Thread Bar Project, nothing is going right and I need help

SO I can just introduce my bit to the wheel to make the right side more flat of an angle and leave the left alone pretty much right? When you say depth of the thread, you just mean the depth I am infeeding at right? Or do I need to make the left angle as long as the thread crest to root? I think I should just start a new tool bit.
 
Justin,
Yep, just grind the right side at roughly 30*, but trying to keep it straight all the way along the ground edge, (dont roll your hand as you grind. I sort of lock my elbows into my waist and get all my movement from the forearms). Once you have got your RH side done, move around and grind the 60* included, on the LH. Check it on your thread gauge and adjust the angle as necessary. I use a jewellers loupe to inspect the fit. Depth of thread, (the amount you are infeeding) is the same as thread crest to root amount. Your tool bit, (the ground, working part), "really" only needs to be as long as your cutting depth in a perfect world, but as perfect as we machinists like to think we are, a bit more length for imperfection is a good idea. Hence the 2-3 times. It also means that a tool ground for a 1/4" thread will also be able to cut a 3/4" thread, with perhaps a slight change to the nose radius.
jlsmithseven said:
...I think I should just start a new tool bit.
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If your tool fits the fishtail gauge as you showed above then you will be right to cut your bar with it as is. Because you're not working to a shoulder then the non offset tip wont, (shouldn't) be a problem for you. Apart from giving you more room to work the offset tip is much easier to craft your 60* angle.
Hope this is clear? Any doubts, misunderstanding or confusion please ask. I'm sure I speak for all here when I say we hope for your success next week.

Cheers Phil
 
I wanted to add that the flat at the tip of the tool should be 1/8XP, where P = the pitch of the thread you're cutting. This is important only if you're submitting your thread for inspection. Even then, I bet you'd need an optical comparator to see it so most of the time, a very tiny flat at the tip is sufficient to prevent breakage. By tiny, I mean 1/64" or so. Let us know how your project goes, okay!
 
I think if I can just shave off the right side and get the 30 degrees on it, that it will make the point more to the left and I will be good to go. I'm gonna try it tomorrow.

UPDATES: I think I fixed it. I will post a pic for you tomorrow Mikey to show you what my tool bit looks like. I want to start threading tomorrow morning so please look out for it.
 
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Looks good, Justin! Congrats!!

Does your instructor require you to check tolerances on your threads to be sure they fall within specs? I assume he is calling out for a 2b or 3b fit, right? If so, then the major diameter and thread depth will have tolerances that you can measure and meet. That will get you your "A" right there.
 
We just need the thread to pass a 3-wire measurement and to thread on the test nut.
 
jlsmithseven said:
We just need the thread to pass a 3-wire measurement and to thread on the test nut.
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Okay, good that he requires that. For us hobby types, we can just cut the nut to match the thread but you have to be able to make the thread to specs so that a female threaded part that is made by someone else will fit. Looks like you got this, Justin, and thanks for following up for us. A lot of guys are pulling for you.
 
Good job Justin. Glad it worked out for you. On a side note, those threads look pretty darn good, but
jlsmithseven said:
....I think I fixed it. I will post a pic for you tomorrow .....
Click to expand...
I'm not seeing a pic of your tool?

Cheers Phil
 
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