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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 3, 2014 - 04:46pm PT
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Today I set out to test drilling speed with a little more duration. I started two holes about 1/10 inch deep and then drilled each to a depth of at least 2 inches. 2 inches is about the minimum depth for the 2.25 x 0.375 inch SS bolts I typically use in good granite.
I started with the McDevitt hammer before lunch and drilled the hole 2.006 inches deeper in 7m25s. I didn't clear the dust out of the hole. I did stop occasionally to shake out my arm. I held the hammer near the end of the handle and tried to make hard hits with a fairly long swing.
A couple hours after lunch I did the same with the Chouinard hammer. I increased the depth by 2.031 inches in 13m39s, nearly twice the time.
McDevitt (26.2 Oz) 3.70 minutes per inch
Chouinard (25.2 Oz) 6.72 minutes per inch
It's hard to be sure but I feel like I worked harder with the Chouinard. Both drill rates seemed to get slower as time went by - probably because I was wearing out and because I didn't clear the dust from the hole. My arm is getting tired and that of course must have some effect on the difference between the two but I think there is clearly a difference.
McDevitt is slightly heavier, has better balance and a longer handle.
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Ksolem
Trad climber
Monrovia, California
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It's not just the hammer. It's the relative weight of the drill to the hammer which determines the best efficiency. Of course technique is a big factor too.
I have a friend who is a mechanical engineer. He weighed my hammer of preference, and took what I hoped would be a good drill, the chuck from a Milwaukee air hammer. He weighed them and measured the angle of the hammer strike (as Banquo showed above), figured an ideal weight for the object (drill) and we cut the chuck down to that weight. It works quite well. BTW it takes an A taper chisel bit. I do not like drilling with SDS bits. For one thing the chisel bits can be sharpened in the field with emery paper (I like back-country). ymmv.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 3, 2014 - 06:22pm PT
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Ksolem-
I have explored drills and drill holders in several other threads. Drilling efficiency has to do with drill diameter, drill length, the shape of the drill shank, The angle of the drill tip, the length, weight and shape of the drill holder, the sharpness of the bit and of course characteristics of the hammer. Also operator issues such as where and how the hammer is held, how hard you hit, how you turn the drill, etc. It turns out to be a pretty complex problem I think. It seems that everybody has an opinion about what works best but the foundation for the opinion is nearly always subjective. I am trying to do the best I can at quantifying things.
The drill and drill holder variables I looked into resulted in differences in drill rates on the order of 30%. With hammers I am getting differences in drilling speed on the order of 100%. In the above test, I drilled 81% faster with a hammer that is only 4% heavier. There must be something other than the weight of the hammer making the difference.
Anyway, I have explored other variables in other threads. In this thread the only variable I am exploring is the hammer.
Like you I believe that an A-Taper bit works better but they are nearly gone from the market so I have switched to SDS. I do make A-Taper holders and some who post here use and seem to like them.
I like carbide tips. They can be field sharpened with a small diamond impregnated file. They sharpen surprisingly fast. A pocket size set of files can usually be found on Amazon for around $10.
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Banquo,
I don't think the McDevitt vs the Chouinard test is accurate unless you use two separate holes. As you drill deeper a few things happen that can skew the results.
First off, you have more dust buildup as you drill deeper as it is much harder to get it out of the hole as you pull the drill out.
Secondly, the drill bit moves less as you get deeper because of the dust buildup and the increased friction in the hole.
Lastly, I believe the impact force to the rock surface is less because as you drill deeper you get more friction in the hole.
I would be very interested in the seeing the numbers for the Chouinard hammer in a new hole.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 3, 2014 - 07:32pm PT
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bhilden-
It was two separate holes. In the picture a few posts above you can see two white spots below the McD hammer, those are the start of the two drill holes before I did the test. Both holes started out 0.090" deep so that I wasn't measuring the time it takes to get a hole started. So, starting with two holes about 0.090 inches deep, I drilled each to just over 2 inches deep. I used the two bits you can see so that dulling of bits wasn't a problem.
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Banquo,
"A couple hours after lunch I did the same with the Chouinard hammer. I increased the depth by 2.031 inches in 13m39s, nearly twice the time."
I read this as you 'increased' the depth of the same hole by 2.031 inches. Thanks for the clarification.
