Replies

1. 
   Malicair | May 06, 2003 10:36pm | #1

   Mike,

   One other thing you can try is to try and get a solid (or as best as possible) hold into the screw and use a light hammer to tap on the end of the tool as you try turning it out. The vibrations sometimes will help loosen real tight bolts, screws, etc... in steel or aluminum assemblies. Works much like an impact wrench but is the poor man's version.

   A couple other options are using a left handed twist drill bit to try drilling the head off and if your lucky it might just back the screw out. Most twist drills are right handed so you would need to goto an honest to goodness tool supplier for it.

   If you did just manage to cut the head of the screw off with the drill then it would serve the same purpose as using the grinder. Just be sure to use a drill bit larger than the thread diameter of the screw.

   Other than that you probably right in "carefully" grinding the head off and removing the screw with vice grips.

   Good Luck!!!

   Mal

1. 
   Accelar | May 06, 2003 11:00pm | #2

   Lee Valley Tool (http://www.leevalley.com) has a product in latest woodworking catalogue - I wasn't paying much attention to the solution but check it outGavin Pitchford

    

2. 
   JohnWW | May 07, 2003 12:49am | #3

   Mike,

   I recently ran into this problem on a brand new jointer where the blade hold down bolts were over tightened by air driven wrenches at the factory. 

   Your solution, to grind the head off, is the most practical one, this is what I did with the machine I repaired.  The best tool for the job would be a Dremel with a reinforced abrasive cut off blade.  A cut off blade works much better than a grinding wheel.  Replace the bolt with one from the manufacturer, not something from a hardware store.  I'd replace all of the bolts, the problem with this one bolt and your "quite tight" comment makes it sound as though all the bolts have been over stressed.  

   If you are going to buy a Dremel type tool get a plug in model, the battery types are underpowered for this type of work.  For your own safety wear goggle type eye protection, the red hot grit and sparks will be flying at high speed.

   Once the blade is removed, the bolt stub should turn easily with a pair of pliers, on the machine I repaired the stubs backed out by just turning them with my fingers.

   If the cut off bolt is solidly jammed in the aluminum cutter head you have probably torn up the threads in the aluminum and for safety the entire head needs to be replaced, especially since many of the other bolt holes may be at least partially damaged by your tightening procedure.

   I have been repairing machinery for a long time and I've seen at least a hundred times more damage done by people over tightening bolts than was ever done by leaving them too loose.  The bolts on a cutter head just need to be tightened until all the slack is gone and then just a little bit more.  Excessive tightening of the bolts will make the machine less safe rather than more because the threads are being repeatedly stressed to near their breaking point, eventually they'll fail as you've just discovered.

   Almost everyone needs to go easier on their machinery, especially modern tools which rely on aluminum for many of their components.  On a well designed tool the collets, chucks, blade bolts, fence locks and the like will hold just fine with far less torque applied to them.  Treated gently, the tool will last longer and hold it's accuracy far better. 

   Hope this helps, John

    

   
   

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   Edited 5/7/2003 5:09:56 PM ET by JohnW

   
   

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   Edited 5/7/2003 5:12:45 PM ET by JohnW

3. 
   robkress | May 07, 2003 01:58am | #4

   Don't even think about taking a drill bit to the screw.  Odds are that it is a socket head cap screw or similar variety and will undrillable.  Those fasteners are usually grade 8 hardened screws and all that will happen is you will dull your drill bit (while pushing forever).

   Sorry to say but you really are in a pickle and there really is no easy solution.  In the future... no need to tighten your screws so tight.  If you are worried about them coming loose, just go get some locktite.  Then the screws will only come out when you want them to and will be easier at that.

   Rob Kress

4. 
   Jeff | May 07, 2003 02:09am | #5

   Mike

   I hate to ask, but have you tried a screw extractor?

   Jeff

5. 
   biznazion | May 07, 2003 06:55am | #6

   One thing you may try is the impact screwdrivers they sell at auto parts stores.  You put in a bit and then set the direction and give it a whack with a hammer.  The force of the hammer blow keeps the bit in the screw head and turns it at the same time.  This will only work if the screw is not too mangled already.

6. 
   mrles | May 07, 2003 07:39am | #7

   Mike

   There is a process to remove that screw, I don't know what to call it but if you call around to some machine shops in your area I'm sure someone will be able to help you. 35 years ago I was working at the Houston Chronicle Newspaper in the pressroom. On the folder where all the sheets come together and made into its final configuration there are some pins that drag the paper around the cutting cylinder. If you will look at the bottom of your newspaper you will see these holes. These pins are made out of a very high grade steel about the size of an 8d finishing nail and set into white brass which screws into a pin holder. Each folder had 36 of these pins. Pins would break, we could not drill them out, like your screw, too hard. The pin holders cost a weeks wages. We had a machine shop in Houston that could blast them out electronically with no damage to the pin holder. They charged us $20 each. Hope this helps.

