Considering Manufacturing via SLA Printers

[alx44]

Hello folks,

I am new to additive manufacturing and seeking guidance on selecting the best printer for my needs. Any input would be greatly appreciated. Also, my apologies for the lengthy post…

Background: I work in industrial design, specializing in computer-related peripherals and office accessories. Currently, I outsource manufacturing to suppliers abroad, but I’m considering bringing a portion of production in-house using SLA printers. After analyzing costs, it seems that using a Formlabs Form 3+ printer could significantly reduce expenses. For example, CNC and injection molding requires costly molds, ranging from $1000 to $3000+ for more complex parts. Many of our products consist of smaller plastic pieces. Additionally, our production numbers are relatively low, not exceeding 250 units, making large-scale manufacturing impractical at this stage.

My plan is to purchase a Formlabs printer, wash & cure station, resin, and necessary accessories within a budget of $2500 - $5000. The Form 3+ complete package, priced at $4250, seems to fulfill most of my requirements. However, I have concerns about the cost of Formlabs’ resin. At a minimum of $150 per liter, I’m unsure of the resin’s yield in terms of units produced, considering the additional resin used for supports.

Ideally, I aim to produce at least 50 units per week, if not 100+. Imagine that the intended product for manufacturing is a partially hollow block measuring 120 * 35 * 20 mm (0.084 L) with a radius on the longer edge (think of a pill-shaped item with a flat top and bottom).

I have a few specific questions:

Should I purchase a Formlabs printer for my current manufacturing needs of 250 units or fewer?

Approximately how many units can be produced with one liter of resin? Assuming I need 150 units of the aforementioned hollow block, a rough estimate would suffice.

Does the Form 3+ complete package adequately meet my needs?

Would it be sensible to consider purchasing a cheaper second-hand Form 2 printer and allocate the saved money towards additional resin and accessories for increased production?

Apologies for the lengthy post; I’m new to this field and would greatly appreciate any input on my situation. Thank you for taking the time to read this.

Best regards,
Alex

[br4n_d0n]

It depends on the orientation of print, but from my quick mockup I would estimate between 10 and 12 items for 1 full liter of resin. That’s roughly 20 to 25 bottles of resin with a price between $3,000 to $3,750 to do 250 units at $150 per bottle. Not cheap, but that depends on how much you were spending before and any other factors that may play a role. Unfortunately, Formlabs products and materials tend to be on the expensive side.

Keep in mind this estimate is under good conditions without failed prints and not including the cost of the disposable trays. This also doesn’t take into consideration the build times.

In my opinion, laser based resin printers have not kept up enough and the LCD versions are faster as they can do an entire layer of the print surface at once whereas a laser needs to move around. This means the larger the print area the slower a laser printer gets if the movement speed stays the same.

[billb]

This model would have to be redesigned to have any chance of getting anywhere near the yield figure you have quoted. Does it have to be solid? Can it be shelled? It probably also needs to be built directly on the build platform.

If the resin used could be halved, then a build of 18 models could be done in around 24 hours and one litre of resin.

Formlabs Preform software can be downloaded so you can experiment with what is possible.

[alx44]

The item is shelled, so it would not be a solid block. Imagine a hollow pill-shaped item with 5mm thick walls and a flat bottom and top. I think I would be able to orient the product vertically, therefore allowing for more units in a single print. I don’t think it would use that much resin since I feel the supports would be minimal, but I am not 100%. I will play around with the Preform software to obtain a better gauge as to the material required for printing. I appreciate your input, thank you!

[alx44]

Thanks so much for your insight; that really helped me!

$3000-$3750 for 250 units does not seem too expensive relative to other manufacturing processes at this scale, but I do acknowledge that the resin costs are a bit steep. I am unsure how that would pan out in the long run once I increase production numbers. Regardless, I know that a Formlabs printer would be stellar for prototyping purposes. Now the 250 units are at the high end of what I am comfortable producing, so I would likely start off with a smaller amount…around 150 or 200 units max, which I think would be feasible. I would be comfortable spending around 2000-2500 just on resin.

Now you mentioned that laser-based printers are not on par with LCD-based printers in terms of speed… On average, Is there a difference in the quality and durability of the parts from a laser-based vs an LCD -based printer? Or is this dependent on other factors, such as the resin type? Or curing/washing process?

I was interested in using Formlabs’ Clear 1L resin (Buy Clear Resin) as its ultimate tensile strength is rated at 66MPa. I produce many products using bead-blasted polycarbonate…a translucent material used for many mechanical keyboards and electronics, with an ultimate tensile strength of 68MPa, so it seems very similar in strength and general qualities. I was looking at cheaper printers by Elegoo and Anycubic. I noticed that the ultimate tensile strength of their resins rarely exceeds 45 MPa, so I am worried about the materials being too fragile. Any thoughts on this?

