Here it is, the new and improved Doc Locker 2.0. Better, stronger, and does not require welding!
Required Components:
*3/4" keyed shaft. You can also get plain and cut your own keyways. Length will be based on your application. Measure your existing span and order the same or longer. You can cut to suit. Wheel retaining options include ordering with Cclip slot, drilled and tapped, or threaded ends. Or, you can cut in your own Cclip slots with a grinder, or drill and tap axle ends for a bolt. You can also use shaft lock collars to hold your wheels on.
*One 3/4" Shaft lock collar. Available for a buck or two at any store that sells shaft, bearings, pulleys, etc, Like Tractor Supply.
*One xseries Weldon hub. You need it to have a 3/4" bore, and an O.D. of 2.5". A few dollars at the same stores.
*About 1.5" of 3/16" Key stock
*About 3" of 1/2" key stock, or 1/2" square solid stock for a Peerless MST series, or 5/8" for a Peerless 900 series transaxle.
*Three washers with an outside diameter of 2", and an inside diameter of 3/4". Got mine at Home Depot.
*Optional axle bearings Two 62033/42RS, for mine. There are two different Peerless axle bearing bores that I know of. I'll get specs for the other size as soon as I can.

Part numbers and prices from Princess Auto. Other sources may vary:

1@ 8079733 3/4 in. x 3 ft Keyed Shaft $34.99 ($34.99)
1@ 3845310 3/4 in. Bore XSeries WeldOn Hub $7.49 ($7.49)
1@ 8075269 3/16 x 12 in. Keystock $2.99 ($2.99)
1@ 3871340 3/4 in. Shaft Collar $3.99 ($3.99)
2@ 3850674 Bearing 62033/42RS $4.99 ($9.98)