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  • Author Author: dougw
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The Spice of Pi - Blog Doug 6

dougw

It has been a heavy week of mechanical design and fabrication. The machine is not together yet, but I wanted to post a blog showing progress:

 

There are still a couple of pieces to design and print, but I have enough to start assembling the machine. Once I figure out how to ream the jar holes on the main platter a bit to make the fit of some of the jars just a little freer, I can work on assembling the rotation mechanism.

 

Design Challenge Links:

Pi Chef Design Challenge

About the challenge

The other challengers

The kit

Terms & Conditions

Summaries by Charles Gantt

 

Project Links:

Blog Doug 1 - The Concept

Blog Glenn 1 - AIY Voice Kit Unboxing

Blog Doug 2 - The Block Diagram and Bill of Materials

Blog Doug 3 - Spice Jar Lift Mechanism

Blog Glenn 2 - Firmware Considerations

Blog Doug 4 - Carousel Design

Blog Doug 5 - Platter Rotation Mechanism

Blog Glenn 3 - Python GUI

Blog Doug 6 - Platter Printing and Main Bearing Chassis

  • in reply to dougw

    Hi Douglas

     

    If you have a wood bit large enough, it might work better than trying to sand the PLA.

     

     

     

    DAB

  • in reply to beacon_dave

    I was using an electric drill with the hone and sanding drum but you can't work it hard enough to generate heat as the PLA melts and messes up the operation.

    Mixed results - the print file was corrupted and stopped printing (after 2 days) before it was complete - there should be a top layer to make the platter stronger.

    I thought the printer CPU had just crashed so I reprinted the file, but it failed at exactly the same point 2 days later.

    Fortunately the partial platter looks fine and seems strong enough as is, because I ran out of plastic.

    PLA is very stable dimensionally - I haven't had any issues with warping.

  • in reply to dougw

    Sounds like you need a machine to automate that finishing process image

     

    What were the 'mixed results' from the reprint, as the first one looked as if it went really well ?

     

    Did you experience any material warping with that size of print ? Looking at the printing video though you appeared to have pretty good adhesion to the printer bed, so perhaps not.

  • in reply to mcb1

    The jar diameters vary by about a millimeter, but PLA is pretty tough to sand down. About half the jars fit without much work, the other half were going to be a lot of work. I figured - let the printer do the work...

  • in reply to dougw

    it took about 40 minutes to get one cylinder close to where I wanted it

    It was that bad .... It just shows there is little attention to sizing of those jars.

     

     

     

    I ended up modifying the file and reprinting

    That's a bit serious ... 2.7 days serious

     

     

    Have you measured the jars to see the range of diameters.?

    Obviously there are some other options if this was for production or you were making several of them.

     

    My thought would be 5 or six 'bumps' on the inside which would allow easier fine tuning, or sloppier but taller holes.

     

    Well done on the attention to detail, it is a key part of the whole design.

     

    Mark