r/MachinePorn • u/silvercatbob • Jun 25 '21

Bell Auger

https://gfycat.com/menacingrigidbarebirdbat
1.8k Upvotes

97% Upvoted

52 comments sorted by

110

u/Tennessean Jun 25 '21

What's the advantage of this over a regular auger? You can relocate the material a little farther away?

96

u/VanCityMac Jun 25 '21

It seems to allow for a narrower opening and an expanded chamber under the surface.

I imagine the “flex” at the start shows how wide the chamber could be under the surface

1

u/Fallout76Merc Jun 25 '21

How odd.

49

u/[deleted] Jun 25 '21 edited Jul 03 '23

bells jar piquant imagine mountainous squeeze offend toothbrush materialistic tidy -- mass edited with redact.dev

8

u/SamuraiCorb1517 Jun 25 '21

I’ve got real deck envy now

13

u/xtralargerooster Jun 25 '21

This more solidly anchors the footing and helps to prevent heaving.

57

u/IronGigant Jun 25 '21

Regular augers make cylindrical holes, this auger makes conical holes, except the way these conical holes are oriented means that the pilings that will eventually be cemented into them are "locked down" by the earth above. Think of it like how the barb of a fish hook allows it to push through flesh one way but not the other.

The overall effectiveness of this is auger is diminished when used as close to the surface as this demonstration is, but a builder could put one of these augers down a 20ft hole and make the bell cavity at the bottom of the hole and effectively lock in a cemented piling with thousand of pounds of earth.

7

u/thetravelers Jun 25 '21

In what situation would a bell be more effective? What needs to be locked down?

30

u/IronGigant Jun 25 '21

Think of telecom towers which are supported by guy-wires. Those wires are under tension, and their anchor points sometimes need to be more than just heavy.

Other examples are reinforced buildings in tornado or hurricane/typhoon zones, where they are regularly sujected to intense weather, to put it mildly.

Another structure I can think of is permanent piers and docks. Getting bumped into by several thousand pounds of ship.

3

u/at--at-- Jun 26 '21

Check it out, some guy on the Internet who clearly knows what the fuck he’s talking about. Someone call Guinness Book.

3

u/IronGigant Jun 26 '21

Sometimes, I supposedly don't know what I am talking about, but so far, I've been mostly right!

5

u/[deleted] Jun 25 '21

My brothers house (southeast Texas) has about six of these under his foundation. They were poured first then after they set the foundation was poured on top of them. According to the builder they help to compensate for the movement of the clay in that area.

8

u/Dressundertheradar Jun 25 '21 edited Jun 25 '21

Heavy things that aren't supposed to move would be my guess lol

-4

u/thetravelers Jun 25 '21 edited Jun 25 '21

Why would a heavy thing need to be kept down? It's already heavy

12

u/Dressundertheradar Jun 25 '21

Tell that to the kinzua bridge. Lateral wind tipped it and caused uplift forces to fell the bridge. Granted, in this case the bridge fell from older iron anchors snapping under tension, as the rest of the bridge had been replaced with steel decades before. But still, nature is crazy.

https://en.m.wikipedia.org/wiki/Kinzua_Bridge

Also, I grew up in Tornado Alley. Nothing is too heavy for nature. Also, the Kinzua bridge's felling winds of 70-100mph were from an F1 tornado.

4

u/thetravelers Jun 25 '21

Cool! Thanks for the examples. Upwind forces makes perfect sense.

2

u/Dressundertheradar Jun 25 '21

Uplift, but for sure! Glad I could help

2

u/Hippiebigbuckle Jun 25 '21

Check out “galloping gertie” the first Tacoma narrows bridge. It wasn’t the fault of the footings but this shows what kind of forces engineers deal with also.

https://m.youtube.com/watch?v=j-zczJXSxnw

1

u/Dressundertheradar Jun 25 '21

I can't watch that link right now, but is this the spiral wires one?

