Screw Drive Home Elevator | 500–5000 kg Small Footprint Lift

1. Whether a screw drive home elevator fits your building

The decision is not "is screw drive good". It is "does the building I own match what a screw lift is good at". Those are different questions, and the second one is answerable from a tape measure, a floor plan and your heaviest routine load.

A screw drive carries its load on a threaded steel column. A motor turns the column; a drive nut threaded onto it climbs or descends, and the car is bolted to that nut. Nothing is hauled over a sheave, nothing is pushed by hydraulic pressure, and nothing needs a counterweight. Three consequences follow, and all three show up in your first site survey.

The three consequences that decide the project

• The load path is short and vertical. The reaction goes down the column into the shaft structure rather than into a machine-room slab or a cylinder base — which is why one mechanism can be rated at 500 kg for a family and 5,000 kg for a workshop.
• There is no machine room and no plant room. No overhead space for a traction machine, no room for a pump unit and tank. In a house not designed around a lift, those two omissions usually decide whether the project fits.
• Position is held mechanically. When the motor stops, the nut stops where the thread stops — a property of the drive rather than an option.

Now the other side. The same mechanism makes one speed, stated here as 0.15 m/s, and it has a travel ceiling of up to 15 m. Neither is a specification you can negotiate upward with a bigger motor. Section 5 works through what that means in a house.

Three-state fit check

Read the card that matches your site; the third lists what to settle before an order is placed.

2. How the mechanism carries 5,000 kg on a single thread

The mechanism is old and simple. A threaded screw column stands in the shaft and a motor at the top turns it through a gearbox. A travelling nut threaded onto the column is prevented from rotating, so as the column turns the nut is forced to move along it — and the car is bolted to the nut. Turn the column one way, the car rises; turn it the other way, the car descends.

Why a thread can hold a load indefinitely

A thread is an inclined plane wrapped around a column, and an inclined plane does not have to be powered to hold a load. Once the motor stops, the nut stays where it is: nothing is balanced by a counterweight and nothing is held up by pressurised fluid. That is why a screw lift is chosen where a car left hanging is not acceptable, and why the brake is a back-up rather than the primary means of support. It also explains the capacity range: load capacity follows the column's diameter and pitch and the number of thread turns engaged inside the nut, so the same architecture carries 500 kg at one end of this page's band and 5,000 kg at the other, both at 0.15 m/s.

What moves, and where the maintenance attention goes

Four things move: the motor, the gearbox, the column in its bearings, and the nut along the column. Everything else behaves much as it would on any other lift, and that concentration tells you where to look as the installation ages.

• The thread is the load-bearing surface and the only surface that wears by design; how fast depends on how clean the shaft stays and how well the lubrication interval is kept. Ask for the method and the interval in writing.
• Alignment matters more than on a rope lift. A long column has to stay straight and the nut square to it, so the rail and column fixings are not the place to save money.
• There is no rope to replace and no oil to change — two items that dominate the maintenance budget of other drive types.

What the mechanism does not solve

Screw drive does not remove the need for a pit or for headroom above the car: the column has to stand somewhere and the drive sits at its head. Nor does it make the lift fast; what it does is put capacity into a small footprint without a machine room and without oil.

3. Choosing a rating between 500 kg and 5,000 kg

The band is ten times wide, so the first question is not which model but which number. Owners usually get this wrong in one direction: they add a margin to a figure they never measured, and pay for structure, door gear and documentation the building will never use. Work the other way round — measure the load, then take the nearest rating at or above it. Four figures inside the band cover almost every project; switch between them below.

How to measure the load you actually need

The figure to specify is the heaviest load that will routinely travel plus the people and equipment with it — not the heaviest load that could conceivably be forced into the car.

• List the top five loads you expect in the first two years, with weights: usually furniture, building material, mobility equipment, a machine or a small vehicle.
• Add the handling equipment — a sack trolley, a pallet truck or a set of skates stands on the platform with the load.
• Add the people, then round up to the nearest rating and stop. Two people at 80 kg each turn a 900 kg project into a 1,000 kg project; one-off loads are not the design case.

The one exception. If the lift is also the route for a machine that will one day be replaced — a boiler, a generator, a compressor — specify the replacement's weight, not the outgoing unit's.

4. The specification in one table

Every value below is read off this page's own parameter tables. Switch between metric and imperial; the table and the rest of the page follow. Rows where the tables carry no value are not filled in with typical figures — they are listed at the end of the section.

Commercial and identification data on the same sheet

Three lines belong here because buyers check them first: the brand on the sheet is YIMEISITE, the place of origin is China, and ISO 9001 is listed under certification. Order quantity, price, packing, delivery and payment terms sit in the table beside the product images, because they change with the order.

What the tables do not state

Two omissions are worth naming before you compare quotations. Pit depth and overhead clearance appear nowhere in these tables and are configuration-specific, so ask our engineers for both. Car and shaft dimensions and the clear door opening follow from the rating, the load and the door type, so they are settled at the layout stage rather than published as one row.

