Build plate adhesion issues?

[Lat2730]

well the grease has worked, the start of the supports have stuck to the build plate, I have another item I would like to print so will clean off the grease, scuff the build plate and see how that goes.

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scratch that it hasn't, as soon as it was done with the supports its failed to attach the base of the model, im guessing the actual base of the model caused a greater bond to the bottom than the legs of the supports. time to clean up and try modifying the plate, and maybe adjust my model

[Lat2730]

So I have cleaned out the well of all the grease, used an orbital sander on the build plate and just started build again minus rafts so flat bottom to the model, I can hear slight pop every time the z-axis lifts up which from the many videos on youtube suggest that is a promising sound as the model detaches from the film, update in an hour or 2

[cliffyk]

I got Shanghai'd early this morning by the "honey-do" list and yet to have time to do anything I wanted to do. But I guess the door on the pump house that blew off in a storm in early August was somewhat important.

At the risk of sounding like a broken record , I will once again state that after seeing a "Pro" build plate "up close & personal" I do not believe the issue to be too much adhesion at the FEP, but rather too little at the platen..

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I called various shops and found that as I had suspected the welding shop would be an ideal place to bring your rusty combine, but not a Mars build-plate. A local poweder coating shop wanted "$20 maybe more once they saw it" to glass bead it. However I am not sinking $20 more into this experiment. After lunch I will hit it gently with whatever disc is in the random orbit sander and go from there

[Lat2730]

I have a "successful" print hitting it briefly with a 260 grit sandpaper on an orbital worked a treat maybe a little too good as it was a challenge to get the model off of the plate, only cause of failure for my model was a support gave out.

[crunichie@gmail.com]

possible share image wat plate look now and ur slicer setting and resin bottle you used as i order new plate to sand and the wham bam flex plates for my pro?

[Kasimira]

It's just strange how there is no problem with clear resin yet the opaque resin won't adhere. I full heartedly agree about the build plate and it's not the first time I've heard of people sanding them to resolve the issue. It's just strange how the clear has no issue with adhesion to the smooth surface. But with exposures increased up to 80 and still issues with opaque, I leave that in the archives of strange science.

I've gone ahead and requested a new build plate with a sandblasted finish from Elegoo. Either the one from the original Mars or the Mars Pro 2. Their initial email was a lot of basic.. did you level the build plate and etc. I went into detail as to our findings on the forums here and that the Mars Pro seems to have these issues for a number of customers. We will see what they say, I will likely still sand mine down a bit.

[cliffyk]

The pigments added to base (clear) resin to make opaque resins--I.e. the stuff used to make clear resin not clear--do not they have the adhesive properties the base resin develops when it cures--they are just "along for the ride"; and actually interfere with curing and adhesion to the platen...

[cliffyk]

Got the urgent "Honey-do" project done, and hit the Pro platen with a 220 grit disc.

But 1st, about that project. We lost the door on the pump-house in a storm in August. And ever since SWMBO has been complaining of having to "look at a water works" from her sewing room window--so in the interest of martital bliss I took a couple days off from "my stuff" (for any younger fella' it would be an easy 1 day project) and made this:



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OK, back to business; here are before and after shots of the platen:



After grinding and polishing ball ends on the lock screws (the industry standard sharp-edged concave nose on the supplied screws is just so wrong for this application). I moumted and aligned it, now printing this guy:



I did throw in a variable though, am using Elegoo's water washable resin--never used it before, we'll see in 4 hours or so...

[cliffyk]

Update:

Just checked on the "Corona Pumpkin"--print failed...

Platen adhesion was great, a bit too much perhaps¹, the problem was that the hangers (supports) let go when the main body began taking shape. This water washable resin seems quite brittle, I rebuilt the .ctb file with "Heavy" supports at 80% density (had been "medium at 50%), and increased regular layer exposure by 12.5% (8 s to 9 s). I'll not be babysitting it tonight, we'll see what it looks like in the morning...

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¹- This can be easily corrected by smoothing the surface finish a bit with some 400 grit aluminum oxide wet/dry paper (used wet).

[cliffyk]

Success! "Jack-O-Corona" printed out fine with the resurfaced "Pro" build-plate and modified hanger structure and exposure time--I think I like this water washable resin. After final curing (40 minute rotating under a 30 W 405 nm LED) it seems quite robust:



pre-post curing and any final finishing


Quick test, does anyone recognize the tool upon which jack is sitting? It is 60+ years old, i used it nearly every day in my very first job.

One "thing" though--it was stuck to the platen like "..it to a blanket"--I had to use a SHARP 2" wood chisel and a 12 oz, ball peen hammer to separate the platen and model.

In retracing my steps I found that between my decision to scuff up the plate, and my actually getting to do it (because of the "honey-do" project); the wife grabbed the random orbit sander from my tool cabinet and used it to sand a "trash day" road-kill 60's end-table she brought home last week--with a 60-grit!!! disc. I "knew" it had a 220 grit disc in it when i scuffed up the platen.

I any event I hit it again with an old 320 grit disc and all is well. The next print, a 60 x 120 x 5 mm test block adhered quite nicely and came off easily with the supplied scraper.

Ironically this screw-up serves to prove that it is the platen's surface finish that dictates it's adhesion factor; and that as Elegoo has found a slightly rough finish is what is needed.