Drats!! Hard lesson learned!

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90LX_Notch

Project of the Month Winner!!!
Project of the Month Winner
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Well, I blew my latest project tonight. What really blows is that it happened on the last cut before beginning the last operation and it was catastrophic to the project. :toilet:

It is my own fault. I originally had additional .125 for the length but decided to shorten it because there was .125 from the bottom of the taper to the thread relief. (Plenty of room I thought!) Right after I shortened it, I realized that I was going to need clearance for the thread tool because of the difference in diameters and that I might break through. Well, I did while I was adding a chamfer to create the neccessary clearance. That little over sight cost me dearly.

Anyhow, what was this piece you ask? It was going to be an adapter for my 8" drill press for drilling tiny holes in the #70 + range. The knurled big end has a Jacobs 33 internal taper and the nose was going to have the .277-40 Dremel thread for the Dremel drill chuck. The nose had already been bored to accommodate Dremel collets and plans are/were to make smaller collets.

I had a lot more work into this then what appears. I had made a MT#2 to JT33 arbor for my headstock just to mount this thing to ensure the Dremel end would be concentric with JT33 taper. I ground my first boring bar to be able to do the internal taper and I ground a new threading tool for this project tonight.

Oh well I learned a valuable lesson tonight. Consider all possibilities before changing a dimension or you'll be doing this -> :wall:



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Bugger! :mad: Never mind, it happens to all of us at some time, or if it hasn't yet IT WILL!
 
i really hate that when it happens. there is always choice words after the fact. i have some holes in the wall and a dent in my book file cabnet.
hope the second one goes better. im sure it will
 
Oh well, since it was just a prototype, you can now make the real thing!!
On your comment about making smaller collets. You can buy Dremel collets all the way down to nothing. Dremel collets seem to have a pretty wide range. I have one that holds a #80 drill and will would probably go up to a #60.
 
Tel - You are right. The samething can said about racing cars. Sooner or later your going to break. (I experienced this one in another life before kids.)

itowbig- No choice words. I knew there was a chance that it was coming; so when it happened what could I do. Did you get the mic wrench? How did you make out?

Stan - Are those after market collets? Dremel only shows a four piece collet set. Where did you get your collet?
 
I don't know anything about the sizes of collets from Dremel. Every flea market in southern Arizona has at least one dealer selling genuine Dremel and aftermarket attachments. Depending on the day, collets are 25 cents or fifty cents each. I have a jar with about 20 collets and just dump them out to find the size I need.

Locally (Alberta), big box stores have been selling imported boxes of approximately 200 pieces of Dremel type pieces for less than $20.00. I bought one that also contains four collets that will cover a pretty wide range. All the collets I have used only grip on a short section at the very end, and that is the part compressed by the nut..
 
yes i did get the wrench THANK YOU VERY much i got it ajusted. :bow: ive been busy working on a beam engine. (or i should say making all kinds of chips and extra parts that might work on something else) :big:
again THANK YOU that was very kind of you. :bow:
 
Ohh have I been there! How many times is it 'just the last cut'! you have my sympathy
 
...... as I was saying ..... :mad:



connecting rod failure#1.jpg


connecting rod failure#2.jpg
 
Sorry to see that happen to you tel.

Maybe we should have a new forum... "Mistakes, Blunders and Boo Boos" that we all could contribute to. It would be both entertaining and educational.
 
90LX_Notch said:
Sorry to see that happen to you tel.

Maybe we should have a new forum... "Mistakes, Blunders and Boo Boos" that we all could contribute to. It would be both entertaining and educational.
Great idea 90LX_Notch , i have a few to post ;D ;D ;D ;D ???
 
I LIKE that idea!

Not that I personally have ever made a Boo Boo!
:hDe:

Rick
 
Rick,

I see that you added a "Mistakes, Blunders and Boo Boos" forum. I think it will be good for lurkers to see that everybody makes mistakes and maybe they'll be more apt to join in. So, it looks like something positive came from my "boo boo". Now if I can keep myself from having to post in the new forum.... ::) But, in reality, I am sure I'll be posting there soon!
 
;D Sadly, no - it's supposed to be a 180° con rod for the Ridley half beam. I've modified the design somewhat and started again - fabrication this time rather than hogging it out of the solid.


second rod#1.jpg
 
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