For forum machinists: a solution to wiggly flow

[steve001]

Metal too gummy to cut? Draw on it with a Sharpie or glue stick, science says

Your everyday permanent markers, glue sticks and packing tape may offer a surprisingly low-tech solution to a long-standing nuisance in the manufacturing industry: Making soft and ductile, or so-called metals easier to cut.

https://m.phys.org/news/2018-07-metal-gummy-sharpie-science.html

 

[paul1598419]

Re: For forum machnists: a solution to wiggly flow

Interesting find, Steve. I guess you need to reapply the glue or sharpie as you continue to cut. I was looking for something that mentioned how far into the metal you can cut, but didn't find anything about that.

 

[RedCowboy]

Re: For forum machnists: a solution to wiggly flow

Interesting find, Steve. I guess you need to reapply the glue or sharpie as you continue to cut. I was looking for something that mentioned how far into the metal you can cut, but didn't find anything about that.

Your depth of cut and feed rate all depend on the material being worked, your cutting tool and what RPM you are running, for instance a roughing end mill or slab mill would cut deeper and faster than a finishing end mill.

---edit---

This mock hardening effect is interesting, I need to see more about it. I expect it would be noticed the most in finishing soft metals and I wonder how it compares to running coolant, and is this all dry cutting ?

If this is only observed in dry finish milling/grinding then the ink may simply be acting as a lubricant, how does ink compare to oil ? Need more info

 

[paul1598419]

Re: For forum machnists: a solution to wiggly flow

According to this article, the ink they are using has "sticky" properties like the adhesive tape and glue. I thought my question was pertinent to this article as they claim the sharpie ink makes copper, as an example, easier to cut. I wanted to know how far into the metal this was true. Still don't know.

 

[BowtieGuy]

Re: For forum machnists: a solution to wiggly flow

That's a very interesting video, Steve!
I can't speak about using white out, glue, or tape when machining soft, sticky, or non ferrous metals,
but I've used inks, markers of all kinds, and various brands of spray on and brush on layout fluids, and have never noticed this effect, either in tool life, or finish quality.
This obviously doesn't mean that appliying these items doesn't work, but I've got to believe, at least at this point, that a lot more testing will be needed.

To be honest, I'd love to be able to apply a coating to soft sticky copper and end up with a quality finish every time. :yh:

Thanks for sharing with us.

 

[paul1598419]

I wonder if freezing the copper would help with this. It seems that the warmer copper gets the more fluid it becomes.

 

[Lifetime17]

Hi,
CU comes in many different forms of molecular structures . So theres a technique for each in a way. CU cute better at lower RPM's like 430/450 . AL is easier still depends on the type being used. Brass is a pleasure to work with again what types .

Rich

 

[GSS]

Nice find Could be on to something good.
Dykem blue has been used for ages and knowing its a very very thin coating but still at some point maby at over application of it someone could of noticed it helped.
Lets see what final cocktail product they might come up with.

 

[BowtieGuy]

Oh yeah, the old Dykem blue; I think I've probably still got some that around, that is if it hasn't dried up yet.
These days, unless a part is very large, I prefer marking it with a wide tip permanent marker, as it's neater and stays on better, the Dykem blue would always tend to chip and flake off, sometimes taking your mark/line with it.

@Alaskan, tapping copper can be a real pain for sure; the 3mm tap size is also what I usually use when mounting 12mm modules in my heatsinks.
There are many special lubricants to use when tapping ("Tap Magic" seems to work well), but I just usually grab a can of "LPS 2" which is a fairly thin lubricant.

What I find when tapping copper, is that frequent stopping and backing off is essential to break those sticky, stringy chips; you can't do this too often, a lot of times a 1/4 -1/3 turn is all I'll do before backing up.
If you're tapping a through hole, compressed air is helpful to clear out chips, if not you may need to take the tap completely out of the hole multiple times.

 

[Lifetime17]

hi
As BTG said tap magic is great for threading, Yes when you tap a hole you need to back it out reapply the fluid and tap again repeating this process eliminates the chance of the tap breaking. The tap won't do a good job unless the chips are cleared out . If you dont clean out the chips the tap has to make fresh threads and also cut threw the chips leading to binding and breakage. Believe me it happened in my early stages of machining.
weather or not your tapping a through hole or bottoming out . Take your time when tapping a thread instead of braking the tap in a valuable piece.

Rich