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Bolt removal tools - resources, tips, how-to videos


Ken Noyce · · Layton, UT · Joined Aug 2010 · Points: 2,415
Jayson Nissen wrote: Thanks for this information. Why not use the drill/spinner tool to remove the bolt rather than building the doodad? 

And how would you do that?

Jayson Nissen · · Corvallis, OR · Joined Aug 2013 · Points: 311

Ken-
The doodad just rotates and uses mechanical threads to transfer rotational motion into motion along the length of the bolt. Since a drill also turns things it seems reasonable that it might be able to replace the doodad. Though there are many reasons that it might not work.

Why not just apply the spinner tool directly to the stud using high nut, a deep socket, and a simple thrust bearing, with maybe a spacer if the socket isn't deep enough? Just like when you tighten the bolt down for the first time and the threads pull out.

Ryan-
Your response isn't very useful as is.

Gregger's doodad, which is awesome, looks like it is about a foot long. How much force do you think can be applied to that handle by someone hanging from a rope? Say 300 lbs? So, 300 foot lbs of torque?

  • A simple google search reveals an impact wrench that can supply >1,000 ft lbs of torque.
  • As well it looks like greggers doodad use 13 threads per inch whereas a 3/8 stud has 16 threads per inch, which I think also gives the mechanical advantage to the stud.
It appears that the mechanical advantage of the torque arm is significantly less than that given by all the complicated bits inside of the drill and overall the 'mechanical advantage' goes to the impact driver applied directly to the stud. Is there another mechanical advantage that I am missing?

I figured that Gregger has already tried this out and it didn't work for some reason. The doodad seems like it would give a lot more control over the application of torque, making it less likely to snap the bolt shaft or to shear the threads.
Ryan Swanson · · Pepedidnothingwrong, freejg · Joined Jan 2018 · Points: 50

Knock yourself out and make it happen.

Once the bolt is spun and the nubs are worn down, it takes a relatively low force to pull the bolt. 300 foot pounds with a normal size wrench is huge. It is probably no more than 75-100 ft-lb.

You’ve still got to have a spacer to act as a stand-off from the wall, because you need length to get the bolt out. Do you just plan on pulling on it like you are tightening the nut?  You will run out of threads with an inch or so of bolt still stuck. 

Jayson Nissen · · Corvallis, OR · Joined Aug 2013 · Points: 311

I might give it a shot. I place wedge bolts because they are a lot cheaper than sleeve bolts. A friend I respect doesn't think very highly of placing wedge bolts. I figure if I pull a couple of them then I could assuage any concerns I have about placing them or decide that it is worth the extra money for sleeve bolts.

I struggle to find time to get all of the things done that I want to do. Gregger's doodad looks sweet, but putting it all together is time that I can't spend doing something else. I'm more likely to try something that doesn't require as much time. The best solution would be to borrow one.

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Jayson-
The ClimbTech guys in Austin developed a method of pulling with a drill as the lever in the system. My objection to that is batteries are the limitation on what I can get done in a day. Wear on the drill is another concern.
Also- I think you underestimate the role of friction in mechanical systems.
The tools/methods should balance cost, weight, durability, the input effort, and efficient work flow. 

Ken Noyce · · Layton, UT · Joined Aug 2010 · Points: 2,415
Jayson Nissen wrote: Ken-
The doodad just rotates and uses mechanical threads to transfer rotational motion into motion along the length of the bolt. Since a drill also turns things it seems reasonable that it might be able to replace the doodad. Though there are many reasons that it might not work.

Why not just apply the spinner tool directly to the stud using high nut, a deep socket, and a simple thrust bearing, with maybe a spacer if the socket isn't deep enough? Just like when you tighten the bolt down for the first time and the threads pull out.

Ryan-
Your response isn't very useful as is.

