Have you ever looked at your scratched up mess of a build platform and thought, “Maybe I should just buy another?”
I found a simple way to restore the platforms to like new status quickly and easily. It takes about 5 minutes and you will need a sanding block, some sand paper, and access to a sand blaster.
Here is my nasty scratched up build platform:
Wet sand it with 250 grit and 600 grit sand paper using some dish washing detergent as a lubricant. Rinse and dry it off completely. It doesn’t need to be perfectly scratch free. I only sanded this for maybe 1-2 minutes.
Sand blast the surface. In my case I have 220 grit loaded so the surface is a little smoother than stock. When done, wash the platform in soap and water again, then dry. 50 or 100 grit would make it look and feel completely stock.
Here is a comparison between the refurbished and a brand new unit. The whole process took me maybe 5 mintues start to finish.
Looks really like a new one again!
But very often a scratchy surface helps sticking parts to it.
Very often I have to prepare the surface to get more rough and that helps a lot if the platform starts “loosing” parts on the tank foliage.
Fortunately I don’t have a problem with parts sticking - quite the opposite in fact. Parts printed directly on the platform tend to break off and leave thin sections on the build platform that have to be aggressively scrapped off. Rafts can also be hard to remove, especially lots of mini-rafts. With the surface refinished, they release about the same as stock, which is slightly easier with less breakage in my case. I can pinch off the mini-rafts with cutters more easily too.
Sanding this again with 600 grit will simply yield a smooth sanded surface if more surface adhesion is needed.
What do you use to detach the prints from the BP? I use this: https://www.moermangroup.com/en/window-cleaning/products/accessories/pocket-scraper
Blades beveled on one side would be beter, but properly tilted the standard ones work flawlessly. You need to apply forward as well as downward force.
@microdev That refurbished platform looks nice. How much “thinner” would you say that build platform is now? Have you already printed again with that platform?
I use snips to pop off the print and a scraper on rare occasions.
Maybe a few 0.02 mm has been removed after sanding and resurfacing. I refurbish and reprint with these all the time. I have printers running about 5 days a week and run about 180 prints through a quarter. I refurbish these about once every 2-3 months or if they get scratched up from a particular part run.
Rougher surface finishes using something like #80 aluminum oxide would probably make it exactly like the stock platform. The #220 I have loaded in my sand blaster results in a slightly smoother finish that wears a little quicker than stock.
The Form 2-3 build platforms typically are concave, by about 100 microns.
We CNC machine them with a 20 mm end mill. DOC typically 0.1 mm.
Once flattening is done, the consistency on the first layers is a lot better.
We leave the bare CNC machined surface as is, until it is heavily scratched.
We then lap sand the platform at 220 grit and sand blast it at 100 grit.
For prints that get stuck to the platform, here is a simple trick.
Don’t bother trying to remove the base layer. Cut the supports right at the base layer, to leave it on the platform.
Then use a heat gun and warm up the layer that is stuck to the aluminum surface, until it softens.
Then use a metal scraper. It will peel off like clay. Super easy.
Of course, you’ll need to let the build platform cool down before the next print, if you had to warm it up a lot.
If you flatten the platform properly, then use the heat technique to remove sticky base layers, your aluminum surface will need very little servicing. We print hundreds of parts per month at our farm and have a park of 4 machines. We use 8 build platforms that rotate between the machines. We surface the platforms once per year. We have never seen the need to change them in 5 years of operations
This is great information! So you you take a stock build plate that has a slight concave surface and mill it flat?