Two months ago, our Rio Grande Racers (NAMBA) club president, Henry Keller, presented me with an old 31.75 inch X 13.5 inch Prather LapCat and stated, “Somehow, make it run”.
This is the build after the fact:
A portion of the cockpit bulkhead had been cut from the fiberglass prior to me receiving the hull, so I made a new bulkhead from 1/16 inch ply to make it water tight once again.
I added 1 inch wide ply pads to the sponson bottoms to reduce the wetted area, & fabricated a motor setback mount of 1/8th ply, covered in epoxied fiberglass.
I used 4-40 rod for the steering with 3 mm X 36 mm turnbuckles incorporated to allow for fine adjustment of the linkage lengths.
Power is from a Leopard 4074 2200 Kv motor, Sea King 180 amp ESC (which I pulled from my yellow cat, as it needs a motor upgrade), & will get juiced by two Turnigy 2S 5.0 batts in series.
I removed the cavitation plate from the OS leg & replaced it with a piece of 5/8 inch wide 1/16th aluminum to accommodate the dual water pick-up I fabricated, which will also allow access to the drive cable cover without having to first remove the original plate (due to it‘s length). I further modded the leg by cutting 7/16 inch off the bottom of the skeg, sharpening the leading edge, & adding a lubrication gizmo.
I forgot to take a pic of the sub cowl hatch cover. It’s made from 1/16th ply with a water tight seal formed with silicone adhesive. I added enough foam floatation into the cowl itself to float it with the added weight of my Garmin Forerunner 201 GPS, which will be mounted under the cowl in a bracket constructed from fiberglass mat using polyester resin.
Should get her wet this coming weekend. Finishing touches will come latter if the performance is adequate.
Pics . . . . .
This is the build after the fact:
A portion of the cockpit bulkhead had been cut from the fiberglass prior to me receiving the hull, so I made a new bulkhead from 1/16 inch ply to make it water tight once again.
I added 1 inch wide ply pads to the sponson bottoms to reduce the wetted area, & fabricated a motor setback mount of 1/8th ply, covered in epoxied fiberglass.
I used 4-40 rod for the steering with 3 mm X 36 mm turnbuckles incorporated to allow for fine adjustment of the linkage lengths.
Power is from a Leopard 4074 2200 Kv motor, Sea King 180 amp ESC (which I pulled from my yellow cat, as it needs a motor upgrade), & will get juiced by two Turnigy 2S 5.0 batts in series.
I removed the cavitation plate from the OS leg & replaced it with a piece of 5/8 inch wide 1/16th aluminum to accommodate the dual water pick-up I fabricated, which will also allow access to the drive cable cover without having to first remove the original plate (due to it‘s length). I further modded the leg by cutting 7/16 inch off the bottom of the skeg, sharpening the leading edge, & adding a lubrication gizmo.
I forgot to take a pic of the sub cowl hatch cover. It’s made from 1/16th ply with a water tight seal formed with silicone adhesive. I added enough foam floatation into the cowl itself to float it with the added weight of my Garmin Forerunner 201 GPS, which will be mounted under the cowl in a bracket constructed from fiberglass mat using polyester resin.
Should get her wet this coming weekend. Finishing touches will come latter if the performance is adequate.
Pics . . . . .
? ONLY IF THEY WORK 
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