Hey look, the tank and build platform are available for purchase separately

When did this happen? I’m happy that they’re up for sale but would have been happier with lower prices.

I’m actually pleasantly surprised about the resin tray.  I figured it would be $100.  If I only need to replace this for say every three-four bottles of resin (hoping, time will tell), then it’s really not too bad.  Added cost of $.02 per Ml of resin (assuming 3 liters per tray), that’s a pretty reasonable cost.

It would be nice to get a discount for returning the old tray, or offer a re-coating service.  It seems wasteful to throw them away if only the silicone is damaged.

I think that chemically treated (strengthened) optically clear glass might be a better option. If/when I get my form1, then ill make a replacement resin tank to see if it won’t fog. That seems expensive to replace those parts so often over time, almost making it unaffordable.

I agree with Temujin that it’s a bit of a drag to learn we have a future of regular replacement of a $70 resin tray to look forward to. Tucker is correct however that it will add about 2-3 cents to the cost of a cubic centimeter of material assuming the tray lasts 2 or 3 bottles of resin. As it now stands, with $130 resin (as a kickstarter backer) and $70 trays, my last print job which I quoted at ZoomRP at $122(+$25 shipping) or $40(+$6 shipping at Shapeways will cost $12.75 on the Form 1 when factoring in the the tank replacement cost. The cost would have been $10.80 without the added cost of new resin tanks. The Form 1 remains a game-changer for a lot of folks working on smaller budgets. I guess that’s why we’re all here waiting for the printers to ship.

Maybe some enterprising Form 1 backer can figure out a suitable replacement material, make an mold and offer a rebuild service. There would seem to be room for a little profit while undercutting Form Labs substantially.

One last thought. Maybe the folks at Formlabs could tell what their experience has been with tank replacement?

It would also be nice to be able to send in your “worn out/damaged” resin tanks to be recoated/refurbished by FormLabs for a fee.

There might be a couple existing options for reconditioning a resin tray.

First would be to remove and pour in a new PDMS layer. Apparently this is what B9Creator owners already do (I have to assume there are pre-made vats available as well though). Here’s a video explaining how it’s done…

I don’t know about the B9Creator but on the Form1 the thickness of the PDMS layer seems to be important. Using the wrong volume of PDMS would likely cause the thickness to be off-spec. I imagine a graduated syringe (or maybe a scale) could be used to ensure you’re using the right amount of PDMS.

Another option would be to remove the PDMS and add in a FEP layer. So far as I know this is untested (except possibly by Formlabs themselves). A major issue I can see is that it’s unlikely that the FEP sticker will be the same thickness as the existing PDMS layer. Since the Form1 “homes” at the top of the Z tower the difference in thickness will mean the build platform will likely be a few whole millimeters above the FEP layer instead of nearly pressed against it. This discrepancy in thickness would have to be corrected somehow. It would be nice if there was a variable in PreForm to compensate. It *might* also be possible to turn the screw by hand to manually lower the platform slightly before starting a print - I’ve tried this a few times but only had success once (that single success may have just been a fluke).

I just ordered some of the FEP sheets from mUVe 3D. I don’t know if I’ll try slapping one on my reservoir right away or not.

Quick update…

I received the FEP stickers I ordered. They’re very thin. My calipers say the actual FEP is close to 2.5 thousandths of an inch (0.0025" or ~0.064 mm) thick. To say it another way: it’s a little thinner than typical printer paper.

Didn’t John Morewood state that he had already replaced the PDMS in his form1?  http://support.formlabs.com/entries/24138171-vs-the-B9Creator-

But in his post he said nothing about whether or not the layer thickness of the new PDMS needs to be exact.

Can we get any more info on this process?

To me it looks like the Form1 “homes” to the top of the Z tower. See the attached picture of what I believe is the home switch. Basically, the machine doesn’t “know” where it is - that’s to say that all the machine can do is move according to a set of instructions. As long as it always starts those instructions from the exact same place it will do the exact same thing every time.

The home position is like the starting point on a treasure map. If you start in the right place and take 10 paces south then 8 paces east you’ll arrive at the treasure. If you start in the wrong place and take the same 10 paces south and 8 paces east you will not arrive at the treasure.

