Tap broke off - nothing I have will extract it

thd9791

Master Member
RPF PREMIUM MEMBER
Hi there.

I have this almost one of a kind saber by TheJrSkywalker and a 4-40 tap broke off while installing a set screw.

I have dulled a bunch of drill bits trying to blow it out and they keep drifting.. i was thinking I could save this by hammering in some aluminum and blanking a hole

Is anyone out there able to mill/lathe out a piece of a hardened steel tap? And blank the hole? I marred the emitter plate because of the drifting. Thanks everyone!
 

Attachments

  • 16097947558196411605053511455712.jpg
    16097947558196411605053511455712.jpg
    3.4 MB · Views: 193
Im willing to try to do this for you. My center drills should cut out the tap. Then drill out the hole to remove all the damage and plug it with an aluminum rod. Did you want to drill/tap another hole in the plug or in a spot like 180 degrees of the plug?
 
I do not know where you live or what resources are available. I would suggest that you find a machine shop that has an EDM. The process has bailed me out on numerous aluminum motor cycle heads with broken cover screws in them.
 
Hah I'm glad this started a little something! I had to put it down overnight.
Im willing to try to do this for you. My center drills should cut out the tap. Then drill out the hole to remove all the damage and plug it with an aluminum rod. Did you want to drill/tap another hole in the plug or in a spot like 180 degrees of the plug?
ZK - thank you so much, I just may be in contact :)

I do not know where you live or what resources are available. I would suggest that you find a machine shop that has an EDM. The process has bailed me out on numerous aluminum motor cycle heads with broken cover screws in them.
For some context, I have a small harbor freight drill press, a couple rotary tools and lots of hand files. (I really enjoy hand sculpting parts out of aluminum)
fullsizeoutput_2109.jpeg


Funnily enough, I raised this little drill press on a cinder block to bore the nipple hole deeper on this saber!

I've gotten some small taps like this out by using a spring powered center punch to shatter what was left of the tap. It's worked for me a couple times.

This just happened to me over the weekend...now I have something to try to salvage it, thanks!

Thanks you two - Adam that's a pretty good idea, I can't see the tap piece yet, it's in there deep. let me see if I can dremel out the area further to expose it. It's a 4-40, so rather small.

I really hope this thread comes up in searches for when this happens to other people

Hmm..I have blanked holes before, let me dig up some photos of crap I've done it with... a Bapty Stormtrooper blaster and actually this very lightsaber - at least with the control box I just drilled the wrong sized hole. You can BARELY see the half of a circle above the fake lever on the lightsaber box
hPOzX4FsQ2CA7k7dvq5dpw.jpg
fullsizeoutput_1cbe.jpeg

I somehow broke a tap off in one of these solid cores, and I was able to drill around it and knock it out. That core was going to be covered by the outer tube anyway so it's basically filed down and hidden inside
fullsizeoutput_20e6.jpeg



I guess I need to get a new 4-40 tap anyways!
 
You can also put the part in water with alum powder and heat it up. The steel tap will dissolve and the aluminum is unaffected. I've used this method succesfully a couple of times. Takes a few hours to dissolve depending on the size of the tap but works great!
 
are we talking a slow simmer like pasta sauce? :D

actually seriously asking, very interesting
 
are we talking a slow simmer like pasta sauce? :D

actually seriously asking, very interesting
I have a small crockpot I got from a thrift store. I keep it in the shop for warming aerosol paint cans. For this method I set it to low. It's hot but not boiling. You also want to make sure there is an excess of alum to react with the steel. I just keep adding until it stops dissolving in the water. You may need to add water as it evaporates to make sure the area where the tap is stays submerged.
 
okay, I got the wrong kind of alum and the package toxicity warnings scared me. surprisingly alum in the spice aisle is almost nowhere to be found here and I have no idea why that is

I tried smashing out the tap too, to no avail. I sent it over to ZombieKiller and we'll see what's next!
 
Okay everyone...

Zombie Killer saved this saber. Even his mill wouldn't get that tap out! He made a larger hole and shattered the tap. He was able to blank the hole, re-lathe the shape, and drop a hole in the right place!!! it's a 4-40, since we in the states usually use sizes like that, and 4-40 is the tap of the graflex front screw. I put 4-40 grub screws into my ESB Stunt sabers to hold the "puck" in the socket of both cored Graflexes I made (We don't have any reference up close of those sabers)

Anyway, these are his photos
ZK1.jpgZK2.jpgZK3.jpg

Just got it today, (sanitized everything of course, nothing against Glen, everyone between him and me could have an asymptomatic case) and I am stunned.
fullsizeoutput_2550.jpegfullsizeoutput_254e.jpeg

As a reminder, this saber means a lot to me. The machinist just kind of "eyeballed" and designed his own. This is how talented he is... my Yuma Stunt compared to the hyper-accurate masterpiece of DaveP and BRRogers
fullsizeoutput_254f.jpeg

fullsizeoutput_254a.jpegfullsizeoutput_254b.jpeg
 
Amazing hilts
this is just an excuse to re-paint the whole thing ;)

So.. lesson learned... I got a bottle of Rapid Tap and watched a few fun videos by asavage on tapping. This hole wasn't blind, but I think it still clogged up or something. Thank you, thank you everyone! Feel free to turn this thread into tapping tips and nightmares, so when people go searching good stuff comes up
 
this is just an excuse to re-paint the whole thing ;)

So.. lesson learned... I got a bottle of Rapid Tap and watched a few fun videos by asavage on tapping. This hole wasn't blind, but I think it still clogged up or something. Thank you, thank you everyone! Feel free to turn this thread into tapping tips and nightmares, so when people go searching good stuff comes up

I didn’t even bother tapping the last one I did, just filled it with plumbers putty and polished smooth

The smaller taps can be a nightmare to use.. didn’t want to risk it
 
Tap magic is a good fluid as well. My Jedi master machinist suggested acetone as lubricant for cutting aluminum. I have also heard of 50-50 acetone and ATF.

One tip I don’t see anyone mention: if the hole goes through, run the tap in to the end of its threads. Then, be sure to clear the exposed threads before you back the tap out. That makes a big difference.

And on small taps (under #8) I always cut 1/4 turn fresh and back up at least 1/2 turn. Slow and steady. You absolutely want to feel how the tap is working. And don’t be afraid to pull it all the way out, clean it, and the hole, really well, re-treat with fluid and go at it again.

Aluminum is bad but oxygen free copper is much worse, and forget about Inconel. You need solid carbide taps and a lot of skill and luck.

Do not cheap out on drills and taps. It’s not worth it!
 
This thread is more than 3 years old.

Your message may be considered spam for the following reasons:

  1. This thread hasn't been active in some time. A new post in this thread might not contribute constructively to this discussion after so long.
If you wish to reply despite these issues, check the box below before replying.
Be aware that malicious compliance may result in more severe penalties.
Back
Top