Help: Broken Tap in Flight Hardware

[2ndGearRubber]

That's why you have to carefully apply. If the break is jagged (good) the break itself would be taking the force, the CA just keeping it together to do so.

CA glue is also easily dissolved with acetone.

This sounds really interesting. So you just use the tiniest amount of the glue on the other piece, so it doesn't ooze out and stick to the copper, and then stick that piece onto the stuck section? Let try and give it a try?

I'll keep that in my back pocket. Sounds tough to get the glue application right though.

 

[Jswain]

Can you get to the backside? If so loop some titanium or stainless, or mig wire down from the top, under the bottom then back up through the top and twist in either direction.

Might take a few tries but if it moves at all, I'd think it will work

If the backside is easily accessible then it may work better with two seperate wires & twisting in the same direction from top & bottom

They make some pretty thin titanium fishing leaders, but since you're aerospace I'm thinking you would have something that works

 

[Marsim]

Socket over hole . Tap a few times with a hammer. If your lucky, it may vibrate out enough to get a grip on it. Sometimes works on aircraft panels.

 

[CGarage]

Lubricant needed

 

[jayemm]

That's why you have to carefully apply. If the break is jagged (good) the break itself would be taking the force, the CA just keeping it together to do so.

CA glue is also easily dissolved with acetone.

Gotcha. If it's broken jagged. Now I understand. Good thinking.

 

[scooby074]

This is a tough one for sure. Tiny hole. Im thinking the only way to do this is to remove it and bore it with something carbide. I dont know if you could rig up some sort of rigged up drill press (clamped metal plates to give something to stick to and a mag drill????). Glad its you not me

 

[908Jim]

I got pretty high in my late teens, but I already said I don't build spacecraft.


I would believe any suggestion would be vetted against what is acceptable risk by the parties involved.. This part is junk, currently. We can either build a new one, or attempt to remove/repair with a variety of suggestions offered.

IMO the tap probably broke because it got bottomed out. HSS should never be losing against copper, unless this is some secret military copper I'm not aware of. Not sure how else it would have gotten broken. OP needs a plethora of suggestions, so no option is unturned. It's think of every possible avenue to repair, or build a new one.

Some electronics screwdrivers, like 000 size, could be thinned out with a die grinder to create a pair of flutes to try and grab/push against either side.

This comment makes me think you're not as smart as you think you are.

Copper is funny and gummy and can be difficult to drill (with regular twist drill bits).

There is a hell of a lot more mass to the copper than there is in that dinky HSS tap. Steel might be stronger than copper, but a copper sledge can still put a hell of a dent in a steel car hood.

C17200 Beryllium Copper is some seriously strong stuff, in many ways it is on par with a lot of common grade steel. Toxic, but impressive.

If Wire EDM is a no-go, I'd consider taking advantage of the CTE mismatch between the copper and steel. If you can heat the copper you may be able to back the tap out with tweezers. Judging by the top side of that hole, this thing is probably getting written up even if you get the tap out.

Keep us posted.

 

[Wamsutta]

What I've done is center punch the broken tap in an effort to fracture it into several pieces. That does work, but the center punch gets trashed in the process. I've also done it with an automatic center punch with a heavy spring that packs a punch.

 

[Michael_in_DE]

I would use drill bits as big as would fit in the flute cavities and grab both with a pair of pliers, and turn.

 

[bcradio]

Got it?

 

[dogdog]

Im thinking some offering suggestions dont realize how small this tap is.

US (Inch) Screw Sizes with Decimal and Metric equivalents

It is very helpful to know the decimal equivalent for a US screw size you have. That is often found when trying to match a screw size using Digital Calipers (Inch Decimal to Screw Size) or drill a hole (Screw size to Nearest Fraction) for your project. The second chart below is a US fraction to...

monsterbolts.com

That tap removal tools claim it is for 5/64 and larger broken taps

 

[HenryAZ]

Could you possibly use something cold to apply to the tap? Like a can of air turned upside down?

I used this method once with a broken off tap. Froze the end of it, then chipped it with a cold chisel smaller than the threads. It took several applications of cold + chipping, layer at a time.

 

[rooster59]

Use a 6” or so piece of flat steel for a handle. Find 2 small drill bits to fit in the gaps between the flutes. Use vise grips to clamp the bits to the bar with the proper spacing, in the middle with the bits perpendicular to the bar and sticking out enough to reach down into the flutes. Use oil.

