Hakki Pilke Firewood Processor - 1:32 Model Kit

[Stabliofarmer]

I originally set up the 3D printing topic to highlight this build but that has taken off on its own so I will make a separate topic for this build. Within the build I'll hopefully highlight some of the uses for 3D printing while integrating resin casting and considering speed and economy of manufacture.

Hakki Pilke are a Finnish brand that build a range of firewood equipment. I originally built a batch of 5 Falcon 35 Firewood Processors in 2018

These were scratch built from plastic and when I shared them to my facebook page the demand highlighted a kit would be a feasible. Time to develop a set of 'castable' patterns was always hard to find and hence 3D printing came into it. 

The process starts on the computer using the 3D CAD (Computer Aided Design) software 'Fusion 360'. The components are draw starting with a 2D sketch from which you extrude a basic shape and from the cut and join features until it resembles the parts you want. The individual parts can then be bought together to check the fit.

This is the basic window for Fusion 360. I have drawn the cross section view of the main body and extruded this to create the shape shown.

Drawing onto the right hand side I create the profile I want to cut out for the splitting area and create a cut command to remove the material.

The cuts and shapes become more complex to develop the shape further. The CAD process is probably best related to sculpting, you can either add material to create new items, or you can carve material away to create gaps and spaces.

Detailing is being added here such as hinges (new material) and recesses for parts that are cast separately (carving).

This process is repeated time upon time to build up each part, then all the parts can be bought together as in the above assembly.

When I am happy with the parts and ready to print they need to be save as '.step' files. This is the type of computer file that the 3D printer splicer software can read. To do this they are exported part by part, the photo shows the many parts that will make up the model.

In order to 3D print these .step files must be 'spliced'. A process of turning the model into hundreds of layers about 0.1mm high. For this I use a splicing software called Chitubox which is recommended by Elegoo who make my printer. The parts can be manipulated into the best orientation for printing and the supports required to build the parts are added automatically.

To highlight splicing this is the spliced model set to about half way through printing, you can see how the model will build up in layers.

 

 

[Stabliofarmer]

The work can now leave the computer and begin to become physical.

I am using an Elegoo Mars Pro 2 printer complete with their Mecury cleaning station. Theres is lots online for those interested in the exactities of how it works but basically the printer works as follows:

• A vat of UV curing resin is suspended over a horizontal smartphone screen
• A build plate is lowered into the vat until it is 0.1mm above the smartphone screen.
• The screen shows a 1:1 scale photo of a spliced layer, the light from the screen curing the resin in the shape projected
• The cured resin, now stuck to the build plate, is lifted 0.1mm and the next photo shown
• This process repeats until the whole model is printed
• The print must be cleaned of excess resin using 100% proof alcohol cleaner
• The print must then be further cured to become stable using a strong UV light (basically a mini sunbed)
• The final print can be cleaned up with any supports removed

The printer showing the vat and the build plate submerged in the vat

The screen on the front shows the spliced image being projected on the smartphone screen at the time. You can see the build has just started (1%) and the expected time to print all 634 layers is 1hr 44min (actually ends up about 2.5hrs).

When finished the build plate lifts to reveal the printed part (successful or unsuccessful).

This view hopefully highlights how the spliced model on the computer lines up with what is printed.

The parts are then put in the Mercury clean and cure station.

This is the cleaned parts ready to take off the build plate and have 5 minutes in the tanning salon.

Once cured the parts are test fitted and any adjustments made in the computer and new parts printed ready to cast from.

 

[Stabliofarmer]

The printed parts cleaned up and ready to make silicone moulds from.

The silicone poured to make up the moulds for casting.

The cast parts that make up the kit.

Test fitting of the resin parts and their functions.

[Stabliofarmer]

A splash of paint, some pins, rubber and decals and a finished model appears ready for the instruction manual.

The kit version lacks a couple of bits of detail that the scratch built version has but this was necessary to make an economically manufacturable kit. I'm quite pleased with the final outcome and plenty of kits have set off into Scandinavia, the machines native home.

Thanks for looking, I hope its been of interest!

[Tractorman810]

those resin printers do look good, especially for detailed parts. have you pondered figures from it yet.

[Stabliofarmer]

1 hour ago, Tractorman810 said:

those resin printers do look good, especially for detailed parts. have you pondered figures from it yet.

I haven't looked at figures no. I'm sure there'll be a good range available to download. I'd love to have the time and finance to incvest in zbrush and learn how to sculpt in it but I think we're away off that!

http://pixologic.com/features/about-zbrush.php