Ultra-flat beds for production printing

[nick-foley 4]

We're getting ready to print several hundred small parts on one of our machines, and one thing that is being obnoxious is the subtle curvature of the acrylic build platform. The parts all have critical tolerances, and so printing with a thick first layer is not possible, and depending on the part's location on the bed, it seems there is a 0.1ish variation in first layer thickness, which makes getting all copies reliably stuck to the bed a more tedious process than I would like.

I know there are plenty of people on this forum who are doing high volume printing - what are you using for a build platform? Aluminum? CF? Acrylic that just happens to be flat? Just dealing with it?

 

[gr5 962]

mic6 aluminum is... well... wonderful. It's very very flat. But make sure you always put kapton tape on it and then blue tape on top of that potentially. This is because you don't want to ever scratch it (aluminum is softer and easier to scratch than steel or glass).

If you get an aluminum plate do not get any other type of aluminum. Get mic6. Look it up on wikipedia.

However you might also have warping/bowing in the hardware that moves the head around!

An alternative would be to characterize your bed and adjust all the Z values depending on XY position. This would be a great plugin - it would add a Z coordinate to *every* move that has only X and Y. And adjust Z by up to .2 or .3mm depending on the XY location. Wouldn't that be amazing?

The plugin itself would be quite easy to write. The hard part would be characterizing your bed.

 

[nick-foley 4]

Yeah, I've been eyeing some MIC-6 from McMaster for a while. I guess it would be a good purchase if I ever wanted to add a heated bed as well. It's cheaper than CF, too.

Seems like you'd need a pretty nice probe to digitize the bed, but I'm sure people are doing it regularly in some industry. I have a 6 axis fabrication robot and we do something similar when milling irregular objects, though that is with a few less decimal points of precision.

 

[mastory 34]

For about $2 you could pick up a piece of 3/32" window glass cut to fit on your acrylic bed. Mask it up with blue tape and binder clip it to the acrylic. Bump your Z switch up and level to the new surface. Better, get 2 or more panes so you can swap them out.

As noted, the acrylic isn't really flat, so there might be some risk of breaking the glass - but hey, its cheap. Worse, the glass may teater, but it should be easy to shim it up with something.

In the states, Lowes will cut glass to size for you. No need for tempered glass. I'm running plain wndow glas on my HBP.