I have a fairly basic question as to what people use as a post process blasting media and life expectancy of the media.
We use a Skatcat siphon blasting cabinet with glass beads per Formlab’s recommendations, which works really well for residual powder removal. We operate closer to 100 PSI because we use a low flow nozzle to get a good removal rate.
A question was asked of me today about how often we change the media in the cabinet. We’ve had the cabinet in operation for about 3 months now and have not really noticed any degradation of the glass, but frankly, we wouldn’t really know what to look for. In looking at media replacement intervals for glass beads, I’ve seen everything from 6 cycles to upwards of 30 cycles, but we have no idea on how anyone measures a cycle against SLS parts.
I’d like to know what everyone else does in terms of post processing and if using a blast cabinet, have you changed your media and if so, when and what do you use?
From what I was able to find (see Skat Blast FAQs), their recommendation is to use the abrasive until it breaks down to dust. Regarding your question about measuring cycles, I’m not quite sure. I’d be interested to hear other users’ experiences with this and get a sense for approximately how long blasting media can be used before needing to be replaced.
At Formlabs HQ, we replace the media in our blasters about monthly but we’re running a lot of Fuse 1 and 1+s. We won’t be able to give you a hard number of cycles when you’ll need to replace your media, it depends heavily on the size of the media, air pressure, build size, blasting time, volume of media, etc.
We decide when to replace our media qualitatively, when the media breaks down and gets saturated with powder you’ll see a sharp performance drop off (ie, parts that take a couple minutes to blast will take twice as long), that is when we recommend changing media. At our production facility they change the media ~weekly.
If you’re running one Fuse it could easily take months to need a media replacement. If you’re running a production facility it could be 1-2 weeks. Fortunately it should be relatively easy for whoever is using your media blaster to tell when it needs to be done.
I’m curious, what drove you to run at 100PSI? We run our blasters at 30-40PSI and get great results.
We have now replaced our sandblasting material for the first time a few days ago.
We currently only have one Fuse1+ with the normal PA12.
According to the dashboard, 28 print jobs were printed during this time.
Since Formlabs does not have its own sandblasting system, we have decided to use the Sinterit Sandblast XL for the time being. Here we also use the corresponding material from Sinterit. These are glass beads with a size of 0.2mm.
We started with 8bar (116PSI) and are currently using 6bar (87PSI). We work with this pressure on the gun in the chamber. Another nozzle controlled by foot pedal for small and filigree components works with 4bar (58PSI).
If Formlabs works internally with less pressure here, I will also regulate the pressure a little lower. However, 87PSI on the gun makes cleaning larger components quite fast. Whether 50PSI is just as fast here remains to be seen.
I would also say that an exact measurement of when a replacement is necessary is not possible. With one system and one replacement so far, I would say after 30 print jobs or 4 months at the latest.
With a second system, I would change it every 2 months. The sandblasting material is not particularly expensive here and the effort is also limited. In my opinion, regular replacement makes sense.
We were once recommended plastic beads by another dealer. This is supposed to achieve a better surface. However, these were considerably more expensive. We will stay with glass beads for the time being.