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the_digital_dentist
Smoothieware was just updated to fix the S3D problems, and apparently S3D did something to their software as well.

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nebbian

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val c.
but i'm dead serious about designing a driveable small car.

Just don't print it in PLA.. it might start sagging if you leave it out in the sun 8-)

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StupendousMan
How much plastic have you been able to push with your large printers? Anyone get past the 40mm3 / second, that is often quoted as the max for Volcano?

I ask, because I'm still on the fence between cartesian simplicity and corexy cleverness. I need about 185mm/s to get 40mm3 with a .6 nozzled Volcano. The machine is a basic cbot style cube of 60x80x80cm outer dimensions, to be built from 40x40 tslot and proper German linear rails.

What would you guys do?

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val c.
but i'm dead serious about designing a driveable small car.

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n8bot
Very nice. Let's see a HUGE print now! :)-D

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JamesK
Electric Yoda head? That might empty the park :D

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JamesK

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val c.
at least save it until I make one of those ubiquitous yoda heads :)

The potential for a 1m³ Yoda head is frankly terrifying!

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val c.
at least save it until I make one of those ubiquitous yoda heads :)

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the_digital_dentist
Wow!

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StupendousMan
I promised to build a largeish (has to fit through doors) printer for a startup. I have neither talent nor time to roll my own, so help me make a choice here, please. I'm open to anything with a decent BOM, these are just what I've stumbled into.

Cbot / Dbot. Proven design, but is it still rigid enough after scaling the size up significantly and hanging double direct extruders on?

Open Gigabot, this is the right size with no changes. Brand new and unproven. Does anyone know more about this?

Traditional cartesian? For example Voxel Ox looks sturdy enough to scale up a lot. Slow?

It will be using two volcanoes with direct extruders (maybe titans), a duet board, 24v, PIR bed (thank you DD!), and printing PLA (for starters).

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the_digital_dentist
Ouch!

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the_digital_dentist

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val c.
wanted to ask you, how did you get the idea to use foam?

I was having trouble getting prints to stick to my printer's glass bed at the time and started thinking about how to fix that. I saw a 90's vintage Stratasys FDM1600 industrial printer at the makerspace that prints on urethane foam (that they sell for a ridiculous price). I tried a piece of the Stratasys foam and it worked well, so I started looking for a substitute that was available cheaply. I figured it had to be something that wouldn't decompose at nozzle temperatures, which quickly led to PIR. Then I checked availability of PIR, found it for sale at Home Depot, and also found a sheet of it in the woodshop at the makerspace so I cut it up and tested it. When I tested it I used carpet tape to hold piece on my glass bed and used the z offset in slic3r to move the first layer up. It was the first material I tried and it worked well. The rest, as they say, is history. The guy who owns the Stratasys printer at the makerspace (haveblue) now uses PIR.

I ultimately went with a heated tooling plate bed for my printer even though it's more trouble to set up, because it has less on-going maintenance to do. For a large printer like yours, where a bed heater would cost a fortune to install and operate, the foam is perfect. There's no messing with different glues and potions because everything sticks to it. There's no waiting for a giant bed to heat up. There's no need to get a perfectly flat and level surface, both big problems for big printers.

If I were making a large printer I'd probably design the frame that holds the foam so it can hold different sized pieces of foam, and then use foam that is sized to match the print. That way you don't end up using big pieces of foam for small parts. Of course, you can always print off-center on the bed and move the prints around on a large piece of foam. Either approach should help minimize foam cost.

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val c.
wanted to ask you, how did you get the idea to use foam?

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the_digital_dentist
I found that the foam is a little springy, and so corners of parts printed directly on the foam (without a brim) tended to lift a bit. Using a raft fixed that- the corners of the raft would lift a little but the print was fine. Also, when printing the part directly on the foam a little of the foam remains embedded in the bottom surface of the print. Not a problem most of the time, but maybe once in a while.

You can sand the surface with a piece of coarse sandpaper to smooth it if it starts getting to uneven.

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the_digital_dentist
How's the foam bed working for you? I can't be sure from the pix- are you printing on a raft?