Build plate adhesion issues?

[cliffyk]

Most Home Depot stores stock the Super Lube PTFE grease, it's something I always keep some about--it's good for lubricating the Z-axis too¹. Please let us know how it works out.

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¹- It's great for lubricating almost anything, good on O_ring sealed push-in fittings to prevent damage to the O-ring, great for electrical switches (put a dab on switch openings and gently blow it in with compressed air) ; I also use it to pack wire terminals before crimping to keep moisture out.r

[crunichie@gmail.com]

That makes sense.  So for a larger flat base to adhere to the build plate in a grey or colored resin.  What would you suggest setting the initial exposure time to?

 any luck with tthe gray and still getting nothing from it really getting pissed at the printer at the moment all want do is print lol

[Kasimira]

That makes sense.  So for a larger flat base to adhere to the build plate in a grey or colored resin.  What would you suggest setting the initial exposure time to?

 any luck with tthe gray and still getting nothing from it really getting pissed at the printer at the moment all want do is print lol

Even with adjusted exposure times I have issues with getting bases to stick to the build plate.  The only way I can get it to work with anything besides transparent resin is to print at an angle.  It's like the initial layers form but then won't attach to the build plate.  However if you build with supports they attach perfectly fine.  So it's something to do with the size of the base and it not getting enough adhesion with the build plate and sticking to the fep.  I don't know why it does this with the opaque resins and not the clear.  That would say it is clearly an exposure issue like Cliff said, but I've raised exposure time up to 75 and left it at 10 for every layer and still the same problems.  I picked up an Anycubic Chiron this week so I've been busy playing with that so I haven't tried any more attempts.  But tonight I'm thinking I'll try one of the mini's they provide on the memory card in grey and see how that works.  The lion printed perfectly in clear blue without any adjustments.  So I'm going to try it in grey I think with no adjustments and see if it fails, the base is rather small so I'm hoping it won't.  

It's hard to decide what to do.  Part of me wants to return the printer and order a new one and see if it's just certain ones that are having issues, since many people with pro's aren't having problems.  Part of me is scared I'll get an even worse lemon as I at least know this one works even if it has to be tweaked and played with.  I'm also hoping when customer support gets back on the 9th they might offer me some solutions.  It would be really nice if they would just send me a new build plate and fep rather than going through the hastle of returning everything, waiting a 7-10 days for a refund then waiting for a new one to come in the mail.  I've also considered just waiting for the Saturn to come out as it has a larger build area... but they're just doing pre-orders right now and even those are closed so I feel that might not be an option until next year.  What I'm trying to get into is larger scale 3d models 7-13 inches, this was a cheap printer so I thought I would learn with it.  Anyways I got a little sidetracked here.

[cliffyk]

I have been following the numerous threads re: new Mars Pro printers and "sticking to the FEP"; and have concluded that the problem is not too much adhesion to the FEP, but rather too little adhesion to the platen (build plate). The many various, mostly failed, attempts to decrease FEP adhesion bear this out.

To put it simply, the FEP is the FEP.

OK, perhaps that was put too simply--fact is nonetheless that it is the same film on all Mars models, and many other SLA printers--however what IS different with the Pro is the finish of the build surface.

For the "Pro" it is described as being a bare aluminum (saw this elsewhere) "CNC turning CD pattern"--as opposed to the machined powder coated finish on my "Silver" April 2020 production plain ol' Mars¹:



For the "Pro" it is described as "Newly designed sandblasted":



I'm certain Elegoo did not change the surface finish twice just for the sake of change but rather to address known issues.

If I had a misbehaving "Pro" I'd do the same to it's platen as I did to my silver Mars (see the footnote), worse could happen is I'd have to buy another plate assembly ($23 on Amazon). In fact, I just now ordered one so I can play with it a bit on my Mars.

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¹ - As described above, the platen on my Mars, received on May 5th of this year, had a very smooth almost glossy powder coat finish; and I had adhesion problems right off the bat. I fixed that by scuffing that smooth surface with a 5" 320 grit disc in a random orbit sander (actually making it look like the bare somewhat rough (perhaps sandblasted?) build surface of my Longer Orange 10 which has never had adhesion problems).

[Lat2730]

Another "fix" I have seen mentioned is popping a couple strips of tape either side of the LCD screen to create a small gap between the resin well and the screen as it can cause a suction cup affect and cause the model to stick to the bottom of the tank rather than the build plate, I have done this myself, on one hand I'm intrigued whether this work, on the other I don't want the disappointment after waiting a couple of hours to find that I have another puck of resin stuck to the bottom of the well and some wasted resin.

Will most likely wait till tomorrow when the synthetic grease turns up.

[earthball]

Kasimira, don't give up. I know it can be frustrating when starting out, but there are all reasons why the prints are failing. None of what you are describing will likely be fixed by getting another printer. These sound like the same issues I had on mine and found just a few tweeks got things running more smoothly. I haven't had a failed print since I stopped printing the rooks.