How to use this table in a tender. Send it as the specification you are pricing against, and ask each supplier to return the same rows plus the two missing figures. Comparing quotations on price alone, when two rows that decide the shaft are absent from all of them, is how a project buys a machine that will not fit.

5. Speed and travel: where the screw drive boundary really falls

Two numbers decide whether a screw drive home elevator suits a building, and they are the two that brochures talk around: 0.15 m/s and up to 15 m. Both are on this page's own tables, so there is no need to soften them — only to convert them into the unit a buyer actually experiences: seconds on a real journey.

What the boundary means in a house

A two-storey house with a 3 m floor-to-floor height is roughly a 3 m journey: twenty seconds of travel before the doors are counted. Nobody notices that, and the same machine carries a 500 kg crate or a 2,000 kg pallet without changing speed — the rating does not buy speed on this mechanism, which is an advantage for a goods duty because the machine behaves identically at every load in the band. A four-storey house with three 3 m flights is a 9 m journey, a minute of travel and a three-minute round trip once doors and loading are added. If somebody is moving boxes, that is fine; if somebody crosses the house several times an hour, the lift becomes a place they wait, and that is the honest limit of the product.

• The 15 m ceiling is physical, not a rate. A 15 m column has to be supported along its length, has to reach the shaft in sections, and the alignment tolerances at the top of the run matter more than at the bottom.
• With 2–5 stops applying at the same time, a 15 m travel is served by a few landings spaced generously apart — a pair of floors in a tall building, or an outdoor run up a slope — not a lift serving twenty floors.

The three questions a critical buyer should ask about speed and travel

Screw drive lifts attract one recurring criticism in buyer guides: that they are slow and limited in travel. Both statements are correct, and neither is a defect. What matters is that nobody sells you a project on the assumption you will not notice. Ask any supplier, including us:

• What is the door cycle time? On a short journey the doors dominate, and this page prints no door timing figure, so it belongs in the quotation.
• What is the acceleration and deceleration profile? A machine rated at 0.15 m/s still has to start and stop; ask for both as commissioning values.
• How is a long column supported at your travel? Above a few floors the column fixing schedule becomes the engineering content of the project; ask for the fixing intervals and the alignment tolerance.

Where the boundary is absolute. Above 15 m of travel this mechanism is the wrong one and no configuration changes it — a traction or hydraulic machine is the correct answer. Inside 15 m, work out the round-trip time from the table above before you order if your routine includes more than three or four trips an hour.

6. Pit, headroom, indoor or outdoor, and the AC or DC supply

Screw drive removes two of the four things that usually derail a house lift project: there is no machine room to find and no hydraulic plant room to build. That leaves four site questions, all answerable before a quotation means anything: where the column stands, how much headroom the drive needs, whether the position is indoors or outdoors, and what the supply will be.

What "small footprint" means in practice

The footprint advantage is not a narrow car; it is that the machinery tucks into the shaft instead of sitting on top of the building. The column runs up one side, the drive sits at its head, and the car uses the rest of the plan.

Two consequences follow. The landing opening is chosen early, because it decides what the lift actually carries: a 2,000 kg rating behind a door a pallet truck cannot enter will never see a pallet. And the column must be plumb over the whole travel, so the structure has to be built to receive it. That is what a small footprint screw lift buys you — machinery inside the shaft, not beside it or above it.

Indoor or outdoor: what changes

Outdoor mounting is one of the configurations this page covers, and it changes the specification list rather than the drive. Each item below is a design input, not a formality.

The pit and headroom question, answered honestly

This page does not state a pit depth or an overhead clearance, and neither does this article, because both depend on the travel, the rating and the door arrangement you order. What can be said plainly: the column has to stand from the bottom of the run to above the top landing, and the drive sits at its head, so headroom above the top landing is always part of the layout. Whether the bottom needs a recessed pit or can be built at floor level is exactly what the layout drawing answers, and it is the first thing to request with a price.

AC or DC: what the supply line is telling you

The power supply row reads AC or DC, which is a wider statement than it looks. Most house installations run the drive from the building's alternating-current supply; a direct-current arrangement is also supported, which matters where the machine is fed from a battery or a DC bus rather than mains. Either way the electrical work is a real part of the project, and the quotation should name the running current, the starting current and the protective device, because your electrician has to size the cable and the isolator whichever side of the drive they stand on.

• Give the supplier your actual supply data — voltage, frequency, phases and available capacity; this page carries no voltage figure, so the supply is matched at the layout stage.
• Ask where the isolator goes, who installs it, and what happens on a supply failure. A screw drive holds its position when power is lost, but the written procedure for releasing a car after a power cut is an item to obtain before handover.

The order to do things in. Shaft plan and landing openings first, headroom and pit next, supply data at the same time, structural sign-off before anything is poured.

