[Lab] Open Question: Dumbest Thing You've Done While Making

Wed Jun 26 12:11:08 EDT 2013

I got a couple of near burns from my 3D printers. Strange how they don't
look any different when they're hot or cold.

CNC milling is a party. I've had workpieces and chunks thrown at me. I've
plunged the endmill into the bed, into clamps, bolts and my needle nose
pliers. I'm getting better at this and it's all fairly uneventful now. In
the past week I've put about 25h on the CNC and only had a piece of a
record thrown out and it didn't come my direction. It's really cool once
and a while when a chip finds itself spinning around on the endmill. After
it gets up to about 9000 rpm it goes for a flight across the room the next
time it lifts out of the work piece.

I had a long break from making things when I went to university and some of
my software career (although I did quite a bit of RC planes). So when I
returned to it (in the current stint), I had a few surprises. I picked up a
soldering iron by the hot part. That hurts for a few days. It's really cool
because you don't have any finger prints for a while.

Driving around town for a part without phoning a head was pretty dumb. I
have procurement down pat now.

The dumbest I an think of was when I was a kid and I was adjusting the yoke
of a TV I found at the dump. I thought I'd be a smart alec and adjust the
yoke while the tv was running. That would save the time of moving it,
powering up to check alignment, moving it some more, turning it on and so
forth. I knew there was 25,000 volts back there but for some reason I
thought my idea of doing it with the TV on was such a great idea, I just
did it right away without thinking. I got a nice shock across my hand (was
already naturally only touching one hand at a time). I've been very afraid
of electricity ever since. I'm even afraid of 9v batteries and flashlights
and stuff. Okay, that part's a joke.

--
Darcy Whyte

Art+ inventorArtist.com | Aviation rubber-power.com | Software Since '88
siteware.com | Contact: darcy at siteware.com | 613-563-3634 by appointment |
Canada N 45° 25'03.1" W 75° 42'21.4"

On Wed, Jun 26, 2013 at 11:53 AM, James Allanson <james.d.allanson at gmail.com
> wrote:

