Enclosure + Air Filtration: Wham Bam HotBox V2 + Nevermore StealthMax V2

Published · Researched 2026-09-21

Cardboard box with a Saran-wrap window. That's the ghost that haunts every enclosure review, and the Prusa forum said it out loud back in 2019: how much better is a branded tent, really? For the HotBox, the honest answer is: flame-retardant coating and convenience. That's it. That's the whole premium.

What these are: the Wham Bam HotBox V2 ($148 official), a fold-flat nylon enclosure for open-frame printers, and the Nevermore StealthMax V2 (~$141 for the full hardware kit), the open-source community-standard activated-carbon + HEPA recirculating filter — currently the default filter in the Voron world.

What's actually wrong. The most important sentence in the research: a fabric enclosure is a passive solution. It does not filter anything. It raises chamber temperature so ABS and ASA warp less, and it does nothing at all about the fumes coming off the bed. If you buy a HotBox for "safety" without a filter or exhaust, you've bought a tent. Chamber temps are modest — a Prusa-forum user measured 36 °C max printing ASA; the enclosure typically lands in the mid-30s, enough to reduce warping but nowhere near a real heated chamber. The StealthMax side has its own honest problem: how do you verify it's actually doing something? A decent VOC meter costs more than the filter kit, per forum.vorondesign.com, so most owners operate on the strong odor reduction and community trust. There is no independent lab test of its VOC reduction — only claims. Then the ownership caveats: StealthMax kits exclude printed parts and carbon (print the parts in ABS/ASA on another printer, or buy printed kits that run ~$185), carbon replacement pricing and schedule were never published by any vendor this pass — the replacement-cost cadence is genuinely unknown — and you need a 24 V source and genuine DIY comfort. The V2's pre-terminated kits lowered the bar from the solder-everything days, but this is still not plug-and-play. The new V2 hardware resolved one real owner gripe and opened another: the official stealthmax_v2 repo (updated ~Apr 2026) documents a new 7020 fan delivering 2× airflow at the same noise with 2× static pressure, and servo-controlled switching between recirculation and exhaust with temperature-triggered venting — which directly answers the V1 owner's manual-vent complaint — but it adds a new moving part with no long-term owner data, and the optional 1.28" display exists with software support described as limited and pending. HotBox details: the built-in thermometer may need LR44 batteries not included (verified only for the Resin HotBox manual), the reseller price was $185 and sold out, and Wham Bam warranty terms weren't verified. Fire awareness is real: fabric + heater + high-temp filaments means the HotBox's fire-resistant coating is reassurance, not a guarantee — keep the PSU and electronics outside.

What's genuinely good. The HotBox does exactly what it's for: users report successful ASA prints in it, it sets up in minutes, folds flat for PLA days, and the V2 added a top filament passage for direct-drive printers, LED-bar loops, and proper cable exits. It fits the whole Ender/Prusa/MK3 class with a published fit list. The StealthMax is the biggest, meanest DIY carbon filter designed specifically for 3D printers (West3D's words), with 2.0 L of activated carbon plus H14 HEPA — the H14 99.995% claim now corroborated at the retailer level by OneTwo3D — a smart sensor stack in V2, and the recirculating design the enclosed-printer community standardized on. For non-Voron printers there's now a StealthMax S for 250 mm beds.

The social pulse. Pragmatic, not starry-eyed. HotBox owners treat it as the pragmatic warp-reducer — it works, the temps stay modest, nobody mistakes it for a heated chamber. StealthMax owners are true believers by the evidence of odor reduction and community trust rather than measurements, and the Voron forum's verification-cost question is the healthiest skepticism in the space. The V2's official documentation this year moved the project from "community BOM" to "maintained product with a roadmap," even with the pending display software. Alternatives get a fair hearing: Creality's cheaper tent, 3DUpfitters' rigid kits trading foldability for sturdiness, the BentoBox for compact builds. Facebook-group signal was effectively zero — forums only.

Value call. HotBox $148 official vs $185 at a sold-out reseller; StealthMax V2 full kit $140.74 plus printed parts plus ~2 L of columnar carbon (price not fetched) plus refills on a schedule nobody publishes. You're in for roughly $350 all-in before your time. That's real money for a passive enclosure plus an unverified-but-trusted filter. It makes sense for open-printer owners committing to ABS/ASA; it makes no sense as a "safety upgrade" without understanding that the filter does the fume work.

Closing line. The tent stops the warping; the filter handles the fumes; neither does the other's job — buy them as a pair or don't buy them at all.

Sources

• github.com — retrieval date not recorded
• onetwo3d.co.uk — retrieval date not recorded
• 3dprinting.com — retrieval date not recorded
• 3dput.com — retrieval date not recorded