 

[toolenthusiast]

I have a space flight piece of hardware

my schedule does not allow…

the removal of this part would require a huge disassembly process that has big risks

I'll share everything with the engineers

Bro, this is a spaceship

I would believe any suggestion would be vetted against what is acceptable risk by the parties involved.

Well, let’s see… a GJ thread has already been entered into evidence in a court of law. Maybe the FAA is up next?

 

[Zewnten]

Is that grease or a piece of metal against the tap threads in the picture? Pretty sure if that’s a piece of metal you’re f’d if it’s grease and you still can’t back it out, did you gall the threads? How did you break the tap off chasing threads, if that is what you were doing as you didn’t actually give much detail.

 

[2ndGearRubber]

C17200 Beryllium Copper is some seriously strong stuff, in many ways it is on par with a lot of common grade steel. Toxic, but impressive.

If Wire EDM is a no-go, I'd consider taking advantage of the CTE mismatch between the copper and steel. If you can heat the copper you may be able to back the tap out with tweezers. Judging by the top side of that hole, this thing is probably getting written up even if you get the tap out.

Keep us posted.

OP said "copper".

IDK anything about c17200 alloy, all my advice is about copper, like regular copper. Copper copper.


So OP if this is fancy copper, disregard my comments about its strength/resilience.

 

[cannuck]

OP already has the solution - USE THE RIGHT TOOL!!!! You can not just jam **** down the hole as it WILL damage the threads. There looks to be swarf down one side, so that has to go or it WILL jam the tap in the hole (probably what is holding it now).

There is IMHO only one thing to do: pick up the phone and call the company that makes the three flute removal tool and get them to make you a two flute tool in a hurry. The solid tube will drive the tap without jambing against the threads (why loose things down the hole will not work).

 

[908Jim]

OP said "copper".

IDK anything about c17200 alloy, all my advice is about copper, like regular copper. Copper copper.


So OP if this is fancy copper, disregard my comments about its strength/resilience.

This was just in response to the comment about fancy aerospace material. I should have clarified that it was just a point of discussion. I have no idea what the material OP posted about actually is.

 

[Davefr]

1. Spray penetrant into the hole
2. Heat soak the surrounding copper with a heat gun
3. Hit the tap with a blast of freeze spray
4. Use short thin nose needle nose pliers to back it out. (ex: Tronex 523 and grind to fit or maybe Xuron 450 Tweezer nose)

P.S. Maybe you could tap a small piece of aluminum bar stock to 0-80 and insert two screw the same spacing as the center of the tap flute openings. The screws might be too fat to fit but custom grinding with a Dremel would make a nice tight custom fit. Now just twist the bar to remove the tap. (like a miniature version of a grinder wrench)

 

[Fixr]

GJ family,

I need some help. I have a space flight piece of hardware that has a broken #2 tap in copper. This is a two flute tap. We are able to get it to wiggle 1/4 turn but have no access to grab any portion of the tap with current tools. Sadly, machine, EDM....etc on flight hardware is a big no no. I can tell this will easily come out with the correct type of extractor. Sadly, my schedule does not allow for custom tooling. Adding to insult, the removal of this part would require a huge disassembly process that has big risks. Thought I'd throw it out there to the group to see if anyone has thoughts. They were only chasing the threads and not cutting so I don't think it is too stuck.

The #2 size is what is killing me.



Does anyone know of a tool like these, but for 2 flute?



or even something like this?

I would try to make a 2-flute extractor tool, making the flutes the same football shaped cross-section as the gaps around the tap, and just long enough to almost bottom out in the holes. That should maximize the strength of the flutes and minimize the chances of digging into the copper threads. Might be able to make the flutes out of drill rod or music wire, shaping the cross section with a stone or a diamond file + a great deal of patience. Leave a round section of the flute to go into holes very carefully drilled in the tool handle. Keep the unsupported flute length between the handle and tap as short as possible, or even machine a boss on the handle that will support the flutes down into the hole. You want to absolutely minimize flex and twisting of the tool.

If allowed, use lubricant meant specifically for tapping copper, and apply differential heating as approved by Engineering.

Not easy, but a decent machinist/toolmaker should be able to create such a tool, and it seems to me that it would have a decent chance of succeeding without causing further damage.. Good luck.

