My 2019 3d food printing resolutions included, not only, a new 3d food printer. Pinya4 is a new iteration on the saga. The fourth one.
As mentioned in this previous post the main goals for my new 3d food printer Pinya 4 are:
- Easy to use
- Automatic multitool
- Clean access to printing area
- Easy to clean
My first iteration, does not tackle all these features. In fact it mostly focuses in a single one. Clean access to printing area.
The reason for this is to actually learn (start to) a bunch of new making skills:
Welding
From day one I wanted to use stainless steel for my printer. It is the “pro” cooking appliance material. Welding the body felt like the right way to get a sturdy frame. Also I got excuse to my first steps into TIG welding.
Following pictures show the evolution for the new food printer first frame.
Of course this took way longer than expected, but through a some trial and error I got the frame done. Stainless steel is a harder material to cut, compare to aluminum, so that was intense. I was happy with the results and I even ended up welding the bolt joins!
CNC
This was a fun one, I wanted the new food printer to have as much as metal parts as possible. I quickly gave up on stainless part for my learning process with CNC. Thanks to the support from Hannah and Boris from New Lab I was able to jump on the Haas and machine the main plate and biceps for the printer.
The following parts are the printer biceps:
SLS PARTS
Having quick access to New Lab printing service, it was a no brainer to take advantage of it. I printed the end effector, the ball joint cup and bicep to shaft thingy.
I used abuse FDM, but for more complex and tiny parts like the ball joint cup it makes a HUGE difference, thanks Alex!
Endeffector picture:
Following picture is the second iteration of the ball joint cup:
CONTROL
My last 3d food printer was using a Smoothieboard. Instead the new 3d food printer uses a Duet3D.
Not a lot of reason was put into this change. Basically I wanted the firmware to have rotary delta kinematics, I was curious about the wifi integration, and wanted to try the RepRapFirmware.
Lessons learned
NO CAD???
I knew that not designing the whole printer in CAD, I use mostly fusion360, was a mistake. But at the same time I knew that If I had to put the hours to make a beautiful and full featured CAD I would had never started the printer.
Due to the lag of a proper full design, I did the following mistakes:
- The printer is shorter in height. By almost 90mm!!!
- The tension mechanism of the motor belts is BAD
- The endstops set up is not friendly
- the ball joints are a never ending mess
- …
Although beyond this issues, I am really happy on how the printer looks and feels specially thanks to welding and cnc wise.
Stainless steel is bouncy
Being this my first (and so far) only stainless steel welding project I had zero idea about how to size the body. I used 1/2 in flat bar, that turn out to make the body quite springy.
Next iteration will have a stronger design, or so I hope!
Gravity (weight distribution)
Never thought about this until I had the first parts on my hand. The hanging head of the printer (includes motors and arms) is pretty heavy! So the tower needed to be at least twice as heavy. Right now it is not and I need to balance the printer with a pot full of coins.
Ball joints
Without thinking much I moved from magnet hold to spring loaded ball joints. I am already into my 3rd design iteration, and for some reason I feel they wont be the last one.
First iteration used only one spring, what made all the joints S-N-A-P
Second iteration used two springs, and a bigger “cup” to slide around the ball. I felt the surface in contact between socket and ball was too big and decided to do a third iteration. Probably this wasnt needed. Although I feel, deep down inside of me I was hoping to solve in hardware calibration issues in the printer.
Rotary delta?!?!
Where to start here. This is my first rotary delta. In fact, I build the hardware before I even had a slightly idea of how to make it work. Obviously I still dont. I have managed to do some quick print, to clearly realize the need for a proper calibration day.
Printing food I have never worried too much about calibration, I dont think 1mm up or down matters much, but at least having a flat layer is a must… so it is clear that that is my next step!
Conclusions
There is still a long road ahead to get Pinya4 up and running, hopefully sooner than later we will get there. Once we have a solid foundation is when things are going to start getting fun, trying to solve some of our early design goals! multitool anyone???
Thanks a lot! Cudos to you if you made it all the way down here.
BTW, if you like what you read here, consider supporting us on Patreon that makes a world of a difference and help us to make more awesome things!
