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Hydroponics phase 2 completed

By Kurt Euler | Aug 8, 2016 | 0 Comments

I recently concluded a couple upgrades to the hydroponics rig.


1) Conversion from constant-flow to fill-and-drain

I read various internet post about some of the benefits of fill-and-drain design over the constant-flow design. Each has its merits, but I like the idea of servicing drained planters, and managing the nutrient liquid when all liquid is in the basin. This is the case when the pump is off in a flood-and-drain system.

To implement this, I devised and deployed check valves as shown in this diagram:


Here’s a close up of a check valve:


For detailed information about this solution, see this instructable.

2) New nutrient management system

The two 5-gallon buckets I’d been using had too low a capacity in both water and flow handling. I replaced them with a 20 gallon trash can from Home Depot. For the plumbing, I constructed a rig (drawing in progress, just below) which is submerged in the can.



Altogether, much nicer to uses maintain

Phase 2 Pic


Note that the aforementioned check valves are denoted by the three yellow drawn boxes along the right edge.

Phase 3 plans

  1. Move the connective plumbing from each planters end-caps to the tops and bottoms of the planter pipes. (See first drawing way above for sample new positions.)
  2. Optimize some of the plumbing on top of the basin.
  3. Experiment with “triple layer” planter pipes to keep light out of the planter interior.

Phase 4 ideas

  1. Add an automatic water refill mechanism. (Toilet float type.) This involves getting pressurized water to system vicinity.
  2. Implement automatic nutrient testing and dosing.


Thanks for reading!

A design for offset bicycle pedals

By Kurt Euler | Jul 7, 2016 | 0 Comments

From the Rube Goldberg department…

I recently wondered if a bicycle could be designed such that its pedals spent most of their time forward of their bearing, on the “power-stroke” side of the cycle.  Apart from any real or imagined utility of such a configuration, I thought it would be an interesting challenge to design the mechanics in Fusion 360. So, after several hours of jostling bodies, components, joints, planes, and sketches, I came up with this:


In the video, you can see that when one pedal is at the lowest position, the other isn’t at the top, but instead is positioned slightly forward, solidly in the power-stroke area.  The design achieves this by placing the axis of the pedal bearings behind the axis of the drive gear bearing (the drive gears pull the chain, not shown), then mechanically connecting the pedals to the drive gears by means of a few cogs and pegs. Note that while the angular position of each pedal is a function of the other, the degrees out-of-sync is variable, not 180 degrees, as is the case for standard bikes.

Two identically sized cogs are placed, one each, inside each pedal plane. They have a wide hollow bearing. The pedal bearings are inside the cog bearing, such that their axis of rotation of the pedals are behind that of the cogs. (Each pedal has its own bearing, although they share a common axis.) Each cog is propelled by a peg in its adjacent pedal, which extends into a slot in the cog, as shown here:

Pedal shaft and peg


A pinion gear on the frame keeps the two cogs in sync:

Pinion gear


The right cog is connected directly to the three drive gears, which share the same hollow bearing. These are otherwise the same gears as is used in a traditional bike gear system.

The video below shows how the pin in the left pedal shaft propels the left cog via the slot in the cog.


Use cases…

This contraption might very well solve a non-existing problem. I’d be interested in your thoughts. One group that could benefit are those with missing or weak lower legs, where starting from a dead start, or going up hill, could be challenging when one pedal is directly above another with a traditional gearing system.

Version 2.0 ideas…

  1. Reduce the size of the two cogs, or better…
  2. Move the pinion to inside the large bearing cavity, and reshape the cogs thus:

Teardrop gear


Footnote: This project was mainly for the purpose of “cutting my teeth” on the Fusion 360 CAD package. It involved a few restarts and backtracking, both from being a F360 newbie and from figuring out what would and not work mechanically in the design. It was worth the effort. I now have a much better “feel” for how to proceed with modeling, and at the same time have a list of questions and recommendations for Autodesk and the F360 Forum. If interested in accounts of my future tinkerings, I humbly invite you to subscribe to the blog in the right side bar of the Home Page. Thanks!

Hydroponics status update…

By Kurt Euler | Jun 24, 2016 | 0 Comments

Hydro_Frame_2016-06-24 About 1/2 way through the development of a A-Frame hydroponics system. For this project, I’m using Fusion 360 primarily for as-built documentation.








A shout-out for Autodesk’s user forums and “IdeaStation”

By Kurt Euler | Jun 13, 2016 | 0 Comments

Well, I’ve been offline for a while, tinkering, but thought I’d slip in a quick post in praise of the exemplary Fusion 360 user forums maintained in Autodesk’s Web site. I’m still an F360 newbie, but already my experience of the forums’ usefulness has vastly exceeded my expectations. I’ve found that within a day or two of posting a question, some expert user responds with an often exceedingly thorough explanation. For example, I recently posted a query in which I asked about the relationship of “models” and “forms” (t-splines) when they occur in the same design project. I received several very useful comments, including a long one that includes animation. Find that post in this thread. Very often, its an Autodesk employee who provides the answer.

