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JohnRobHolmes · 09-30-2006, 09:33 AM

I have a 1.5mm hex grub screw that was threadlocked from the factory. I must remove it. The problem is that the grub screw is hardened steel and no 1.5mm allen can loosen it, even the high dollar hexes have stripped. I need to get this screw loose! I know that heat will do it, but the screw is on a motor can and the magnets cannot be heated above 100C. I believe that 150C or above is needed to degrade threadlock.

The one solution I have is to sink the motor can in water, and heat up the screw with a torch. This should keep the magnets cool enough, but I dont know if the screw will be able to get hot enough. All I can do is try it and keep a temp gun handy. Anybody have any other suggestions or solutions to get this damn set screw loose? It is not exposed above the surface either, so I cant dremel a slot in the screw.

Unholy · 09-30-2006, 09:54 AM

Last time i had that problem... I took an old allen wrench, stuck it in the grub screw, then took a torch and heated the allen wrench. Heat transfer went straight to the grub screw to break the threadlock, without transfering too much heat to the surrounding area.

ColquittCustom405 · 09-30-2006, 10:07 AM

Use PB Penatrating Catalyst.Works for me.Spray it,let soak....repeat, then let it sit.Should work.Safer than using an 1000 degree torch

TMXONR · 09-30-2006, 11:02 AM

Get a reverse drill bit. I have used them for drilling holes when using a screw extractor, sometimes the screw backs out when drilling the pre-hole and you don't even need the extractor.

Mnster · 09-30-2006, 12:32 PM

Use your soldering iron, just push the tip into the hex. Irons are usually 400 some degrees. Since there is no flame only thing you would have to worry about would be the heat transfer to the can. Just wrap a wet rag around the can. I guess this would only work if you can reach it though.

JohnRobHolmes · 09-30-2006, 08:06 PM

Tried other heating methods and soaking in Acetone, neither yeilded success. I just used a center punch to remove the shaft with tight set screws. Fortunatly the shaft is smooth and it slid out without too much coaxing. Makes me think twice about doing this to every motor that comes through my hands. The plan is to turn down the shafts so standard pinions work. I dont want to fudge up motors by beating on them with a hammer.

Unholy · 09-30-2006, 10:38 PM

Seems like a lot of work!
Probably easier to drill out a pinon and include it!

Me being lazy i would probably try and run the motor and turn down the shaft while it spins instead of taking it apart and putting it on a lathe!

JohnRobHolmes · 10-01-2006, 12:36 AM

While it has me tempted to try and make a small setup for that, I dont know how well the can and bearings will take the side load of cutting unless my bit is oHH so sharp. Tis a good thought though.

Micropuller · 10-01-2006, 02:45 AM

Sounds to me like you're using the wrong kind of loctite. There are many different grades available. On screws that have to come loose easily (for instance screws that go into threaded aluminum) I always use loctite 222 (purple/pink in colour)

JohnRobHolmes · 10-01-2006, 10:09 AM

This is from the factory, I would never use such a strong bonding threadlock on such a tiny screw!

Cubman · 10-14-2006, 11:55 PM

Quote:

Originally Posted by johnrobholmes

It is not exposed above the surface either, so I cant dremel a slot in the screw.

Quote:

get your rotory tool and make a solid line on the screw then use your flat head srew driver to take it out.

...

Soya · 10-15-2006, 12:07 AM

It's ok, some people don't read anymore.

clodstall · 10-17-2006, 04:01 AM

i use blue on everythng that i use threadlock on.. glad to see you got it off.lol before it broke..

09-30-2006, 09:33 AM	#1
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	Breaking the loctite threadlock bond I have a 1.5mm hex grub screw that was threadlocked from the factory. I must remove it. The problem is that the grub screw is hardened steel and no 1.5mm allen can loosen it, even the high dollar hexes have stripped. I need to get this screw loose! I know that heat will do it, but the screw is on a motor can and the magnets cannot be heated above 100C. I believe that 150C or above is needed to degrade threadlock. The one solution I have is to sink the motor can in water, and heat up the screw with a torch. This should keep the magnets cool enough, but I dont know if the screw will be able to get hot enough. All I can do is try it and keep a temp gun handy. Anybody have any other suggestions or solutions to get this damn set screw loose? It is not exposed above the surface either, so I cant dremel a slot in the screw.

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09-30-2006, 09:54 AM	#2
Unholy I wanna be Dave Join Date: Mar 2006 Location: One Legend. Posts: 2,134	Last time i had that problem... I took an old allen wrench, stuck it in the grub screw, then took a torch and heated the allen wrench. Heat transfer went straight to the grub screw to break the threadlock, without transfering too much heat to the surrounding area.

09-30-2006, 10:07 AM	#3
ColquittCustom405 I wanna be Dave Join Date: Dec 2005 Location: Orlando Posts: 7,420	Use PB Penatrating Catalyst.Works for me.Spray it,let soak....repeat, then let it sit.Should work.Safer than using an 1000 degree torch

09-30-2006, 11:02 AM	#4
TMXONR Quarry Creeper Join Date: Oct 2005 Location: Bryant, AR Posts: 463	Get a reverse drill bit. I have used them for drilling holes when using a screw extractor, sometimes the screw backs out when drilling the pre-hole and you don't even need the extractor.

09-30-2006, 12:32 PM	#5
Mnster MWRCA'er Join Date: Apr 2004 Location: Machesney Park IL Posts: 3,995	Use your soldering iron, just push the tip into the hex. Irons are usually 400 some degrees. Since there is no flame only thing you would have to worry about would be the heat transfer to the can. Just wrap a wet rag around the can. I guess this would only work if you can reach it though.

09-30-2006, 08:06 PM	#6
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	Tried other heating methods and soaking in Acetone, neither yeilded success. I just used a center punch to remove the shaft with tight set screws. Fortunatly the shaft is smooth and it slid out without too much coaxing. Makes me think twice about doing this to every motor that comes through my hands. The plan is to turn down the shafts so standard pinions work. I dont want to fudge up motors by beating on them with a hammer.

09-30-2006, 10:38 PM	#7
Unholy I wanna be Dave Join Date: Mar 2006 Location: One Legend. Posts: 2,134	Seems like a lot of work! Probably easier to drill out a pinon and include it! Me being lazy i would probably try and run the motor and turn down the shaft while it spins instead of taking it apart and putting it on a lathe!

10-01-2006, 12:36 AM	#8
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	While it has me tempted to try and make a small setup for that, I dont know how well the can and bearings will take the side load of cutting unless my bit is oHH so sharp. Tis a good thought though.

10-01-2006, 02:45 AM	#9
Micropuller Newbie Join Date: May 2005 Location: Holland Posts: 21	Sounds to me like you're using the wrong kind of loctite. There are many different grades available. On screws that have to come loose easily (for instance screws that go into threaded aluminum) I always use loctite 222 (purple/pink in colour)

10-01-2006, 10:09 AM	#10
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	This is from the factory, I would never use such a strong bonding threadlock on such a tiny screw!

10-15-2006, 12:07 AM	#12
Soya Quarry Creeper Join Date: Oct 2004 Location: illinois Posts: 433	It's ok, some people don't read anymore.

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10-17-2006, 04:01 AM	#13
clodstall I lost my vendor privileges Join Date: May 2006 Location: TOP OF THE HILL Posts: 3,014	i use blue on everythng that i use threadlock on.. glad to see you got it off.lol before it broke..

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Thread: Breaking the loctite threadlock bond