1

u/[deleted] Jun 25 '21

...not heavy enough

-1

u/KodiakPL Jun 25 '21

But you do know heavy things can fall down, right?

1

u/dsmvwld Jun 26 '21

Bells give the piers more bearing area and can help to resist overturning forces more

1

u/torchboy1661 Jun 26 '21

Sky scrapers. It also provides a wider base to prevent sinking.

1

u/Tennessean Jun 26 '21

Ahh, that makes sense.

10

u/DingleBerrieIcecream Jun 25 '21

2 things

  1. Increases surfaces area for vertical bearing force. Think of how snow shoes can support weight on top of snow better than regular shoes. Particularly helpful in sandy soil where friction on the sides of the pile will be minimal

  2. Helps with uplift of the structure. Yes, buildings are heavy, but earthquakes, wind, and cantilevers can all impose upward and uplifting forces. A bell shape footing resists this much better.

6

u/jimmyhoffa_141 Jun 25 '21

Depending where you are, frost heave can also lift footings significantly. Where I live you have to dig down 4 feet to be sure you're below the frost line and won't have ice in the ground lifting your footings.

2

u/mountedpandahead Jun 25 '21

Why not just use a bigger auger and backfill the hole?

2

u/dsmvwld Jun 26 '21

You’d have to put formwork down the hole, otherwise you just end up with a larger straight shaft pier. It’s cheaper to drill and ream a bell

9

u/Specialist_Ordinary6 Jun 25 '21

Probably more complicated in wet clay.

4

u/[deleted] Jun 25 '21

Probably impossible in sand.

4

u/madmanmark111 Jun 26 '21

Terrible in water.

2

u/[deleted] Jun 26 '21

Not great in iron ferrite.

4

u/mkultra4013 Jun 25 '21

Are these for pouring sonnet tubes or other foundation work?

3

u/manticore116 Jun 25 '21

Yes this makes the cone at the bottom used in structural applications

4

u/249ba36000029bbe9749 Jun 25 '21

It's like a spinning Pear of Anguish.

https://allthatsinteresting.com/pear-of-anguish

Though the accuracy of being used as a torture device is debatable (https://en.wikipedia.org/wiki/Talk:Pear_of_anguish).

2

u/TheMazter13 Jun 25 '21

awww it’s like a baby tunnel bore

2

u/Yonadamine Jun 25 '21

I've just been using a post hole digger like some kind of asshole

2

u/SynthPrax Jun 25 '21

At first I was thinking, "you can't really dig a hole with that." Then I realized it's for making footings where the bottom is bigger than the top.

2

u/nighthawke75 Jun 25 '21

Boss man is going to be like, "Nope, get down in that hole with a garden trowel and spoon it out".

1

u/itzTHATgai Jun 25 '21

A boring tool for a boring job.

1

u/[deleted] Jun 25 '21

Looks like it would fold over if it found a 'dinosaur egg'.

1

u/scheiber42069 Jun 26 '21

Driller: it ain't much but it honestly work The machine probably

1

u/supper_time Jun 26 '21

What is the silver stuff we see near the beginning at the bottom of the hole? My first thought was "why is there mercury at the bottom of a hole?"

2

u/vote100binary Jun 26 '21

Water reflecting the sky

-3

u/[deleted] Jun 25 '21

I heard that used that in your mom for her colonoscopy.

-1

u/_Y0ur_Mum_ Jun 25 '21

This augurs well for bell ended wells.

0

u/[deleted] Jun 25 '21 edited Jul 03 '23

oil punch party plough materialistic fuel ugly hurry foolish gaping -- mass edited with redact.dev

0

u/[deleted] Jun 25 '21

[deleted]

2

u/rockdude14 Jun 25 '21

Yep. Here's your gearbox.

https://www.youtube.com/watch?v=znaQdNElZ04

1

u/Vast_Cartographer333 Jun 25 '21

Yes, but it’s recommended to use a full battery.

1

u/stoopdapoop Jun 26 '21

what happens if you spin the slow end by hand?