Printing without the wiper blade


#1

I’ve been printing for a few weeks without the wiper blade, in Grey v4. Just unclipped it, put it in a box, otherwise running the machine entirely as normal.

No crashes, no frothing, no splashes, all builds 100% AOK. No scrapes on the tank floor (LT), just 100% perfect builds. I realise just by writing this I have just damned my machine to eternal doom, but hey, I thought I’d raise the point anyway.

I just wondered if anyone else had tried this.


#2

I’ve accidentally run a few prints without a wiper in the tank (I had switched out tanks and forgot to put a wiper back in :stuck_out_tongue: ) and the prints came out perfectly fine. I know the printer’s Open Mode was designed to be able to run without the wiper so I figure its not a huge deal if there’s no wiper on a closed mode print. Now if only Formlabs could implement custom printer settings (i.e. no wiper, custom heat temp. options, etc.) to maybe boost print speeds that would be awesome


#3

Like most companies that sell a machine with the need to purchase materials after want to keep you buying the materials, resin in this case, to make money. Once a machine is sold it’s a cost to the manufacture if they have to service it, not so with material supplies. HP printers is a good example. They all but give the printer away then sell you ink at a very high price.


#4

Hey everyone! Just thought I’d chime in here!

It’s certainly possible to print without the wiper, but given the job it was designed to do, I wouldn’t recommend it. The printer won’t know if something drops into the tank during printing and then you could pretty seriously damage the resin tank, the printer itself, or cause some pretty gnarly spills.

Just so I can pass some feedback along, do you mind if I ask what you gain by removing the wiper? Genuinely curious and we’d love to know. :slight_smile:


#5

Certainly.

I have had numerous failed builds, a fair few caused by Black v4 staying soft, and parts breaking free. If this had happened without the blade, it would have been a mess, but the fragments would have stayed more or less where they dropped, and had the machine carried on printing, I would have had a few patches of exposed resin stuck to the bottom of the tank, easy to clean up, a few loose parts, easy to bin, and maybe a few parts that survived.

As it was, the blade carried on sweeping back and forth, smashing the debris into the remaining parts, knocking them off as well. It shunted the debris back and forth across the tank, ploughing up the surface. And where anything stuck to the floor of the tank, the blade tripped up over them, flicking resin and debris out of the tank. Several times. 4, at least, so hours of my time, laser time, tank time, resin all wasted and several disappointed customers…

Since having removed the blade, all the builds have completed perfectly, Now, agreed, changing to Grey v4 may have something to do with it, my laser being able to cure it properly and I haven’t had anything fall off the support structures. So not a perfect test, but the resin doesn’t get frothed up (a real worry !) and I have a perfectly serviceable tank still, and dozens of perfect parts.

I am still not really sure what the blade is supposed to do, other than keep the resin mixed. It seems to be so risky, and destructive, if things go wrong, while the resin will be mixed by the parts being lifted into and out of the resin anyway. On balance, and based on my experience, I’m not going to run my machine with the blade. I can’t afford it!!

Happy to keep you posted with progress of course…

Tim


#6

Hi Tim! I’m a service engineer on Dan’s team and I thought I’d chime in with some the thinking behind the wiper design. We definitely had more in mind than just mixing the resin, although that is one of the major purposes.

The wiper does three main things: keep the resin well-mixed and homogenous, help with failure recovery, and make sure the resin and tank surface are oxygenated. Of the three, keeping things mixed is actually probably the least important (although it’s still very helpful.)

I find the description of the wiper making failures worse interesting, because one of the main ideas of the wiper is to improve the results of a failed print. Without a wiper, once a part starts failing, the failed “pancake” on the tank bottom will stay there and grow bigger over time, wiping out more and more of your part and often getting so big it interferes with other parts as well. With the wiper, however, the hope is that as a failure starts, the seed of the “pancake” will get swept away and deposited at the side of the tank where it will be out of the way, and the part that was beginning to fail may be able to recover, or at least avoid affecting other parts near it.

The wiper getting stuck on things in the tank and “flicking” resin is certainly an issue (and, as you’d expect, not something we intended!) but we find that it happens very rarely combined to doing its intended job of taking an incipient failure and turning it into a successful part. In this case, it looks like your parts were just too far gone for the wiper to save; I can see how, once you’re in that spot, the wiper moving the failed chunks around is less than helpful. Did you nail down what was causing those failures in the first place? Black 04 is always going to be a bit softer than Grey 04, but it shouldn’t be failing on you like that—if you wanted to open a support case with our team, we’d be happy to dig into why that was happening.

