First threads!

After reviewing this again, you are correct. :apologize: The compound needs to move more since it's at an angle.
 
going back to the fistail gauge I want one of these
Anything must be easier than that standard version.
 
Made this chart today. My eyes are pathetic.
 

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DavidR8 said:
Made this chart today. My eyes are pathetic.
Click to expand...

That compares to this one I did for my lathe. It's not that my eyes are pathetic, it's just easier to see than bending down, wiping off the chart and selecting the feed I want.
 

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mikey said:
No, don't think so.

Besides, I do it like you - I don't rely on calculations. I start checking early, and the more critical it is for that thread to be right, the earlier I start to check. You know how that flat at the peak of the thread starts to narrow? I tend to watch that and when it starts to look like I'm close, I pull the thread mic out and start measuring. I cannot tell you how many threads I've overshot using formulas!!
Click to expand...

mikey said:
No, don't think so.

Besides, I do it like you - I don't rely on calculations. I start checking early, and the more critical it is for that thread to be right, the earlier I start to check. You know how that flat at the peak of the thread starts to narrow? I tend to watch that and when it starts to look like I'm close, I pull the thread mic out and start measuring. I cannot tell you how many threads I've overshot using formulas!!
Click to expand...
I can see why you over shot your threading the formula is 0.75 divided by the TPI with the compound
If the tool is accurate and set up properly it works
 
You know what, you and @devils4ever are correct. If feeding with the cross slide, the formula is 0.75/tpi x cosine of whatever you set the compound angle at. If feeding with the cross slide compound, which is the actual depth of thread, then the formula is 0.75/tpi.

I don't know how I got this wrong in my head because I've been doing this for a long time. I am embarrassed but I'm owning up to it right now.
 
Last edited:
mikey said:
No, don't think so.

Besides, I do it like you - I don't rely on calculations. I start checking early, and the more critical it is for that thread to be right, the earlier I start to check. You know how that flat at the peak of the thread starts to narrow? I tend to watch that and when it starts to look like I'm close, I pull the thread mic out and start measuring. I cannot tell you how many threads I've overshot using formulas!!
Click to expand...

Mikey,

If you ask any top benchrest gunsmith in the country they will tell you to err on the loose side to allow the barrel tenon and action shoulders to mate squarely.

Nez
 
mikey said:
If feeding with the cross slide, the formula is 0.75/tpi x cosine of whatever you set the compound angle at.

If feeding with the cross slide, which is the actual depth of thread, then the formula is 0.75/tpi.
Click to expand...

Wait, which formula is for cross slide feeding and which is for compound feeding?


Sent from my iPhone using Tapatalk
 
DavidR8 said:
Wait, which formula is for cross slide feeding and which is for compound feeding?


Sent from my iPhone using Tapatalk
Click to expand...
I use 0.742 divided by the TPI for the compound feed for 29.5 degrees
Use 0.75 divided by the TPI for the compound feed for 30 degrees
Check early say .008 before final cut in case your set up is off a little
Never threaded with cross feed only maybe someone else can enlighten us
Would like to try a thread mike or wires but might be out of my price range
Followed your thread on the mike 100 bucks but only good for up to 1 inch
Wires might be cheaper if they work accurately up to 4 inches
Have set of 1 to 6 inch mikes
 
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