supported rods and will cost you 200$.