• The new model and mould

    Punit4 days ago 0 comments

    This is the new model but it is still untested, but after comparing it to the old version I can see that most issues are fixed.

    In the full assembly you can see the addition of screws and standoffs. The screws are to hold the middle and translucent section together and the standoffs are to hold the top disk (the one that the encoder screws to) to the middle section. I also found that the knob didn't sit parallel with the middle section, not sure if that is because of the encoder coupler but it seemed like a very good fit, it could be that the coupler itself is not sitting perpendicular inside the knob. I will be making a new knob with a better mould, details are in the next paragraph. 

    The new mould should hopefully fix a couple issues I have with the current mould. 

    1. Trying to push the top disk onto the cement is difficult because the seal is very tight between the disk and the PVC walls. New version has indents around the circumference in order to let air through. 

    2. The bottom disk which forms the cavity for the encoder coupler left a cavity which was too tight and made it hard to insert the actual coupler. New version will leave a bigger cavity.

    You can see the indents around the top disk here

  • Complete revamp

    Punit4 days ago 0 comments

    I finally gave in and ordered some pro mini's

    Currently redesigning some parts after learning from mistakes in my current version.

    One big thing I forgot is how I will hold all the parts together so in this version I will be sure to add some screw holes (want to avoid glue).

    Will need to make the housing taller since the pro mini now comes into contact with the encoder.

    I will publish a more detailed log showing the changes I made when I am finished

  • Mould done but.....

    Punit7 days ago 0 comments

    I got impatient and proceeded to start moulding the cement, I forgot to drill a small hole in the top disk so the air that was trapped (the seal between the disk's and the PVC sheet was very tight) could not escape and made it hard to push the top disk down into the mould. 

    Some water was able to leak out from the edges (where the PVC sheet and the bottom disk mate) and this made the knob crumbly around the circumference but it was very slight and ended up looking like a fillet. 

    The bottom disk with the encoder coupler blank piece got stuck in the knob and so I had to break the coupler blank away from the bottom disk and then use my hot air rework station to melt the plastic and pull it out. The cavity left by the blank was too tight for the actual coupler to slide in so I should make the blank a little bigger next time.

    The top surface was ok but had lots of lines (from the bottom surface of the top disk which was 3d printed) so I had to give it a light sanding to remove those and also to level it (ended up also leaving behind a nice textured surface that looks like stone).

    I have finally given in and ordered a pro micro, the idea of two attiny85's worked in my head but turns out there isn't enough voltage to power the neopixel ring. At least I will now have the hardware capability to use the neopixel to its full potential (may even add a small button to change colour sequences etc), changing colours when muted or unmuted etc etc. Hopefully will all work out in the end, however I am not sure how I will make the usb port accessible enough for a cable to plug in. I may need to allow for the whole body of the micro usb end to go inside the housing otherwise the corners of the rectangular PCB will protrude out of the housing. I will show an example once I design a new housing.

  • Progress so far

    Punit11/15/2020 at 20:10 0 comments

    My bag of cement (wrongly called it concrete in past posts, I am not adding sand to it so technically not concrete) is arriving tomorrow so in preparation I have printed the parts that I will need, the encoder coupler (printed twice because it was too loose), the bottom disk with the blank shape of the coupler on it and currently being printed, is the flat top disk and one more part which is an outer ring to fit outside the PVC sheet to sandwich it to the bottom disk to help it hold its shape, and hopefully squeeze the sheet as close to the bottom disk as possible to prevent water leaking out.

  • Re-order the mould

    Punit11/14/2020 at 13:42 0 comments

    I need to flip the mould design upside down, the disk with the encoder coupler should be placed at the bottom, cement poured on top and then the top flat disk placed on top as flat as possible, this is to introduce air bubbles into the top surface which looks a lot more interesting that a smooth or uncovered surface. If you look at the image below you can see the effect of placing a disk on top of the cement and in my opinion it looks way better. I am also considering mixing some black cement dye into the mix in order to produce a black knob which I think will look very interesting. (taken from DIYPerks youtube video which originally gave me the inspiration for this project).

  • Trying to render

    Punit11/14/2020 at 02:20 0 comments

  • Mould design

    Punit11/11/2020 at 21:13 0 comments

    I am now planning my approach to mould the concrete into the knob shape. The mould consists of:

    - A bottom disk 

    - Acetate sheet to form the wall of the mould

    - A top disk with a blank piece shaped like the encoder coupler (the encoder coupler is to provide a better/replaceable connection between the knob and the encoder shaft because the only way to access the inside of the knob is to take the knob off first, so over time the concrete can wear, but with the coupler in place, I can just print a new one if it gets too loose).

    In these images I forgot to include another disk that the encoder will mount to in order to keep it centred, I have also found that clicking the encoder while it is on the disk and in the enclosure makes a louder and more satisfying sound.

    I hope that the encoder's stepping will become more distinct with the concrete knob on as well as allow me to effortlessly flick/spin the knob due to the momentum of the knob.

  • Pictures of progress so far

    Punit10/31/2020 at 23:41 0 comments

    I've already started this project but so far I have:

    - Tested the neopixel ring

    - Learned how to use the digispark

    - Tested the Volume knob program that is in the trinket HID library

    - Produced a program that will handle the RGB ring

    - Found out that pin 5 on these clones are actually set as a RESET pin and so I had to use an Arduino Uno clone to disable it so I can use it as a GPIO

    - Realised that the ATTINY85 doesn't have enough flash for the volume knob AND RGB code therefore I have just decided to try use another of the digispark boards just to handle the RGB. Sadly wont be able to have the neopixel ring change colours etc based on what you do with the knob (for example, I wanted the ring to turn red and fade brightness up and down when you press the knob down to mute the audio)

    This brings us to the present day where I am now waiting for adapter PCB's to convert SOIC8 to DIP8 so that I can solder the "RGB controller chip" to a small PCB I will have inside the enclosure.