The third job of the wiper, and actually the most important one, is keeping the resin in the tank oxygenated. I was confused to hear you say that you worry about froth in your resin—I’d love to hear more about why it’s something to worry about. In our book, bubbles in the resin aren’t just not a problem, they’re actively good, since they show that the resin is well-oxygenated. Oxygen in the resin keeps peel forces low, reducing stress on your part, which has myriad benefits: lower failure rates, less warping of the part, less obtrusive layer lines, and so forth. It also slows down the pace of clouding in our standard resin tanks.

We’re certainly not going to try to stop you if you’re seeing good results running without a wiper, but I hope this helps clarify the reasons we included it in the Form 2 design. Definitely let me know if you have any more questions about any of the above!


#7

Declan, many thanks for the background to the wiper blade, much appreciated.

I have raised the black resin issue with support, I have 3 kgs of the stuff which I now dare not use, after a string of failed builds, but I am very reluctant to bin it as if there is a solution to the soft (and i mean SOFT, not just a bit more like polypropylene than ABS!) cure, I’ can definitely make use of it! I still don’t know if I had a poor batch or two, but switching to Grey immediately improved things, so from now on I’ll stick with Grey. Had I been using the 3D Systems SLA 250 I learned the Dark Art on 15 years ago, I could just up the laser power and get it curing!!

Frothing. Only an issue with Grey v4, for some reason, and with the wiper. It got so bad on couple of builds it almost fell over the edge of the tank! No. NO no no no !!! I REALLY do not want to have to clean up a resin spill as well!! I can understand the chemistry of the oxygenated release surface, but on balance, my builds have been perfect since I took the blade out, so I consider those benefits are relatively minor, against the multiple failures I have already had while the blade was in, and while I was using the black resin. If you are trying to run a business and have clients waiting for parts, that you have promised you would deliver, having an intellectually challenging reason and possible solution to a problem is irrelevant; they didn’t get their parts, and I’ve lost a customer!

Vid of the soft black, might be of interest! https://youtu.be/V6ZtF1m1Eng


#8

The black resin has been nothing but trouble for me. It never really seems to cure properly and causing warping during print and after. Yeah I have been printing my clear resin without the wiper and heater because of cartridge and tank errors. The prints all come out perfectly fine and faster I might add. Less errors slowing things down and no wiper to interrupt every layer. My biggest gripe with open mode is the fact that the heater gets shut off. The resin flows much better especially when its cold with the heater on. The only reason we dont have more control over how our printer prints in open mode is likely to keep us buying their resin and overpriced tank system.


#9

The Black V4 resin is nothing more than misery for us(brittle, cracks easily, deformed parts).

So we’re sticking with clear for now.

We are thinking about buying the color base resin and add black pigment to see how that goes.


#10

Exactly the same problem I have been fighting!! Resin is very pliable when removing. I just got the fourth print in a row fail for the same reason. My management is pissed because now we are behind on projects…

Originally the issue was sent to support because we were covering most of the build plate and support told us to reduce the number of copies of the model. Still everything is failing. I’ve waster almost a full jug of resign at this point.

This is black V4, so I guess I will try another resin. Already tried a brand new tank and no help. Maybe it is a bad batch of resin as I make 4 builds completely covering the build plate and they came out perfect, then all hell broke loose after a new resin jug.

@Declan See the above picture for a good example of a wiper making things worse. 3 models detached at the supports from the base… wiper pushed them to the side (good) BUT now for every layer the wiper peels the small layer of cured resin and deposits the cured film all over the place and gums up every other part that could have potentially still build properly.

I agree the wiper makes sense on single models, but for multiple copies of prints in the same build it seems better chance of recovery without it.


#11

Exactly…


#12

Do you regularly shake the bottles and move the resin in the tray around before printing? Black is heavily pigmented which can settle in the bottle.


#13

Yes, before every build…and always have done.


#14

Hello everyone, my problem with the wiper is the following: when the platform goes down towards the tank it hits the wiper in its widest part. It only happens with a wiper (I have 4 tanks 3 of which do not give problems) but also the others are really very close to the platform, more or less a millimeter.


#15

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#17