Setting up to cut tapers

[TORQUIN]

I feel as if I am missing something and the handbook and internet have not helped me snap it into place. I am hoping someone here can help.
My goal is to cut a reamer to the taper of a tie rod end for a Dodge Ram. This is 1.5" per foot. I have an old tapered reamer that is a different angle that I am grinding on my Monoset tool grinder.
I calculate the taper angle to be 7.12 degrees, from the arc-tangent of 1.5/12. This comes to 3.06 degrees, as I am cutting one side of the round reamer, right?
As I need this to be very accurate, I am using an indicator over a measured 1" of travel by the spindle head to measure half of .125 (1.5/12), .0625, since I am cutting one side of a round reamer. The tool head has the angle set to the calculated angle.


Am I setting this up correctly or did I miss something in my calculations?

Thanks,
Chris

 

[benmychree]

If it was me, I'd buy a purpose made reamer, they are commercially available, and not too expensive, and work well. I would not count on a dial indicator setup to accomplish the feat; I made a reamer from scratch once with spiral flutes, first I made a tapered plug gage to fit the existing taper hole, then made A ring gage to fit the plug, then ground the reamer cylindrically to fit, then backed it off for clearance.
https://xkut-reamers.com/

 

[TORQUIN]

If I was doing something in production, I'd buy one also, but in this case, I have a tool grinder and old reamer that needs sharpening anyway, and a desire to learn something, both about taper cutting and tool grinder usage. I don't actually need to use the reamer for anything, but It's what I have a plug and pitman arm for.

Thanks,
Chris

 

[Bi11Hudson]

Quote:
My goal is to cut a reamer to the taper of a tie rod end for a Dodge Ram. This is 1.5" per foot. I have an old tapered reamer that is a different angle that I am grinding on my Monoset tool grinder.
I calculate the taper angle to be 7.12 degrees, from the arc-tangent of 1.5/12. This comes to 3.06 degrees, as I am cutting one side of the round reamer, right?


To butt in and correct your arithmetic, I got to put in my 2 cents worth. Half of the seven(7) is 3.5, so your total would be 3.56 degrees. Some silly little mistake would screw up the job and be the cause of a major headache. Sorry, but I couldn't pass by. And not being a drinking man, I can't even offer a shot to ease the headache.

Bill Hudson​

 

[TORQUIN]

Quote:
To butt in and correct your arithmetic, I got to put in my 2 cents worth. Half of the seven(7) is 3.5, so your total would be 3.56 degrees. Some silly little mistake would screw up the job and be the cause of a major headache. Sorry, but I couldn't pass by. And not being a drinking man, I can't even offer a shot to ease the headache.

Bill Hudson​

Ha, story of my life, either calculating wrong or typos. Sorry about that.
Thanks for the correction.

Thanks,
Chris

 

[Tozguy]

Sounds like you are good to go. Please let us know how it turns out, we would like to learn along with you.

 

[akabud]

3.5763° .0625 per inch.

 

[TORQUIN]

3.5763° .0625 per inch.

That's what I did and it turned out nice. Unfortunately after cleaning up previous screw ups, it doesn't have much flute depth and can't clear chips very well. This is OK, though, as this was a learning experience more than trying to accomplish something bigger.
Pic of reamer and measuring one inch for setting taper size below.



Thanks,
Chris