Jackie Schmidt

adamsgt

adamsgt

Jerry Adams
I was reading your article on single point turning of case necks and am somewhat confused on the terminology you used in describing the method of grinding the tool bit. You said "The next step is to grind your neck turning tool bit. On the left hand side of the tool bit, you grind a cutting surface 90 degrees to the shank. The back half, or right side, of the tool will be ground to a 30 degree angle. The point where the straight side and the 30-degree side meet should have about a .020 radius".

I have an unused bit in front of me as I write this and as it is square, all surfaces are already 90 degrees to each other and the shank. Unfortunately it is difficult to see the tool geometry in the picture in the article. Also, where is the 30 degree angle measured? Is it the included angle between the left side and right side or the angle between right side and the line perpendicular to the shank of the tool?

I'm probably sounding incredibly anal but during the last few years I spent at Lockheed before retiring, I was heavily involved in ensuring that written specifications detailing system behavior contained no ambiguities or contradictions. That turns you into a real nit picker.
 
Look at the tool in this photo;
2ngegoz.jpg

Looking from right to left on the turning tool you will see the 30 degree, then the radius (in keeping from undercutting the shoulder/neck intersection), then a edge that is just back relief. Jackie may make this part straight (90 degrees to the shank) so as to be able to feed faster and not have as much phonographic finish.

(the case shown in this photo is actually a 40 degree shoulder where your PPC is 30 degrees, the idea is the same)

Notice that where the tool tip is setting is the diameter of the finished neck OD. That way if the tool moves any you can see it. Also, if you will make the diameter of the turning arbor exactly the diameter of the bullets you use, then you can turn the neck diameter to exactly what you want the finished neck to be. Make this fit (diameter) slightly longer than the case neck. This will push any "donut" to the outside to be turned off.
 
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It is also a good idea to set a 0.0001" dial indicator directly on the tool holder shank.
You will not be able to use a cross feed dial to get to the exact tenth (0.0001") you want.
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2tylj.jpg
 
Rob, I good job on the neck turning video.

I followed a link on your site and found a headline stating the following'

""National Coaltion for Gun Control calls for ban on The Junior Shooter magazine""

Looks like you Aussies need to get someones tea wet!! It worked for us.... for a couple hundred years. We may have to do it again??
 
Rob, also agree that is a very good video. Thanks

Jerry, thanks for the tip on using a dial indicator for determining depth of cut. I don't think I have a dial indicator that reads to .0001 at least an analog one. I have a couple of electronic ones that will do that but I'm getting disenchanted with electronic calipers, micrometers and dial indicators. Batteries run down and you have to turn them on and zero to use. I'm starting to buy analog indicators for situations where I just need to pick up the tool and use it.

It's been over twenty five years since I last ground a tool bit and did a set up, so I need to refresh and relearn tool geometry and grinding. I've somehow got myself into a mode of needing to do something perfect the first time out. That then gets me into analysis paralysis. I need to just get on the machine and pray and play and see how it turns out. I vaguely remember a quote from Thomas Edison that he learned two thousand ways to not make a light bulb. Can't be afraid to try and fail. :)
 
JerrySharrett said:
It is also a good idea to set a 0.0001" dial indicator directly on the tool holder shank.
You will not be able to use a cross feed dial to get to the exact tenth (0.0001") you want.
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2tylj.jpg
Click to expand...

Jerry,
Your "tenth" Arnold indicator caught my eye............
Excellent...

-Dave-:)
 
Jerry, I was just looking at the J&L site and they have a Mitutoyo .0001 that would be $95.55 after their current 30% off. They are available in 0-10 or 0-5-0. You show the 0-5-0, is that preferable to the 0-10 for any reason? Without knowing anything else I think I lean to the 0-10.
 
adamsgt said:
Jerry, I was just looking at the J&L site and they have a Mitutoyo .0001 that would be $95.55 after their current 30% off. They are available in 0-10 or 0-5-0. You show the 0-5-0, is that preferable to the 0-10 for any reason? Without knowing anything else I think I lean to the 0-10.
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Guys we need to get jackie in here somewhere. He's going to think he's been jilted!

As to dial configuration it is according to your intended use. Most common is the 0-xx (0-50, 0-100, etc). This type dial is for reading absolute travel. The 0-x-0 (0-50-0, 0-100-0) type is normal application would be for reading variance or tolerance. i.e. set it at 0 on the specimen or master, then you can take readings as to plus or minus from that base setting.
 
Dave Short said:
Jerry,
Your "tenth" Arnold indicator caught my eye............
Excellent...

-Dave-:)
Click to expand...
They are smooooth and accurate. I have a couple of them. Not many of those around anymore. I think they are/were an Ohio company??

Made like a Swiss watch....but better!!
 
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A name not often heard in the land of Mickey-toy-o users is SPI, Swiss Precision Instruments. I feel you get vary good products from that company.

They are on the web.
 
JerrySharrett said:
Guys we need to get jackie in here somewhere. He's going to think he's been jilted!
Click to expand...

I suspect I offended Jackie by the manner in which I posed my question. In my life's history I've had to interpret language quite literally and I've always attempted to RTFI (Read The Frigging Instructions) first. So if something isn't crystal clear to me when I read it, I raise questions about it. I know my wife doesn't like that at all and it's a wonder that we just completed 47 years of marriage last week.

Jackie, I'm really sorry if you feel that I cast aspersions on your article, I was just trying to get a clear picture of what I need to do to create a good tool bit for this purpose. :eek:
 
Big Al said:
A name not often heard in the land of Mickey-toy-o users is SPI, Swiss Precision Instruments. I feel you get vary good products from that company.

They are on the web.
Click to expand...

There isn't a thing Swiss about that stuff...........It is made in China.
Come to think of it, there ain't much about it thats precision, either.

-Dave-:)
 
JerrySharrett said:
They are smooooth and accurate. I have a couple of them. Not many of those around anymore. I think they are/were an Ohio company??

Made like a Swiss watch....but better!!
Click to expand...

I've handled a few of them; they're sweet. I have an ancient Ames .0001 that is good also.

I used to grind crankshafts. The Arnold "gaging while working" gage is a fine gage that rides on the journal during the grinding operation. They'll go for years in that wet, abrasive environment without a glitch or showing any signs of wear.

-Dave-:)
 
Dave Short said:
There isn't a thing Swiss about that stuff...........It is made in China.
Come to think of it, there ain't much about it thats precision, either.

-Dave-:)
Click to expand...


I did not know that! I wonder how they get away marking the tools "made in Switzerland"? I've had some of there instruments as long as 20+ years, their test indicators are no different than my "Last Word". :confused:
 
Big Al said:
I did not know that! I wonder how they get away marking the tools "made in Switzerland"? I've had some of there instruments as long as 20+ years, their test indicators are no different than my "Last Word". :confused:
Click to expand...

Sorry, Al,
Looks like I just I haven't seen any of their good stuff that is old enough to have actually been made there. Any of it I've seen has been of recent mfg.; it has all been marked "made in China"....................and has been pretty shabby stuff...............

-Dave-:)
 
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