EIBOS Polyphemus 3D Printer Filament Dryer: problems, parts and running costs

Checked: 2026-10-19

Summary

The issues owners hit most are a +7 °C temperature overshoot at low setpoints, no gasket so the unit cannot store dry filament once powered off, and a rotation motor that stalls with two 1 kg spools or walks and binds under 3 kg spools. Running cost is desiccant refills plus electricity at a 130 W rating, with no published yearly figure. It is a good buy at or under $110 direct, fair up to $130, and weak above $150.

Common problems and fixes

Temperature overshoot at low setpoints — 3DPrintBeginner measured +7 °C at 50-55 °C setpoints (50 °C set read 57 °C), tightening to ±1 °C at 60-70 °C, and linked it to the bottom-mounted sensor. Fix: set 60 °C or higher for accuracy within ±1 °C, or verify with a separate thermometer. No warranty terms are published, so this is not a covered repair item. [7]
No gasket, so it cannot store dry filament — there is no rubber gasket on the cover or base, moisture returns once the unit powers off, and the desiccant slots do nothing unpowered. Fix: use the humidity-hold storage mode while the unit is on, and use a separate sealed dry box for anything longer. [2][7]
Rotation motor stalls and struggles with heavy spools — the instrumented test caught the motor stalling with two 1 kg spools in some cases, and one owner (Dec 2023) warns against 3 kg spools: the spool walks to one side despite printed fixes and the rotation cam, a small O-ring, meets heavy resistance. Fix: avoid 3 kg spools; the motor is user-replaceable from the underside, rated 1500 h, with a spare included. [1][7][8]
Slow heat-up and a warm bottom — AMSTUDIO reports heat-up slower than other dryers and a noticeably warm bottom. Fix: place the unit on a heat-resistant surface. [5]
Lid does not latch, one shared chamber — the lid does not latch to the base, so the unit cannot be carried by the handle with spools inside, and both filament types share one set of parameters in the single chamber. No fix; plan transfers, and buy a dual-chamber unit if you dry two materials on different schedules. [6]
Price drew criticism at 2025 street prices — at $139.99-143 (Feb-May 2025) reviewers found it hard to justify against dual dryers in the $60-80 range; the $99.99 direct sale price changes that math. [1][5][6]

Parts and consumables

Spare roller and cam O-rings — a spare roller (allows single-side rotation while printing from the other side) and two spare O-rings for the cam gears are included in the box. [1][2]
Silicone sealing plugs — for unused filament holes, included in the box. [1]
3 kg expansion kit — needed for the ø250x170 mm 3 kg spool size; listed by EIBOS as a $15.00 accessory in its dryer collection (a parts/accessory listing, treat with caution). [1][3]

Yearly running cost

Not enough data. No source reports a typical owner’s yearly spend, and no electricity price or average run hours are published. [1][5][7]

When it is a good buy

$110 or less: defensible for dual-spool motorized rotation plus humidity-hold storage — the feature set is not common at this price. EIBOS direct listed the Polyphemus at $99.99 on sale, marked down from $149.99 (shop.eibos3d.com, October 2026), and West3D listed it with the 3 kg extension at $109.99 on sale, regular $159.99. [1][4]
$111-130: fair value.
$131-150: weak to fair — the 2025 street prices of $139.99-143 (The Gadgeteer, Feb 2025; AMSTUDIO, April 2025) drew explicit criticism against dual dryers in the $60-80 range. [5][6]
Above $150: weak unless the rotation feature or the 3 kg expansion specifically matters, and the 3 kg path carries the owner warning about spool walking and rotation resistance. [1][8]
Alternatives: the Creality Space Pi at $89 is the better choice when you only need dry filament and want to spend less, and the four-spool SUNLU S4 at about $149 is the better choice when you want four spools; both come from AMSTUDIO’s May 2025 comparison. Dual dryers in the $60-80 range are the better choice when rotation is not a priority. [5]