Author Topic: Hand drilling technique  (Read 6168 times)

briham89

  • Mudders
  • **
  • Posts: 233
Re: Hand drilling technique
« Reply #40 on: February 17, 2020, 12:57:16 PM »
I drilled a bolt hole at Pinns yesterday, less wailing and more consistent tapping seemed to work better. I choked up on the hammer quite a bit too which helped. I tried out the consistent turning method with about 120 degree turns before grip changes and I liked this too. Will keep trying this out and see the difference over more bolts, but overall seemed better.

JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #41 on: February 17, 2020, 03:51:10 PM »
I drilled a bolt hole at Pinns yesterday, less wailing and more consistent tapping seemed to work better. I choked up on the hammer quite a bit too which helped. I tried out the consistent turning method with about 120 degree turns before grip changes and I liked this too. Will keep trying this out and see the difference over more bolts, but overall seemed better.

Me too but it was nothing new for me.
It's easier on your wrists and your equipment too  :thumbup: :biggrin: :yesnod:
One wheel shy of normal

Brad Young

  • Grand Master
  • ***
  • Posts: 6664
Re: Hand drilling technique
« Reply #42 on: February 18, 2020, 05:59:29 PM »
All of you missed two of the most critical "techniques."

1. Periodically miss with the hammer and scar the knuckles on your other hand;

2. Swear a lot.


briham89

  • Mudders
  • **
  • Posts: 233
Re: Hand drilling technique
« Reply #43 on: February 18, 2020, 07:36:05 PM »
Oh don't you worry, I have those two techniques DOWN already!

JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #44 on: February 19, 2020, 09:04:14 AM »

I drilled 3 bolts yesterday and was reminded that every hole is different (insert joke here?).
My technique varies somewhat on a case by case basis. I did notice that I tend to tap 6 or 7 times per 90 degrees of rotation. The last tap is more from inertia. My wrist doesn't go 120 degrees - so I am tapping 24 to 28 times for a full rotation and if the hole is going well, it takes very little force to turn the drill. if the rock gets chunky I let the drill bounce a bit in the hole (loose grip) and try to never force the turning. Forcing the turning will mess up your wrist and can also break the spring in the Rocpec. I think I have broken 4 springs over the course of hundreds of bolts. Petzl sent me replacement holders for all of them.   
One wheel shy of normal

Gavin

  • Moderator
  • *****
  • Posts: 484
    • Gavin Emmons Photography
Re: Hand drilling technique
« Reply #45 on: February 19, 2020, 08:12:05 PM »
Forcing the turning will mess up your wrist and can also break the spring in the Rocpec. I think I have broken 4 springs over the course of hundreds of bolts. Petzl sent me replacement holders for all of them.   

Huh, I hadn't heard about Petzl sending you replacement holders... I'll have to see if I can find my Rocpec holder with the busted spring and send it off to them.

clink

  • Meanderthal
  • ****
  • Posts: 4003
Re: Hand drilling technique
« Reply #46 on: February 19, 2020, 08:17:09 PM »
Quote
2. Swear a lot.

 Brad should start a thread about swearing technique

 He is both a master swearer and able refrainer when he chooses.
Causing trouble when not climbing.

Brad Young

  • Grand Master
  • ***
  • Posts: 6664
Re: Hand drilling technique
« Reply #47 on: February 19, 2020, 08:26:16 PM »

 Brad should start a thread about swearing technique

 He is both a master swearer and able refrainer when he chooses.


I'm an amateur compared to Katie. She knows all the cool words.

One of the latest trends? Calling someone who's an a##hole a "douche canoe."



JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #48 on: February 20, 2020, 06:07:05 AM »
Huh, I hadn't heard about Petzl sending you replacement holders... I'll have to see if I can find my Rocpec holder with the busted spring and send it off to them.

They have a 3 year warranty.
One wheel shy of normal

JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #49 on: February 20, 2020, 06:08:18 AM »
I'm an amateur compared to Katie. She knows all the cool words.

One of the latest trends? Calling someone who's an a##hole a "douche canoe."

That's so last year...
One wheel shy of normal

Atomizer

  • Atomized
  • *
  • Posts: 836
Re: Hand drilling technique
« Reply #50 on: February 20, 2020, 08:26:16 AM »
No offense to any GOPs around here but I think TRUMP is the newest swear word.

clink

  • Meanderthal
  • ****
  • Posts: 4003
Re: Hand drilling technique
« Reply #51 on: February 20, 2020, 11:47:03 AM »
 Our rent-a-potty door on the job site was inscribed with a sharpie as Trump Tower sometime earlier this week. Someone was obviously oozing inspiration.

 
Causing trouble when not climbing.

