Tuesday, July 31, 2018

Bathtub Drone

Some of us thought the bathtub drone project looked like fun so we're researching the idea. Testing indicates that nobody's lawnmower is going to fly with a passenger but it seems that treadmills use motors up to 3 hp, 6 of which look like they would do the trick. The big holdup right now is propellers. Seems you can get small ones at the hobby shop at pretty reasonable prices, probably because they get crashed and broken often enough that mass production drops the prices. When your payload gets to 220 lbs however, the required prop tends to be the sort that real aircraft use and those don't come cheap. The other problem is that if I were building an electric ultralight, one prop would suffice and one that size wouldn't be too bad. On a drone where you need 4 to 6 props, the size falls between large hobby and small aircraft and is much harder to come by.

Preliminary testing suggests that 1-1/4 hp/motor would lift a large drone if the pilot were limited to a lightweight dummy and the actual pilot were operating it from the ground. This opens up the path for building the structure and sorting out the control software first, then upgrading to more powerful motors later.

As has been noted before: Engineers should never be unemployed.

Fun With Headlines

From the Best  Of The Web column I get, this:
No Greater Progressive Love 
“Justice Ruth Bader Ginsburg wants 5 more years on the Supreme Court, and people are offering their organs to keep her healthy,” ThisIsInsider.com, July 30

Far more likely is that Bernie Sanders has figured out that with the increased death rate that nationalized medicine routinely generates, there should be an adequate supply of other peoples organs along with other peoples money to pay for the procedures.

Tuesday, July 17, 2018

Musical Interlude

Let me say up front that I do not use weed. I even voted against the legalization of the stuff here. Let me also say that I like music, all sorts of it. My life has a continuous sound track running in my head which is kind of nice. I also like to build things weather the need is urgent or not. I mentor students at a local K-12 school helping them to build robots.

Building something for me can be kind of a manic experience, blazing along at full speed until whatever it is rolls out in all its glory. On that note, first listen to the tune "I Smoke 2 joints" by the Toyez

Next, consider these alternative lyrics:

I buy 2 Screws
I make 2 drafts in the morning
I make 2 drafts at night,
I make 2 drafts in the afternoon
And I think I got it drawn up right.

I make 2 drafts in time of peace
And two in time of war
I make 2 drafts before I make 2 drafts
And then I throw 'em on the floor.

(My contribution to paper recycling.)

Me neighbors they come tell me all that bangin noise it's bad
The Po-lice came an told me, this project's a little too rad.
They say it rolls too fast or it throws too far or the smoke don't smell so sweet,
So knock it down or get it outta here 'cause I can't do my testin in the street.

I buy 2 screws in the morning
I buy 2 screws at night,
I buy 2 screws in the afternoon
And I run them all down tight

I buy 2 screws in time of peace
And two in time of war
I buy 2 screws before I buy 2 screws
And then I buy two more.

(Ace Hardware loves me.)

I cut 2 bars in the morning
I cut 2 bars at night,
I cut 2 bars in the afternoon
I trim 'em till they fit just right

I cut 2 bars in time of peace
And two in time of war
I cut 2 bars before I cut 2 bars
They don't fit, I just leave 'em on the floor.

(I got a messy floor.)

Me neighbors they come tell me all that bangin noise it's bad
The Po-lice came an told me, this project's a little too rad.
They say it rolls too fast or it throws too far or the smoke don't smell so sweet,
So knock it down or get it outta here 'cause I can't do my testin in the street.

Sort of an anthem to all you makers out there.

Saturday, July 14, 2018

Conestoga Project 5.0 - Final?

One can hope. My customer tried the bike and trailer out and pronounced it to be about 98% done. Seems the offset pedal cranks don't quite get her legs far enough off the motor. We found some extensions for the pedals at the local bike shop that moved them about 3/4" (20mm) further out but after trying them out we decided to get some just a bit over an inch (27mm) long.

One advantage to the extensions is that a 50mm extension on the right hand side would allow the use of the stock pedal crank and chain ring set which would be MUCH easier than trying to adapt something to the crank that came supplied with the kit.

Don't know where those sizes came from, but that's the sizes they come in. Of note is that the longer ones were out of stock while the short ones were available. This should be a clue as to which ones actually work.

Here's the assembled combo:

Cruizin' along. We're thinking that it might be easiest to simply throw a pup tent over the trailer when it's parked than to add the structure to support a fixed cover.

Test snooze. GSXR the dog is checking to see if there's room for her as well.

Friday, July 13, 2018

New Social Media

I feel like starting a new social media company. No censorship, and if you're offended, tough. Say anything you like and I don't care. I think I'll call it "Woodpecker" . Just sit down and bang one out.

I even saw a great inspiration for a company logo:
Whaddya think? Woodpecker. Say anything.

Thursday, July 12, 2018

Cali Backs Off Gun Registration

Cali's latest anti gun law required all owners of "assault weapons" to register them by electronically sending in 3 photos of each gun in question showing left side, right side, and a close-up of the serial number. There's more, but given that everyone had about 2 weeks to comply, the system failure was easily predictable.