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Roger Brown
climber
Oceano, California
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Dan,
I always read your drilling posts and they are always an interesting read. I am always looking for new ideas for replacing bolts. I have been using the A-5 that Chris gave me at Facelift last season. The size,weight seem about right for me. The fastest I ever drilled a 2 bolt anchor was 20 min.+- and that was near the end of the season a couple years ago. Early season it seams to take me forever to drill a 2-1/4" hole. I have come to find that it is really about body positioning. Comfortable stance, drill just over the right shoulder, and nothing in the way of a clear hammer blow. Wow, how often does that happen? Then there is the rock. I have been over on the Chaple wall lately and that rock seems really hard. But then again it is early season. If I am comfortable and it is late season I have to be careful not to hit too hard or I can destroy a bit on the first hole. I have tried every type of drill holder I can find, and every type of hammer and by late season it is all about the same. I have never really been very fast. I am running around 1400 swings per hole right now and that will drop to around 1200 in a couple months. I am amazed at how fast some of you guys can drill a hole. A guy posted once that he could drill a hole in 450 swings, now that is bad-ass!
Oh, yea, the tunes!!
If the right song comes up on that MP3 player blasting in my ears, I can really get into it and blow out a bit half way thru a hole:-)
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 4, 2014 - 03:28pm PT
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Hey Roger,
I'm always happy when you chime in. You have swung more hammer than anybody on this forum and I am sure you could show us a few things.
I haven't tried an A5 or D5 hammer. They have sold on Ebay recently but I can't justify $160 and up for a hammer. perhaps I'll get my hands on one someday.
So tell us how you swing a hammer. A carpenter I once worked with told me to throw the head at the nail and to get my shoulder into my swing. A blacksmith once said to use all four joints; shoulder, elbow, wrist and hand. By hand he meant a loose grip that allowed some motion.
Take care,
Dan
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Banquo,
the results of the McDevitt vs Chouinard are so significantly different have you thought about repeating the test and doing the Chouinard first, have some lunch and then the McDevitt just to verify that the results are accurate?
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 4, 2014 - 10:33pm PT
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bhilden -
Yeah, I was thinking the same thing. I am probably the main uncontrolled variable. I'll do something when I get the time. I also want to try a significantly heavier hammer.
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Roger Brown
climber
Oceano, California
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Dan,
Ha,ha, I really don't know how I swing a hammer. Been a carpenter all my life and I still bend nails. BITD it was all piece work. Paid by the square foot not by the hour. The more nails you drove the more money you made. Summer time meant you could work daylight till dark 7 days a week, be in top shape, AND make a bunch of money. Maybe that history is what makes bolt replacement kinda fun rather than work. Alone, high up there in a sea of rock, tunes blasting in your ears, driving steel. Yea, it don't get much better than that.
I am home for a few days and when I go back up on Monday, I'll throw an extra D-5 hammer in the car.(I have 2) You or a friend will surely be in "The Valley" sometime this summer. You can use it for your testing, bolt replacement, or whatever, and I will get it back when I see you next season. I have a lot of hammers but it is either the A-5 or D-5 that I keep coming back to. I use a Wilderness Drill Holder with SDS bits to complete the set up.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 9, 2014 - 11:24am PT
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So yesterday I got out a new drill bit and tried to repeat the Chouinard hammer test. I got about an 3/4" down and inadvertently moved my drill to the wrong hole for a minute or two and had to abandon the test.
After resting for a day and covering the old holes with masking tape, I tried again today. I drilled hard with the Chouinard hammer and actually feel my arm is getting stronger from all the drilling.
I increased the depth of a starter hole 2.000" in 13 minutes and 42 seconds.Drilling speed was 6.85 minutes per inch or 0.146 inches per minute. Almost exactly what I got last time (6.72 minutes per inch).
I don't know what is happening here. The only thing I have noted is that the Chouinard hammer is old and the handle was a bit loose. I did add a wedge to the handle last week.
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deuce4
climber
Hobart, Australia
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...material science...
The BD hammer is cast. Probably the worst way to make a hammer. Even the cheapest hardware store hammers are forged or machined. (Though the BD is investment cast, which is the best method for casting, but still not a good grain structure for a percussion tool).
The McDivitt, I believe, is machined. Better, as the grain structure is uniform and in line.
