This hobby comes with adult responsibilities

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Bill Kahn

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I messed up this evening in chain of events I had not foreseen. (I guess all mess-ups are not foreseen?)

On the 3" 5-cutter carbide face mill and 2" wide Ti 6-4 I had figured out I could do .002 depth cuts at 700 rpm without any spark shower.

When much to my surprise a had a torrent of sparks. Way more than anything I had ever seen. Not just beautiful. Honestly scary. After a startle reaction time (1 second? Maybe 2?) I stopped the feed. Spark shower continued, only slightly diminishing. I worked my way from the right side of the machine where I was feeding from and hit off. Sparks stop.

Diagnosing the problem, the .002 feed was way off. I never figured out how much--maybe .010?

The problem turned out to be the Z-axis DRO mounting screws had worked loose. Screws were rattling. I went through them and tightened them up. Will put some aluminum stock in tomorrow and reestablish confidence in the DRO.

I had never thought to have checking the DRO mounting for continued security. Will need to do so now and then. This chain (on the edge of working the Ti and the DRO looseness) took me like just 1 step from the brilliant sharf actually creating a problem. Gotta keep the shop neater. And I learned that Ti sharf can be ignited by the burning Ti. At the sharf density/surface area/air flow I happened to have it was not any chain reaction, but it did ignite. Ti is not a normal material. Not sure I really want to work with it. Maybe finish my little project and then leave it to the pros.

And check my DRO mounting now and then.

Amazing hobby.

-Bill
 
Bill, Thanks for sharing your near miss. This will help others from falling victim to a similar situation. The advantage of formal training really comes to play here. Even basic HS shop classes teaches the safety considerations well before any machine is operated. This brings me to the subject of hot work in a hobby environment. I encourage everyone who machines to learn to weld (many already do). This added skill set will open opportunities to expand your ability to do even more, but I'v seen some photos of home shops that really present a potential for a fire hazared . As your tital states, we also owe this responsibility to our loved ones besides ourselves. Machine maintenance is equal to shop maintenance (house keeping). We love our hobby and our shops, but we should love our wellbeing the most. Every shop should have a fire extinguisher/s and a basic first aid kit. I don't think you should give up on working with Ti, but take the appropriate precautions. Use blue loctite on critical machine fasteners and keep on keeping on.
Failure is only that when we make the same mistake again my friend.

Tip: After preforming any form of hot work, take the time to clean up the shop or find something else to address. This time spent will serve as "fire watch".
Thanks for considering this guys.

Merry Christmas,
Paco
 
This is a reminder, glad it turned out ok. I think I will start using somthing on my screws to help keep them tight.
 
Takes a bit of heat to start, but Ti swarf makes lovely fireworks.

Cheers
Roger
 
Bill Kahn said:
When much to my surprise a had a torrent of sparks. Way more than anything I had ever seen. Not just beautiful. Honestly scary. After a startle reaction time (1 second? Maybe 2?) I stopped the feed. Spark shower continued, only slightly diminishing. I worked my way from the right side of the machine where I was feeding from and hit off. Sparks stop.

Diagnosing the problem, the .002 feed was way off. I never figured out how much--maybe .010?
Click to expand...

After you touch off and zero the DRO, also zero the dial(s).
Then use the dial(s) to verify the DRO reading.
 
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