My camera is a Sony Cyber Shot, a typical pocket camera. It has a default picture size of about 2Mbytes unless you set it to something reasonable. Or maybe you want close-ups of flowers in which you can count pollen grains, whatever. I bet most people leave the default settings on their cameras and collect very detailed snapshots.

Now multiply the 6Mb of snapshots by the number of people with "assault weapons" trying to get registered in 2 weeks. Yup, crashed the system. The program has been halted, probably only temporarily, but who knows. Governments are notorious for being the last to upgrade anything so there's probably some poor IT wonk trying to explain to a senior bureaucrat why it's going to take about 50 years to get all those pics downloaded over the states 1200 baud modems.

Just a thought, but any time the government demands photos, set your camera to the highest level and make any snapshot you send a 6Mb file.

Tuesday, July 10, 2018

The Gun Debate - Pulling Out The Anti Gun Rug

The DOJ has thrown in the towel in a lawsuit brought by Defense Distributed which opens up a lot of doors and windows. See the story here.

But wait, there's more. In the settlement, the DOJ said:
Significantly, the government expressly acknowledges that non-automatic firearms up to .50-caliber – including modern semi-auto sporting rifles such as the popular AR-15 and similar firearms – are not inherently military.
Removing the antis "Military style firearms" and "weapons of war" argument from the table.

Thursday, July 5, 2018

Does This Look Like Fun?

Here's some Germans with a drone apparently capable of carrying a human passenger over some distance. Noting that Google also has a one-man drone they're flying on Lake Mead in Nevada, I'd say that the flying cars we've been waiting for are being prototyped right now. They just don't look like cars with wings.

Seemed like so much fun that I started collecting old battery powered electric lawnmowers for the motors. Seems the ones I got all had lead-acid batteries which I already know are prohibitively heavy, but that's why they make Lithiums, right?

Some time back when I was toying with the idea of an ultralight aircraft, I noticed that the magic minimum horsepower requirement for reliable flight seemed to be about 12HP. What this suggests is that the mower motors are dismally underpowered with the 24V types putting out about 1/4HP at 3400 rpm with a 24x10 propeller. Almost enough to lift itself. The 36V motor I got was rated at 1 HP at 4000 rpm which is certainly enough to get itself off the ground but...

The 36V motor listed a part number and maker from Canton province, PRC so I checked them out. They also make motors for treadmills rated at 2-3HP 4000-4500 rpm. Now we're talking. 6X2 or 4X3 = flying. Best part is that people put treadmills up on Craigs List for free on a regular basis. All I have to do it go get them, remove the usable parts, and toss the rest.

The 24V motors will get donated to the school robotics club. The big problem now seems to be sourcing appropriate propellers at a reasonable cost. Suggestions anybody?

Tuesday, July 3, 2018

Extend Your Life?

Study suggests that 8+ cups of coffee a day can help you live longer. I think that all it actually does is keep your body fidgeting after you die, giving the illusion of extended life.

Of course the rattling coming from inside your coffin at the funeral might be disconcerting to the attendees, but just think of it as your last joke on them.

Unless of course it turns out you are in fact still alive in which case the joke is on you.

Zap Your Brain

I've seen this before with various claims attached ranging from a cure for depression to increasing your IQ. I suppose you could do it yourself by making a simple puleation circuit with 2 knobs, one for pulse width and one for intensity, 0-9VDC and embedding the rig in an innocuous sweatband.

Sure: Try different settings for a week each, and test yourself every Sunday by asking yourself if committing a heinous crime sounds like more fun than inventing anti-gravity.

I'm experimenting with motors, amp draws, and the like in the garage right now. All this without the benefit of an electronic headband. Just think how much fun this would be to pull the drain plug as you fly over the Antifa rallye.

Sunday, July 1, 2018

Conestoga Project 4A

So it all bolts up and starts up and runs.

 The motor kit came with a cheesy clamp for the muffler which I now can't find, to keep it from vibrating and cracking.

 Gotta get that on. The rear sprocket bolts to the spokes and stays centered fairly well, but I'd feel better if the spacer I made to center it on the hub was metal and welded to the sprocket.
The motor started on the second or third pull of the rope and idles well. The machine accelerates just fine with no pedal assist at all with my 160 lbs on board. The motor manual is quite adamant about getting 10 hours of run time and an oil change before visiting Bonneville so I don't know how fast it will go but as a bike booster I'd say plenty fast enough.

Billlls rule of engine swaps says that any engine will fit any frame*.
*Note carefully that some fit MUCH better than others.

This motor kit is intended to fit a heavy weight cruiser bike and NOT a modern derailleur rig. OTOH if you really want to do this, it's not impossible. Keep in mind that I have a lathe, a small bench mill, and a MIG welder in my garage and access to the big stuff if (when) I need it.

Thanks as well to DuBach Tool and Machine, 3910 S. Mariposa St, Englewood, CO without whose assistance and supply of leftovers this project would have taken much longer. Got some small parts you need stamped out in quantity? Give him a ring.