Parallel axis actuator

From Opendildonics.org

This page probably needs renaming when a more exact term is coined. It refers to the device which provides linear motion parallel to the penis for a vagina type teledildonic playback device and in-and-out motion for a penis or dildo type playback device.

Many common types of linear actuators share a problem that the device will be at least as long as the range of motion. That is, a device which can move a dildo in and out with a range of 6 inches will tend to be at least 6 inches long. In order to prevent the device from becoming unwieldy, careful attention must be paid to this tendancy during design. Simply attaching a 6" vaculock dong to the end of a 6" ball screw linear actuator will produce a device which extends nearly a foot from the orifice at all times. The leverage produced by such a device will make it uncomfortable in wearable applications and more difficult to fit in fucking saddle and lovedoll applications. A more careful device which swallows the linear actuator in the base of the dildo will be only 6 inches long. Another design which may be worth further consideration is a flexible dildo which is forced through turning rollers before entering the orifice, allowing more of the device to sit parallel and close to the body.

The 21 inch long Priceless is a good example of how a teledildonic playback device can become very long if the actuator is simply attached to the end. See the priceless faq titled "It looks too big" on the Priceless manufacturer's website. Now imagine a redesigned Priceless where the shuttle assembly surrounds the fleshlight - the resulting product would be around 9 inches shorter.

The fuckingmachines.com machine list shows a thumbnail matrix of many sex toys with parallel axis actuator, and includes links to pages with larger pictures and videos of some of the machines in use.