easy way to remove sheared dawg screw?

[Definitive Dave]

finished tearing down the 12mm 044 that is going to be the donor saw for Al's uber-head
this is what I found on the lower felling spike mounting hole, it protrudes just a little, no way I could grab it with any tool I have or know of
I am guessing that drilling and then using an easy out screw extractor is the way to go.
I have plenty of good quality bits small enough but the piece is awkward and I am pretty sure it will be hard to drill right with a tiny bit in my BS little crapsman benchtop drill press. And I have no extractor small enough.
I will probably take it to a local machine shop unless somebody has another better idea.
I don't want to make it an oversized thread if at avoidable.

otherwise looks to be an easy swap, good bearings and seals, just a little cleaning

Dave

 

[super3]

Left hand drill bit is a good start.

 

[Big_Wood]

My first try would be to cut a slot on it with a dremel cut off disc and try turn it out with a slot blade screw driver. If that didn't work, then I'd try an impact screw driver. Might remove the mount and apply a little heat as well. Not a crazy amount. Just enough to expand the case slightly. Machine shop here is an hour minimum. I'd live with no spike before I paid them to do anything on it lol

 

[54stude]

Weld a washer to the stub with a mig welder, use a fender washer with an id for a #10 screw. Then set a 1/4 or 5/16 nut on top of the washer and weld the interior of the nut to the top of the washer. Wait for the red color to dissipate after welding, and spin it out. Works 95% of the time due to the thermal shock you apply to the stud. Good luck!

 

[Definitive Dave]

Indulge my stupid follow ups please, I have zero machine shop experience

Left hand drill bit is a good start.

my drill press only runs forward, does a left handed bit require the drill to run backwards as well and will it extract the broken screw or is that the first step.

My first try would be to cut a slot on it with a dremel cut off disc and try turn it out with a slot blade screw driver. If that didn't work, then I'd try an impact screw driver. Might remove the mount and apply a little heat as well. Not a crazy amount. Just enough to expand the case slightly. Machine shop here is an hour minimum. I'd live with no spike before I paid them to do anything on it lol

I can heat the case a bit I may try that in conjunction with a bit of penetrating oil over night and slotting the end as 54stude suggests, I want to preserve the case and if it cost me a few bucks and a few minutes at the shop around the corner it wont break me up too much, but doing it myself would be great, cause I wanna get this saw together and make some cuts while we still have summer in December
thanks for the ideas

Weld a washer to the stub with a mig welder, use a fender washer with an id for a #10 screw. Then set a 1/4 or 5/16 nut on top of the washer and weld the interior of the nut to the top of the washer. Wait for the red color to dissipate after welding, and spin it out. Works 95% of the time due to the thermal shock you apply to the stud. Good luck!

I have a welder but I have no welding skills, that is beyond me at this point

 

[murfpcola]

An auto mechanic friend suggested we do the weld a nut to the stud trick and it worked on an exhaust bolt on a Briggs we were working on. As for the left hand drill question, yes the twist is left hand so the drill press or motor has to turn counter clockwise as well.

 

[Flat47]

My first try would be to cut a slot on it with a dremel cut off disc and try turn it out with a slot blade screw driver. If that didn't work, then I'd try an impact screw driver. Might remove the mount and apply a little heat as well. Not a crazy amount. Just enough to expand the case slightly. Machine shop here is an hour minimum. I'd live with no spike before I paid them to do anything on it lol

x2. Seen it done and done it myself. Heat is helpful, too. Doesn't take much time either.

 

[beaglebriar]

Left hand drill bits are the cats a$$. They will save you all kinds of time and frustration. Irwin makes a real nice set that comes with some other extractors.

 

[kuhndog]

Sometimes you can use a prick punch.Punch a hole on outer edge and then angle punch and tap it around to loosen.

 

[drf255]

Tig welding a bead to it and then grabbing with a vice grip works the best.

The heat from the weld and the difference in metal expansion frees it quick.

I wish I lived closer Dave.

The dremel and weld with the fender washer above it sounds great too.

 

[fearofpavement]

If you don't have small extractors, get some. You'll need them in the future.

 

[Big_Wood]

I have a welder and I still wouldn't use it on this unless for an absolute last resort. It just is not needed at all. If we were talking about making it more work then it needs to be then I would say bust out the welder lol

 

[huskihl]

I just did it with a dremel. Works good. Might add some heat as well. If that fails, I'd find that fender washer that fits tight to the bolt and weld it to it. Then weld a nut to the washer. I'd think a few tack welds on each would suffice

 

[Gypo Logger]

Sometimes you can use a prick punch.Punch a hole on outer edge and then angle punch and tap it around to loosen.

That method worked for me too on one dawg bolt, but the other one was recessed and angular. So I tried to drill it on a press, but the drill glanced off into the casing, so i stopped before I did further damage. This was on a 385.
The left hand drill sounds like a good idea.

 

[2stroker]

That method worked for me too on one dawg bolt, but the other one was recessed and angular. So I tried to drill it on a press, but the drill glanced off into the casing, so i stopped before I did further damage. This was on a 385.
The left hand drill sounds like a good idea.

I've had success using a roll pin with an inside diameter the same as the outside of the protruding broken screw. This acts as a drill guide to keep the drill bit centered on the broken stud while drilling. I then can enlarge the hole, if needed to accommodate a screw extractor.
If it's broken below the surface this works well to keep the drill on track.
Good luck with the removal.
2stroker

 

[Marco]

Tack a nut to it with a wire feed, get a nut of the same thread size and try to turn it on what is left. Something that small you want a wirefeed welder, the flux on a stick don't let you get to the outside of the interior of the nut. Don't hook the ground to the crank, you'll pit the bearings, Bar stud looks handy. Let it cool before trying to move so the broken fastener can shrink back down. Work it back and forth, don't try to just crank it out. I got the helicoil and all on this one

 

[Rx7man]

I like an automatic punch to get a mark in the center of it to keep a drill on track.. the roll pin is a good idea I'll keep in mind though.

Left hand drill bits and extractors are very useful... i will second the motion that you need to have some.. don't need to run it in the drill press, a good cordless drill will do, just make sure you can clamp down the work piece and you get started on center

 

[Marco]

The thing that is awesome with extractors, what ever is broke broke full diameter. Now we are going to drill alittle hole in it and back it out with this file hard piece of kryptinite called an extractor.

 

[olyman]

I have a welder but I have no welding skills, that is beyond me at this point [/QUOTE]
what 54stude said,,is what ive done for years, EXCEPT, I weld another washer on top of that one, and use a vise grips for a larger dia grab area.......if you predrill the bolt, it relieves the internal pressure.....leaving enough to weld to... tho I have set the washer,,and backwelded the hole, then welded to the washer. the heat seems to crack em loose...but not always the first time!!!! ive also,,after I welded the washer,,waited for it to get to black color again,,then hit it with penetrant of your flavor....reason being, steel and aluminum don't like each other, it gets a bit of lube in there....

 

[Trx250r180]

The welding a nut is my pic,


Second


If have a sharp flat chisel can pound a flat slot screwdtiver groove with it and remove with a svrewdriver maybe