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Thu May 21, 2020 6:37 am

Saved many things with EDM, including my ass! Broken dowels, ez outs and dozens of broken taps!

Thu May 21, 2020 6:01 pm

I am happy to post that I used a M8x1.25 helicoil in the head and it actually worked. After drilling the hole in the head with a 21/64" drill bit and using the helicoil kit, I was able to install the muffler to the head without a problem. I just tightened the nuts on the heads pretty strong. Do you think I need to get my torque wrench out and torque them to 12-14 lbs. as suggested? Anyway, my first helicoil installation went really well. Take it slow and easy was my mantra all day. Thanks for all of the advice.

Thu May 21, 2020 6:13 pm

Phillip3560 wrote: Do you think I need to get my torque wrench out and torque them to 12-14 lbs. as suggested?

Depends on how strong and/or lucky you feel. I always use one my first time installing a fastener to get the "feel" for it, especially since you're dealing with a repair that is accessable with a torque wrench. Be glad you didn't strip the lower one…

Robbie

Thu May 21, 2020 7:16 pm

RWK wrote: Saved many things with EDM, including my ass! Broken dowels, ez outs and dozens of broken taps!

I suspect you have a later version of something I ran across years ago. There was a shop that serviced CalTech and JPL when I lived in Pasadena in the early 1970's. I broke an easy-out off in an Opel Manifold trying to get the system apart. It was awful because the car was too new to find them in a wrecking yards, and too old to have new manifolds for that engine (I doubt I could have afforded one. I had to buy a new down pipe to replace the broken one that started the whole fiasco, but had to take the lower manifold to this special shop. They used a process where a high voltage rod is slowly brought to the center of the easy out. The spark and electrolysis eats a hole in the middle of the area over a period of many hours. They slowly move the probe thru the broken extractor, and stud, then move it outwards a few thousands at a time until just a shell of the extractor and stud remained. Then it comes right out. All done with electricity.

Thu May 21, 2020 7:50 pm

asiab3 wrote: Phillip3560 wrote: Do you think I need to get my torque wrench out and torque them to 12-14 lbs. as suggested?

Depends on how strong and/or lucky you feel. I always use one my first time installing a fastener to get the "feel" for it, especially since you're dealing with a repair that is accessable with a torque wrench. Be glad you didn't strip the lower one…

Robbie

"Strong" is not a good word when it comes to tightening fasteners. Torque is way more of a feel thing than a strength thing. I can usually hit torque by using dead reckoning dead nuts on, but know that most people can't. Especially for small fasteners I worry more about not being able to feel the click of a torque wrench or see the marks on a bean wrench than I do about tightening a fastener by feel.

I vividly remember when I worked my first industrial job as a kid watching the old fart I was working with tighten the fasteners on a high pressure sight glass. He got out his 1/4 torque wrench, tightened the fasteners carefully, signed a document saying he had done so and what torque he had used, and then he got out his 3/8" socket set and snugged them down some more by hand. Didn't learn much else from that old fart, but what I learned in that one instance has served me well.

It helps to own the correct tools for doing a job, tighten an 8mm fastener with a 1/2" breaker bar and you will likely find out why they call it a breaker bar.

Fri May 22, 2020 4:17 am

Steve, we call what u saw tap extractors, made just for that, burning out broken taps, drills whatever is f,ing up part,or just putting a hole in hard material, they even make them portable now some use water for the fluid, no electrolysis used in them, spark jumps from electrode to part + to - hits the part causing small disintegration, (spark erosion) fluid provides a medium for spark to travel through and flushes the waste away. What I show is a conventional EDM its full 4 axis CNC, common tool& die, moldmakers machine, its nice because you can burn in any axis, like in pic going in X or side ways, crank too long to stand up in machine, you must (should) keep burning action submerged.