Atomizer

  • Atomized
  • *
  • Posts: 836
Re: Hand drilling technique
« Reply #52 on: February 20, 2020, 12:06:49 PM »
Our rent-a-potty door on the job site was inscribed with a sharpie as Trump Tower sometime earlier this week. Someone was obviously oozing inspiration.

 

        Holy Shoot!
That was your job site?

mynameismud

  • unworthy
  • Posts: 5972
    • Mudncrud
Re: Hand drilling technique
« Reply #53 on: March 05, 2020, 08:44:07 AM »
I can confirm he is not liked in Cuba.
Here's to sweat in your eye

Banquo Merrick

  • LoadStone Lovers
  • *****
  • Posts: 2
Re: Hand drilling technique
« Reply #54 on: April 08, 2020, 11:43:23 AM »
Reading through this thread, I see lots of questions and few answers with a basis for them. There are some research papers out there that provide basic information and it isn't hard to do testing of your own.

Rotation (indexing). There is data on rock drill bit indexing. I know of a paper from the 1950's that quantified the amount of rock removed by a hit adjacent to an existing hit. They used a chisel bit and made parallel craters. They got an ideal spacing of something like 1/2 inch. I did some tests with rotational indexing of a 3/8" bit ground to a square chisel point and found that 45 degrees on a flat granite surface works very well. In actual practice, I think that drilling in a confined hole with a v-shaped tip is optimum at a smaller angle. Maybe 15 degrees between strikes.

There is also data for the rock volume removed in relation to the energy of the strike. The researcher varied the angle between the two faces of the drill tip and the energy of the strike. With a 60-degree tip angle, about 75 ft-lbs was optimum. I think this was a 1/2" bit. Energy is 1/2 mass times velocity squared. Solving 75 ft-lbs for a 16-ounce hammerhead arrives at a velocity of 69 ft per second or 47 mph. (somebody check my math). pretty slow compared to a 90 mph fastball.

All of the above will vary with the type of rock.

Sharper bits drill faster and bits with a smaller angle between the faces drill faster. But, too sharp and too acute results in tips that shatter or wear out quickly.

Howard Hartman, Basic Studies of Percussion Drilling, Mining Engineering Jan 1959

Howard Hartman, The Simulation of percussion Drilling in the Laboratory By Indexed-Blow Studies, Society of Petroleum Engineers Journal, Sept 1963

Kahraman Bilgin & Feridunoglu, Dominant rock properties affecting the penetration rate of
percussive drills, International Journal of Rock Mechanics & Mining Sciences 40 (2003)

Dingxiang Zou, Theory and Technology of Rock Excavation for Civil Engineering (Chap2 Rock Drilling) Springer, Nov 21, 2016

John Musselman, Rice University Thesis, May 1967

Terralog Technologies, Fundamental Research on Percussion Drilling (for DOE), Dec 2005

clink

  • Meanderthal
  • ****
  • Posts: 4003
Re: Hand drilling technique
« Reply #55 on: April 08, 2020, 12:48:16 PM »
 
Quote
Maybe 15 degrees between strikes.

 24 strikes per rotation
Causing trouble when not climbing.

JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #56 on: April 08, 2020, 04:55:39 PM »
  24 strikes per rotation

Even taking your shoes and socks off would not have allowed that cypher.
You must have had help  :lol: :prrr: :ciappa:
One wheel shy of normal

clink

  • Meanderthal
  • ****
  • Posts: 4003
Re: Hand drilling technique
« Reply #57 on: April 08, 2020, 07:09:15 PM »
Quote
Even taking your shoes and socks off would not have allowed that cypher.
You must have had help

 It was easy, just think of Earth's orbit around the Sun divided evenly into 1/24th of a year. The earth travels 15 degrees in that time(24,347,338 miles) If you had an enormous bit that was 189,015,270 miles wide and were drilling on July 4th as the sun was about to rise you could clean out the Sun, Mercury, Venus and about half of Earth. What type of alloy your bit would have to be I don't know.

Note: To pull this off on January 2nd you would need to downsize your bit to 182,798,908 miles wide or you would take the Earth completely out(and the moon) with your bit.
Causing trouble when not climbing.

F4?

  • unworthy
  • Posts: 6172
Re: Hand drilling technique
« Reply #58 on: April 08, 2020, 07:37:02 PM »
Just bring along a "Jim", he will bang out the bolts pretty fast.
I'm not worthy.

JC w KC redux

  • Moderator
  • *****
  • Posts: 6563
  • my density has brought me to you...
Re: Hand drilling technique
« Reply #59 on: April 08, 2020, 07:42:32 PM »
What type of alloy your bit would have to be I don't know.

Unobtanium
One wheel shy of normal