Category Archives: Tool builds improvements and repairs

Monoprice Select Mini 3D Printer Upgrades – Improved Knob / Button

MP select mini 3D printer knob

The first upgrade to the Monoprice Select Mini 3D printer has to be replacing the god awful input knob/button that came on the printer.  This printer uses a standard rotary encoder with push button for it’s single user input.  The UX is pretty miserable with the OEM knob/button.  I designed a nice SLA printable version, and have included an FDM version as well for those without access to higher quality 3D printing options on printers like Objets or Formlabs.   I printed mine in Formlabs Tough resin, because with the led lighting this translucent material looks magical on the printer.

3D printer upgrade MP select Mini knob

 

This button upgrade is available for download for free on Pinshape here at this link:  Link to Monoprice MP select Mini 3D printer upgraded button knob.  Installation required me to bend some stiff wire with short 90 degree ends to get under the original button and pull it off. It takes a bit of force to remove the OEM knob/button but it comes off with some careful pulling/wiggling.

 

MP select Mini 3D printer upgrade button knob

I hope you print one of these for yourself and it makes your mini 3D printer experience more enjoyable.

 

Making a DIY Printed Circuit Board (PCB) vise

Printed Circuit Board holder

I have needed a printed circuit board vise of some sort for a while and have not found a lot of good affordable options that I liked.  I had an old Panavise style hobby vise kicking around the shop for years and I recently decided it was the perfect solution for this project.   I used two different types of 3D printers to make the parts for this project.  My printer, an FDM machine I built myself was used to print up the ABS stronger quick attach mount to attach the vise to my electronics bench.   I used a Formlabs Form1+ SLS 3D Printer to print the PCB holders/grips in a tough 3D printable material that was launched a few months back, appropriately called “Tough”.

 Printed Circuit board Clamping fixtures SLA printed -3321        Printed Circuit board Clamping fixtures SLA printed -3318

The backbone of this project is an old wide opening Panavise.  These were a staple of the hobby world.  I routinely see them for <$1 at flea markets and yard sales.  I had this one kicking around in my metalworking shop for ages.   I must have  picked up somewhere for $0.25 as it still had the yard sale sticker on it.   These originally came with a variety of low quality rubber “grips” and some sort of mount, often a poor quality plastic suction cup thing meant to quickly attach to your presumably smooth workbench.  I gave away a handful of these to fellow hobbyists a couple years ago but this one survived the culling, and I’m glad it did.

Formlabs Touch SLA Printed grips

All of my previous posts on 3D printing used my machine.  I now have available to me one of the other types of 3D printing technologies, SLA.   This type of printer grows parts out of liquid resin, typically with a laser or projector system.  I’ve been using a Form1+ model SLA printer.  It’s a pretty fantastic machine with amazing resolution and detail.  There are also some great materials with different properties that I can not print on my Zac built FDM type 3D printer.   These include the Tough material I used to make the PCB grips for the old panavise clamp I wanted to put to good use for this project.  Formlabs tough resin is, well tough.   Meaning it’s not brittle like may SLA resins.  It also has a good feel to it and excellent mechanical properties for things like vise jaws.  The vise jaws are shown on the build platform after printing.  These are designed to slip over the metal “jaws” of the old Panavise I am using.  If you want to print out your own set of these jaws, circuit board vise jaws for panavise vice clamps.

 

FDM printed Vise quick attach mount

The other piece of the puzzle I needed to make this project work was a way to quickly attach and detach this vise from my electronics bench.  I do not plan to use this vise all the time.   It would be in my way a lot, meaning it needed a quick attach system.  I quickly drew one up and printed it out on my personal 3D printer.   I print in ABS and for this application this material is perfect.   Thequick attach vise mount for workbench.

 

081715  PCB holder 3d printed vise inserts-3551      081715  PCB holder 3d printed vise inserts-3550

Both parts of the quick attach vise mount printed out in a few hours.   The mounting bolt on the panavise clamp is threaded 3/8-24.  I ended up using a bolt and a nut to tighten the clamp to the mount.

081715  PCB holder 3d printed vise inserts-3553            081715  PCB holder 3d printed vise inserts-3554

As you can see the two parts interlock.  there is a taper that locks the vise in place, but comes free with a quick tap upwards from underneath.

Panavise quick attach workbench PCB vise

Testing the location on the bench.  Can you see what’s wrong with my design.  I had a home ‘doh! moment when I saw what I did.

081715  PCB holder 3d printed vise inserts-3556      Printed Circuit Board holder

081715  PCB holder 3d printed vise inserts-3557

The thing I did wrong, is design the quick attach mount with the upper screws at the top.  The problem is that this design screws in edgewise to the plywood top of my workbench.  It is never a great idea to screw into the edge of plywood and expect it to hold.  This application is low force so I think I will be ok.  A better design would have the upper screw mounts 0.75″ lower, I will change my part files for others who want to use my design for themselves have a better design.

Printed Circuit Board holder

081715  PCB holder 3d printed vise inserts-3558

081715  PCB holder 3d printed vise inserts-3561

The above pics shows the vice holding an audio amp circuit board I needed to do some testing on.   As you can see the new PCB vise works great.  It can also hold smaller circuit boards vertically with the middle groove I added in my third and final iteration on the design.  I have used this great circuit board vise a handful of times already and I love it.

More on my other PCB holding and testing stations experiences in a future post when I have time.

The greatest electrical tool of all time, the LCR Tester!

