Not many of those oldies out there any more!
Sorry, Neptune,
The last undercounter Hobart Dishwasher to use the cast iron blue beauty washarm was the Kitchenaid 14 series which was discontinued in 1964 and replaced by the now famous Hydrosweep arm used first in the 15 series There are still some out there. There were some still in boxes when Whirlpool took over and even some large distributors across the country had some still boxed up. In fact, in one of the forunms at Kitchenaid.com. one of the moderators mentioned that they had found a brand new 14in one of the warehouses. I suggested that they place it next to the KD10 they have at the Kitchenaid Museum in Greenville Ohio.
But the Last Commercial undercounter to used the arm (p/n 73515) was the model UM series and that was oficially discontinued in late 1979/1980 though there were still some being installed after that. I was told by a highly placed sales manager that the reason the UM was actually discontinued was because the dies had finally worn out and there was no interest in retooling for new ones. Pretty plausable since they had already been producing the 15,16 and 17 machines and had introduced the 18 series by then.
They were still producing the WM series which was based on the 15/16 tanks and did so until the early mid 80's when they released the WM-5 Series. Now this was based on the 18 series but the tanks were actually brought over from Europe. It was unique in that the whole tank was made from a single sheet of Stainless Steel which was punched and bent and then folded and roller sealed to form a complete dishwasher tank.
The European units were more complicated than the American units and they also used the same designs for the KDS18E series machines, made in Germany and distributed to the rest of the world for Domestic consumption!
I have pictures of that unit in PDF format if anyone would like to see it. It is to large a file to post here.
For the record, the last Big machine Hobart made with the cast Iron washarms(top and bottom) was the AM10-11 series.Talk about a wall of water!! This was a radical departure in Electrical design of Hobart dishwashers. It was the first machine they produced that had Solid State controls. It had a master board to which numerous other boards were clipped on to control the timer, fill, motor protection and temperature functions.
The following model paved the way for lighter Stainless steel embossed arms which had large openings in the upper and lower washarms similar to the look of the holes in the Hydro Sweep arm only much bigger. Another wall of water machine. This unit continued with the controls of the previous 10-11 models.
The next improvement came in 1983/84 with the AM14 series which shared all the mechanicals with the 12 series, but now had a single control board to do all the functions of washing and rinsing the dishware. Unique to this machine was the electrical controls were all 24 volts which improved the reliability of the machine tremendously. As technicians, we appreciated the durability and ease of repairing these units. There were only a few typical mechanical repairs that they ever needed and it was very rare to have to replace a conrtol board on one. Even to this day there are some very old am14 machines with all their original electrical controls working day in and day out.
Boy do I get long winded! Sorry Guys!