Ended
Pausable Hourglass
A hand-blown hourglass with a needle valve at the neck, so the sand can be stopped and started again.
€15,040
pledged of €16,000 goal
- Backers
- 192
- Funded
- 94%
- From
- €59
Backed by Gareth W., Mei L. and 190 others
Pledging has closed
Story
Sand has never been able to stop. For about seven hundred years this was treated as a property of the hourglass rather than a defect.
The valve
A PTFE needle valve sits in the neck, between the two bulbs, and is turned by a brass key on the frame. A quarter-turn closes the 1.6 mm bore completely. Sand above the valve stays above it; sand below stays below. A test glass was left closed for 1,400 hours. No grain passed.
Turning it over
Turning a paused hourglass over exchanges the time remaining for the time elapsed. The valve stays closed through the turn, so the exchange is exact to the grain. Early testers found this more useful than they expected and could not always say why.
Calibration
Each glass is blown by hand in Jena and filled with sieved olivine sand of 90 to 125 µm. It is then run three times against a reference clock, and sand is added or removed until the glass keeps time to within two seconds per ten minutes running. Paused time is not counted. The hourglass has no means of knowing about it.
Durations
The Pausable Hourglass is offered in 3, 10 and 30 minutes, in a walnut or oak frame. A 60-minute glass needs a taller frame and a second blowing mould, and is the stretch goal at €20,000.
| Glass | Borosilicate 3.3, hand-blown, 1.2 mm wall |
|---|---|
| Height | 18 cm (3 min), 22 cm (10 min), 28 cm (30 min) |
| Valve | PTFE needle valve at the neck, quarter-turn |
| Bore when open | 1.6 mm |
| Sand | Sieved olivine, 90–125 µm |
| Accuracy | ±2 s per 10 minutes running, paused time excluded |
| Pause tested | 1,400 hours closed, no grain passed |
| Frame | Walnut or oak, brass fittings |
Stretch goals
- €20,000A fourth duration: 60 minutes(not yet)
Rewards
The Pausable Hourglass
€59
One hourglass in its frame, with the brass valve key.
- Ships to Domestic, Europe, Rest of world
- Est. delivery Dec 2026
- 160 claimed
Desk pair
€109
Two hourglasses of the same duration, so one can run while the other is paused.
- Ships to Domestic, Europe, Rest of world
- Est. delivery Dec 2026
- 20 claimed
Workshop edition
€149
A 30-minute glass signed and numbered by the Inventor, with its calibration record.
- 18 of 30 left
- Ships to Domestic, Europe, Rest of world
- Est. delivery Jan 2027
- 12 claimed
Add-ons
- Spare brass valve key€9
Just support it
Pledging has closed. Bonus support is no longer accepted.
Updates
What happened next
The first glass run has been priced again at a smaller size. Nothing has been ordered.
The Campaign has ended
The Pausable Hourglass closed at 94% of its goal, short of what the first glass run needed.
192 Backers pledged €15,040. Nobody has been charged. The moulds are kept, and the Campaign may return with a smaller first run.
On the 60-minute glass
The 60-minute stretch goal needs a second blowing mould and a frame 38 cm tall. Trials show the valve holds the larger column of sand as well as the small one. It will be offered only if the Campaign passes €20,000.
The first week
The first week closed at 41% of the goal. The 10-minute glass is the most chosen duration, and walnut leads oak by about two to one.
Several Backers asked how long a glass can stay paused. The test glass is still closed, now at 1,400 hours, and still has not passed a grain.
Backers also backed
- FIG. 1 · TF-0001Live
- Pledged
- €27,200
- Funded
- 340%
- Remaining
- FIG. 1 · TF-0005Funded
Pocket Sundial with Snooze
Outdoors · Lucía Ferrer
- Pledged
- €37,800
- Funded
- 210%
- Backers
- 1,020
More from this category
- FIG. 1 · TF-0003LiveEnding soon
- Pledged
- €7,420
- Funded
- 92%
- Remaining
- FIG. 1 · TF-0004Upcoming
- Goal
- €15,000
- From
- €19
- Launches in
- FIG. 1 · TF-0013Upcoming
- Goal
- €30,000
- From
- €79
- Launches in
Comments
Does the sand settle differently after a long pause?
It packs slightly. The first second after reopening runs about 0.3 s slow, which the calibration already allows for.
Backed the 10-minute in walnut. I use a kitchen timer for meetings and it cannot be paused either.
Can the valve be left half open, to slow it down?
It can, but the glass is only calibrated fully open. A half-open 3-minute glass runs for between 7 and 11 minutes, which is not a duration.
The desk pair is a good idea. One for work, one for the break, never both at once.
Hoping this makes it. 88% with six days to go.
Sorry to see it end so close. I would back a second round.
Thank you. Nobody has been charged. The test glasses are paused, as they have been since the first prototype.