The project was to build a workbench that could also pick up a motorbike so the client could maintain it, the lifts on the market you couldn’t get a wheelchair under so were not acceptable.
To produce a workbench that has no step below or ramps to allow wheelchair access and could lift more than 125 kg, I looked at commercial solutions but the frame on the floor was too big and the wheelchair would not fit under the workbench. I measured a commercially available workbench that my friend has and increased the measurements so that the wheelchair would be able to fit under it, also the operating mechanism would need to be fitted to the top of the workbench and the lower frame would be attached to the floor to increase stability.
A local fabrication company supplied all the metal and also laser cut the sides, Initial build was quick and the basic item worked, getting it to lift the 250 kg was the problem as i had increased all the measurements to allow wheelchair access under the workbench. Initially I used electric jacks and then electric actuators. Both worked until I tried to test with weight, they then both failed. Using electric screw type actuators would have also given the workbench a locking mechanism but i was unable to find a electric actuator with enough power at a reasonable cost. To get the power required I asked an hydraulic company to assist and they supplied a pump and cylinder to enable the workbench to operate and lift the weight required. This then brought its own problems with a control box for the pump and safety mechanism. The hydraulic cylinder is fitted with locking valves but I felt that it also required a ratchet type lock when the workbench was raised, so in the control box is a Pico relay. This is similar to a PLC (programmable logic control) but not as complex, this now lifts the ratchet safety mechanism out of the way before the workbench can power down and then drops the spring loaded ratchet back into the correct position. The workbench was secured to the floor and all the operating system is secured to the wall of the workshop.
The work bench is just what the client was after so he can carry on maintaining motorbikes and do his wood working projects, he does require assistance to get his motorbike on and off the workbench and secure it in the wheel clamp that was donated by my friend.
as soon as the client could get into his shed he was away stripping the motorbike. doing what he had wanted to do for a long time