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Things to NOT do... — Parallax Forums

Things to NOT do...

ctwardellctwardell Posts: 1,716
edited 2011-07-04 17:33 in Robotics
The discussion on gloves, clamping etc. on the Hole Punching thread made me think a things to NOT do thread woul d be a good idea...

http://forums.parallax.com/showthread.php?131771-Techniques-for-punching-holes-in-metal-for-panel-mount-components

My first contribution is do NOT use standard length drill bits at high speed in a tool such as a Dremel. I was using an standard length 1/8 drill bit at 20,000 RPM and it went out of balance and bent at about a 45 degree angle, it took a nice swipe at my hand in the process. Use the short bits sold by Dremel or something of similar size.

C.W.
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Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-06-13 07:37
    Do not forget to wear safety glasses no matter how simple, easy, or quick the task.

    I knew a very careful, very skilled machinist who spent decades working with killer machinery and he never hurt himself or anyone else. Then one day at home, he was under his car performing a simple maintenance task and, while reaching up to tighten a hose clamp, dropped his screwdriver. It fell point first into his eyeball and he lost the eye.
  • ercoerco Posts: 20,256
    edited 2011-06-13 09:16
    Ouch on both cases!

    @ctw: I would add to use only quality drill bits. I can't believe your bit BENT. That means it was an unhardened cheapie. A quality bit may break, but will never bend. Yours was probably soft and dull, which may have caused or contributed to your problem.

    And surely I don't need to say never try to cut sideways by pushing a drill bit sideways... that would just be wrong!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-06-13 09:34
    I second the safety glasses comment. I always use safety glasses when I use super glue now. After getting super glue in my eye twice. Ouch!

    My wife and I were making a parachute once. I wanted her to teach me how to use the sewing machine. I couldn't believe they got their (people who sew) eyes so close to a high speed needle without wearing safety glasses.

    BTW, sewing was too hard. I pinned all the panels in place and my wife sewed them all.

    Duane
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-06-13 09:37
    erco wrote: »
    ... I would add to use only quality drill bits. I can't believe your bit BENT. That means it was an unhardened cheapie....

    I'm not a materials science guy, so I'm just guessing a bit here (no pun intended). But I know if you run a dull bit too fast and hard, it can over heat, and maybe the frictional heating could possibly serve as a bad heat treatment, causing the steel to lose its original properties, making it softer?

    In any case, moral of the story: maybe use a little bit of cutting oil when drilling steel or hard aluminum.
  • ercoerco Posts: 20,256
    edited 2011-06-13 09:50
    Duane Degn wrote: »
    My wife and I were making a parachute once.
    Duane

    @Duane: No matter whether you do it right or wrong, you only need to make a parachute once.
  • SRLMSRLM Posts: 5,045
    edited 2011-06-14 09:47
    Always wear eyeglasses when soldering directly to a battery (a risky proposition in any case...). I made the mistake of forgetting that when supervising a friend, and the lithium coin cell exploded in her face. Fortunately she wasn't hurt.
  • ctwardellctwardell Posts: 1,716
    edited 2011-06-14 12:22
    I'm not a materials science guy, so I'm just guessing a bit here (no pun intended). But I know if you run a dull bit too fast and hard, it can over heat, and maybe the frictional heating could possibly serve as a bad heat treatment, causing the steel to lose its original properties, making it softer?

    In any case, moral of the story: maybe use a little bit of cutting oil when drilling steel or hard aluminum.

    In this case it was plastic, one of those blue project boxes that RS used to sell. It was an el-cheapo bit. Rumor has it that I MAY have been using the side of the bit to cut an oblong, but that's surely not true...

    C.W.
  • markaericmarkaeric Posts: 282
    edited 2011-06-14 19:35
    It's sad how many people know the importance of safety glasses but don't use them until it's too late. I had pieces of a bit slice both of my eye brows when it snapped halfway through what I was drilling. Yet, I still don't wear them.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-06-14 20:15
    erco wrote:
    And surely I don't need to say never try to cut sideways by pushing a drill bit sideways... that would just be wrong!
    Doing so only worries your way through the substrate, since drill bits have a cutting edge only at the tip. To cut through sideways, use an end mill or router bit. (Now having said that, I can relate that, due to rotational effects and grabbing, it's almost impossible to guide one of those bits accurately by hand.)
    SRLM wrote:
    Always wear eyeglasses when soldering directly to a battery (a risky proposition in any case...). I made the mistake of forgetting that when supervising a friend, and the lithium coin cell exploded in her face. Fortunately she wasn't hurt.
    'Been there, 'done that. That's why I want a cheap spot welder. 'Anybody know where to get one?

    -Phil
  • TtailspinTtailspin Posts: 1,326
    edited 2011-06-15 19:03
    Do not touch the spinny shiny part.
  • RS_JimRS_Jim Posts: 1,766
    edited 2011-06-19 06:41
    Phil,
    I thought the Epilog could be taught to spot weld?
    Jim
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-06-19 07:07
    I wish! The CO2 laser just reflects off of anything metallic without even warming it.

