Hello. This is about something I’m making but I’m not a member so posting it in this forum so as not to tread on any toes. I thought it might appeal to those whose hands are forced to be idle at the moment. Mods please feel free to move it if that’s preferred.
This is a table from hell for several reasons - one is that it rises from under the ground, and another is that it uses a hydraulic mortuary trolley to do so. But the main reason is it’s such a stupid, impractical project. I am channelling Magnus Magnusson in asking about it here. I am fine with electronics but am not a mechanical engineer.
The table has a flap along either side - a substantial piece of ash 2240x230x35. These flaps need to be completely folded underneath when the table descends, and obviously need to be held rigid unfolded when the table is in use.
In the horrible lash-up experiment photo you can see a motor under the tabletop on the left (originally used to move body trays on and off the trolley!) which pulls the yellow cord over the white pulley to fold the flaps underneath. It has an output shaft on each side and is powerful enough to do both flaps. I have ordered some smaller pulleys which can be recessed into the underside of the main tabletop so that the cords can be attached invisibly to the undersides of the flaps. (Hard to find anything - had to order sliding door rollers from China.)
So the flaps can be wound under from vertical, and the cords can be further unwound to allow them to be extended. The problem is the extending mechanism, and seeing as the rest of the thing is automated, it would be nice to automate this too. If I use actuators as shown (one at each end of the table), the blocks they are mounted on would need a solenoid latch where the angle bracket is to allow the blocks to hinge backwards when the flaps are wound under. A strong latch would be required. This would flatten things sufficiently to accommodate the mechanism under the floor, but when extended it takes so much room that no-one can sit at the ends of the table.
Another possibility is to use shorter actuators and mount the blocks on runners so that they can slide closer to the edge of the table. These runners would have to be recessed into the underside of the tabletop and there would be a lot of torque on them.
I have considered hydraulics (including buying some old convertible car roof parts, not realising they had incompatible connectors) and pneumatics (presumably no good as they’d be bouncy). If anyone has any ideas for alternative arrangements I would be delighted to hear!