Hi, I have a, perhaps mundane, issue around removing supports.
The model is done in PLA. It was late and I wanted to kick this job off so it could run overnight. I was tired, and I didn’t think to use SupPLA/PETG for support interfacing. That said, I haven’t had any intractable problems removing PLA supports before, but these are being a real bear:
(Sorry to say, but I don’t know what the support settings, and speeds were. )
Here’s what I’ve tried:
Standard ‘pick it apart with needle nose pliers’ – this got most of the VOLUME of the support off, but the interface part did not come off.
I tried going at it with various razor blades, from a standard single-edged (both by hand, and in a window-scraper), and a surgical 10 blade.
I tried a (very sharp) wood chisel.
Finally, I tried a palm sander with 180 grit on it, which ultimately just melted/gooped-up the part (bottom finger in the pic).
I saw the thread over here that mostly indicates that printing a PLA part with Support on PLA is a recipe for a ruined part. As is perhaps obvious from the pics, this is not some complex model of a dragon or a skull or anything like that – all flat surfaces – but they are relatively tight-register fingers that need to interlace with their mirror image. Each part takes about 5hrs to print, and 200g of PLA, so trial and error is not really viable.
This particular print is now effectively garbage, but I was wondering if anyone had any hot tips on removing PLA support in situations like these. I plan to use the dedicated support material going forward, but I’ve probably put in as much time trying to remove the support interface as it took to print the part (~5hrs), so if there IS a secret, I’d love to know it.
Not too much you can do with the current print but pick at it. If the plastic welded when supporting it won’t come off cleanly. The best I’ve ever done is light sanding by hand. Takes forever and leaves a lot to be desired unless you take your time.
About PLA support. If you choose to buy the spool from BL be sure to dry it throughly before you use it. As you may have read in that thread you could also use PETG.
If it’s a complicated model PVA is dissolvable in water, but it too needs to be very dry. When it contains moisture it becomes a little stickty and the AMS has issues with it.
I’d recommend PETG. Just get a cheap spool and go from there instead of dedicated support for PLA.
My 5 cents in terms of fixing messed up support surfaces:
200 grit wet and dry sandpaper - preferably the stuff with the fabric backing not the paper ones - the fabric ones last much longer and cost a bit more, your choice.
I have several thing I abuse for my sanding needs by gluing the paper onto them.
Wooden, plastic and metal spatulas of various sizes and shapes…
Glass strips and plates (to get a perfectly flat surface)…
The big problem with our printed plastics is that using machines can result in softening the plastic or even melting it.
Trying by hand takes far too much time and strength - or does it ?
Hard plastics like PLA you can sand dry but clogging still happens and cheap sandpaper can be eaten away quickly.
Sanding the part wet, be it under running water or by keeping it wet with a spray bottle makes sure the debris is gone with there is also added lubrication.
Best of all, if there is different materials using those tools and doing it wet means you get a smooth finish.
Sometimes, though I cheat, especially if the surface is invisible in the completed model and needs to be smooth, like for a moving part.
A teflon sheet and iron will do fine here, set it to cotton and off you go.
All the humps and bumps get smoothed out…
Could you elaborate on what you mean by “teflon sheet and iron will do fine here, set it to cotton and off you go”? I know what an iron is, but I don’t know what the teflon and cotton are for? Aren’t most irons covered in teflon already?
I can
The teflon sheet is there to protect the hot iron.
Trust me, you don’t wanna have the missus find her iron with melted plastic stuck on it!
Takes quite a bit though to actually melt the plastic like this, PLA is easy though
The sheet also helps to get a better surface on the plastic as it stays in place while the iron moves.
Not ideal but it works nice for quick fixes of parts not really visible.
Especially for loose hanging bridging bits it is great to bring them in line and tack into place.
)