If I’m right about where the Form1 homes than it always starts its operations from the top of the Z tower. The first step is always “move down 180 mm” (I’m not sure what the actual measurement is). It moves down 180 mm because it knows the top of the PDMS layer should be 180 mm from the home position.

If the PDMS layer is 2 mm thicker the top will actually only be 178 mm from the home position - but of course the machine has no way to know this. In this situation the initial attempt to move 180 mm will be cut short.

And of course if the PDMS layer is 2 mm thinner the top will be 182 mm from the home position. In this situation the initial 180 mm movement will work correctly, but the build platform will be 2 mm above the top of the PDMS layer. Once again the machine won’t have any idea that this is the case and will continue with the rest of its instructions as if nothing was wrong.

I hope this makes sense. Another analogy would be a “10 foot” diving board over a pool. If you took 1 foot of water out of the pool the effective height of the diving board would become 11 feet. Adding an extra foot of water would make the effective height 9 feet. If you had a robotic diver it would probably have problems executing a 10’ dive when it actually only has 9’ to fall.

I understand what you are saying about the Z calibration process for the Form1. I perhaps wrongly assumed that the B9 and the form1 had a similar calibration method for the thickness of the PDMS. Going with that assumption in the video for replacing the used PDMS for the B9 they said it’s “not supper critical that it’s 45ml” leading me to believe that the same could be said for the Form1.

Given the information that the Form1calibrates at the top of the Z tower, do we know what the tolerances are for the layer thickness of the PDMS?

I would imagine if the tolerances are extremely tight that measuring the new PDMS would be easier by mass instead of volume? From what I understand achieving a high degree of accuracy from most inexpensive glassware is difficult. Also achieving accuracy could be made more difficult if the new PDMS layer gains or loses volume when it cures to a solid.

It would be great to hear from John about his process for replacing the PDMS in his Form1.

I agree with Tucker that it just seems wasteful and expensive to throw away the used trays.
Could Formlabs supply a pre-measured bottle of PDMS? Or a bottle pre-calibrated to the exact volume needed to replace the old PDMS?

It looks to me like the resin tank uses about 100 ml of PDMS. Assuming the numbers stated in the B9Creator video are accurate that means we could get about 4.5 recoatings out of that 0.5 kg PDMS kit.

I don’t know if you have seen this but here is the guide to the Z calibration for the B9.


I hope that there is a similar method for re-calibrating the Form1!

Any luck with the FEP stickers?

I haven’t tried the FEP stickers yet. Well, I’ve cut a couple small pieces off and stuck one to a piece of acrylic I had lying around but I haven’t tried it in the machine yet. I plan to try it soon though - I’ll probably start a new thread once I do.

The FEP is much less transparent than I expected. It basically has an “orange peel” texture. The backing paper also has a pronounced texture (it looks like leather) which makes me think the FEP would be smoother if they used smoother backing paper. I, of course, do not have any idea whether the texture will have any affect on the quality of the prints. I imagine that a very thin/flat texture might not disrupt the laser very much and will therefor not have a negative impact on the print - I mean: it apparently works fine with the mUVe 3D printer so it can’t be THAT bad.

I accidentally ruined my first resin tank. I had a print fail and it left a large blob of cured resin on the PDMS layer. While trying to remove it I ended up tearing the PDMS. :frowning:

Since it was ruined I took the PDMS out and measured it as well as I could using my cheap set of digital calipers. The PDMS seems to be 161 mm square by 3 mm thick. That makes the PDMS layer ~78 ml in volume. (My previous, incorrect, estimate of 100 ml was based on trying to measure the thickness of the PDMS while it was still in the tank.) That means we should be able to reliably get 5 recoatings out of each 0.5 kg PDMS kit.

@Hirudin: thanks for posting your experiments with the tank. As I’m in New Zealand its and expensive trip to send out new tanks all the time, so I’m really greatful to all those folks like you who are experiementing.


That sucks what happened to your vat, but I am relieved to hear that the we should be able to get 5 coatings instead of 4.5.  From what I understand PDMS doesn’t have a very long shelf life so I was expecting to eat the .5 leftovers.

Hi there, can PTFE spray replace the PDMS layers?