Knurling advice

M

Maplehead

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i am trying to knurl a 1/4" wide brass rod. Have tried on 34" aluminum as well. I set up on my Grizxly micro lathe but I leave the lathe off and instead hand turn the chuck. I am using the littlemachineshop clamp knurling tool. I am using the light knurls. (I prefer the coarse knurls but they won't work at all.) my method is to place the knurls over the widest part of the rod, clamp down tight enough to grip, turn one rotation and then continue to tighten and turn. Two things keep happening: the tool angles of perpendicular of the rod and the pattern is messy and never that deep.
Any advice on how to do this better is greatly appreciated.
 
If the knurler is like the Large Capacity 1911 one on the LMS site then it's similar to the one I have for my mini-lathe which I get good results with.
My method is as follows. Turn the circumference of the work to close to an integral number of knurler tooth pitches (mine has an 0.8mm pitch, so a 14mm diameter is approx 55 pitches and works well). Fit the knurler in the toolpost and make sure the wheels are perpendicular to the lathe axis and the toolpost and tool fixings are tight. Bring the two wheels into contact with the work so they're diametrically opposite one another. Tighten the nut until the wheels touch the work, then give it another 1/2 turn tighter. Oil the wheels/work liberally. Turn on the lathe at a slow speed and move the carriage along the work to produce the length of knurl required. At this point I tend to give the knurler another 1/4 turn tighter and feed back to where I started from. Stop the lathe, loosen the knurler and admire your handiwork! Works OK in EN8 steel for me, so should be good in Al / brass.

Hope this helps.
Rob
 
Yeap, be sure you are considering the knurl pitch and the diameter of the piece.

There are many calculators out there. Take a look at this google search.
 
Hi Rob
Thanks for the reply.
Technically I do not need to move the carriage as I am only knurling a 1/8" portion of the brass rod. The rest of the rod on either side of the knurl gets turned down to .112". The knurled portion is for finger gripping to turn what eventually is essentially a "screw".
I'm assuming the numbers you are running up there is to make sure the knurl lines don't get too messy. I'm not even at that stage of detail or quality yet. I can't get the teeth to cut in enough to really feel the knurl.
And yes, I have the same knurler as you.
 
Running these numbers is for making a quality knurl? One that doesn't have overlapping?
Is that what that's all about?
 
Yes, knurling displaces material therefore you need to track in the same grooves to get it to work. Once you get a set of grooves started it helps the tracking/displacing process. Otherwise it makes a mess.
 
Welcome, I have been knurling for 50 years and have NEVER done any math calculations. I realize/understand the reasoning about using math but the knurl comes out beautiful without the math for me. I use the scissor type. I DO NOT start on top the project sight. I start off at one edge and guess on how much scissor to apply (can be tweaked latter). Then feed across with lubricant. Do not let the knurls ride too long in the same spot. Get the knurl done and get out. Flooding with coolant would be a good thing. The longer you knurl in one spot the worst it gets because chips with get embedded in your knurl...Good Luck
 
I have that knurler also from LMS. Mine was very low quality. The top nut stripped out, the arms became floppy loose.
So here is how I abused it...Put it on your stock and run the nut down till it contacts the work, then back the cross slide back and turn the nut down some more then advance it into the work with the cross slide with the lathe running. If the knurl is not deep enough repeat that process.
Have to be careful with small stock that can bend using this method, or support the end with a center.
 
Thanks chips&more
My knurling needs require knurl patterns that are narrower than the knurling wheel itself, so I don't carriage slide the knurler.
Given your thoughts above, should I be doing this knurl in only one rotation?
On another knurling question, since I am hand turning the chuck, lathe torque seems to not be of matter here.
I am assuming that the torque of the lathe is not what allows the depth of bite from the knurl but instead the ability to turn the rod under the biting knurl.
My other question here is can you get a good bite depth on these little clamp knurlers?
Is it all about how much I turn that clamp wheel?
 
Hi rgray
Yeah, I'm not overly impressed with that tool. Mine has a lot of lateral play in it. Plus, those little C clips stink.
 
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