7. Cabin, doors and what has to pass through them

On this page the door line reads automatic, with centre or side opening as the choice. That row carries more of the project than any other: the door decides what the lift carries in and out, where the landing wall has to be opened, and how much landing floor area the slide takes.

Centre or side opening: how to choose

• Both arrangements are automatic, and both arrive with the operator, the reopening device and the landing locking arrangement that make an automatic door rather than a gate. Car and landing doors are interlocked, so the car cannot move with a landing door open.
• What to request with the quotation: the clear opening and the car plan as drawn figures, plus the door cycle time for the journey calculation in section 5.

Three things to fix before the wall is opened

• The clear opening, measured against the widest thing you will move: a loaded pallet truck, a wheelchair with an attendant, or a car with mirrors folded. Clear opening is not leaf width.
• The landing side the door sits on. On a retrofit, moving the opening to a different wall is often cheaper than moving the shaft.
• What happens at each landing. A garage or yard entrance is often given the wider arrangement while internal floors use centre opening.

Do not buy a rating and then squeeze the door. Fix what has to pass through first, then choose the car plan and rating that carry it.

8. Safety devices and what to verify at handover

This page's parameter table lists three safety features: emergency stop, overload protection and safety gear. Three items is a short list, so it is worth being precise about what each one is, what it does not replace, and what has to be checked on site.

The three listed devices

What three devices do not tell you

These three are the disclosed protective features of this machine. They are not a statement that the installation complies with a particular national lift standard, and this page names none. That is the gap to close at contract stage: the build and test standard, the door interlock arrangement, the levelling tolerance, and the inspection regime your authority applies to a machine of this load and travel.

Handover checks worth walking through

Whether the machine is for a family or a workshop, the same seven items decide whether the installation is finished. None can be verified from a brochure.

One sentence to keep. The features listed on this page are the ones fitted; the standard the machine is built to is a separate question. Ask both in writing and keep the answers with the machine documents — an inspector will ask, and so will a resale buyer.

9. Maintenance, warranty and the parts that wear

The maintenance line reads low maintenance, and the mechanism earns it: no rope to replace on a schedule, no hydraulic oil to sample and change, no cylinder seals to weep. What remains is a smaller set of wearing parts, concentrated in one place.

Where the wear actually goes

The shape of a sensible schedule

This page publishes no maintenance interval, so treat the following as the structure of a schedule to agree with the supplier. An owner's log of dates and observations beats a memory, and lubrication deserves its own line at the manufacturer's interval — ask our engineers for it, with the lubricant named and the wear measured rather than estimated. Behind that sit the mechanical and control checks — rail fixings, guide shoes, safety gear, nut assembly, door interlock, overload setting and levelling — at the interval the supplier specifies for your duty, because those are the functions that fail silently.

Warranty: one year, and what to pin down

The warranty line reads 1 year. What that covers varies more between suppliers than the number does, so settle four items before the machine ships:

• Parts, labour and travel — which of the three the year includes, and where the technician comes from.
• Response time for a stopped lift, in writing. A household with the only lift out of action has a different urgency from a workshop.
• What voids it: third-party service, a rating change, unauthorised repairs, or an outdoor installation without the specified weather protection.
• Spares availability after the year, and for how long: ask about the nut assembly by name, because it is the part that will eventually be replaced.

Why low maintenance still needs documents. A machine with fewer wearing parts is cheaper to keep, but only if the parts that do wear can be measured and replaced by any competent technician. Ask for the inspection method, the wear limit and the part numbers at handover.

10. Screw drive home elevator questions

These are the questions buyers ask after reading the specification and before placing an order. Each answer is written against this page's own parameter tables, and each one says where those tables stop.

11. What a quotation for this lift needs from you

A screw drive quotation is only as good as the site information behind it. If you are pricing a screw drive lift for homes rather than a light commercial run, the same eight items apply: send them together and the answer comes back as a configuration with the missing figures filled in, rather than a band to interpret.

What the answer should contain

• The pit depth and overhead clearance for your configuration, in writing — the two figures this page does not publish.
• The confirmed rated load, travel, stop count and door arrangement, on the machine plate as well as the quotation.
• The electrical data: running current, starting current and recommended protective device.
• The build and test standard and its certificate or declaration — separate from the ISO 9001 quality-system line.
• The maintenance schedule: lubrication method and interval, nut wear limit, spares position.
• The warranty scope and the scope boundaries: parts, labour, travel, response time and what voids the warranty; then freight, unloading, installation, commissioning, local approval, and who builds the shaft.

Related pages worth reading next

• Screw driven elevators — the whole family, with the lighter and shorter members of the same type.
• Compact screw drive home elevator — the light end of the family, for houses that do not need the heavy band.
• Heavy-duty screw drive elevator, 5,000 kg — the top of this band, built as an industrial machine.

If your project needs more speed than 0.15 m/s or more travel than 15 m, say so in the enquiry: the answer will be a different drive type, not a different screw drive.