My Custom Designed 25W RMS ipod/mp3 Player Speaker Sound System

September 3, 2014 in and cool stuff., Arts Crafts and other, Woodworking and Furniture

mp3 speaker dock sound system

I’m big on recycling and feel the highest form of recycling is to re-purpose and reuse things that would otherwise be discarded.  This project is built largely from re-purposed recycled components. It’s fabrication used 3d printing, cnc machining, electronics, and woodworking.  The inspiration came about when I was visiting my buddy and he asked me to help him move a giant older DLP television out of his basement to the curb.  Realizing it was going to the dump, I asked if I could take a few useful parts from it.  Originally planning to only grab the connector plate off  the back that I needed for another project, we ended up taking the TV apart and I recovered the power supply unit, speakers, some circuit boards and the connectors I was originally after.  Research online showed that the speakers were really quite nice units, fully shielded with decent Theile/Small specifications.  There was an onboard self contained amplifier chip in the TDA family that was easily desoldered and built into a small stand alone audio amp.   I had been wanting a small nice powered speaker unit for some time and  I now had all the parts I needed to build myself one.

Desktop Active Speakers -0811      Desktop Active Speakers -0810

I went with a slightly retro design for this unit.   I didn’t really reference anything outside of some basics, like the golden ratio and standard speaker enclosure practices.  I’m very happy with how it looks and sounds.  I think it’s very attractive, fitting well with the rest of my things.

 

Maple desktop powered speaker system - insides

Before buttoning it all up there was several rounds of testing out the electronics, switches, power supply, etc to ensure everything worked correctly.  In the end I removed the screw terminals on the PCB and soldered the wires directly worrying that they might come loose with vibration from the music.

 

Desktop Active Speakers -0635        Desktop Active Speakers -0751

The amplifier housing on the left is 3d printed in ABS, as is the power supply housing on the right in the above photo.  I went with a machined metal vent/cover plate milled on my converted CNC machine.  I’m a big fan of Krylon’s ultra Flat Black paint and used this on the back cover for a nice matte black finish.

 

Desktop Active Speakers -0749

The power supply is a standard unit I kept from some piece of electronics that was out dated.  A few minor modifications, remote plug, switched line inputs and an active LED on the front panel all were done the power supply.   Then I designed and 3D printed a case to mount it safely into the speaker unit.

 

Maple desktop powered speaker system

The lighter wood for the outer bodycame from a storm downed maple that I milled into lumber three or so summers ago and dried.   The front and back boards came from a log off a riverland maple my lifelong friend’s father let me take when he cleared some off his property a couple years ago.  Even the front plate is machined from aluminum recycled from an old PC case.

 

Desktop Active Speakers -0814

The finished speaker unit sounds amazing.  I missed a few pictures in the build process. The inside is fully sealed with a divider keeping the two chambers separate.  I also used some polyester batting as internal dampening to increase the effective internal  “volume” of the speaker enclosures.  This unit survived a 48 hrs continuous stress test without any issues.  I love how it looks as well as how good it sounds!

Diode replacement on Lincoln Weld-Pak 100 Welder Repair

August 13, 2014 in around the house repairs and DIY fixes, Tool builds improvements and repairs

welder diode replacement     While working on another project, a diode shorted out in my Lincoln Electric Welder,  a Weld-Pak 100.   I needed to replace this diode but finding information online was challenging.  To help others, and myself in the future,  I am sharing data and specs for the replacement parts I ordered to fix my Lincoln Welder.   I knew the issue was a diode and not a transformer short because it still  made an arc (very poorly), but became a buzz box with the right sound without throwing the internal breaker.  A short in the transformer would likely trip the breaker quickly and not continue to generate an arc.    Opening up the weld-pak 100 and testing the diodes with my digital multimeter with it’s diode setting quickly identified the problem diode.  To do this you have to first remove the diodes from the aluminum plate that acts as their heat sink (or at least the output wires from the plates).