Electrical component tester

This little guy is the greatest thing to happen to electrical projects since the invention of the hammer.  If you are like me, you have a million components on your bench or bins for electronic repairs, upgrades, and circuit design.  I stumbled across this tester on a forum and quickly ordered myself one from ebay.  You can find it by searching for LCR tester.  Why is it the best tool to add to your collection?  Well let me tell you….

measure resistors     Capacitor tester

First, it measures values of resistors and Capacitors (including ESR) with the push of a button.

 

Capacitor tester

It also does diodes…

Electrical component tester     Electrical repairs tester

But BEST OF ALL!  It tells you if  transistors, MOSfets, and the like are good.  But also tells you the values you need to work with these components in your projects.   This is why it’s the best thing since the hammer.  I have tons of components I’ve pulled from boards to use in projects, but finding data sheets etc is a pain.  This makes life easy, especially for breadboard proof of concept and educational circuit design experiments.

The LCR tester comes as a loose board, and is very cheap. I think mine was $15 shipped.  It runs on a 9V battery, and I printed a case on my 3D printer. I’ll find the model and share it here later.  This little device belongs on everyone’s electrical project bench (or toolbox).

 

PROJECT SNEAK PEAK:

LCR TEster pics-2780 LCR TEster pics-2782 LCR TEster pics-2783

 

Partially so I can find the driver board specs in the future, but I’ve been playing with Lasers for the last 6-9 months working on some different types of rapid prototyping machines.  More to follow but the sneak peak photos show some of my test parts as a tease.

 

Comparison of 12V DC LED light strips in shop light conversions (3528 vs 5050 vs 5630)

Shop light using 12V DC LEDs using 3528/5050/5630 Flexible Light Strips   In an earlier post I shared how I converted shop lights to low cost LED lighting using readily available 12V DC LED light strips with 3528, 5630, and 5050 SMD LEDs as pictured above.  These lighting strips are very low cost ($5-8/ 5M roll shipped)  and provide an easy way to add light to any place you need it, not just for a shop light conversion.  You can run them off an AC to 12V DC power supply or a 12V battery, which makes them extremely handy in the case of a power outage.   In this post I compare the differences between each LED strip and share which one makes for the best shop light conversion.

SMD LED light strip comparison

Theoretically the 5630 LED is one and half times brighter than the 5050 LED which is three times brighter than a 3528 LED.  However, this does little to tell you which one is really the best light.  Interesting is that the part number actually refers to the size of the individual device, with 3528’s being 3.5 x 2.8 mm and so on.  All have approximate 120 degree emitting angles, the angle at which the light radiates outward from the chip.  You have to be a bit careful with the whole lumens or candela rating on LEDs. These are measured  via standards and tell you nothing about the color/quality of the light produced.

12V DC LED Light strip Comparison

Above shows one of my shop lights converted with 3528 LEDs light strip.  I used three lengths of light strip on this lamp. It produces an amount of light that is considerably less then two 48″  T32 bulbs, but is still more then adequate for some shop spaces.   The power rate of 0.08W/led for 3528’s makes it the lowest power per LED device of the three.  It also has the lowest rated light output.  The light output by these strips is a good color.  By this I mean observed quality.  I am not talking about measured wavelengths.  It has a very very slight cool or  purple tinge to it, but it is almost unnoticeable. Not noticeable at all without a grey card Kodak photo scale reference handy. For lower power less used areas I think these strips are good. I would not use these in an area I was using all the time as they do not emit enough light.  I used these 3528 LED light strips inside my 3d printer enclosure and they work wonderfully for this application.  If there’s not enough light you can simply use more of the strips.

12V DC LED Light strip Comparison    Rated at 0.5W device on strip, the 5640 LED’s are theoretically the “brightest” of the three I’m comparing for shop light use in this post.  I find the light emitted from these to be very purple and harsh.  I strongly suspect, that the LEDs used in these strips are a low cost clone of the Samsung 5640 OEM chips and thus the poor light quality. This is my least favorite of the lighting strips. I would not recommend the 5640 light strips for any applicaton, the light generated irritates me.  Additionally, even with 3 rows (instead of 2 of the 5050 strips)  it has less apparent light generated then the 5050 lamp with 2 rows.  The real drawback is the color on this one,  Have I mentioned that I find it highly irritating?  I only converted one lamp to these and I will put it in a location I almost never use because of my dislike of the output lighting.  I may even change it over to 5050 strips eventually.

12V DC LED Light strip ComparisonThe clear winner of these three and my favorite is the 5050 LED strips.  With a power consumption of  0.24W per device, they have a  good balance between color output, and total light intensity.  Two strips seems more then adequate, vs three of the other strips.  I really like the quality of the  light produced by these strips.  It is a bright white without any weird or subtle tint.  It almost feels like natural lighting.  These strips are so good I ordered several more rolls of this light strip for the remainder of my shop light conversions as the bulb or ballasts continue to fail.

One last thing to note, the angle of light produced by led strips is 120 degrees. This is different then fluorescent tubes that generate light in 360 degrees.  I find these LED conversion shop lights work better in high bay applications then in lower ceiling spaces.  the 10 ft ceilings give the light plenty of room to spread out, at 8ft you get a lot less square footage covered by the direct light.  I suppose some sort of plastic diffusion panel would help with this somewhat.

As they say, your mileage may vary, but this post aims to share my experience. It may be that the strips I purchased on ebay are to blame for my opinions.  If you want to order the same strips I did, here is a link to the ebay listing for strip lights.  If the link no longer works, the sellers name is  cnredceo.  If you search you should find them easily enough.  His shipping is very fast, and the packaging is excellent.

** If something should change in 6 months or a year, I will return and edit this post to include any noticed issues or failings.