Here is the parts list for the pads I built for TriCities Rocketeers in Eastern WA.
3"x1"x.125"wall Rectangular tubing (approximately 6.5 foot long)
3/4"x3" long cold rolled round stock, that I drilled and tapped for 3/8x16 thread (6 pieces required or however many stations you want, these are the round pieces coming up from the rectangular tube, cold rolled stock is easier to use as it doesn't require removing mill scale unlike hot rolled product). Its nice if the drill press has a large enough chuck to where you can chuck the round stock into the drill chuck and then mount the drill bit in the vise as it makes center drill much easier, I ended up making some kind of jig to do it as my drill press has a max size of 5/8", in hindsight I would probably down size the round stock to fit my chuck.
1"x3/8"x2.5" long hot rolled flat stock (6 pieces used as upper section of pad adjustment mechanism, each one drilled and tapped 8-32 on the side to coincide with the 1/8" hole drilled in the top for the rod, iirc the holes were drilled slightly oversize to allow rods to easily slide in, one rod holder was also drilled for a 3/16 rod as well).
1"x3/8"x1.5" long hot rolled flat stock (6 pieces for lower section of adjustment mechanism,these were center drilled on the end for a 3/8x16 bolt with the head cut off to be inserted and welded).
Handwheels, plastic from Amazon, sized 3/8x16 thread and about 1.5" diameter
The two parts of the adjustment mechanism were clamped together (one long and one short) and a 3/8" hole drilled through both on the sides for a bolt to pass through both. When possible stainless steel hardware is used.
The first picture was the demo/prototype I made to pitch the idea to the club, there are probably 40ish hours in the building of the two 6 pad units, with the welding, drilling and tapping, possibly even including time to go get another tap as I broke one of my 8-32 taps.
All steel parts were precut by Pacific Steel for me on their band saws, that was better as a abrasive saw doesn't do as nice job and the cuts are not always perfectly square.
Tools needed were a drill press with vise and large enough bits to drill a slightly over 3/4" hole, 3/8" bits and bits for the 8-32 size tap. A welder and I used 1/8" 7018 rod.
I don't remember how much the pads cost but it was about $100 dollars for materials iirc.
Edit: the flat stock pieces that make up the two parts of the top section may have been 1/2" thick instead of 3/8" as it would have been easier to drill, my memory is fuzzy on that and the units are across town stored until next spring.