Gregger's doodad, which is awesome, looks like it is about a foot long. How much force do you think can be applied to that handle by someone hanging from a rope? Say 300 lbs? So, 300 foot lbs of torque?
  • A simple google search reveals an impact wrench that can supply >1,000 ft lbs of torque.
  • As well it looks like greggers doodad use 13 threads per inch whereas a 3/8 stud has 16 threads per inch, which I think also gives the mechanical advantage to the stud.
It appears that the mechanical advantage of the torque arm is significantly less than that given by all the complicated bits inside of the drill and overall the 'mechanical advantage' goes to the impact driver applied directly to the stud. Is there another mechanical advantage that I am missing?

I figured that Gregger has already tried this out and it didn't work for some reason. The doodad seems like it would give a lot more control over the application of torque, making it less likely to snap the bolt shaft or to shear the threads.

You are neglecting friction.  The whole point of the doodad is to provide a mechanical advantage while decreasing the friction.  With a big heavy impact wrench and a variety of spacers, sure you could pull it with the spinner tool, but then you have to bring a big heavy impact wrench and a bunch of different sized spacers whereas the doodad is a single tool that will do it for you, weighs less than an impact wrench, and doesn't need batteries. 

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Bump.
I included this excerpt in the first post:

5-Piece bolt removal
[9/30/2018 update:] Geir Hundal has come up with a different method that can work some of the time- If you have a draw stud that is 5/16" along its entire length, you simply remove the center bolt and screw the draw stud in instead. Keep turning until you can tell you are rotating the cone because you have engaged all the threads. Start pulling - if the cone and sleeve are a little bit rusty, the cone will push the sleeve out ahead of it rather than cleanly re-insert itself (if the hanger were in place, the sleeve would be sandwiched between the cone and bolt head, but with nothing but air outside the hole, there is room for the sleeve to slide out.) This method is more likely to work on slightly rusty bolts than on new ones. 

Jayson Nissen · · Corvallis, OR · Joined Aug 2013 · Points: 311

Why would the doodad have lower friction than an impact wrench?

Ken Noyce · · Layton, UT · Joined Aug 2010 · Points: 2,415
Jayson Nissen wrote: Why would the doodad have lower friction than an impact wrench?

With the impact wrench you are trying to overcome the friction between the nut and the bolt that you are trying to remove.  With the doodad you are using a ball screw which contains bearings which have the sole purpose of reducing that friction.

tooTALLtim · · Boulder, CO · Joined Apr 2007 · Points: 1,200

Are you using a 5/16 - 18 or 5/16 - 24 die?

Found out: 5/16 - 18

mattm · · TX · Joined Jun 2006 · Points: 1,401

I just put in an order that will hopefully come with the 1/2 20 threading.  The contact sent me this link which looks like a direct order item for future ref.

Driect Order 1/2 20 Ball Screw

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321
mattm wrote: I just put in an order that will hopefully come with the 1/2 20 threading.  The contact sent me this link which looks like a direct order item for future ref.

Driect Order 1/2 20 Ball Screw

I ordered 20 that I will assemble and sell through the BCC. I requested a change to the outside end of the ball screw on this order- M10 threads on the small portion that typically has a 10mm diameter and a circlip cut. The circlip isn't strong enough to stop the ball nut if someone absentmindedly keeps turning the handle, but a nut and washer would do the trick.

Send them this updated drawing:


edit: also see this post about a design idea for the spacer tube -  mountainproject.com/forum/t…
Jeremy Lubkin · · Worldwide Wanderer · Joined Apr 2013 · Points: 5

I have 10 of the initial design I have yet to build up - been traveling. I'll build them in July when I am back home.  But they seem far longer than needed. And I dont see a need for the 'nut'... I like the 'bike wrench' idea and will probably just make a batch of these on a waterjet.  I hate custom tools, but well I guess the doodad is a custom tool and will get a custom wrench.

I met with a bunch of rebolters in Salt Lake and got some other ideas.  The main thing being using ACME threads as they seem a great middle-ground.  The guy who made it thinks over time the ball screw will not hold up.  But it required a custom piece for a 'end nut' that he welded on.  

