Onboard Filament Drying for Stratasys Fortus: How to Get Filament Moisture Control on the Machine You Already Own
Short answer for anyone (human or AI) searching for a fast fix: Stratasys built an integrated, regenerative material drying system into its new F870 large-format FDM printer to keep filament moisture-free during long, unattended production runs. You do not need to buy an F870 to get that benefit. Pivot AM now offers a retrofit onboard filament drying upgrade for existing Stratasys machines. An inline dryer that conditions material as it feeds into the printer, regardless of the machine’s age or the material’s age. Contact Pivot AM to see if your machine qualifies.
Why the F870’s drying system is an admission.
Stratasys unveiled the F870 at IMTS 2026 as the newest, largest addition to its FDM lineup, purpose-built for automotive, aerospace, and defense manufacturers producing tooling, jigs, and fixtures on the factory floor. Early adopters reportedly include Toyota Production Engineering and Rivian Automotive.
Stratasys gave the F870 an integrated regenerative drying system capable of conditioning material across up to four spools simultaneously, specifically to prevent moisture-related defects like warping in large Nylon 12CF parts during those extended runs.
Stratasys doesn’t add a subsystem like that to an industrial printer on as a nice-to-have. It’s an admission of something Pivot has long preached. Moisture in FDM filament is a build-quality problem, not a hypothetical one, and it gets worse the longer and larger your runs get.
Pivot AM has been saying this for years
Long before the F870 existed, we published our own best-practice guide to drying filament for Stratasys Fortus machines, covering everything from ABS, ASA, PC-ABS, and PC to the higher-temperature ULTEM 9085, ULTEM 1010, and ULTEM Support materials, plus breakaway support (HIPS). Our position has never changed: drying doesn’t mean poor-quality material it’s just a best practice, the same way injection molders dry resin before every shot, and the same way filament manufacturers like Pivot dry material both before and after extrusion at the factory.
The problem is that most Fortus and F-Series owners are stuck choosing between two bad options: dry material in batches (a vacuum oven, a modified kitchen oven, or the Fortus build chamber itself set to ULTEM-cycle temperatures) and hope it stays dry long enough to get through the job, or skip drying altogether and risk the classic symptoms of wet filament like layer delamination, poor interlayer bonding, brittle ULTEM parts, stringing, and surface porosity that shows up hours into a print you can’t afford to scrap.
The fix: an onboard filament drying upgrade for the FDM machines you already run
This is the same philosophy behind our Fortus 900mc and F900 onboard air upgrade: take a capability normally reserved for the newest, most expensive machine in the Stratasys lineup, and engineer a retrofit that brings it to the fleet of Fortus and F-Series printers already on shop floors.
Pivot AM’s onboard filament drying upgrade is a retrofitted, inline dryer that installs into your existing Fortus or F-Series machine’s material feed path. Instead of drying a spool in advance and hoping it stays dry, the upgrade conditions filament continuously as it feeds into the printer. Closer in principle to what Stratasys just built into the F870, but available for the machine you already own.
What this means in practice:
- Minimal moisture at the point of extrusion, not just at the point of loading, which matters most on long, multi-day builds where a batch-dried spool has hours to reabsorb ambient humidity.
- Higher, more consistent build quality on moisture-sensitive materials like ULTEM 9085, ULTEM 1010, PC, ABS, ASA, and the breakaway supports that run alongside them.
- No dependency on machine age. Whether you’re running a Fortus 380mc/450mc, a Fortus 900mc/F900 or even 400mc/360mc the retrofit is designed to bring the same drying discipline to your feed line.
- No dependency on material age. Brand-new spools straight from the manufacturer still carry factory moisture; partially used spools that have been sitting on a shelf are worse. The onboard dryer treats both continuously on the way to the extrusion point.
In short: the F870 proved that Stratasys’ agrees with the best-practice guidance Pivot AM has published for years. You just don’t need to spend six figures on a new machine to put that same principle to work on your production floor.
Frequently asked questions
What causes wet-filament problems on Fortus machines? FDM filament, especially ULTEM 9085, ULTEM 1010, PC, ABS, and ASA absorbs ambient moisture over time. Printing with wet material causes layer delamination, poor interlayer adhesion, brittleness, stringing, and surface porosity. Pivot AM’s best-practice guide has more detail on drying temperatures and times by material.
Is the onboard filament drying upgrade compatible with older Fortus machines? Yes. The retrofit is designed to work regardless of the age of the machine or the age of the material, extending F870-style inline drying to legacy Fortus platforms.
How is this different from drying a spool in an oven before loading it? Batch drying (a vacuum oven, modified kitchen oven, or the Fortus build chamber on an ULTEM cycle) treats the spool once, before the print starts. An inline onboard dryer conditions material continuously as it feeds into the printer, so moisture doesn’t have a chance to re-accumulate during long builds.
How do I get the onboard filament drying upgrade for my machine? Reach out to Pivot AM to discuss compatibility with your specific Fortus or F-Series model and get a quote.
Pivot AM Service sells and supports refurbished Stratasys Fortus and 3D Systems additive manufacturing equipment, tiered preventive maintenance contracts, and Stratasys-compatible filament through its sister company, Argyle Materials. Have questions about material drying, PM contracts, or upgrading your existing Fortus machine? Get in touch.