****This project, like many projects by Zac is not a task for the unskilled or those lacking knowledge. Electricity is dangerous!  It can and will kill you!***

If you don’t know exactly what you are doing to be safe, do NOT attempt any kind of repair like this.   Always unplug, and check (verify with a meter safely) that any and all capacitors are discharged fully before testing or working on any electronic device.  I’m sharing this info, primarily to have the data easily accessible should I need to replace or repair my welder again in the future.

welder diode replacement

The Lincoln Weld-Pak 100 diode replacement is a huge PITA.  There is not one smidge of extra wire inside to allow things to move freely making it challenging to work on.  In addition, the transformers are made from wide aluminum strips, and it’s pretty much impossible to move this aluminum strip in the wide direction.   The trick I found to getting the diodes out (they are attached to the rectangular aluminum plates on the left bottom of the above photo) is to undo all of the bolts before trying to get at them.

welder diode replacement Removing what passes for the heat sink (aluminum plate pictured above) from the welder is problematic as well.  Working on this welder is not easy because there’s not a lot of wiggle room on any of the wires.  From a design standpoint this makes sense, least amount of wire will result in the lowest losses.   To get the heat sink plates out use a thin screw driver to pry the inside plastic  clamp and pull the plate towards the front and then up.  I broke off one of the little tabs that locks the plate in place due to prying a bit too much. Thankfully there are two on each plate.

welder diode replacement Above is a side by side photo showing the original diode on the left and the replacements I ordered on the right.  The original rectifier diodes used in the bridge rectifier assembly to generate the DC current used for welding are International Rectofier parts:  IR M9661 40RU (reverse configuration) and IR M9661 40U.  There are 4 diodes in total, and 2 of each part number making up the bridge rectifier assembly.  One of mine was blown, being shorted out such that it allowed electricity to flow in both directions.  These diodes are rated at 70A and 300V based on what I could find on the net, in welder forums and user groups.  The original replacement parts are available from Lincoln and welding supply companies for about $24-30 each.   While that is an option, most of the welder forums recommended replacing the diodes with higher voltage ratings as often they blow due to repeated voltage spikes during the welding process.   I decided to replace all 4 o the diodes in my Lincoln Weld-Pak 100 Welder.  I started my search for replacement parts at Digikey.com (my favorite supplier of electronic parts) but they do not stock higher power rectifier diodes.  I ended up finding what I needed at Newark.co. There were lots of options to choose from,  my choice might not be the best one. If you follow in my footsteps understand this fact.   I as not 100% certain the diode replacement would entirely fix my welder, as such I went with the cheap option.  I ordered two Solid State 85HFR120 and two of Solid State 85HF120 diodes from Newark.com with a total cost plus shipping of considerably less then one replacement OEM diode.   These diodes had the same form factor as the originals and are rated at 85 amps forward current and more importantly a much higher repetitive reverse voltage max of 1200V.

welder diode replacement

Above is the wiring diagram for the Lincoln Weld-Pak 100 Welder.  Thankfully it was inside the welder.  When I looked online I couldn’t find a wiring diagram for my Lincoln Electric Welder and thus I’m sharing it here.  Sometimes it is nice to find things like the circuit diagram for your Weld-Pak welder before you open it up.

welder diode replacement

In order to get the second aluminum plate heat sink out from the welder I had to completely remove the fan assembly.  The plates are supported as well as electrically isolated by the fan assembly so be sure to go careful and not break anything.  When you put it back you need to be very careful that everything is floating in air and no uninsulated parts are touching any other metal parts.    This welder uses air gap to electrically isolate some of the components.

*** Special note ***  DO NOT CUT THE WIRES TO THE DIODES!   There is no extra wire, you MUST DE-SOLDER the wires, and then put them through the new diodes for soldering!   Yes this is not easy, but trust me, if you cut them you will not get it back together without having to replace more things and take the entire welder apart.

welder diode replacement

Replacing the Diodes on the Weld-Pak 100 is pretty straight forward in theory.  Desolder the wires from the old parts, solder on to the new ones.  You may have to squish the wires  while hot with needle nose pliers to get them through the new diodes, or wiggle them in while the solder is melted (using tools not fingers, melted solder is hot).  With all of the diodes replaced you are ready to carefully reassemble the diodes and heat sink plates.  I’m not sure one way is easier then the other. I put the aluminum plates mostly in place but not fully.  This way I could wiggle things into place and then tightened down the nuts.   BE SURE TO USE HEAT SINK PASTE ON THE DIODES when mounting to the Aluminum plate.  I did not have torque specs on the diode nuts, I just made them tightly snug.  Enough so I was sure they wouldn’t come loose, but not tight enough to break anything.

welder diode replacement Once you have it all back together, be sure to check that you have nothing touching that is not supposed to be touching. I used a little bit of Kapton film to insulate the transformer “wire” strip on the off chance that something came in contact with it in the future.   I loosely layed the cover back on and did some test welding.  The welder worked marvelously. I suspect perhaps my diode was iffy for a while as I was once again getting that nice sizzle sound from mig welding.  I realized on hearing it I had not heard that sound quite right for some time.   The bead of weld my weldpak 100 layed down was perfect.  I’ve since welded quite a bit with the repaired welder and everything seems to be great having replaced the rectifier diodes on my Lincoln Weld-Pak 100 Welder.

