Making a wooden scissors lift table #1: Scissors Lift Table

This the approach I took to making my scissor lift table.

The plan was to make an adjustable height table no bigger than my moveable table that I have used for years in the shop. That is 24×30. So for rough dimensions the frame on the bottom was 24×30 with 1 1/2” wide frame members so the inside was 27” long. The width would be planned for 21” but that would not be decided on until the scissors was built and I knew exactly the width of the bearings riding on the bottom steel strips. Working backwards that meant the spacers on the inner scissors would be 14.400” long and that is what I made them.

So with the inside of the frame at 27”, I made the arms of the scissors 26 1/2” and the center to center of the bushings at 25 1/2”. I made 8 arms and used a template to bore all three holes.

Then I made the side rails for the bottom at 27” long and with 18” long steel strips for the bearings to ride on.

I turned 20- 1 1/2” long bushing and 4- 2” long ones for all the pivot points out of 3.4” OD and 1/2” ID DOM ( Drawn Over Mandrel) tubing. It is right on at .750” and .500” and no weld seam. I also made 12- 1/2’ x 3 1/8’ long pivot rods and put an internal 1/4- 20 thread in each end . But for the fixed pivots on the top and bottom I made T -Pins instead of the rods so I could just push them in from one side and secure them with a small screw.

The scissors was built and I could take a measurement to complete the bottom frame.

I drilled blind dowels in the frame member s so they would be located right on for the glue up. That drill press angle plate came in real hand to hold them perpendicular.

The rod between the bottom bearings was blued to prevent rust and so it did not have anything like paint on it so it would not slide through the bushings for installation.

I made the top frame 27 1/2” inside to accommodate that big block with the nut mounted in it and then had to measure the width of the bearings for constructing the top frame.

The scissors was inserted in the base and secured with the T-Pins

I made the crank handle using the nut as a broach for shaping the hex pocket

The top frame was made with dimensions take off the other end of the scissors

With it all the way down, that nut block went all the way to end of that top frame. Goodt hing I made it 1/2” longer inside.

The screw used is a 3/4”-6 Acme thread and the coupler to make the drive nut in that thread was $20 so I bought a 3/4”-10 couple for $3 and chased a 3/4”-10 thread over the 3/4”-6 acme thread. It was not pretty but it is only to screw it on and have it welded in place.

I spotted the center in the back member of the top frame for a Delrin bushing, but I tried to use a forstner bit on a right angle drill and it walked off 1/4”. So I had to cut out a pocket and install a Delrin block which I could drill out off the frame once it was again spotted for center.

I wanted a laminate top on it so glue will clean off easily and found one at Steelcase employee sales that was bit bigger. I cut it down and re-glued the edgeband on the cut areas.

All the bushings and the screw thread were greased with Teflon grease and it went together very well and adjusts from 17” to 57”. It was about 3 week project.