Even more impressive is the degree to which the F360 group encourages ideas for future updates. The interface, shown here , presents a forum-like design, but cleverly asks other users to comment on each idea, and to vote on it also. Over time, Autodesk staff updates the status of the idea based on user interest, the product road map, etc. New entries are given a GATHERING SUPPORT status. As votes and comments are processed, an idea’s status can be updated to UNDER REVIEW, ACCEPTED, IMPLEMENTED, FUTURE CONSIDERATION, etc. If an idea is implemented, the contributing user is emailed a notification. How cool is that!?


Speaking of road maps, Fusion 360’s is shared, and commentable! Here’s their May 2016 roadmap update.


Even if your new to Fusion 360, the forums will serve you well!

Some 3D Printing Highlights from the 2016 Bay Area Maker Faire

By Kurt Euler | May 28, 2016 | 0 Comments

This post briefly highlights what I thought were the most interesting products and events related to 3D printing at the May 2016 Bay Area Maker Faire.

The faire had its usual wide variety of projects, products, and services from various vendors and exhibitors. As is usual at maker faires, majority of attractions had to do with arts and crafts projects. However, there were several booths that sophisticated tools that makers would use to make stuff, most notably 3D printers, routers, and laser cutters. Below are a few of these that caught my attention. P1040042


Formlabs: Formlabs was showing off their new Forms2 machine, which they bill as “The most advanced desktop 3D printer ever created”, and I believe it. The printing process is stereolithography, an amazing technology in which lasers are used to “photopoymerize” layers of resin to create the desired object. The picture at right shows a demo 3D lattice. At $3,500 just for the hardware, it’s not destined to be on the desktop of every maker, but schools and pro-makers, its just the ticket for creating working prototypes and one-offs (or “few-offs”).

P1040066CNC Router Parts: Meanwhile, the machines over at the CNC Router Parts booth were cranking out functional ukulele’s: Body and neck in wood, and metal sound board. (There was a Ukulele raffle every hour or so.) This company specializes in selling router machine kits, including standard and proprietary components, which customers then assemble themselves. Three lines of equipment are available, “Standard”, “Pro”, and the lower-end “Benchtop”.

I personally like the assemble-it-yourself “kit” concept. Not only are kits far less expensive than pre-assembled solutions, but the assembly process gives users a more complete understanding of the mechanics of the equipment. (Besides, what maker wouldn’t want to build their own equipment?!) This company will certainly be on my short list of router vendors when I become in the market for a machine.

The kits range in price from $2,195 for the Benchtop Standard CNC Machine Kit, to $6,125 for the giant PRO60120 5′ x 10′ CNC Router Kit.

P1040054See Me CNC: The See Me CNC products are among a few filament-based 3D printers on the market that use a “delta” rig. Essentially the print head is attached to the base of 3 guide arms. The print head moves laterally when the top of each  arm is moved vertically with respect to the other rods during the printing of a particular layer. All arms move up the same amount (or, the platform is lowered) to advance the print head to the next layer.

Like the CNC Router Parts machines, the See Me CNC devices come in kit form, but for extra $s can be bought pre-assembled. They were highlighting their Rostock MAX V2 model, selling for $999 (kit) and $1,899 (pre-assembled).

P1040060Glowforge: There was a lot interest in laser cutting products, most notably for the yet-to-ship Glowforge printers. It was standing room only in the Glowforge booth. They had an impressive display of sample cut and etched items created by their Basic- and slightly more powerful Pro machines. The hexagon puzzle at right was one of the most impressive creations. It’s clear that Glowforge is also putting a lot of effort into their software to make printing a snap for any user. For example, users can design, position, and send their drawings to the printer.

My own thoughts are that the Glowforge products would be of primary interest to artistic types as opposed engineers whose requirements often demand a larger printing “canvas”, and need to cut through thicker or tougher materials than the present Glowforge models could manage. (This isn’t to discount the Glowforge as a business investment: There’s a burgeoning industry artisans selling craft made by laser cutters.) Do take a look at the well done Glowforge Website and related videos on YouTube.

As of this post, pre-order pricing is $2,395 for the Basic  model, and $4,795 for the Pro version.


I’d be interested to know readers thoughts on these products, especially if you have first-hand experience. Meanwhile, in the OMG department, take a look at this youtube video showing the “printing” of a play castle out of concrete. See a related news clip here. Macro printing is definitely worth a future post.

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