If you found this post useful, let me know, leave a comment. It’s nice to hear someone found my post useful.

 

 

Technical issues with Projectsbyzac.com

July 24, 2014 in Messages from Zac

I lost my desktop during a lightning storm a while ago.  With it I lost a lot of my setup for posting here. Thus the lack of new posts recently. I have many projects to post and update.

 

In the meantime,   my email on this site is not working.  Use the etzy links to mesg me through there if you are interested in buying toys from me for now.  I’ll take this post down when I’ve figured out all the email routing issues and have everything up and running.

 

I’m also not getting notifications of comments at this time. I’m sorry for the delay in responding to your comments and questions on my posts.

 

Thanks,

-Zac

 

Child Safe Natural Wood Finish – by weight this time

May 15, 2014 in Arts Crafts and other, Woodworking and Furniture

Kid safe wood toy finish

In my earlier post, I shared details of how I make the child safe wood finish made from purified beeswax and mineral oil that I use on my wooden creations meant for little ones.  In the past year I’ve had several emails asking for a more specific ratio of wax to oil.    As I needed to make more of this kid safe finish for my wooden toys available in my etsy shop, I used a scale and took notes while cooking up a batch.

1 pint of Mineral Oil  ~ 380g

Shaved purified Beeswax ~ 25g

Making it about 6% beeswax.  I hope this helps answer your questions if you want to make larger batches or be more precise in mixing up this nontoxic finish that works great on wooden toys you may be crafting.

 

***  Using hot oil and wax over an open flame can be dangerous.  If you have a gas stove, you should use extreme caution or a double boiler.  It’s not really any different then deep frying with oil or crisco on your stove top but I had a friend who suggested I put a warning up here about using oil on a stovetop and I think he is correct.  An alternative method is to use a double boiler with a jar as your container for the wax and oil.   As with all things, use your head, be smart when doing projects at home, and above all BE SAFE! 

 

 

Ducted fan designs, an early project sneak peek

April 11, 2014 in and cool stuff., RepRap 3D Printer

3d printed ducted rotor aircraft engine

This post is an early sneak peek at a project I have been working on in my spare time.  I showed a friend who stopped by and he told someone else an I was pestered to share pics and a video.  I have been experimenting with ducted fan thrust generation with a planned application.  As for what  that application is…  Well it is not ready for the world yet and I will let you use your imagination.

thrust generating ducted rotor     3d printed ducted fan thrust generator

Mostly eye candy at this stage of the game, I have tested 3 different rotor designs without getting into complex blade geometries to date. I have primarily been focused on printing rotors that have little wall clearance and hand finishing them to minimize the gap between the duct and rotor blade.  Research papers I have read shows that this area is critical to ducted fan efficiency and design.

ducted fan design 3d printed-9400

I am currently using a set up with a friction fit on a taper to lock the two halves together so I can get at the motor.  This little bad boy screams when she spools up.  In the shop it sounds like a mini jet engine starting up.   I am working on test platform speed a controller for it using an Arduino nano and components..

rotor design for ducted fan

You can see that this needs lots of cleaning and smoothing before final thrust measurements.  I plan to put it through an acetone bath treatment and then do a bit of hand finishing to smooth out the inner walls to reduce any drag from the 3d printed irregularities.  Eventually I’ll make a rotor balancing jig to fine tune the balance on the rotor.  Future iterations will likely have continually reduced rotor mass to decrease inertia.  I am testing behind a 1/4″ polycarbonate shield in case of catastrophic failure.

ducted fan design 3d printed-9401Here’s one with my hand to provide you with a sense of scale.  I will try to get a video of it spinning at moderate speed.  Without a speed controller I’m reluctant to limit test the high speed operation at this stage of development.  I will put a video up here later this weekend if I can find time. 

