Wednesday, September 28, 2016

2016-09-27 (Tu) Clockwork Theremin

A Dremel contouring sander was purchased in order to smooth the valleys between the gear teeth. This area has been notoriously difficult to reach with power tools. A week ago a tooth sanding tool was created for this very purpose but a power tool solution would likely save time, work and wrist fatigue.

 Sanding attachment on oscillating tool next to gear

Only the coarse sand paper was used so some of the edges were not entirely finished. This small level of detail should not be noticeable from a distance and may wear off during use.

Close up of sanded teeth

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The rest of the posts for this project have been arranged by date.

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Disclaimer for http://24hourengineer.blogspot.com/

This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.

2016-09-13 (Tu)

Tuesday, September 27, 2016

2016-09-26 (M) Clockwork Theremin

A couple weeks ago an enclosure for the project was designed. This enclosure would house the electronics but not the gears. This would need to have room for all the operating equipment including the distance sensors. 2' x 4' x 3/4" (609 x 1220 x 20mm) MDF was purchased although it would be possible to scale the size down slightly if the metric equivalent wasn't quite large enough.

The panel layout, linked at the bottom of each Clockwork Theremin post, was printed full size and adhered to the MDF. The design assumed the material would be exactly 24" wide so if a slightly smaller piece was used it must be scaled accordingly. Two straight cuts were made on a table saw so the cuts would be straight.

Layout printed, adhered and partially cut

The duplicate pieces were clamped together and sanded so they were close to identical. These pieces will be supported by bolts run between them so any flat surface mean to span the gap should be able to rest easily between them.

Duplicate pieces bolted and sanded

Unfortunately, bolts were not planned ahead of time so reasonable locations had to be sketched on the MDF. Holes were drilled for the cross-connecting bolts. 1/4" (6mm) bolts were decided since they should provide very rigid support. The first hole was simply drilled with a 1/4" (6mm) bit and there was significant hole blowout. For the rest of the holes, pilot holes were drilled.

Board with one blown out hole and seven pilot holes

1/4" (6mm) holes were drilled from each side of the boards and there were no more blown out holes. The long boards were cumbersome and long clamps used on the boards were unwieldy so once a couple holes were drilled bolts were used to hold the pieces together. Since the holes were drilled through boards at the same time there was no trouble putting bolts through the holes.

Cut and drilled boards

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The rest of the posts for this project have been arranged by date.

First time here?


Completed projects from year 1.

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Completed projects from year 3.


Disclaimer for http://24hourengineer.blogspot.com/

This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.

2016-09-13 (Tu)

Monday, September 26, 2016

2016-09-25 (Su) Clockwork Theremin

Experimenting with the miniature version of the theremin made it quite clear that driving a large gear directly from the motor was a poor choice. This was supposed to be a 200mm gear but that would likely prove unworkable.

An internal ring gear [convenient list of gear types] was the easiest choice since it could be hidden under the 200mm gear. This type of gear uses teeth on the inside of a cylinder and can be driven by a regular spur gear from the inside. Rather than research the intricacies of this gear, an existing model was found on Thingiverse by Jag. His planetary gear reducer was downloaded and the OpenSCAD files were modified to produce an isolated internal ring gear.

Model of internal ring gear

Before printing, the model was changed from the one shown above to one with mounting holes and a solid bottom. The purpose of the solid back was so that the small gear would not catch on the spokes. The mounting holes were placed beyond the rim of the gear so no screws would be inside because that could also cause the gears to snag.



Downloads:
Parts list:

The rest of the posts for this project have been arranged by date.

First time here?


Completed projects from year 1.

Completed projects from year 2.

Completed projects from year 3.


Disclaimer for http://24hourengineer.blogspot.com/

This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.

2016-09-13 (Tu)

Sunday, September 25, 2016

2016-09-24 (Sa) Clockwork Theremin

I'm no illustrator. When I draw it is usually limited to technical drawings. Someone more experienced in this field probably wouldn't have made a whole day out of this animation.

One of the things I fail to do at the beginning of a project is to show what I hope to accomplish by the end. I have a grand idea in my mind with details and approaches but when I get to these journals I only share the details and document the procedure. This way the overall goal isn't shown until the end. That's not a good way to communicate an idea. This should journal have happened on the first day rather than a couple weeks into the project.