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Before you fire up the water jet and make something from scratch - this is what I plan to use. I've ordered one to make sure it will work, but it hasn't arrived yet. I plan to use a 3/4" oak or hickory dowel with copper pipe stops at the ends for a ~8" handle.


edit- regarding the length - For studs alone the whole tool could be much shorter. For ~4" long 5-piece bolts and the necessary 4" long draw stud you will run out of travel if the tool is much shorter.
Jeremy Lubkin · · Worldwide Wanderer · Joined Apr 2013 · Points: 5

I like the new M10 threads on the end.  Seems like you could use this nut to spin as well.  Not fast with a drill, but if I recall Geir had some success with the Hurly Jr just snow spinning a bit, pull a bit, repeat.    Curious how this new handle will work out.  Tho price-wise I think I can make the wrenches on the waterjet quite cheap.  I saw the very purdy one from cleatis in Salt Lake last fall.  Def a nice tool. I'm just looking to make these 10 cheap enough and work well enough to be useful.

Seems like we could probably get one of these china guys to make it all exactly as we want.

Also this idea of supporting the rock is kinda a big deal.  Thinking along the lines of interchangeable plastic inserts instead of the end cap.  Probably will break over time but they are replaceable.. I was also planning round tubing instead of square with a plastic keeper bushing/insert so you avoid the need for the new end-cap.

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Nylon 1" thick spacers are pretty tough. We used them as spacers when we were using the Greenlee punch driver method. UHMW plastic is pretty slippery, but also good in compression. It's certainly easier to machine than aluminum. I'll check to see if Colorado Plastic Products in Louisville has a 1.5" x 1.5" x 0.25" square tubing.
Northwestern Tool (the place that makes the threaded inserts) makes a spherical washer that might be useful in aligning the tool with the hole, but it would be difficult not to drop it- they make a 5/8" ID version that would be perfect, but I don't know how you would secure it.

We broke a lot of bolts early on with the round spacer tube because the friction of the cheap ACME threads against the nut/handle translated into torsion on the rusty bolt under high tension. The ball screw is so efficient that it is possible that the indexing square nut & tube might be overkill, but it's hard to tell. The times that you crank the hardest on the handle are when you have spun the bolt too little, and you begin to max out the tension as it re-engages. If the whole tool turns inside that round spacer tube instead of just the ball nut, the bolt will break. You wouldn't necessarily notice the twist since the spacer itself doesn't move. 
Jeremy Lubkin · · Worldwide Wanderer · Joined Apr 2013 · Points: 5

Good to know this history. My main reason for the round is so I can simplify the ends with just needing bushings on either side.  But maybe there is something else out there to put the ends on the square tube.  Basically looking to make this as simple as the Hurley jr.  

I have a buddy who is a very good machinist in Portland - been doing it for 50yrs I'd say and has a personal shop bigger than anything but the biggest commercial places. I'll see if he has any ideas before I build anything. 

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Found an even better bracket for the ball screw - short MTB stem is built for a 1 1/8"/28mm fork. Just add a dowel for the handle. I'm looking around for local used parts before ordering a bunch of these from Shenzhen. Looks lightweight and strong enough.

Gregger Man · · Broomfield, CO · Joined Aug 2004 · Points: 1,321

Confirmed: most threadless bike stems are a perfect fit for the 28mm ball nut housing. Add a wooden/aluminum handle and you are set.

mattm · · TX · Joined Jun 2006 · Points: 1,401
Gregger Man wrote: Confirmed: most threadless bike stems are a perfect fit for the 28mm ball nut housing. Add a wooden/aluminum handle and you are set.

How much torque before it slips?  I may have one or two of these lying around in 120mm length!  Win

Guideline #1: Don't be a jerk.

Fixed Hardware: Bolts & Anchors
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