But forged hammers are best. The original Chouinard hammer, the Forrest hammer, the A5 and the D5 are all forged hammers. Ask a carpenter what kind of hammer works best--they're all forged, of course. They have the least amount of vibration and the most efficient transfer of momentum. Your elbows will thank you.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 9, 2014 - 01:09pm PT
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deuce4-
That may be it. I was also thinking about how soft the Chouinard hammer is. Any energy spent in plastic deformation of the face of the hammer can't be transmitted to the drill. Hardware store hammers typically have a hardened face.
The Chouinard hammer may have been primarily intended for placing pitons which hopefully doesn't take as much pounding as bolts and since pitons are hardened a hardened hammer may not be a good idea.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 9, 2014 - 04:59pm PT
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I decided to test the bigger hammer is better theory. I bought a small Estwing "Drilling Hammer" at the hardware store for $15 plus tax. This is as small as drilling hammers get at 2 pounds. It seems pretty well balanced and has a hardened face but the plastic handle vibrates a bit. I used the bit from the previous test so it had seen about 3 inches of drilling but was fairly new. I started with a 0.099" inch deep hole like the other tests and went to 2.096" in 20m and 58s. I pounded like a madman and was completely drenched in sweat.
This was the heaviest hammer, slowest result and biggest disappointment to date.
Edit: Estwing claims a forged steel head:
http://www.estwing.com/ss_2lb_3lb_drilling_hammer.php
Comparison so far:
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deuce4
climber
Hobart, Australia
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Jul 10, 2014 - 03:07am PT
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Never did understand those Estwing hammers--what they were designed for--too heavy, and handle too short, and thus very unbalanced.
Looking forward to see how the A5/D5 fares in your tests...
Edit-You should also try to get a hold of an older Chouinard wall hammer and perhaps a old Forrest wall hammer, too.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 10, 2014 - 04:13pm PT
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This morning I got out the Omega Pacific hammer. Surely the ugliest hammer of the lot. I got out yet another new drill bit and made my usual 0.1" starter hole and then drilled to 2". Precisely it took 11m 14s to go 1.917" for 5.86 Minutes/inch. Better than I expected and better than the Chouinard.
I was starting to think the McDevitt results 3.70 min/in) had to be in error so this afternoon I went to the grinding wheel and sharpened one of the bits I have been using. I figured with a sharper bit it had to drill at least as fast as the first McDevitt test. Plus, I only went 1 inch in the first test. Once again I started a hole and then drilled to 2 inches. I went 1.987 inches in 4m 40s for an astounding 2.34 minutes per inch. This is almost 3 times as fast as the Chouinard hammer.
I think I really like the McDevitt hammer. These are machined, not forged or cast so they would seemingly be fairly easy to make if one had access to a milling machine. Preferably CNC.
I really wish I had an A5/D5 hammer to try. Anybody selling?
Current data:
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bhilden
Trad climber
Mountain View, CA/Boulder, CO
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Jul 10, 2014 - 06:13pm PT
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Banquo, Deuce,
I have a Chouinard Yosemite hammer circa 1975. Does that have a forged head? If so, I am heading from my house in Boulder to my house in Mountain View on Saturday so we can work out a way to get that hammer to Banqo for testing.
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mucci
Trad climber
The pitch of Bagalaar above you
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Jul 10, 2014 - 07:49pm PT
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Hey Dan,
I have a D5 and a 70's era Chouinard hammer you can borrow if you want.
Let me know.
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Banquo
climber
Amerricka
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Topic Author's Reply - Jul 12, 2014 - 10:40am PT
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mucci has offered to loan me a D5 hammer so maybe I will get to fill in that blank soon.
If you have been bored by this thread so far, prepare for worse. I have a small 200g, 3 axis accelerometer. I attached it to a hammer handle and took some data. The axis parallel to the handle didn't show much of interest. The axis perpendicular to the handle and the head didn't show much either. As expected the axis perpendicular to the handle and parallel to the head was where all the action was. If the center of gravity is below the head in the handle, one would expect a jolt towards the knuckles (down if hammering on a level surface) when the head strikes. Data sampled at 3600 samples per second. The magnitude of the signal can't really be compared since it is dependent on how hard I strike but the duration of vibration is of interest.
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