Knurling Vial Caps

[wrustle]

Have a job running in house right now that requires knurling.

Honestly......have always avoided knurling like the plague!

Never had any luck (ok....skill) doing it manually, and figured......SCREW that....not going to give it a go in Cnc either. Especially when you consider the cost of Cnc knurling tooling.

BUT.....when your number one customer comes to you and says,.....

"Russ, we would really like you to make these parts for us."

..........you lend an ear.

No need to fear.....place a call to my trusty tool rep. We'll just call him Joe Schmoe......hahaha......Ken's probably hatin' on me now......

Anyways, sure enough, Ken comes through with flying colors and steers me into the proper direction. Don't worry Ken, in the other forum I WILL refer to you ONLY as Joe Schmoe!

About $660.00 later I am set up with a damn nice Cnc "cut" knurling tool.

The "cut" knurling tool I picked up from Accu-Trak Tool Corp.





Here it is loaded up in the turret in my Okuma Cnc lathe.




The centering of the tool was extremely simple and was achieved just by using the opposing set screws to move the head up or down to engage the knurls on the dia. I simply brought the tool down close to the diameter to be knurled and then using the pulse wheel moved .001" at a time until one of the wheels engaged the piece. Then it was just a simple process of moving off the piece, adjusting the set screws and touching off again.

If there's a quicker method.......I'm all ears, but really it only took perhaps five minutes to get it set to once one wheel engaged I only had to drop down another .001" to get the second wheel spinning.

I found the biggest drawback to a "cut" knurling tool versus a "bump" is the distance you must stay away from the jaws, or a shoulder if there was one, as it is nearly .500" from the cap screw to the point of engagement on the knurl.

The real beauty of the "cut" knurling tool though is in the design. There is very little pressure on the part as the knurl cuts into the material with the edge of the wheel rather than forming it with the entire wheel surface.

It only took me one piece to get the knurl tool set for depth and starting point and we were into production.

This order is only for 50pcs, but I have another one right behind it for 400pcs.

Needless to say, the first order actually cost me money out of my pocket to make the parts for my customer.

The second order however.........


Here's a pic of some of the cut blanks waiting to go into the machine.

2.250" dia. 6061 aluminum




Here's the final result.







We also made the acrylic vial in the middle as well which has 2"-20 threads on each end for the caps to screw onto.

Video to come soon!! Stay tuned!!

Best Regards,
Russ

[PixMan]

Damn nice looking parts, mi amigo!

Cut knurling tools work SO much better than the forming tool versions. I wish I could afford one. Perhaps I can take measurements from yours and make one myself?

Nice micrometer too, BTW. I have a similar (if not the exact same) one. Mine is a #293-344 which has the soft feeling ratchet/friction thimble, and I love it. I found mine on Craigslist from a guy up in north-central Vermont for $100, well worth the trip on my bike.

[EdK]

I plan on building this one that was featured in "The Home Shop Machinist" magazine.

Ed

       

[PixMan]

Ed,

That's a pretty tool, but it's overkill. There is no need for all that gearing, and in my opinion it just weakens the overall mass of the tool that is so important to smooth cutting action.

[EdK]

(10-16-2013, 06:54 AM)PixMan Wrote: Ed,

That's a pretty tool, but it's overkill. There is no need for all that gearing, and in my opinion it just weakens the overall mass of the tool that is so important to smooth cutting action.

You might be right Ken, but that's the only one I've found plans for and I certainly don't have the skills to design one of my own. It would likely be rigid enough for my 14x40 hobby lathe, but then I don't know that for a fact.

Ed

[awemawson]

I thought that this commercial 'Boni' one was a neat and relatively simple rigid design that I might copy when the 'roundtuits' overflow.

The separation of the two arms is set by a left and right hand screw adjuster which is an off the shelf item, and the centre height is set by sliding them up and down the grooves. It's certainly the simplest 'stiff' one I've found so far

Andrew

[stevec]

Ed, I tried to look up the plans for the knurling tool on the HSM sight but the only thing I could find was the date and issue with an article about "Rudy's knurling tool"?. It's in "HSM Vol. 25 No. 2 Mar-Apr 2006". We moved in 09, so that issue is prolly in a box somewhere here.
I was curious to see what sort of "linkage" is used at the angled part of the knurls. Is it like a universal joint?

[Mayhem]

Very nice looking parts there Russ. Glad to see that your job recouped the outlay and is now turning a profit.

[EdK]

(10-16-2013, 07:17 AM)stevec Wrote: Ed, I tried to look up the plans for the knurling tool on the HSM sight but the only thing I could find was the date and issue with an article about "Rudy's knurling tool"?. It's in "HSM Vol. 25 No. 2 Mar-Apr 2006". We moved in 09, so that issue is prolly in a box somewhere here.
I was curious to see what sort of "linkage" is used at the angled part of the knurls. Is it like a universal joint?

Steve,

You got the months correct but the year would be 2010, so the March/April 2010 issue is the start of the series of articles.

Ed

[DaveH]

Very nice Russ

DaveH