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Hi Everyone,

My company currently uses the Makerbot Replicator 2 for prototyping. We are looking to add another, that hopefully doesn’t cause as much shrinkage. Does anyone have any recommendations that they have had success with?
It must be <15k in price, be able to print waterproof parts, and print more accurately than our current printer. We are also looking into possibly going with a CNC machine instead, but am worried they might be more difficult to use.

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Unsure what you mean exactly by “waterproof”. As far as I know, the machines themselves aren’t really going to reduce shrinkage as much as they will prevent “warpage” due to being either enclosed or open. Materials themselves are what cause “shrinkage” along with the settings you use when printing with them.

Part accuracy is going to come down to a LOT of different factors: the printer structure being very strong and rigid, printer settings for acceleration/jerk, nozzle diameter, print speed, cooling settings, materials used, warping/shrinkage of material used, etc.

Do you have a need for dual extruders so you can use water soluble supports? What kind of build area do you need? Do you print parts that require a lot of support material? What materials do you currently print with? Do these parts need to be structurally strong or are they mainly cosmetic parts (no load/stress)?

A CNC machine is good for many parts when strength is required, but even a 5-axis CNC will not be able to reproduce the parts that a FDM/SLA/SLS machine can produce. However, if the parts are very simple and do not require very small features to be created, maybe the CNC is what you need. I’m just not sure what you’re creating to make a good decision about this.

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Hi @achelp, as @Jory has said, shrinkage is not really machine-specific but rather the nature of the plastics used in FDM printing. FDM really isn’t that dimensionally accurate (at least not in precision engineering terms).

“Waterproofing” is a whole other issue. Most FDM prints may look solid and watertight, but as soon as you fill them with water they’ll leak like the proverbial sieve. This is because there are tiny fissures between the layers that liquids can find their way through, especially if under any kind of pressure. Using the right material and the right settings can help and you can always coat the finished model in resin or post-process in some way to “seal” the outer surfaces, but I wouldn’t rely upon even these for anything mechanical.

SLA technology will get you a lot closer to your goals on both fronts. Dimensionally SLA is a far more accurate than FDM and the printing technology itself forms better layer-to-layer bonds, as well as being totally solid, making them naturally much more water-resistant. You’d still have to test just how well they respond to holding/resisting liquids, but they’ll be better than FDM straight off the bed.

With a 15K budget (£ ? $ ?) you could just about scrape into the SLS market and that’s another possibility. Again, the layer bonding is better than FDM and dimensional accuracy is high. SLS is also a good bet if you’ll be producing multiple parts and/or making small production runs.

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Someone selling a Sinterit Lisa with upgrades over in the “For Sale” section.