All posts by Nashua Area Radio Society

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3D Printing a Raspberry Pi Case

In a previous article, I wrote about jumping into 3D printing for fun and home-brewing.  I decided I wanted to try printing a custom case for my Raspberry Pi 2 Model B that I found on Thingiverse.  I chose one that had VESA mounting tabs with 75mm spacing in order to mount to the back of an older LCD monitor I had laying around.  I am doing this to create a dedicated computer for running my M3D 3D printer.

Raspberry Pi Case
Custom Cases for Raspberry Pi found on Thingiverse.com

I’m printing the case you see above on the left.  There are other upper case options for mounting mini-fans should you need to provide extra cooling for your Raspberry Pi.  And if you are handy with one of the many 3D modeling software packages out there, you can mod this case (or any case) to fit your specific needs.

PRINTING THE CASE LOWER

I acquired a spool of black PLA filament (Hatchbox) from Amazon.

3D Printer Filament

While not specifically branded by M3D, I wanted to try other sources because the Hatchbox brand was less expensive on the order of 2.8:1 than the M3D branded filament.  I was taking a chance because I am learning that getting the temperature right for a brand not tested by the printer manufacturer can be tricky.  I did have issues of the print starting to lift off the print bed (M3D is non-heated).  But I recovered from that by tacking down the corner with a hot glue gun.  Maybe this would have printed better on a heated print bed or if I would have controlled the surrounding temperature better.

Almost completed lower Raspberry Pi cas
Almost completed lower Raspberry Pi case
Completed Raspberry Pi case lower
Completed Raspberry Pi case lower

 

Back of case showing "raft" before removal and cleanup
Back of case showing “raft” before removal and cleanup

 

Cleaned up lower ready for test fit
Cleaned up lower ready for test fit

 

Fits like a glove!
Fits like a glove!

PRINTING THE CASE UPPER

Given the experience I had with printing with the Hatchbox filament, I wanted to see how printing the case upper would be using the M3D filament.   I just chose one of the other M3D filaments to contrast the black lower.  The printer’s program calculated this to be a 14 hr print.  But, the output is looking good for far–no lifting of corners or warping.

Printing the Upper Case Printing The Upper Case

About 12 hours later… DONE!

Print completed for the RasPi case upper
Print completed for the RasPi case upper

 

After removing the raft and cleaning up stray flashing
After removing the raft and cleaning up stray flashing (inside)

 

After removing the raft and cleaning up stray flashing (outside)
After removing the raft and cleaning up stray flashing (outside)

 

Fits great!  Just need to figure out the case screws.
Fits great!  Just need to figure out the case screws.

As mentioned earlier, I wanted to print the case version with the VESA mounting tabs on the back of a monitor.  In this case, they needed to be 75mm spacing.  Aligned nicely!

Final Assembly Final Assembly

This was a fun project.  While not a perfect printing experience, it was good enough for a first major print project.  Lessons learned will be turned back into the printing experience and improved upon on subsequent projects.

After mounting this Raspberry Pi w/case to the back of the monitor, the next mini-project is to get the Raspberry Pi working with the 3D printer.  There appears to be groundwork already done in this area, and I will follow the path already paved.

Wayne / AG1A

NEAR-Fest XIX

NEAR-Fest XIX  – April 29 – 30 will be held at the Deerfield Fairgrounds –  34 Stage Rd, Deerfield NH.  Open: Friday 9:00 AM to Saturday 1:00 PM – the Grand door prizes are drawn at 1:00 PM Saturday.

More info:  near-fest.com (be sure to scroll down).

Lots of buyers and sellers usually attend (depending on weather) plus some commercial vendors.  Sellers are dispersed over a significant portion of the fairground, so be prepared for a little bit of walking –  usually, 2 or 3 trips around the grounds will give some good ideas of what is available.  Most sellers will negotiate – so make an offer, but don’t wait too long – great deals go quickly.

The best part of the event is the people!  You’ll likely run into a few of your radio buddies as you wander the fairgrounds.

Baofeng/Pofung Radios: A Review For The New Ham

Baofeng UV-5R
Baofeng UV-5R

You may have run across the names Baofeng/Pofung here and there. They are a Chinese manufacturer of two-way radio equipment. What makes these radios attractive to the new ham is their low cost. If you look carefully on Amazon, you can buy a UV-5R+ dual band HT for around $40. Add a programming cable for $10, pair that with the free, open source programming software called CHIRP and you’ve got a very capable portable station.

The UV-5R+ covers 136-174 / 400-512 MHz (transmit and receive) with two power levels, 1- and 5-Watts. They also feature a dual-watch function, DCS/CTCSS encode/decode, DTMF keypad, VOX, and a handy LED flashlight. The front mounted speaker provides 1 Watt of clear audio. The audio and reception reports I’ve received were excellent. There is a two-pin, Kenwood compatible socket on the side of the radio for an optional speaker mike. An earphone-microphone is included.

One drawback to these radios is the fact that programming them manually is a bit of a challenge. However, with some practice, it is possible to program the radio without the aid of a computer. There are many YouTube videos on programming. It’s usually a good idea to learn how to program any radio in the field because your laptop/desktop computer may not be available to you in an emergency situation.

So you’ve got your new radio, you’ve charged the battery, turned it on, was greeted by the cheery voice telling you that you were in the frequency mode (yes, the radio will talk to you in English or Chinese)…now what? The first thing you should do is get CHIRP installed and running on your PC. Next, download the virgin configuration from the radio and save it to a file on your computer. That way you’ll be able to revert the radio to its factory fresh state in case you accidentally mess things up. More about CHIRP in another article.

One accessory you might want to consider is an antenna. The stock rubber antenna isn’t very good because of mismatching. You’ll find that most users recommend Nagoya antennas. These seem to be well made Taiwanese antennas that are much better than the one that came with the radio. Unfortunately, there is a rash of counterfeit Nagoyas out there so be careful. I have had good luck with the MFJ-1717S dual-band antenna. Just remember to get an antenna with a female SMA connector.

Another nuisance I’ve found is the retaining nut for the antenna connector on the radio coming loose after a couple of days use. The simple fix for this is to remove the nut and apply a small amount of thread locking compound to the threads. Tighten the nut well and that’s it. Just make sure that the thread locker is removable because there will come a time when you have to take the radio apart for servicing. I recommend Loctite Blue.

I’ve had my UV-5R+ for two years and it just runs. Last year I bought a BF-F9+V2 which is the tri-power version of the 5R+ (1/5/8 Watts). These low cost, easy to use radios will make a welcome addition to any emergency Go Box.

Bill, KA1SSR

Radio Amateurs Developing Skills Worldwide