WPM


Albert's PistenBully 400 ParkPro 4F

 
Last change: Dec. 15th, 2017

I had the idea to build a ParkPro version already for quite some time, and as we can now make our own micro hydraulic cylinders the realization became possible. The large movements of the blade can be realized almost only with model hydraulics. Also the nick cylinder is mounted on the pushing frame and not on the chassis tub. This cylinder has to be functional for the ParkPro blade because the blade will change it's nick angle when raised, as the parallelogram kinematics are missing.

Also the possible application range is greatly enlarged: instead of preparing a slope track by track behind the house a fun park can be built with kickers and obstacles.

And of course it had to be the top model for park building, the PB400 ParkPro 4F.

Besides the cool paint job in red/black the new air intakes are the most striking visual changes to the PB400 base model.

The model is a conversion of my PB400 which is described here in detail.


The german magazine Rad & Kette 1/2018 issued an article by me about building the PB400 ParkPro 4F body. It's in German language. Part 2 about the accessories will follow.

I even made it again on the front page!

The article can be downloaded here as PDF, with friendly permission by the magazine.


Kässbohrer was so friendly to quickly send me the necessary drawings, and Adrian Humbel supplied the urgently needed detail photos of the air intakes and the back pack. Big thanks!!!

So after some long time I was into 3D modeling again in CAD to create the shape of the air intake. A comparison of the original and the CAD model can been seen to the left.

I CNC-milled the molds for vacuum forming on my Stepcraft 400 which thus had it's first real 3-axle job. It was controlled by the proven Mach 3 software. One milling job takes about 1,5 hours per air intake.

Vacuum forming molds for the 4F air intakes before sanding with clearly visible milling paths

After the molds have been sanded and painted the first air intakes could be vacuum formed (see picture to the left).

The sheet metal parts of the back were designde in CAD and laser cut out of special aluminum sheet. The exhaust was made as a 3D printed part. A few other details like the tank inlet for the urea tank were made as cast resin parts. They were printed with High Definition Acrylate, a new printing technology allowing finest details, and than a mold was made from silicon. Due to the large air inlets I modeled the visible details behind the air inlets in CAD and had them printed. On the driver side the hydraulic controls for lifting the driver cabin and loading platform can be seen, and on the passenger side is the engine radiator with the pre-heating plug.

3D CAD model of the backpack


Painted side parts behind the air inlets

The finished backpack on the model.

Exhaust 3D printed part with finished paint job


Air inlet with details of the hydraulic controls

Combination rear lights at the model...


... and the original.

The rear combination lights were a challenge. At the original they are a ring of LEDs for the rear light and a flashing light in the center. I designed the parts in CAD and had them printed. The drillings in the ring simulate the LEDs of the original, which looks quite realistic as can be seen in the picture above. The rear light is a red 1.8 mm LED, the flashing light is an amber light 5 mm LED which I sanded flat. The red glas was also printed, molded in silicon and then casted with red colored transparent resin. This resin has to be cured at 70°C for 90 minutes in an oven. So all in all it was quite some effort.


Parts of the combination rear lights

 

I also changed the light controls to Pistenking Kingbus light modules which are available for the PB400 as well. The great advantage is that only two wires are coming out of the cabin and that the board with the resistors is no longer needed. Thus the operating safety is enhanced. Furthermore the Kingbus can be connected directly to the ScaleArt Commander and icons on the display show exactly which lights are on. Very cool!

As there is no KingPad needed for the ScaleArt Commander I applied icons to help find the right switch.



The ParkPro features a lever control contrary to the other PistenBullys. This makes it easier to maneuver the vehicle in the park. Therefore the steering column was removed also in my model and replaced by control levers on the arm rest. A foot rest is installed instead of the steering column at the ParkPro.

Finally the driver cabin's lower part was painted black. The ParkPro logos were generously supplied in printable format by Kaessbohrer. Also the mirror mounts and hand rails war painted black.

PistenBully 400 ParkPro 4F

Next step will be to change the front attachment carrier to ParkPro mechanics. The parts are already in works.

And last but not least the good news: the parts for the PB400 4F backpack are available at Pistenking as kit by AT modellbau. And also the stickers and lever control for the ParkPro.

 

 

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