> Multiple Ultimaker burns, from my own Ultimaker as well as the first
> Artengine Ultimaker.  Usually doing something stupid like cleaning the bed
> while the machine is moving the heated head around.  I don't think I've
> learned my lesson on that one as I've made the same mistake many times.
>  But I have been conditioned now to yank my hands out of the machine when I
> hear the stepper motor(s) engage.
>
> I did learn I have an extremely foul mouth when I burn myself though. :D
>
>
>
> On Tue, Jun 25, 2013 at 8:07 AM, mike Jans <mjans at live.com> wrote:
>
>> I had a similar experience at a young age, I had a habit of prying things
>> open to see what they had on the inside. I got my hands on a disposable
>> camera and used a flat screw driver and a pocket knife to pry it open. I
>> couldn't see it, but I managed to get each tool on each of the capacitor's
>> leads. I sat for a couple of minutes trying to understand what had happened
>> and then I went to tell my dad. He showed me what happens when you short a
>> full charge. I still have that screwdriver with those scars on it somewhere.
>>
>>
>>
>> > Date: Mon, 24 Jun 2013 17:31:13 -0400
>> > From: rgb at tricolour.net
>> > To: jason.cobill at gmail.com
>> > CC: lab at artengine.ca
>> > Subject: Re: [Lab] Open Question: Dumbest Thing You've Done While Making
>>
>> >
>> > On Mon, Jun 24, 2013 at 04:53:04PM -0400, Jason Cobill wrote:
>> > > That's amazing! I had no idea the uO solar car generated that much
>> current!
>> > > What kind of motor was all that power being used to drive? I was
>> under the
>> > > impression it was a tiny motor running at high RPM and geared down for
>> > > torque.
>> >
>> > It was a Uniq Mobility 10kW motor. That motor/controller combination
>> > wasn't nearly as effective at shorting out the battery pack as a small
>> > gold ring. ;-) Much of the competition was using Solectria motors at
>> > that time. Within about 5 years, pretty much the entire field had
>> > switched over to in-wheel motors made by New Generation Motors (NGM), a
>> > company founded by a number of George Washington University solar car
>> > team members.
>> >
>> > > Zot's a pretty cool nickname, though. ;)
>> >
>> > It makes me think of the "BC" comic strip... (I say this as I watch a
>> > huge black cloud criss-crossed by jagged white lines completely fill my
>> > large west-facing 4th-floor window at UQO on Tache in Gatineau.)
>> >
>> > > -Jason Cobill
>> > >
>> > > On Mon, Jun 24, 2013 at 4:49 PM, Richard Guy Briggs <
>> rgb at tricolour.net>wrote:
>> > > > On Mon, Jun 24, 2013 at 04:00:51PM -0400, Jason Cobill wrote:
>> > > > > Experiments gone wrong? Tools gone out of control? What's the
>> dumbest
>> > > > > thing you should have caught before you nearly set your house on
>> fire?
>> > > > What
>> > > > > did you learn from it?
>> > > > >
>> > > > > Me first: I plugged in a table saw without checking the switch
>> first -
>> > > > > it was on. And it was covered in 2x4s and sheetwood scraps, which
>> it
>> > > > > proceeded to launch across the garage and nearly take out a
>> window.
>> > > > > It _should_ have been off, but I _should_ have checked. So now I
>> > > > check.
>> > > > > Every. Time.
>> > > >
>> > > > Oh, this one's easy. ;-) I have two related to electricity.
>> > > >
>> > > >
>> > > > 1) When I was about 10 I had a power transformer that I had taken
>> out of a
>> > > > wood-cabinet vacuum tube TV set. I had learned to solder when I was
>> about
>> > > > 8.
>> > > > I knew which side was the primary and I wanted to test the
>> secondaries. I
>> > > > knew
>> > > > they would be high. I had a cheap analog multimeter from Radio
>> Scrap with
>> > > > a
>> > > > 750V rating. I carefully attached and shielded the primary wires to
>> a
>> > > > standard two-prong plug. I was sitting on my bed (so no danger of
>> > > > grounding out, plus it was an isolated secondary). I pinched one
>> > > > secondary wire with the meter test lead, then grabbed the second
>> test
>> > > > lead and went to pinch it with the other secondary... (It was about
>> 350V.)
>> > > > I haven't done that ever again! Now I used insulated leads.
>> > > >
>> > > >
>> > > > 2) In my last year of Electrical/Computer Engingeering at U of
>> Ottawa,
>> > > > I was working on the U of Ottawa solar rayce car RALOS-II, wiring
>> up the
>> > > > main power backplane of the car (I was the Electrical Systems
>> > > > Co-ordinator) working on some low-voltage wires on one card that
>> > > > happenned to be facing a high-voltage, high-current card connected
>> to 7
>> > > > car batteries in series (90VDC, 1000A?). As I pulled my hands away
>> from
>> > > > my work something sparked. Naturally I pulled back, jamming my
>> family
>> > > > gold ring into the high-voltage card. Once the sparks stopped, two
>> of
>> > > > my fingers were black. After a quick throw of the main power switch
>> for
>> > > > the car to avoid any further incident, one of my teammates packed
>> me off
>> > > > to the hospital to clean things up. On the way to the hospital, I
>> was
>> > > > babbling with all the wire cross-sectional diameters, materials and
>> > > > resistances per metre still fresh in my mind, calculating that must
>> have
>> > > > been a 100kW arc welding burn.
>> > > > I was lucky. I still have all my fingers, but one has an
>> > > > interesting ring-shaped scar (that was 20 years ago this month) and
>> the
>> > > > bloodstone with the family crest in the ring cracked. I thought of
>> > > > getting it repaired, then decided to leave it as a reminder. I was
>> very
>> > > > lucky it didn't instead hit the iron ring on the adjacent finger
>> that I
>> > > > had earned not 2 months prior. Gold is a much better conductor, so
>> it
>> > > > didn't heat up much compared with the other parts involved. The two
>> > > > one-inch spade terminals on the card along with 1/2" PC board traces
>> > > > vanished. I had to check a second identical card to find out what
>> was
>> > > > there. I earned the nicname "Zot" for that one...
>> > > > I now remove my rings when working with high voltage/current.
>> > > >
>> > > >
>> > > > I still love electricity! :D
>> > > >
>> > > >
>> > > > > -Jason Cobill
>> > > >
>> > > > slainte mhath, RGB
>> > > >
>> > > > --
>> > > > Richard Guy Briggs -- ~\ -- ~\ <
>> > > > hpv.tricolour.net>
>> > > > <www.TriColour.net> -- \___ o \@ @ Ride yer
>> > > > bike!
>> > > > Ottawa, ON, CANADA -- Lo_>__M__\\/\%__\\/\%
>> > > > Vote! -- <greenparty.ca
>> > > > >_____GTVS6#790__(*)__(*)________(*)(*)_________________
>> > > >
>> >
>> > > _______________________________________________
>> > > Lab mailing list
>> > > 1. subscribe http://artengine.ca/mailman/listinfo/lab
>> > > 2. then email Lab at artengine.ca
>> >
>> >
>> > slainte mhath, RGB
>> >
>> > --
>> > Richard Guy Briggs -- ~\ -- ~\ <hpv.tricolour.net>
>> > <www.TriColour.net> -- \___ o \@ @ Ride yer bike!
>> > Ottawa, ON, CANADA -- Lo_>__M__\\/\%__\\/\%
>> > Vote! -- <greenparty.ca
>> >_____GTVS6#790__(*)__(*)________(*)(*)_________________
>> >
>> > _______________________________________________
>> > Lab mailing list
>> > 1. subscribe http://artengine.ca/mailman/listinfo/lab
>> > 2. then email Lab at artengine.ca
>>
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