Edwards Radial 5 build thread --- PHOTOS!

Dissolve the broken tap with alum. It's slow, but won't wreck your lovely part.

Thanks for great updates and pics. Keep em coming!
 
If this works out I may have to try one to. I already have an airplane to put it on. This is way beyond any project I have done to date. I love it, keep up the reports.

Good luck with the broken tap.
 
Looking good, following along. I'm building an Ohrndorf 5-cyl radial. Quite similar to the Edwards dimensions & overall layout (and my first go at anything this complex). I also broke a tap in my 2024 crankcase size M3, my own fault. The alum solution didn't work well at all. My conclusion on succes related to this is 'it kind of depends'. Mine was a coated tap as opposed to bright HSS which may have had something to do with it. It made a complete mess of the part long before the tap dissolved. Personally I would try & drill past it with a mini annular cutter, tap the hole & insert an aluminum plug permanently with Loctite & go from there. If you want to read about my grizzly details I can link my post over on Home Model Engine Machinist. There have been a few Edwards builds documented there btw if weren't already aware.
 
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try one of these, the simple one work great if a bit slow. Its saved me a heap of times
https://www.hobby-machinist.com/threads/tumbler-reverse.10122/ from post 19
mikesworkshop.weebly.com

A spark erosion apparatus

Ever since I broke a tap whilst making the Improved chuck for taps I have been thinking of making a simple spark erosion apparatus. When making the hexagonal hole in the mill quill lock lever I again...
mikesworkshop.weebly.com
 
What about trying mechanical tap extraction. I have a set of tap extractors with little fingers that slide down the flutes of the tap and let you try to drive it out. Full admission, I have never used them yet, but it seems like it could work in principle.

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I tried those to no avail, I believe some have had success with them but not me.
 
***Spoiler alert***

I did this all a couple weeks ago and am just now catching up with writing about it.

I tried using the 'dissolving it in an Alum solution' method with absolutely zero success. Worse, actually.

Hopefully I'll have some time today to write up a more detailed post on the topic.

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