Ferrari 308 GTS Magnum PI Plastic Model Kit Built

March 23, 2014 in Arts Crafts and other, Custom Cars and Automotive

Ferrari 308 model built

While looking through old photos to find some for a longtime friends upcoming retirement party I came across these pictures of the Magnum PI Ferrari 308 GTS model kit I built as a Christmas present for my good friend who owns one of these cars.  You may have seen my earlier posts where I built a custom Stainless Steel Exhaust for my friends Ferrari 308, if not please check it out as it is a thing of beauty.  Final pics are in this second post on the Ferrari custom exhaust project by clicking here.

magnum PI Model Kit      magnum PI Model Kit 2

    My friend had bought his Ferrari early in the year.  We had many fun times driving in it, working on it, and reveling in the fact that he owned the car we always dreamed about when we were younger and fans of Magnum PI.  I decided I would put my model building skills to work and make him an almost identical replica of the car for his desk at work as his Christmas gift for that year.  I had done this for another friend the year before and I regularly heard how much he loved it when we chatted.  The challenge was of course finding a kit, as the show and car were both over 25 years old.  I went to Ebay, and even there I had little luck.  Finally I came across a mint in the box still sealed kit at an online webshop that specialized in Old Out of Production (OOP) plastic model kits.  I payed a small fortune, but I purchased the kit. I had been taking lots of detail photos of his car when we went out cruising in it so I had reference material to base my model off and match details exactly.

Custom Ferrari 308 Quatrovalvo model -0927

Custom Ferrari 308 Quatrovalvo model -0930

Custom Built Ferrari 308 Model

I think the model came out pretty good. I would even go so far as to say I am quite proud of it.   There is not a lot of how to in this post, just wanted to share this model and the memory with some of my friends.  Hope you enjoyed the pictures.

 

Salt Powered Robot Kit Build and Review

March 4, 2014 in Arts Crafts and other

Salt Water Powered Robot Kit-7767

I love the modern prevalence of robot kits available for children to build.  They have many different types of kits available for different age groups.  My nephew visited me a while back and I had picked up a The Salt Powered Robot Kit for us to build together.  This post shows the build process, which he did almost entirely himself.

Salt Water Powered Robot Kit-7740      Salt Water Powered Robot Kit-7741

This Salt Powered Robot Kit is made by 4M as part of their Green Science line, and comes in a nicely illustrated box. My Nephew was super excited when he saw that I had a robot project for him during his visit.  In the past we had great fun building a Tin can robot kit.   

Salt Water Powered Robot Kit-7744     Robot kit build

With this kit I let my nephew do all the work, while I offered guidance and took photos. Taking the parts out of the box, we quickly realized it could have been in a much smaller box.  Just one small bag of parts and some detailed instructions.

Salt Water Powered Robot Kit-7747     Salt Water Powered Robot Kit-7746

Expanding the photos above will allow you to read the instruction sheet for the Salt Powered Robot.  In case someone needs them in the future.  The single sprue of plastic parts is laid out and the other bags contain the small parts needed to make this robot go, a motor, screws, cathode and anode plates and a separator.  You have to supply your own salt and water.

Salt Water Powered Robot Kit-7749      Salt Water Powered Robot Kit-7752

I’m pretty proud my lil Nephew managed this robot build all by himself.  At the age of 6 years old, he did (almost) everything to build this kit by himself, .

Salt Water Powered Robot Kit-7753    Salt Water Powered Robot Kit-7756

We spread out the parts after cutting them from the sprue.  Assembly following the instructions was quite straight forward.  My little nephew could read and follow the instructions easily. The one part that he was not able to do himself was snapping the two axles into place.  He was not strong enough for this part.  Even when he put his entire weight on them they refused to snap in place.  My only contribution to this robots construction was that I helped install the two axle pieces.

Salt Water Powered Robot Kit-7758    Salt Water Powered Robot Kit-7759

There were a few small screws which he managed to put in entirely on his own with a small screwdriver.

Salt Water Powered Robot Kit-7763     Salt Water Powered Robot Kit-7767

This was a fun kit to build. You have to mix up salt water, I used a shot glass and a tablespoon of salt into warm water.  The instructions call for a saturated solution, meaning you have solid salt remaining after stirring so the water has as much salt dissolved in it as possible.   The two plates used to make the “battery” that powers the motor last for some time.  The robot went for some 10-15 minutes. 

Video of the Salt Powered Robot in action

The above video link shows the robot kit in action.  This robot kit and many others are great fun for children.  Next time you need a gift for a little girl or boy, consider an educational kit like this over another stuffed animal, doll, car, or action figure.