Lag screws vs everything else...

[Popeye]

Did it bend or twist?
If the shaft bent I'd expect a force perpendicular to the shaft. Think what wouldhappen if you set a pipe over the lag and pushed perpendicular to the lag.
If the shaft twisted then the bolt has at least temporarily stopped turning and the impact wrench is producing enough torque to twist the bolt. A smaller (thinner) shaft size will drive easier.

[Popeye]

Just thinking, if the problem is that the lags are twisting and you have the same problem on playa then you might try lubrication. Drive the lags half way or so, back the out and pour a little water in the hole, drive again.
Ground is different on playa and your problem might go away.

[Joeln]

Another good tool for extracting stuff is a large vise grip. gives you a nice handle to pull and twist.

Problem-- when we set up a test rib last weekend, at home in "regular dirt", one of the lag screws bent slightly. Could still get it out of the ground with the impact driver no problem, very slight bend. But it makes me think, hmm, what if one bends really badly on playa?

[torrey.smith]

Sextant is excited to be making the debut of our own super lag that we made in our shop at m0xy Oakland.

These are 17-4 Stainless Steel. 36" penetration.

James "Heavy Metal" Erd is the machinist/metal artist within Sextant that made this possible.

[EGAZ]

That is a freakin' lag screw!!

[Papa Bear]

What on earth do you drive that with?

[DoctorIknow]

What on earth do you drive that with?

Beautiful job. Congrads!

I think the Makita driver was them playing with us...

[Papa Bear]

I think the Makita driver was them playing with us...

Yeah, that I had picked up on.

It's just that now we've been treated to that kind of lag screw porn, I want to see the power tool porn that goes with it.

[Traveller in Time]

It's a real work of art.

How about using a number of smaller screws if something the size of a zeppelin has to be secured on the spot.

[torrey.smith]

Sextant traditionally utilizes the corded, brushed, Makita TW-1000, rated at 738 ft-lbs.

It works great with the PE26 and struggles with the PE46 penetrators.

For our custom anchors, we are hoping to see the TW-1000 be effective in our 36" prototype seen above.

The cordless, brushless Makita XWT07Z seen above is actually rated to 780 ft-lbs. We are going to be evaluating it as a replacement or augmentation to the TW-1000. Sextant is transitioning to 6 amp-hour batteries to support this effort. We'll post an update after Playa to let you all know.

Make sure to drop by Sextant at 6:45 & Esplanade this year if you want to talk big screws!

[maladroit]

This is an unfinished project until I see a T-rex drill one of those anchors into the ground with stubby little arms. Any way that might be possible?

[torrey.smith]

This is an unfinished project until I see a T-rex drill one of those anchors into the ground with stubby little arms. Any way that might be possible?

You know, maladroit, there are certain things in this world that are simply a bridge too far to ask for.

In what theme camp could that even happen???

[princevalium]

Sextant is excited to be making the debut of our own super lag that we made in our shop at m0xy Oakland.

These are 17-4 Stainless Steel. 36" penetration.

James "Heavy Metal" Erd is the machinist/metal artist within Sextant that made this possible.

Wow, this is truly a piece of art...

[maladroit]

This is an unfinished project until I see a T-rex drill one of those anchors into the ground with stubby little arms. Any way that might be possible?

You know, maladroit, there are certain things in this world that are simply a bridge too far to ask for.

In what theme camp could that even happen???

I thought you were SexTANT not SexCANT

[letsburn21]

I already have a Milwaukee m18 1/4" impact driver.

Tried drilling into San Diego (Ramona) high desert soil today with the recommended 1/2" -18" lags, and was only able to drill 8 1/2 holes before letting the drill cool off. Was kind of getting worried the impact driver was going to give. The soil here is really hard and packed and 4-5" in the lag was pretty sturdy and I couldn't pull or make it budge myself.

Was wondering if my drill will make it out there?

I have a Makita lxt 1/4" impact driver as back up just in case.

And I obviously am bringing a breaker bar as well.

Any info regarding this would be appreciated.

[BBadger]

I have a similar impact driver by the same company and it started giving up the ghost last year, even though it worked perfectly the previous year. I had to resort to a ratcheting wrench to finish the job last year after driving it most of the way down. I would bring a backup (including a manual backup like a wrench) to fall back upon.

You probably know what you're doing, but just in case, make sure that you're not applying any downward pressure on your impact driver as you drive the screws in. Let the driver apply its rotational drive, as it is meant to, in order to drill that bolt in. Downward pressure just creates excess friction, and I don't think my driver appreciated it.

[letsburn21]

I have a similar impact driver by the same company and it started giving up the ghost last year, even though it worked perfectly the previous year. I had to resort to a ratcheting wrench to finish the job last year after driving it most of the way down. I would bring a backup (including a manual backup like a wrench) to fall back upon.

You probably know what you're doing, but just in case, make sure that you're not applying any downward pressure on your impact driver as you drive the screws in. Let the driver apply its rotational drive, as it is meant to, in order to drill that bolt in. Downward pressure just creates excess friction, and I don't think my driver appreciated it.

Thanks for responding. I ended up just upgrading my impact driver from the 1/4" to 1/2". Feel more confident in driving bigger lags now

[legionvr6]

So we have a 30x30 flat top canopy with legs every 10 feet. each foot pad will have a 14" lag that goes straight down. We plan to use tie downs every 10 feet along the perimeter going to a Lag so we can have added security.