   I would try tapping it around with a small chisel the way some post suggested first or the left hand drill might work. I've had success doing both. Biznation suggested the impact screwdriver, might check your friends that have motorcycles. I don't think you can work on one without an impact screwdriver, I couldn't.

   Gods Peace

   les 

   
   

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   Edited 5/7/2003 12:47:26 AM ET by les

1. 
   Len | May 07, 2003 04:49pm | #8

   It's called "electric discharge machining" EDM. We use the process to remove taps that have broken off in parts.

   You might also try heating the part up with a torch. Not the srew itself but around it. The heat will cause the part to expand slightly and you might break the screw free with any of the previous metioned methods. We actually use a brass rod dipped in liquid nitrogen and hold that to the screw/bolt to cool it down. You can do the same by freezing the brass rod. I've seen it work several times when I thought we would have to send it out to a machine shop.

   Good luck,

   Len

2. 
   JohnWW | May 07, 2003 04:54pm | #9

   The electronic process you are describing is called electrical discharge machining commonly shortened to EDM.  The part is submerged in a liquid, oftentimes just water, and a cutter, in the shape of the hole to be made, is lowered against the broken stud.  A current is run thru the cutter and the small sparks at the end of the cutter erode away the metal.  Because there is no force involved, the process allows you to remove a very hard bolt from a much softer surrounding material.  If you attempt to drill out the bolt in this situation the drill will veer into the softer material every time.

   It would probably be cheaper to replace the cutter head than have a machine shop remove the stud with an EDM machine.  The labor involved would be the same in either case, since the head would have to be removed to for either solution.  You should have success with grinding the head of the stuck bolt off.

   John

   Edited 5/7/2003 3:07:40 PM ET by JohnW

   Edited 5/7/2003 5:14:40 PM ET by JohnW

3. 
   Accelar | May 07, 2003 04:58pm | #10

   Follow up to yesterday's post re Lee Valley Tool... I tried to find them on website for you and couldn't without the catalogue - so back to the catalogue to get the product codes - and voila...

   Two options: 

   The first is a "screw extractor kit" page 122 of the "Fine Wood Working Tools" 2002-2003 catalogue.  Basically you drill a hole using a really hard (rc62) bit into the problem screw.  The extractors come in multiple sizes.  Then from what I can tell, you reverse the bit end for end, and the reverse end has an edge that screws into the damaged screw and then engages at the bottom of the hole you drilled and unscrews the screw.  Full set about $40 US.  Individual selections between $10 and $12.  Product code 66j20.10

   http://www.leevalley.com/hardware/page.asp?SID=&page=32272&category=3%2C41306%2C41329&ccurrency=2

   The other solution is on page 129 - "Screw Grab" is a liquid with some kind of filler crystals that lodge in the screw / hole you are attempting to remove and fill in the space between the screw and the driver, in effect cancelling the stripping you have already done - IF not too far gone.    This is the cheap solution - about $4.00 US for a small tube.   Product code 94k07.01

   http://www.leevalley.com/hardware/page.asp?SID=&page=32212&category=3%2C41306%2C41329&ccurrency=2

   My experience with Lee Valley is that if they make a claim in the catalogue, it can be relied upon.  Their reputation in Canada among woodworkers is such that a gift certificate for Lee Valley is at the top of everyone's Christmas and Birthday list. 

   Good luck.Gavin Pitchford

    

7. 
   BertJ | May 07, 2003 10:11pm | #11

   Mike, I have the same Delta planer and if memory serves the small bolts have socket heads which are tightened/loosened with an allen wrench. Also, I believe you BACK OUT the bolts to tighten the blade and SCREW IN the bolts to LOOSEN the blade. Check your manual.

   For the record, I had a similar problem with corrosion locking up the bolts. I installed a de-humidifier in my shop and no longer have a corrosion problem.

   Some day I will upgrade to the new 2-speed Delta planer which has, I understand, a much better blade installation process, lockable cutter head, etc.

   BJ

8. 
   parrothead | May 08, 2003 03:26pm | #12

   Thank you all for your suggestions. I finally got it out using a combination of ideas. I tried the poor mans impact driver and it did not work. So I proceeded to cut the head off using a Dremel with an abrasive cutoff blade. I was taking it easy so I would not damage the blade holder, and took off the top part of the screwhead, leaving me about a 1/16" thickness. Then I took a hammer and chisel on one half of the head and just tried to get it to loosen up, and that worked. I was then able to use the screw extractor to remove it the rest of the way. I guess removing that much of the head removed most of the tension on the threads.

   Thanks again for all the help.

   Mike