Cutting shallow narrow slots on lathe 0.01" or less

[mikey]

I'm in the process of buying a mill, so the slitting saw idea might be an option. I have a rotary table already.

I'm with Brino on this one. A rotary table and a slitting saw will give you consistent results and with fine control.

 

[francist]

These are 20-thou wide grooves, about the same for depth, and about the same for step-over. Material is 360 brass, cutter was a blunted and honed Exacto knife blade. Just free handed.

-frank

Edit: Ah, methinks I have misunderstood the direction you want the grooves! Sorry, disregard all my previous nonsense!

 

[darkzero]

Ok so a variety of options. I imagine if I cut a custom bit for it, it should resemble a V with a little squared off nipple at the tip?

I'm still learning what the different tools are called, but maybe a center cut type tool (V shaped tip) cut with a much sharper angle than my LH/RH tools would provide an adequate groove.

When you say V, by these 2 posts I'm not sure what you mean. At first I thought you meant the profile/shape of the blade, like an upside down triangle, ∇. That would be best IMO. But your second post you said "V shaped tip". When I see V shaped I think of a parting tool with a groove on the top, hence a V shape.

If the latter, the V/groove is not necessary in your case. The V is good for parting tools or deep grooving as it causes the chip to fold & evacuate out the groove easier.

You're depth is only 5 thou which is nothing. A flat tip would be best IMO since your groove is so shallow so you get a nice looking flat groove.

Then again your groove is very narrow so you might not notice the profile a V groove tip in the groove depending on how deep of a V groove you make on the tool. And for a .010 wide grooving tool, good luck on trying to grind a V groove on it if that is what you meant.

All the inserts I use for my Nikcole Mini Systems tools are flat, no V groove. The widest insert I use is .073" wide with a max DOC of just over .23". They do perfectly fine even on harder materials.

 

[Aaron_W]

These are 20-thou wide grooves, about the same for depth, and about the same for step-over. Material is 360 brass, cutter was a blunted and honed Exacto knife blade. Just free handed.

-frank

Edit: Ah, methinks I have misunderstood the direction you want the grooves! Sorry, disregard all my previous nonsense!

View attachment 241498 View attachment 241499

Nope you understood fine, that is basically what I was looking at doing. Blunted xacto, that is an idea. I'm sure I could find a way to mount it to something so I could make a series of evenly spaced grooves, I'm not sure I would be steady enough to make 5 or 6 uniform grooves.

 

[Aaron_W]

I'm with Brino on this one. A rotary table and a slitting saw will give you consistent results and with fine control.

I hadn't planned on a slitting saw because I wasn't sure what they were for, but I can certainly add one if they would do this job.

 

[francist]

Oh, and here I thought I had given myself an extra helping of bonehead juice this morning.

A small c-clamp could clamp the blade to the side of a regular cutter. Might be more fussy than just holding by hand, but that's your call. Don't do anything you are not feeling comfortable with.

-frank

 

[Aaron_W]

When you say V, by these 2 posts I'm not sure what you mean. At first I thought you meant the profile/shape of the blade, like an upside down triangle, ∇. That would be best IMO. But your second post you said "V shaped tip". When I see V shaped I think of a parting tool with a groove on the top, hence a V shape.

If the latter, the V/groove is not necessary in your case. The V is good for parting tools or deep grooving as it causes the chip to fold & evacuate out the groove easier.

You're depth is only 5 thou which is nothing. A flat tip would be best IMO since your groove is so shallow so you get a nice looking flat groove.

Then again your groove is very narrow so you might not notice the profile a V groove tip in the groove depending on how deep of a V groove you make on the tool. And for a .010 wide grooving tool, good luck on trying to grind a V groove on it if that is what you meant.

All the inserts I use for my Nikcole Mini Systems tools are flat, no V groove. The widest insert I use is .073" wide with a max DOC of just over .23". They do perfectly fine even on harder materials.

No, I was just picturing a pointed tip with the point of the V towards the work like a left or right cutter except centered. It would make V shaped grooves instead of flat sided grooves, but as long as they were nice crisp lines I don't think it would be obvious they were V grooves instead of flat bottom grooves without a magnifying glass.

Francist's idea of an Xacto blade actually seems reasonable and the least complex. I could probably just JB weld it onto a piece of 1/4 key stock so I could put it in a tool holder.


Sorry for the multiple replies, trying to figure out what I'm doing wrong with the multi-quote in one post function.

 

[darkzero]

No, I was just picturing a pointed tip with the point of the V towards the work like a left or right cutter except centered. It would make V shaped grooves instead of flat sided grooves, but as long as they were nice crisp lines I don't think it would be obvious they were V grooves instead of flat bottom grooves without a magnifying glass.

Ah I see, pointed tip, that describes it much better & would be much easier to gring on a .01" wide grooving tool. When I hear V I keep thing of a grooved chip breaker.