    -Phil
  • $WMc%$WMc% Posts: 1,884
    edited 2011-06-19 13:13
    Phil
    '
    _Grizzly.com_ has the HOBART spot-welder for $400 not a bad price at all.(US made) 220/240v 1 phase. only $18.00 to ship.
    '
    Harbor Freight as a cheap Hobart spot-welder knock-off. ~$200.
    Get the 220v model. The 110v model doesn't make strong enough welds.
    '
    The HOBART works much better and is well worth the extra $.
    '
    P.S. Don't touch both of the big bare copper tongs while pressing the weld switch. 1.5volts @ 5000 amps !!!!
  • prof_brainoprof_braino Posts: 4,313
    edited 2011-06-20 13:30
    Never skip the gloves. The only time you wish you were wearing the gloves is after you weren't wearing the gloves.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-06-20 13:39
    Never skip the gloves. The only time you wish you were wearing the gloves is after you weren't wearing the gloves.

    There was some discussion about why wearing gloves in some operations is NOT a good idea. Check out this: http://forums.parallax.com/showthread.php?131771-Techniques-for-punching-holes-in-metal-for-panel-mount-components&p=1008681&viewfull=1#post1008681
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-06-21 20:52
    Why a good solid safety rope is important:
  • RavenkallenRavenkallen Posts: 1,057
    edited 2011-06-26 13:48
    YES, safety goggles are instrumental in any form of dangerous activity. I wear them when i drill, solder, make pcb's, mow the lawn, split firewood.... I remember one time where i was mowing the grass and a big old piece of wood flew into my face, and had i not been wearing safety goggles, i might have one less eye than i do now. Always wear them. Your eyesight is a precious gift that has to be protected!
  • ajwardajward Posts: 1,130
    edited 2011-06-26 17:44
    Never drill the sheet metal you are holding in your hand... even with gloves!!!
  • HumanoidoHumanoido Posts: 5,770
    edited 2011-06-26 19:03
    Wear a filter mask to keep dust, smoke, filings and shavings out of your lungs. Even if you have no effects now, later in life lung problems can surface.
  • kwinnkwinn Posts: 8,697
    edited 2011-06-26 22:59
    $WMc% wrote: »

    P.S. Don't touch both of the big bare copper tongs while pressing the weld switch. 1.5volts @ 5000 amps !!!!

    The tongs might get hot enough to give you a blister but 1.5V will NOT give you any kind of electrical shock.
  • HumanoidoHumanoido Posts: 5,770
    edited 2011-06-26 23:52
    Many people touch their tongue to 9-volt battery terminals to test it.
    Keep your tongue in your mouth.
    Aside from destroying taste buds over time, it's not recommended.
    Mainly don't do any tests like this at the AC fuse box!

    :tongue:
  • xanatosxanatos Posts: 1,120
    edited 2011-07-01 18:00
    Humanoido wrote: »
    Many people touch their tongue to 9-volt battery terminals to test it.
    Keep your tongue in your mouth.
    Aside from destroying taste buds over time, it's not recommended.
    Mainly don't do any tests like this at the AC fuse box!

    :tongue:

    Plus it just tastes bad!
  • HumanoidoHumanoido Posts: 5,770
    edited 2011-07-02 02:40
    xanatos wrote: »
    Plus it just tastes bad!

    xanatos, you're exactly right! The people looking for an energetic meal say the flavor of AC and DC is quite different, noting they are both electrically on the bitter side. AC has a repeating sour but MilliAmps taste the worse - those millis need lots of sugar. Though we can't recommend the taste test for anyone, if one must indulge in a charging diet, make sure the electricity is fresh. There's nothing worse than stale electric.

    :)
  • MicrocontrolledMicrocontrolled Posts: 2,461
    edited 2011-07-02 13:10
    @ajward: Ouch! I've done that before! I needed a small fan blade for a motor, but I didn't want to go to the store to get one. I instead cut a propeller out of sheet metal and bent it to create airflow. When I drilled a hole in the middle for the motor, the bit caught and it spun the sharp-edged propeller. It sliced my hand in several places before flying off and impaling a cardboard box. I've only bought them since!
  • WhitWhit Posts: 4,191
    edited 2011-07-02 19:43
    Never solder in shorts.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-07-02 20:12
    Whit wrote:
    Never solder in shorts.
    ... but especially not without shorts!

    -Phil
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2011-07-02 20:14
    Whit wrote:
    Never solder in shorts.
    But if you do solder in a short or two, solder wick is your friend!

    -Phil
  • JoannaKJoannaK Posts: 44
    edited 2011-07-03 04:38
    If you'll ever drop soldering iron, don't try to catch it midflight.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-03 10:29
    Humanoido wrote: »
    Many people touch their tongue to 9-volt battery terminals to test it.
    Keep your tongue in your mouth.
    Aside from destroying taste buds over time, it's not recommended.
    Mainly don't do any tests like this at the AC fuse box!

    :tongue:

    Reminds me of something an old veteran told me when I first started. He was a radar technician working with the British in WW2 and had been sent to examine a captured German radar station. When he arrived there was a Russian technician already examining the equipment. The Russian tech had arrived without any test equipment so he had been estimating the voltages by brushing his finger across the contacts or conductors. After using his test equipment to measure the voltages and comparing it to the Russian's estimates he was surprised to find how close they were. No guess was off by more than 25% and most were much closer than that.
  • WhitWhit Posts: 4,191
    edited 2011-07-04 17:12
    ... but especially not without shorts!

    -Phil

    Or fry bacon...
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