I've described that there will be large gears moving according to distance sensors but this is significant because the gears do two things. Functionally, they move a couple of potentiometers on a frequency generator. Theatrically, they move according to the movements of the performer. Hopefully, the gears will turn quickly enough that it will appear as if the performer has strings attached to her or his hands. This is exciting to me. The comically large gears will be right out in front of the performer and in plain view

Enough background
----------

Basic shapes were sketched on graph paper. Transparency between sheets of paper was useful as a dark sketch of the gears was made then transferred to the pages above it. The left and right side were both sketched to act as templates but only the right side was used.

Flipping through the sketches

Sketches were scanned and imported to GIMP. GIMP has been used several other times in this blog and it was used exclusively for this animation. Images were brought in, isolated, and scaled. The round gears were drawn twice and to show motion they were toggled between the two drawings. This was not meant to act as an accurate representation of interlocking teeth or gear movement proportions. The whole process took hours and was undoubtedly a matter of inexperience with graphic editing.

Animation showing the operation of the Clockwork Theremin

Downloads:
Parts list:

The rest of the posts for this project have been arranged by date.

First time here?


Completed projects from year 1.

Completed projects from year 2.

Completed projects from year 3.


Disclaimer for http://24hourengineer.blogspot.com/

This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.

2016-09-12 (M)

Saturday, September 24, 2016

2016-09-23 (F) 2 Cyborgs and a Microphone EPISODE 10


Episode ten was edited. There was some debate about using different intro and outro music as well as the idea of playing a music track softly in the background. Each of these was tried but neither of them seemed appropriate. That may have been because Tim and I were so used to the old music that 0music track four just became part of the show.

Track six of 0music replaced the music but it didn't sound right. We also tried using track seven as the background music and it was looped very quietly. Neither sounded right.

Please head over to the show page and listen to the latest installment if you haven't already subscribed through another source.

I'm on the left, Tim's on the right


Ad spot for 2 Cyborgs and a Microphone

The rest of the posts for this project have been arranged by date.

First time here?

Completed projects from year 1.
Completed projects from year 2.
Completed projects from year 3.



This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.


2016-09-15 (Th)

Friday, September 23, 2016

2016-09-22 (Th) 2 Cyborgs and a Microphone


Episode ten was supposed to be about interfaces but at the last minute I asked Tim to split the episode into two parts, input then outputs. So we recorded a full show about input devices. It turns out this wasn't easy to define but in my mind I see the division. I'll try to clarify a bit here. Input devices are ones which provide information to a processor.

An output device presents information to a user.

Example: Cyborg Distance Sensor. An ultrasonic distance sensor acts as the input by collecting information about the nearest object. Processing happens in the middle to translate data. A solenoid acts as the output by stimulating an internal magnet.

A large chunk of the episode was devoted to talking about MIT's DuoSkin which you can read up on here before listening to it in the show. This link also has the information necessary to make your own functional temporary tattoos.

Me - Left. Tim - Right


Ad spot for 2 Cyborgs and a Microphone

The rest of the posts for this project have been arranged by date.

First time here?

Completed projects from year 1.
Completed projects from year 2.
Completed projects from year 3.



This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.


2016-08-25 (Th)

Thursday, September 22, 2016

2016-09-21 (W) Clockwork Theremin

H-Bridges have never been used in any project on this site but their concept was clearly explained and they are a logically designed tool. A small one was attached to a small 3.3V motor and an Arduino UNO. An Arduino Micro Pro was selected for this project but the UNO is notoriously simple to connect and the model on hand already had header terminals attached so no soldering was necessary.

Motor - H-Bridge - UNO

Programming was not difficult. A PWM signal was applied to one pin or the other and the motor ran one direction or another at the desired speed. The gearing scheme was too much for the small motor to handle and the tolerances of the gears were insufficient for appreciable movement. A video was taken showing a gear glued to the motor axle and turning another gear mounted with a sewing pin.

The program activates the gear at maximum power in order to overcome inertia then ramps the speed (duty cycle) down to slow the motor. Code is freely available through codebender.cc



Downloads:
Parts list:

The rest of the posts for this project have been arranged by date.

First time here?


Completed projects from year 1.

Completed projects from year 2.

Completed projects from year 3.


Disclaimer for http://24hourengineer.blogspot.com/

This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.

All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.

All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.

Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on their post.

This blog, including pictures and text, is copyright to Brian McEvoy.

2016-09-11 (Su)