How should I make this longish screw?

[WobblyHand]

I'm just speaking from the experience I have learned over the years . For bench grinders there are many ways to dress the wheels . Diamonds , wheel dressers , Aluminum oxide sticks , Norbide sticks are a few . All work ok . The use of a Norbide stick does not need a holder , and it allows for forming on the wheels to form your tools . The SC wheels ( green ) break down so quickly grinding carbide it wouldn't pay me to dress them with a diamond set up such as the one posted . I'm sure it will work just fine , but this is not for me on a bench grinder . YMMV .

This is good to know. The primary wheel I have is a white wheel (alumina), and is rounded over with a radius of about 1". I'd like to flatten it some, so there's actually a flat surface! The secondary wheel is CBN resin bonded to aluminum. It's flat right now. Haven't even gotten to the point of making profile tooling yet. The Norbide stick that I saw seems kind of small, was worried that the little sucker would be plucked from my hand in an instant.

Still going to make the tool, since a) I designed it, and b) I hope to learn something from making it.

 

[rabler]

I'm guessing you will have a little trouble with deflection given that length to diameter. Can the 5.42MM dia area be left any thicker?
You're going to obviously need to use the tailstock. Maybe you already planned that but that's how I approach it, how am I mounting it first.
From there, I agree with Dan. Turn things down to succesively smaller diameters. I'd put a center in the threaded end, extend it out for the tailstock with the chuck holding excess stock beyond the knurl. Turn the whole thing down to the diameter of the knurl. Then turn everything but the knurl down to the diameter of the locating ring. Turn down the threaded side to the 6.3 mm. Work down, but do the area between the locating ring and the knurl after knurling. Then part off the excess at the headstock end.

 

[Janderso]

First time I used one of these, it was an experience.

 

[WobblyHand]

Were I doing your project, I'd opt for a 1/4 40 die for the threads. Yes, expense, but a quarter inch shaft, 4" long is going to flex as you thread it, cutting less deep in the middle of the cut. Perhaps not enough to worry about, but with a die you would know the thread was good.

Honest, straight forward comment. From a seasoned warrior in these battles.

Thanks for your comment. I was a bit concerned about the length and single pointing the whole thing. That's why I was thinking of machining in stages, keeping the diameter as large as possible for the longest time. I do have a 1/4-40 die (and tap). Was thinking of starting the thread doing single point and finishing with a die. The single point will help me start the die correctly (I think). I've done a test thread this way on 1/4" rod and it worked out for a 1" long thread.

 

[WobblyHand]

First time I used one of these, it was an experience.

Have one of those contraptions. Hope not to use it. Looks like a fast way to disaster.
Were you able to use it successfully? Perhaps I'm the victim of an overactive imagination!

 

[mmcmdl]

I love making things and improving things also . Diamond holders , angle dressers , radius dressers were big things for me . The Norbide stick is just another tool that speeds up tasks . Radii and fillets could be ground quickly and checked on Micarta sheets on a comparator . Not everyone needs them , but they are handy .

 

[WobblyHand]

Can the 5.42MM dia area be left any thicker?

Was hoping for the screw to be able to go into the nut a bit. 5.42 was just under the minor diameter of the nut. At least it looked that way in CAD.

 

[mmcmdl]

Have one of those contraptions. Hope not to use it. Looks like a fast way to disaster.
Were you able to use it successfully? Perhaps I'm the victim of an overactive imagination!

A star wheel dresser . Why would you be afraid to use it ?

 

[WobblyHand]

I love making things and improving things also . Diamond holders , angle dressers , radius dressers were big things for me . The Norbide stick is just another tool that speeds up tasks . Radii and fillets could be ground quickly and checked on Micarta sheets on a comparator . Not everyone needs them , but they are handy .

No doubt tools benefit us and are fun to collect and use. Afterall, a tool's purpose is to make something easier (or possible). I will keep this magic stick in mind for future acquisition.

 

[WobblyHand]

A star wheel dresser . Why would you be afraid to use it ?

Seems like bringing a toy rawhide mallet to a knife fight. Kind of seems the opposite of a precision device. Of course it works, but based on past experience, it's not very pleasant nor easy to control precisely. For this exercise, I'm trying to save the white wheel not obliterate it.

To be fair, the star wheel dressers are to be used to re-establish the cutting edges of the stone. I haven't seen them ever pictured dressing the flat face of a carbide grinder wheel, but that may be my inexperience. Maybe I will end up using it, after getting the stone face moderately flat.