To get the most out of lags on the playa, should be try to get a good 90 degree angle to the load?

[Canoe]

... To get the most out of lags on the playa, should be try to get a good 90 degree angle to the load?

That's usually how it's done. Do make sure to put the head right down to the playa, so the load doesn't have leverage against the soil from exposed shank/threads. The two chain links will of course angle to the load.

Two guylines at a corner is recommended. Makes the whole structure a lot more stable in the wind.

Search for photos of shade structure setups?

[legionvr6]

Thanks for the input. We are doing 4 tie downs per side so each corner will have 2 tie downs. should be pretty secure.

[hedofun11]

Will a 1/2 in. x 10 in. Galvanized Hex Lag Screw hold down a Kodiak Canvas Flex-Bow 4-Person Canvas Tent, Deluxe?

[Traveller in Time]

1. -- I have not the faintest idea

• -- Bring more then enough

• -- Run them deep enough (this will require tools)

• -- Use a good attachement to your lines/straps

• -- Use kind of shock absorber

All issues mentioned somewhere in above conversation

Have a good Burn

[Kenshiro]

The cordless, brushless Makita XWT07Z seen above is actually rated to 780 ft-lbs. We are going to be evaluating it as a replacement or augmentation to the TW-1000. Sextant is transitioning to 6 amp-hour batteries to support this effort. We'll post an update after Playa to let you all know.

So how did that Makita do? I’ve seen that although it is officially rated around 750lbft some independent reviewers have measured as high as a full 1000lbft. I would wonder about the battery capacity trying to drive more than even one of those things.

[FlyingMonkey]

Sextant is excited to be making the debut of our own super lag that we made in our shop at m0xy Oakland.

These are 17-4 Stainless Steel. 36" penetration.

James "Heavy Metal" Erd is the machinist/metal artist within Sextant that made this possible.

My what a large "penetrator" you have.

Impressive.

Will make great robot porn for 2018's theme.

[torrey.smith]

Alright here's a set of videos to recap the Sextant 2017 cycle as it pertains to ground anchors.

A basic observation is that although the corded, brushed Makita TW-1000 has a slightly lower rated torque (738 ft-lbs) vs the cordless, brushless Makita XWT07Z LXT (780 ft-lbs), the TW-1000 seems to deliver a significantly higher average torque. You can see in the videos that the TW-1000 drives the PE-26 much faster than the XWT07Z LXT.

Still, that cordless baby was awesome on Playa and both tools travelled around to various installations during Build and Strike.


PE26 installation with Makita TW 1000 at NOETICA




PE26 installation with Makita XWT07Z LXT by Bonnie Morgan at the Sextant Tesla Coil



We were incredibly honored to have Shane "Dream Crusher" Sischo and Gary the crane guy come over with the big stick and a 10,000 lbf load cell (borrowed from Mary Poppins over at Man Base) to play with our custom 36" Penetrator. Zach Coffin, Handsome Rob, Maeia, and everyone else from HEaT and DPW were super fun to work with and Sextant hopes to continue building these relationships as we go higher.

James "Heavy Metal" Erd of Sextant worked tirelessly to machine the custom penetrator from 1.75" 17-4 PH Stainless Steel bar stock. We will heat treat them to Condition H900 once we're done tweaking the shape.


Anchor installation by Shane with Makita TW 1000




Crane pull test




Crane pull test (video of load cell readout)



Ultimately we found that our thread pitch was too fine (0.500" is the coursest our Monarch 61 lathe can cut) which lead to gumming of the threads and not pulling out the full cone from the point of the penetrator. A good penetrator will pull a cone out, with the cone angle depending on the soil type. The volume of that cone of soil and the density is what gives you the pullout rating of the anchor. For reference, we have measured about 2,100 lbf pullout on the Playa with the PE-26, which equates to about Soil Class 1.5 on this chart.

We pulled a number of times, averaging about 3,800 lbf on our custom 36" penetrator. I was hoping for at least 7,500 lbf, which I think we'll get once we incorporate what we learned into the next generation and get the full cone.


Here's the partial cone:



With the partial cone, we decided to give the standard DPW "Red" helix plate anchors a test. We were fortunate to be able to have a crew come to our test site in front of Sextant and install one. It pulled at 6,200 lbf. With that value we decided it would make sense to request DPW anchors for our Zip-Line guy line anchor points. We've done a lot of solutions over the years and this call had mainly to do with maximizing safety and letting James leave our machine shop at m0xy in Oakland (he'd been finishing up the remaining 3 anchors we needed) and actually come to Burning Man.


DPW helix plate anchors installed by HEaT




How one thanks HEaT for ground anchors:




Testing the Sextant Zip-Line




Here is why ground anchors matter:




Mortal Kombat on the Tesla Coil with a pan around vünderbar towards the end

[Kenshiro]

Sweet work! Very impressive, even if you are still aiming for higher numbers. I wouldn’t be shocked if even just leaving’em in for a while to let the dirt reset around them might get you a lot closer to the numbers you were shooting for.

Nice to see the battery-powered Makita held up pretty well. I just picked one up a few weeks ago. I already knew it was WAY overkill for my humble applications, but when their 700+lbft model is only $70 more than their 200lbft model...

[EGAZ]

Good stuff torrey.smith!! great post.....

[FIGJAM]

Bump

[FlyingMonkey]

Bump

Well yeah!

[JayBobBoy]

What a great post! Thanks for the details. I love what you do!

When my camp grows up, it wants to be just like you!