I built a Trac-Vac clone mostly from scratch. I used my cheap dump cart, 32" wide by 36" high by 42" long, rear door flips up to unload. The unloading the cart was the thing that needed improvement the most, I ended up digging it out with a pitch fork. I bought about $150 worth of steel, I used some angle iron and sheet, and a foot of 1" round steel bar I had to build the impeller. Wyatt Compton took pictures of it all hooked up ready to run one weekend. I used it 5+/- years, I was getting 24-25 loads off my 2.3 acres. I added to and improved the design several times. I had the grass in the yard get away from me one year, I mowed it, let it dry 2-3 days and vacuumed the clippings up, I could fill the cart in about 5 minutes, they packed in to a fairly solid brick. I ended up using black poly corrugated 6 inch drain tile to connect the chute on the deck to the blower and connect the blower to the cart. Using 8 inch hose would have been better. I used a freshly rebuilt K-161 7 hp Kohler to run the blower, I never had to run it much above an idle. I had a special set of blades I used on my 38" 3-blade deck when using the vac, I welded larger fins or wings on the blade, about 4-5 inches long by 1-1/4" tall, That REALLY improved the amount of air the vac moved, it would duck leaves under the deck housing from 6 to 8 inches away. Overall, I was pretty happy with it's performance. At the time my #72 Cub Cadet had a K241 10 hp engine, and with the tractor weight, blower weight, and a full cart of leaves, clippings, it was about all I wanted to pull.
Wyatt came out one Sunday and put his 44" deck with GATOR blades on his #169 and mowed and mulched ahead of my vacuuming. A cloud of leaf dust surrounded his Cubby. He was pulverizing those dry leaves into powder. I'd vacuumed all day the day before, did around 15 loads on half the yard. With Wyatt mulching ahead of me I got about 11-12 loads off the whole rest of the yard. Makes me think running Gator blades on a mower doing vacuum duty might be a good idea.
My vac unit is "semi-mounted", it's got a single pivoting caster wheel on the rear, and pins to two brackets clamped to the rear axle carriers, as I turn, the carrier swings outside the path of the tractor's rear wheels, the cart perfectly follows in the rear wheel tracks of the tractor, makes trimming around stuff amazingly simple for something almost 20 feet long, it can turn as tight as the bare tractor possibly can.
When I got my Pronovost P503 hyd tandem axle dump cart I REALLY wanted to build up sides and a top for it so I could increase loads from 28 cubic feet to 72 cubic feet and dump them from the seat. I DID increase the #72's horsepower to 14 to pull the greater weight.
I haven't used the vac since I got the zero-turn, the deck on the zero-turn mulches leaves many times better than the old IH decks ever could.