 

[rust in the eye]

Yikes, that's tiny.
Looks like some debris in the hole. Can you put some high pressure air to it and maybe clear the hole? Jiggling the tap at same time.
The tweezers used for electrolysis (hair removal) are the pointiest ones I've ever seen, if they can get into a hair folicle, they'll fit in that hole. Granted your tap is a wee bit tougher than a hair but.........

 

[KnurledNut]

Looks like some debris in the hole.

Might be part of the pliers he mentioned grinding down that broke off.
Of all the suggestions here, I’d still try my original thought of attempting to spin it free with a couple angled dental picks or small sewing needles.

Another idea is filling it with melted 3D printing filament and molding a raised stub or casting two needles in the liquid filament, and using that to try to unthread it once it cools and contracts. If it doesnt work, it can be remelted and sucked out.

 

[bcradio]

OP?

 

[CB350F]

Inquiring minds want to know...

 

[308guru]

Does anyone know of a tool like these, but for 2 flute?

Grind off two of the "fingers" and you've got what you're looking for.

 

[jayemm]

Talk to a watchmaker. They work with tiny stuff and may have some tools or suggestions.

 

[LopezBart]

The coefficient of expansion of copper is about 1.5 x that of steel per degree. You may be able to loosen the tap somewhat by raising the temperature (within safe bounds for the rest of the assembly, of course).

 

[Omnirod]

You can't drill a tap. Taps are twenty times harder than any drill bit. Unlikely that even solid carbide would work.

Carbide burrs and drill bits will work.

GJ family,

I need some help. I have a space flight piece of hardware that has a broken #2 tap in copper. This is a two flute tap. We are able to get it to wiggle 1/4 turn but have no access to grab any portion of the tap with current tools. Sadly, machine, EDM....etc on flight hardware is a big no no. I can tell this will easily come out with the correct type of extractor. Sadly, my schedule does not allow for custom tooling. Adding to insult, the removal of this part would require a huge disassembly process that has big risks. Thought I'd throw it out there to the group to see if anyone has thoughts. They were only chasing the threads and not cutting so I don't think it is too stuck.

The #2 size is what is killing me.



Does anyone know of a tool like these, but for 2 flute?



or even something like this?

That is great news that it is wiggling. Use a pick and a blow gun and get all the junk out of the hole that you can. Spread a cotter pin and slide it down both flutes. Get some vice grips and see what happens.

 

[AirMech#406]

Well, let’s see… a GJ thread has already been entered into evidence in a court of law. Maybe the FAA is up next?

Or NTSB when whatever this thing is comes crashing back to earth.

 

[no704]

Might be some chips it’s binding on. Maybe try a water pic like for cleaning teeth loaded with some appropriate solvent.

 

[KnurledNut]

Or NTSB when whatever this thing is comes crashing back to earth.

Tap removal isn't rocket science. Oh, wait...

 

[Wrench97]

Bro, this is a spaceship, not a Silverado. They cant bring it back during lunch tomorrow because the bolt fell out.

Have you explained that to Boeing?

 

[Bubba Fett]

Beowulf, we need an update. Don't leave us hanging!

 

[dnschmidt]

Have you explained that to Boeing?

That is the saddest thing. At one time Boeing was considered the world's leading manufacturer. If it was Boeing it was the best of the best. Now you've got to put on a parachute when getting into one of their planes prior to boarding.

 

[noid]

Sadly, my schedule does not allow for custom tooling.

It sounds like budget might not be an issue here.

That being said, there are numerous machine shops and metal 3D printing outfits that could have a working custom tool in your hands in a matter of hours.

 

[bronuc]

You can't drill a tap. Taps are twenty times harder than any drill bit. Unlikely that even solid carbide would work.

Amazon.com

Made for this sort of thing.

 

[nadogail]

I realize that I am late to this party; my "Go To" is EDM, Electrical Discharge Machining, for removing broken taps.

 

[joe_padavano]

I realize that I am late to this party; my "Go To" is EDM, Electrical Discharge Machining, for removing broken taps.

Go back and read post #1, though as an aerospace engineer, we had no issues using EDM on spacecraft flight hardware, including removing broken taps. To the OP: is this a copper thrust chamber with a lot of internal cooling passages?

 

[Toold_up]

I'm starting to think this is fake news...

 

[Kurt4440]

I'm starting to think this is fake news...

The boy who cried broken tap?
Mandatory updates?