That blows!

Doing some work on our furnace, I had the opportunity to take a picture of the blower.1Yeah, I know–it’s dirty. That’s why I removed it. And, thanks to this work, I now have a much better understanding of the sensors, switches, blowers, and valves, and how they all interact. So cool!

I’m looking forward to spring when I get to do the same sort of maintenance on the air conditioner.

Old man’s fancy

In the fall an old man’s fancy lightly turns to thoughts of debugging HVAC systems.1With apologies to Alfred Lord Tennyson. Unfortunately, not only in the fall. Now it’s the heating portion. A few Augusts ago, it was the cooling portion. The resources I found then will come in handy.

Longboard Footstop in OpenSCAD

My local library, the Hillsboro public library, has 3D printing open labs — every Monday evening for a couple of hours, the library accepts .stl files on thumb drives and prints them for free over the next week. This is such a cool resource, it seems irresponsible not to take advantage of it.

For my first project, I decided to design a longboard footstop.1If imitation is indeed flattery, RipTide and PSD Designs should feel complimented. ;-) Earlier this week, I started researching 3D CAD software and settled on OpenSCAD.2Pronounced open ess cad. OpenSCAD is different from most 3D CAD software in that you program a part instead of manipulating objects on a screen. For example, this is how I defined the tab of the footstop:

union() {
tab_s = tab_length - tab_width/2;
tab_r = tab_width/2 - stop_chamfer;
tab_h = 2*(tab_height - stop_chamfer);
translate([-tab_s/2, 0, 0]) cube([tab_s, 2*tab_r, tab_h], center=true);
translate([-tab_s, 0, 0]) cylinder(r=tab_r, h=tab_h, center=true);

Designing the footstop, some of OpenSCAD’s other limitations became obvious: fillets and chamfers are not easily defined, especially along curved intersections of primitives.3I’m gathering resources that address this issue.

This is my third iteration of the footstop and I think it’s good enough to print next week so Jamison can try it out. I suspect I still have a lot to learn when it comes to getting a design ready to print. For example, how important is it that this footstop be hollow? If it needs to be hollow, what’s a reasonable wall thickness? I experimented with MeshMixer a bit, but expect I’ll need to wait until Monday.

I wonder what I should design next. I think I’d like to try some sort of GoPro mount.

DIY Panniers

I love panniers. I just don’t like spending $100+ for a pair of ’em. When Jamie showed up at Starbucks with a DIY pannier on his bike, I knew I had to do some research. Here’s what I found:

Looks like I’ll be making more than one of these. :-)

My A/C Works!

Yes! I got my air conditioner working. Total cost: $38 for a new 24V transformer.

A couple of bonuses:

  1. My air condition will be more efficient without a layer of “felt” on the condenser coils, and
  2. I learned a lot about how air conditioners work.