by slomobile » 11 Aug 2022, 04:43
Maybe it is different in other countries. In the US, a basic chair is a group 2. They do not have tilt, or lift as a bureaucratic rule. A group 3 or 4 is a rehab chair and may have tilt, or not depending on who it was ordered for with what injury. If your model of chair is available with tilt, but your unit does not, you're usually best off using the actuator from the sister model that comes with actuator. Sometimes there are several different actuators for a given model. They may look very different from each other because they use a different motor/gear arrangement but be completely interchangeable. Or, 2 actuators may look identical and not be interchangeable.
The important things are
style of mount points (clevis, bolt, pin, ball and socket, etc),
clears obstructions on chair,
Stroke length,
closed length (or open length is specified sometimes instead),
force minimum,
and having the feedback type your particular controller expects (internal limit switches broken out to connector, limit switches in series with 2 motor leads, external limit switches, softpot, external pot, absolute encoder, incremental encoder and home switch, programmable actuator).
You may be able to change programming to expect a different type of feedback, but I wouldn't count on that.
If you are adding a tilt actuator to a basic chair that never had one available, use a 2 wire internal series limit switch actuator and a DPDT momentary toggle switch to reverse polarity.
Less important are connector type, speed, style of actuator drive, brand, voltage.
A fast actuator is more easily backdriven by leaning on it. If you are heavy, get a slow actuator.
They are almost always 24v actuators because that is what the chairs have on them. 12v actuators will live for a little while behind 24v. 24v actuators will work indefinitely at 12v, but will have half the rated force and speed.