[br4n_d0n]

@billb I think the shape @alx44 is referring to, and what I quickly made, was similar to a PEZ candy.

@alx44 I’m not certain on the quality of the LCD based printers as I don’t own one, but the well known ones seem to be built to a price. They may lack some features, but also give you a lot more freedom in the software and resin departments. Currently the Form 1 and 2 are the only devices to officially support 3rd party resins, but disable features on the printer when you do this. Formlabs is lame and chips the bottles and tanks like some inkjet printer brands do. There are ways around this, but it could be considered too much of a hassle for some. There are also companies such as ApplyLabWork that offer laser, dlp, and msla resins at a lot cheaper price with similar qualities to Formlabs.

On a side note, I feel the Formlabs Cure Stations are WAY overpriced, too small, and not as well designed as 3rd party alternatives. Heck, you can even make your own for cheap if you like. Key is to have reflective material all around and a controllable heating element. To achieve a good all around reflection, you can use a piece of glass at the bottom that’s lifted somewhat acting like a shelf.

I’m not sure on price and functionality of the wash stations, but my gut feeling tells me you can get a nice ultrasonic cleaner for a similar or cheaper price.

[alexhawker]

These cost estimates assume your time is free (it’s not, I would put a healthy hourly rate on it for your calculations) and unlimited (it’s not). I would also factor in some amount of scrap parts that need rework or must be discarded. Similarly, you may need to do extensive and laborious hand finishing to get the level of polish you need for an end-use consumer part.

[alx44]

@br4n_d0n I took a look at ApplyLabWork, and their clear resin has a tensile strength of 53-67, so that’s similar to the Formlabs Clear resin, and it’s $80 vs $150.

My idea now: get a Form 2 printer and use 3rd a party resin for $80/liter. The resin alone is 53% cheaper than the Formlabs version. As for the Form 2 printer, I’ve seen used ones going for $500 - $800. I can pick up two for under $1500.

I also ran some numbers using the Preform software and estimated, using one Form 2, I could print 125 units in 35 days. Now that is assuming nothing goes wrong. Let’s add 10-20 days, so a rough range of 45-55 days to produce 125 units accounting for post-processing and hiccups along the way. Materials costs: $5.7 for part 1 and $6.66 for part two of my design (using third part resin). Total cost = $3090 ***initial cost of printer and my hourly rate are not included in this calculation. Accounting for my time involved, assuming 4 hours of work per day * hourly rate of $38 = $120 of my effort/day. 45-55 days of my effort is worth $6840 - $8360. Now this is intangible so I will discount it for simplicity’s sake. @alexhawker

If my estimates are accurate, this is a solid alternative route. I could make 125 units for the price of a new form 3+ package. I would be sacrificing time, as the Form 3+ is much faster, but I don’t think the extra benefits of the Form 3+ outweigh the value of my alternative route with the Form 2 and 3rd party resins. Assuming my product sells well, the proceeds would fund the purchase of a form 3+ printer with the automation system and more within 6-12 months after release.

As for your perspective on the Formlabs curing station, I completely agree with you…way too overpriced. I was also thinking of DIY’ing a curing station for a fraction of the cost, but I was curious if it would compromise durability. But now that you mention it’s possible, I will likely go with the DIY route.

Thanks again for everyone’s input! Y’all are awesome

[br4n_d0n]

You may want to see how long it takes to print flat vs vertical because a few faster prints with less chance of failure may end up saving time compared to printing a bunch of vertical ones all at once and get a failure screwing the entire batch.

[leonhart88]

Although the Formlabs machines are great for prototyping and also low volume production, one thing that’s often forgotten about is all the post processing involved.

Whether that’s removing supports or buying/recycling/disposing of solvent, the post processing can introduce a lot of extra labor you may or may not want to take on, not to mention additional cost.

If your parts are small, it’s probably better to just outsource overseas to an MJF or SLS supplier.

There are definitely scenarios and good reasons to produce parts in house on a Formlabs machines (we’ve done it) - but if cost and time are your major driving factors, it might not be the best choice (unless you don’t value your time and labour ).

I would still highly recommend getting a printer regardless though if you’re in the design business.

[Rimsa]

100% agree on the post processing that @leonhart88 mentioned.
And it can get very labor intensive for both SLA and SLS regarding what is the outcome that you are willing to achieve.

Regarding the laser vs LCD - I have not heard of print quality differences in means of strength. What I have red about is that the entry level priced LCD SLA printers tend to break down quite fast. And the thing that wears down is the LCD witch is deteriorated by the UV light. That said there are some relatively high end manufacturers that make LCD SLA printers, for example nexa3D.

MDF isn’t an option ? It would be very affordable, cheap material, low post processing (if not going for vapor smoothing )

[br4n_d0n]

Besides LCD versions, that may not last as long, there are also DLP projector based ones which are very similar and would probably last longer. Problem is the distance/size and cost of the projectors.