First, I am pretty sure the failure of the test rooks is due to the contact area with the build plate being too small. Mine always failed at the first layer that cures over the entire diameter (base of the stairs) and is nearly the same area as the build plate. This means that the suction forces on the FEP and the bond at the build plate are very similar and often result in the part being pulled off the plate. If you take the rook and add a raft or supports, I suspect you would have much more luck with the grey. I print everything with supports generated in Chitubox. If you aren't yet experience with generating supports, you can try just using a raft, which will add a lot of contact area to the plate as well. This made the biggest differnece in my case.

Second, You can try slightly sanding the build plate surface. You need to be careful not to change the shape of the plate, but just give enough "micro-scratches" to help with adhesion. I used a 600 grit Silicon-Carbide (grey color) wet/dry sand paper that you can get at hardware stores or autoparts stores. I used a granante surface plate to be sure I kept the surface flat, but if you don't have a very smooth surface (like a sheet of glass), then just be very gentile while sanding and ensure you evenly cover the surface. Also, I cut my finger once on the edge of the plate when I tried to dislodge a stuck print, so I recommend rounding over the outside edges slightly to "debur" the plate.

Third, I actually found when I replaced the factory FEP with a new sheet, I had better prints. Maybe it was form my initial failures and trouble shooting, but the quality did improve. This shouldn't be necessary to prevent the built plate issues, but something to consider after you get the hang of things.

Finally, I am using the Mars Pro with standard grey too, and the default 60sec/4 layer bottom and 8 sec exposures were enough for good prints. I actually think they may be over-kill and I think I can get better sharpness on my prints if I turn things down a bit. I have successfully printed with 55sec bottom and 7sec standard exposures for 50um layer height. Settings also change if you use different layer heights, so stick with the .050mm until things start working. I also added 1s "Light Off Delay" and "Bottom Light Off Delay" to my Chitubox settings. Not certain how much impact this has, but was attempting to again get sharper prints. Also, be sure the resin is mixed well each time you print. This resin has a rather low viscocity and letting it sit even for a day or two can cause the pigments to settle out and cause exposure isses, especially on the first layer. Use either the plastic scraper (I like to use an old hotel key card) to lightly stir the tank and scrape pigment off the FEP.

Hope this gives you some ideas. I recommend only changing one thing at a time so you know what did the trick. Let us know how future attempts go.

Also, don't be discouraged if you have more failures. This is part of the "hobby" and the more mistakes you make and fix along the way, the easier it gets to trouble shoot and prevent future issues. I know it seems like a lot now, but you will get the hang of things with practice.

[cliffyk]

I received the Mars Pro build plate I had ordered from Amazon (yesterday-BTW) and upon un-packaging it I found the reason new "Pro" owners are experiencing build plate adhesion problems--it was obvious to me that it (at least the one I received) is FAR too smooth and shiny to possibly perform as required--I don't know what Elegoo's engineers were thinking when they elected to polish it to this extent--they obviously have recognized the error of their ways as the platen on the latest Mars 2 Pro has a sandblasted finish :



For surfaces with same overall dimensions that with a rough finish surface has greater area than that having a smooth finish due to the "nooks & crannies" of the rougher finish, just like English muffins. Here we want the build plate to have more surface area than the FEP to cause cured resin (the same "stuff" at both junctures) stay with the platen and release from the film--as the platen and the FEP have the same basic contact footprint, the platen needs to have a rougher finish in order that it have more surface/better adhesion.

Here is what the new "Pro" plate looks like; damned near a mirror finish, very much like the FEP:



And here for comparison is the "Pro" plate next to the plate from my plain ol' Mars--a proven performer since I scuffed up the glossy powder coat finish with a 320 grit disc in a 5" random orbit sander (not a single platen adhesion problem since doing that last May, though I have ripped up models in adhesion battles between the FEP and the plate):



I did not run any tests with the new plate as I do not care to waste any resin, and I do need to run tests to know it will not perform--this based upon my practical experience with 6 SLA printers from 3 makers ('til I "added 'em up" I didn't realize there had been that many since I began just about a year ago now).

In the morning I plan on either a) scuffing up the new plate with some 220 grit paper, or b) bringing it to a local welding shop and having it sand blasted or glass-beaded with some fine grit media. I am leaning toward b), however being a welding shop specialising in farm equipment they may not be set up to do finer finishes.

i shall return...

[Kasimira]

Kasimira, don't give up. I know it can be frustrating when starting out, but there are all reasons why the prints are failing. None of what you are describing will likely be fixed by getting another printer. These sound like the same issues I had on mine and found just a few tweeks got things running more smoothly. I haven't had a failed print since I stopped printing the rooks.

First, I am pretty sure the failure of the test rooks is due to the contact area with the build plate being too small. Mine always failed at the first layer that cures over the entire diameter (base of the stairs) and is nearly the same area as the build plate. This means that the suction forces on the FEP and the bond at the build plate are very similar and often result in the part being pulled off the plate. If you take the rook and add a raft or supports, I suspect you would have much more luck with the grey. I print everything with supports generated in Chitubox. If you aren't yet experience with generating supports, you can try just using a raft, which will add a lot of contact area to the plate as well. This made the biggest differnece in my case.

