Printing on HDU foam (butterboard)?

I'm still working on getting my printer together, but I do have an extruder to fool around with. I've been experimenting with different materials to see if ABS will stick to anything not heated. (I'm designing my own printer and a heated bed is proving to be inconvenient.) I've been test extruding ABS onto any random material I have laying around the shop. (It's remarkably resistant to sticking to anything that isn't heated.)

However, it did seem to stick pretty well to a piece of HDU foam (aka butterboard) that I got from McMaster. It's the higher density 48lb/ft^3 variety. I was just moving the block of material around by hand underneath the extruder nozzle, and the ABS stuck quite nicely. I could only build up a few layers (very crudely) doing this by hand, but the ABS stayed adhered and I had to use a little fingernail force to get an edge pried up to peel it off.

Has anyone else tried this material? Does this seem practical - using HDU, unheated, as a build surface for ABS?
-Jeff

Edited 1 time(s). Last edit at 05/21/2013 02:31PM by LoboCNC.

What are the temp ratings on the HDU foam? Will it melt if a heated nozzle crashes into it?

tenacious Wrote:
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> What are the temp ratings on the HDU foam? Will
> it melt if a heated nozzle crashes into it?

The softening temp of HDU seems to be around 120C. In testing by hand with the nozzle at 230C, I pretty much just jammed the nozzle right up against the HDU with no visible marking. I suspect you'd need more prolonged contact to mar the surface with a hot nozzle.

You just gave me an idea,

I wonder how cement board (tile backing) works.

I have some extra of it lying around.

I took the foam base out of one of my Stratasys machines and gave it to a friend to try on his MegaMax, and the results were excellent (it was a 4# density polyurethane foam board - Last-A-Foam FR-7104, to be exact). He's now been experimenting with printing on the foil-sided PIR foam sheets you can get at the home improvement store with excellent results (after removing the foil, of course). It grips much better than the heated bed: [vimeo.com]

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[haveblue.org]

It looks like the foam is damaged after removing the part. I guess it's cheap and easy to replace though.

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The foam gets damaged a little, but you can keep reusing it. My Stratasys foam bases loook pretty rough after a while, but since you're intentionally burying the tip by perhaps 1mm into the foam for the first few raft layers, it really doesn't matter. A suitable square of foam for a large printer bed cut from PIR sheet is only about 50 cents of material, and you can flip it over and use the other side when it gets ratty.

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[haveblue.org]

Have Blue: Curious - it seems that common wisdom is that you need a heated bed for ABS. Printing on foam sheet seems like a much nicer solution than trying to keep everything hot. Have you tried higher density HDU foam? It is much harder than the PIR foam and may not suffer so much damage when removing parts. The smaller pore size of the HDU foam may also make parts stick a little less aggressively, which, from your video, might be a good thing.

-Jeff

He hasn't tried any higher density foam - if we can find some, we'll give it a shot, though! The nice thing about the PIR is that it's cheap and readily available. A denser tooling foam is going to be more expensive and not nearly as easy to find locally.

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[haveblue.org]

Finally managed to do a quick test printing ABS on unheated HDU foam (the 48lb/ft^3 stuff). Is stuck really well. (Maybe too good.) I liberated it by sliding a razor blade under the part around the perimeter, and then it popped off with just a few tiny specs of the foam board stuck to it. Much less damage to HDU foam than to the lighter density foam in the video posted above. Of course, the higher density foam is a lot more expensive. If I could find it in 1/8" thick sheets, though, it wouldn't be too bad. Thin sheets would also make it easier to flex and peel parts off.

I'll post photos once I get my printer set up properly.

Jeff

is this not the same stuff as this? great stuff, is great stuff and its fricken spray foam too just fill in the voids! Just imagine, spray the foam down on the bed, then attach a dremel to the carriage, mill the foam flat. bam self leveling foam bed.

[www.amazon.com]

Edited 1 time(s). Last edit at 05/25/2013 07:24AM by aduy.

Unfortunately, 'Great Stuff' and castable foams have too variable a pore size to make for a good printer base.

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[haveblue.org]

well it sticks after you cut it, but its soft and it rips. but it does stick.