Completed: D-Lev Digital Theremin Prototype PIII

Posted: 5/21/2021 1:45:38 PM
pitts8rh

From: Minnesota USA

Joined: 11/27/2015

"How did you select top panel tilt angle?" -Buggins

I set the panel angle to stay within the recommended LCD viewing angle for both standing and sitting positions.

"What angle you are using in your design?"

The angle was initially planned to be about 20 degrees from horizontal, but in the end the internal dimensions needed to fit everything inside drove this to the uneven number of 21.7 degrees. You would want to check your own display before deciding on the panel angle.

"Is screen visibility good enough?"

Visibility and contrast is excellent from both positions.  Even the white on black display which is more sensitive to viewing angle looks great from both positions.  The D-Lev LCD does have a pot for optimizing display contrast, which I did adjust to give equal contrast at the two playing positions.

"What is spacing between encoders? Is it feasible?"

The vertical spacing is 25.4mm. This spacing is knob-dependant, and you can have tighter spacing with smaller knobs (look at how they do it on compact Euro-rack modules).  Small-diameter and easy-grip knurled or rubberized knobs like those used on audio mixers work, but you do end up with the pointers which are unnecessary and kind of annoying for continuous-rotation encoders.

Posted: 5/21/2021 2:45:34 PM
Buggins

From: Theremin Motherland

Joined: 3/16/2017

but you do end up with the pointers which are unnecessary and kind of annoying for continuous-rotation encoders
-- pitts8rh


It looks like for encoders we need knows w/o pointers, and for pots - with pointers, and they should be in the same style. Is it ever possible to buy such knobs somewhere?

Printed knobs could be a solution. I don't have 3d printer. Is there any service for 3d printing, similar to one for PCB manufacturing?


Posted: 5/21/2021 3:50:22 PM
pitts8rh

From: Minnesota USA

Joined: 11/27/2015

"Printed knobs could be a solution. I don't have 3d printer. Is there any service for 3d printing, similar to one for PCB manufacturing?" - Buggins

There are lots of them here in the US, so I would guess you have some as well, but it doesn't take too many prints before you would have paid for a printer.  I think Eric got his Creality Ender 3 for around $200 USD. 

Another option that makes a very functional encoder knob is to find some silicone vacuum caps like these cut them to the right length:

https://www.ebay.com/itm/254292999101