Second, You can try slightly sanding the build plate surface. You need to be careful not to change the shape of the plate, but just give enough "micro-scratches" to help with adhesion. I used a 600 grit Silicon-Carbide (grey color) wet/dry sand paper that you can get at hardware stores or autoparts stores. I used a granante surface plate to be sure I kept the surface flat, but if you don't have a very smooth surface (like a sheet of glass), then just be very gentile while sanding and ensure you evenly cover the surface. Also, I cut my finger once on the edge of the plate when I tried to dislodge a stuck print, so I recommend rounding over the outside edges slightly to "debur" the plate.

Third, I actually found when I replaced the factory FEP with a new sheet, I had better prints. Maybe it was form my initial failures and trouble shooting, but the quality did improve. This shouldn't be necessary to prevent the built plate issues, but something to consider after you get the hang of  things.

Finally, I am using the Mars Pro with standard grey too, and the default 60sec/4 layer bottom and 8 sec exposures were enough for good prints. I actually think they may be over-kill and I think I can get better sharpness on my prints if I turn things down a bit. I have successfully printed with 55sec bottom and 7sec standard exposures for 50um layer height. Settings also change if you use different layer heights, so stick with the .050mm until things start working. I also added 1s "Light Off Delay" and "Bottom Light Off Delay" to my Chitubox settings. Not certain how much impact this has, but was attempting to again get sharper prints. Also, be sure the resin is mixed well each time you print. This resin has a rather low viscocity and letting it sit even for a day or two can cause the pigments to settle out and cause exposure isses, especially on the first layer. Use either the plastic scraper (I like to use an old hotel key card) to lightly stir the tank and scrape pigment off the FEP.

Hope this gives you some ideas. I recommend only changing one thing at a time so you know what did the trick. Let us know how future attempts go.

Also, don't be discouraged if you have more failures. This is part of the "hobby" and the more mistakes you make and fix along the way, the easier it gets to trouble shoot and prevent future issues.  I know it seems like a lot now, but you will get the hang of things with practice.

I will definitely give some of those suggestions a try.  I'm going to stick with it, especially since we seem to be getting somewhere in this thread.  I do enjoy the little printer and I'm sure I will enjoy it far more once I work out the bugs.

---

Yes Cliff, that is exactly what my build plate looks like as well. Much thanks for going out and ordering a plate just to try to solve people's problems here. I'll keep an open eye on this thread to see what the results are from you scuffing up or sandblasting it.

[Lat2730]

I received the Mars Pro build plate I had ordered from Amazon (yesterday-BTW) and upon un-packaging it I found the reason new "Pro" owners are experiencing build plate adhesion problems--it was obvious to me that it (at least the one I received) is FAR too smooth and shiny to possibly perform as required--I don't know what Elegoo's engineers were thinking when they elected to polish it to this extent--they obviously have recognized the error of their ways as the platen on the latest Mars 2 Pro has a sandblasted finish :



For surfaces with same overall dimensions that with a rough finish surface has greater area than that having a smooth finish due to the "nooks & crannies" of the rougher finish, just like English muffins. Here we want the build plate to have more surface area than the FEP to cause cured resin (the same "stuff" at both junctures) stay with the platen and release from the film--as the platen and the FEP have the same basic contact footprint, the platen needs to have a rougher finish in order that it have more surface/better adhesion.

Here is what the new "Pro" plate looks like; damned near a mirror finish, very much like the FEP:



And here for comparison is the "Pro" plate next to the plate from my plain ol' Mars--a proven performer since I scuffed up the glossy powder coat finish with a 320 grit disc in a 5" random orbit sander (not a single platen adhesion problem since doing that last May, though I have ripped up models in adhesion battles between the FEP and the plate):



I did not run any tests with the new plate as I do not care to waste any resin, and I do need to run tests to know it will not perform--this based upon my practical experience with 6 SLA printers from 3 makers ('til I "added 'em up" I didn't realize there had been that many since I began just about a year ago now).

In the morning I plan on either a) scuffing up the new plate with some 220 grit paper, or b) bringing it to a local welding shop and having it sand blasted or glass-beaded with some fine grit media. I am leaning toward b), however being a welding shop specialising in farm equipment they may not be set up to do finer finishes.

i shall return...

The synthetic grease has turned up, I am going to try with that first combined with a couple of strips of tape either side of the screen to create a small air gap, if that fails will try scuffing the plate a little bit, I have an orbital sander with some some cuts of sandpaper so will report back in a few hours

[cliffyk]

THe problem I see with the PTFE grease is that the first layer you print will have to have a bit of the PTFE between it and the next layer, this contamination cannot promote better adhesion between those layers. Subsequent layers wil likely carry PTFE between them as well, though in lesser quantity.

After seeing the "Pro" platen first hand I am pretty confident that it's near mirror-like finish is the problem--again, this confidence bolstered by Elegoo's decision to sandblast finish the platen on the "M2P".

In a couple hours I'll make some calls to see if I can find a shop that can do a fine finish sandblasted or glass-beaded finish; if not I'll hit it with he sander and print "larger"something. Got this in mind given the season: