beehive varroa barrier

This is a second post of two, hoping to address the needs of beekeepers in preventing the Varroa mite from entering the beehive’s brood chamber, devastating the pupae inside.


The mite jumps onto the adult bee’s back while it’s foraging for pollen and then rides back to the hive. Once inside, it lurks near the brood cells after the queen has laid a round of pupae. While those cells are being capped off by the bees, the mite jumps into one of the cells and feeds off the young.

This design involves a means of brushing off the mites as the bee enters the hive. Mylar door gates differentiate entrances from exits; the longer entrances incorporate the brushes which will remove the mites which fall through a mesh into a tray of oxalic acid where they may be counted.

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save the bees, save ourselves

Bee colony numbers have been in decline over the last 70 years. I’d suggest that coverage maps like this are behind one of the reasons.


Now imagine that you’re a bee and that those signals from the cellphone towers disrupt your ability to navigate. Just like the way that water molecules are targeted to spin in a microwave oven (by carefully tuning the frequency of the radio waves), the tiny magnetic beads in the abdomens of honey bees are the accidental victims in this “marvel” which we call wireless communications. Bees depend upon their own ability to interpret the “feeling” they get when those magnet beads orient themselves in the Earth’s magnetic flux; they are flying compasses if you think about it.

For every particular antenna length, there is a corresponding center frequency upon which it may communicate. The higher the frequency, the smaller the antenna. Conversely, the higher the frequency, the smaller the antenna which will pick up that signal on the receiving end. Today’s race for higher bandwidth and “coverage everywhere” means that wireless communications in the high frequencies used create perfect resonance for those tiny beads and that there’s nowhere for the bees to hide to escape this magnetically-noisy confusion.

History of the cell phone

The real history of the cell phone begins in 1946 when Bell Labs used WWII technology to commercialize wireless telephone in the states. Here is a graph indicating the number of cell phone subscribers from the period beginning in the mid-80s to about 2003.


Compare this to a graph of the count of bee colonies since 1940, noting that the cell phone was introduced commercially in the year 1946 and would represent the year that cell phone towers started being erected here in the states.


Where’s the nearest cell tower?

There was a time when you could drive out of the city and immediately be frustrated by a lack of cell phone signal. That’s not so, today. You can drive almost anywhere in the U.S. and get a signal from either your own carrier or someone else’s if you have roaming turned on.

But in our own quest for always staying connected with friends and with work we have really hurt nature this time. We’ve hurt the honey bees’ ability to navigate successfully and they’ve attempted to move away from the disruption, flying further from cities and into zones which are dryer (less irrigated by humans).

Reviewing Verizon’s coverage map above, you realized that there’s nowhere to hide now if you’re a bee. They’ve been pushed to the brink. The further they travel, the less likely there is that there will be water to keep the hive alive and a steady supply of water is crucial for honey production.

What bees mean to us

If you think that bees are only good for creating honey, then think again. Bees are important for our own survival. It is estimated that a third of all food that we eat is pollenated by bees. But then, what about the feed for the chickens and cattle which represents the meat that we eat? The bees pollenate the wheat and the corn as well.

In short: when the bees die off, we’re next.

It’s in our best interest to help the bees as much as we can. We need to learn from our mistakes and to make the tough decisions required for the bees to return in number so that our future will have enough food to eat for our ever-increasing population.


Speaking of which, more people means we need more pollination for the food crops and the feed crops, right? There are about three times as many people in the states since 1946 so we’d need the bee colony numbers to increase at the same rate or we’ll be hit by ever-higher food prices, one could suggest. The decreasing bee colony numbers mean that food prices will have inflated more than other consumer items over that same period. If you’re older like myself, you would reasonably agree with me on this one.


Lose the towers, change the technology

The best solution would be to radically change our wireless strategy and to ban the use of frequencies which negatively impact honey bees. Given the US$272B which the carriers alone will make in 2018 and the untold amount received in the sales of the phones themselves, it should be impossible to wean these vendors from this business model. Even if you presented the data to them, they wouldn’t believe it. They are simply making too much money from our own daily “need” to take selfies in the Grand Canyon and to instantly upload them to FaceBook or Instagram or similar.

They [the carriers and smartphone manufacturers] are simply making too much money from our own daily “need” to take selfies in the Grand Canyon and to instantly upload them to FaceBook or Instagram or similar.

We’re to blame in this one. A corporation has no soul nor a conscience. We did this to ourselves.

Help the bees in other ways

Perhaps the best thing that we could do is to attempt to help the bees in other ways. This is the approach that I will be taking personally since it’s something that I can hope to accomplish in my lifetime.

Varroa mite

At the moment, hives are under attack from an aggressive mite by the scientific name of Varroa. I am designing prototypes which should hope to help prevent the mite from entering the brood chamber of a typical hive.

A little help from us

Beekeepers typically introduce a foundation sheet of pressed beeswax to make things easier for the bees to start a frame. These sheets may only be shipped from spring to fall since the cold weather will result in frames which have become cracked and brittle. It would be good if beekeepers themselves could create either the foundation sheets themselves or an even better solution.

I’m currently designing 3D-printed molds so that the sheets may be cast in place in the frames in beeswax in the beekeeper’s home (and even during the winter months).

Lowering the cost of beekeeping

Finally, if we as volunteers can introduce free designs into the open source space, beekeepers may take advantage of these designs and to make their own solutions locally. The honey-producing industry includes many vendors who hope to solve the beekeeper’s many problems as they try to remain profitable only these solutions can be quite expensive.

My approach is to provide free solutions and let the beekeepers benefit from my help. By helping them, I’m helping the bees. And when I help the bees, I’m helping myself. I don’t see this as lowering the cost of honey production; I see this as saving the human race, to be honest.

orbi to the rescue

Q: What’s the difference between a used car and a cable Internet salesman?

A: The used car salesman knows when he’s lying to you.

So a couple years ago we signed up for Cox cable Internet and the speed was supposed to be something rather big, like 30Mbps. The download speed from the Internet has been getting worse lately and I ran one of those typical speed tests. It kept coming back with about 6Mbps. It seemed a shame to keep paying so much money per month for a small fraction of what we’re paying for.

In some way, it’s like the cable companies are selling you bandwidth that you can never use because your computer can only consume a small fraction of what they’re selling. It’s a convenient model for them since they can oversell the same capacity to many customers. One big problem, too, is that the average cable salesperson doesn’t know the technology that well.

The Big Picture

In trying to understand what the problem was, it was important to break up the pieces to see what was failing.

  1. The cable modem itself
  2. The Ethernet-attached devices
  3. The wi-fi mode/type and channel
  4. The neighbors competing wi-fi zones and their channels in use

Although here in the states the original style of wi-fi technology has 11 channels only three of them are unobstructed to their side-channel neighbors, if you will: this only leaves channels 1, 6 and 11.

It turns out that there are over 30 zones within reach of my MacBook in my bedroom. If all of them are on the earlier 2.4GHz style of wi-fi then on average that means that 10 of them are on the same channel as mine and that’s bad news. Imagine having 10 or 30 street performers all on the same side of the street and on the same block and they’re all singing different songs, all competing for your attention. That’s what it would feel like to be a wi-fi adapter in this space.

Imagine having 30 street performers all on the same side of the street and on the same block and they’re all singing different songs, all competing for your attention.

Testing the connectivity by directly plugging into an Ethernet jack proved that the problem was definitely in the wi-fi area of all this.


Here, I list some of the ways of combatting this madness.

Block the competing signals

They have paint that you can apply to your walls which absorbs/blocks the incoming wi-fi signals from your neighbors’ devices. Unfortunately this wasn’t an option.

Change technology

They have a new technology called Li-Fi which uses light to transmit/receive packets of information rather than the standard variety radio waves. Unfortunately, it doesn’t work in the dark so I ruled that out as an option.

Replace the cable modem router

I did consider buying the approximately $400 beefy cable modem router with tri-band wi-fi on it.

Replace the wi-fi part of the modem router with local wi-fi devices

This is the option I chose, turning off my Netgear’s wireless functionality and replacing that with two new devices from Netgear called Orbi.


Netgear now brands some devices which move the signal closer to where you are at any time. I chose the two-router version.


It took longer than I thought to install these since I have so many things which connect via wi-fi and I wanted to make sure that I documented things well for this install. But ultimately, I made the final configuration change to put the Orbi(s) into “AP mode” which meant that the original cable modem would issue out IP addresses and everything fell into place.

Testing after the install

Re-testing showed me that the Orbi was well worth the money. It’s now testing in the 30-34Mbps download range which is at least five times faster than it was before the install.

It’s now testing … at least five times faster than it was before the install.

Overall, I’m very pleased with the performance of the Orbi RBK50.

edit gcode externally

I’ve been making some updates to a command line interface (CLI) program lately. I wrote it in the Go language and it’s useful for editing 3D printer gcode files.

A GCODE file is a set of toolpath instructions for both 3D printers and CNC machines.


The program is called GcodeEdit and it can so far do the following:

  1. Update the hotend’s temperature, useful for changing the filament material you’d like to use for the part
  2. Show a variety of information from the file, like number of layers and the slicer software which was used to create it, for example
  3. Remove all heat-, fan- and extrusion-related commands so that you can watch the printer go through a “dry run” without wasting any plastic
  4. Repeat the indicated layer but without extruding any plastic, suitable for “ironing” out the last layer and useful during the first couple of layers, for example

I intend to keep adding options to this program and I use it myself, for what it’s worth.


recycle, reuse, reinvent

Someone had a dual-monitor desk stand for sale (something like $10) and I bought it without much in mind for it. I liked the sturdiness of it and it’s been in my foyer for several weeks.

Yesterday, I designed a VESA mount in PLA and printed it over the span of fourteen hours and it turned out to be perfect. It now accommodates the first of two filament spools for the 3D printer.




black pearl

Since I’ve had the 3D printer for nine months now, I thought it was time for a facelift. I decided to re-theme it completely on the software side of things. The first step was to change out the web interface (stripping away all of Robo’s theme and modifications) and now I’ve replaced the LCD menu as well, which now looks like this:



I created this design using Conky, a system monitor from the UNIX world. The theme was inspired by an earlier, larger desktop version of this by Ninquitassar but this was a total re-write.

I hope to now re-theme the web interface to match this styling and to then fork & recompile Conky itself to natively provide the details of the in-progress print job itself. It would be nice to have a feedback loop for the Amazon Echo Dot so that the voice controls will in some way alter the screen as an acknowledgement.


hot-crossed filament

The dirty little secret in the world of 3D printing is that things go wrong (a lot). This week’s problem to solve is the frequent cross-threading of the rolls of filament itself.  Filament manufacturers don’t seem to understand the requirements necessary for doing this right so it’s up to the rest of us to fix the problem ourselves.

Each time cross-threading occurs during a print job, you lose the entire print since the feeding of that filament just stops. In this photo, the printer has actually lifted the entire holder assembly off the workbench:


Spool Guide

To deal with this problem, I decided to re-invent the spool holder itself by changing the inner topology from a rectangular shape to parabolic. It now delivers filament in a straighter path to the filament sensor block on the printer, minimizing cross-threading.

The reusable spool guide design incorporates eight individual parts which attach together using standard aluminum hex head bolts.



understanding blockchain

Bitcoin is a relatively new phenomenon, getting its start only nine years ago. Since that time, it is now enjoys a market cap of about US$150B at the time of this post. That’s an admittedly-large sum of money for something that’s completely digital and you can’t hold in your hand at the end of the day. I guess it shares the same status then with stocks, bonds, mutual funds and other trading instruments that are a bit ethereal, if you ask me. That said, though, it has come a long way since its inception and there are a thousand or so copycats in one form or another. And yet, does the average person know anything about the underlying code and how it’s implemented?

I thought I’d put together a collection of terms to shed some light on the underlying technology to make it easier to understand.


A node is a single identifiable unit in a variety of storage systems. It often includes a unique ID of some kind to make it distinguishable from its neighboring data. A node could be as simple as the following:

1,This is the data part
2,And this is more data

Linked List

A list is usually something like a comma-separated list of data. A linked list is one in which each new bit of data points back to the previous one in some way. And there are even varieties of this in which the new data points backward and the existing data points forward as well. Here is another example which includes backward-facing pointers:

{ID=1,Data="This is the data part",Previous=0},
{ID=2,Data="And this is more data",Previous=1}


In the cryptographic world, a hash is usually a large number which was generated from a collection of data. You should assume that the same collection of data as seen later would continue to produce the exact same hash as an output. Furthermore, no other collection of data should produce the same hash. Here’s another example with short versions of hashes included:

{ID=1,Data="This is the data part",Hash="5a285ab1945",PrevHash="00000000000",PrevID=0},
{ID=2,Data="And this is more data",Hash="b6f7f023f02",PrevHash="5a285ab1945",PrevID=1}

This storing-of-the-previous-hash-value in each record is important to prevent any tampering by someone else.

Digital Wallet

Now that you know what a hash is, it’s not too difficult to imagine that a digital wallet (financial account) is represented by one of these as well.

Transaction Ledger

A financial ledger in the form of two paper-based books is something that accountants used to fill out to maintain a company’s finances. A ledger is a history of all the adding and subtracting for the different accounts.

If the data part in our examples above actually represent those +/- activities and correctly identify a pair of financial accounts, then this might be an excellent way of publicly keeping a record of how much different accounts hold in some form of currency.

Block Number

Now that you know what a hash is, that unique identifier/number for each node or block of data is yet another hash number.

Merkle Tree

Since a block can store not one but several transactions in it, the method of storing the data is important. A merkle tree is a way of storing data with individual hashes on each branch plus combined hashes as well at the point of intersection of those branches.

So as we described above, a block can have multiple transactions stored in it. Each individual transaction would include a hash and the accumulation of transactions also gets a combined hash for the sake of safety.


A Bitcoin miner is a computer whose job it is to create and add blocks to this public ledger. More accurately, though, a miner is usually a single graphics card in a computer which has been setup to mine coins. It requires a fair bit of processing power to do what should be a simple task.


A nonce is usually an integer and in our context, it means a special integer which—when added to the contents of a block—produces a hash which begins with four zeroes. As you might have guessed, it requires a bit of work to produce a working hash for a block of transactions and this is the “work” which Bitcoin miners do, for example.

When the correct nonce is guessed and a valid hash produced, it is published along with the block. If this is unique work and was done first then the miner might be rewarded with an amount of digital coin.


A blockchain, then, is a public, distributed ledger of groups of transactions stored in blocks. Each block has been assigned a hash which was programmatically difficult to produce. Each block includes information about the previous block in the chain, making it nearly impossible to alter after-the-fact.

A blockchain allows a digital wallet (as identified by a hash) to have a balance which is the collection of +/- transactions into that account.


j.a.r.v.i.s. realized

If you remember from my earlier post, I wanted to build the cool AI interface from the Iron Man movie series: J.A.R.V.I.S., as voiced by Paul Bettany.


Well, I’ve done it. I wrote up several intents in an Amazon Alexa Skill, created an Amazon Lambda function as the end-point, created a proxy in Node (which is served up by a Raspberry Pi Zero W single-board computer) to forward inbound Internet traffic and I’m now able to ask an Amazon Echo Dot how my printer is doing at home.


Remotely Control a Printer

For example, I can say:

Computer, ask Jarvis for my printer’s status.

…to which she will reply:

charming-pascal is ready and operational.

Now remember, I’m two miles away from home while I’m doing this and all of this still works.  I could ask:

Computer, ask Jarvis which file is selected.

…and she’ll say:

RC_microSD-clip.gcode is currently selected.

This is useful to know when I later code this up to remotely print a job as well. I can also ask:

Computer, ask Jarvis for the job status.

…and the reply might be:

charming-pascal is finished printing RC_microSD-clip.gcode

In the collection of skill intents, I now have the following:

  • Stop the print job
  • Start the print job
  • Pause the print job
  • Resume the print job
  • Ask for the print job status
  • Ask for the selected print job file
  • Ask for help
  • Open the Jarvis app

And I’ll need other intents to select a file to print, preheat the extruder and possibly other things yet unimagined.

I’ll definitely want to remotely see the output of the internal webcam inside the printer to make sure that it’s happy; sometimes print jobs go afoul for a variety of reasons.

Remote Power Control

In addition, I also purchased a TP-Link Smart Plug to control power to the printer. I now have an Alexa skill to turn the printer on and off remotely.


Computer, turn on my 3D printer.