Please Explain the difference between VC and SFM if any?

[[email protected]]

I would like to know the difference between VC and SFM. I am used to seeing SFM and using it like this: 35 SFM for Stainless Steel drilling with 1/8 dia. HSS drill. I would do 35 x 3.82=133.7 and then divide 133.7 by .125(dia. of drill) to get 1069.6 for my spindle speed. I was trying to find a clear explanation but seemed to find some odd looking stuff on Mitsubishi's website and others... just looking for a quick explanation or a link to one.

[JParis]

I see VC referred to more in turning work...

Think about like this RPM = VC

In a lathe when you're turning and using SFM(VC) when you are cutting at different diameters, the actual spindle speed will change based on the SFM....VC is that value at the different dia's...

For 99.999% of programming, you'll set the SFM and the machine handles the spped changes.

[[email protected]]

I did notice it was for turning on mitsubishi's site. I just started using F S wizard and it showed VC for Drilling so I was a bit lost as to why...but I just won't worry about it too much...

[Skylar Roberts]

VC is a type of private equity investment. Investors give money to companies that have been backed by venture capital in exchange for a piece of the company. VC usually means giving money to new businesses or companies in their early stages of growth. 

SFM is a more standard way of managing investments, with the main goal being to reach long-term financial goals. SFM is a way to manage a portfolio of investments by making a plan that takes into account the investor's risk tolerance, financial goals, and time horizon.

[crazy^millman]

CHAT GPT is in the house.

[Newbeeee™]

On 4/22/2023 at 3:04 PM, crazy^millman said:

CHAT GPT is in the house.

Hahahaha!

I just argued a reply about custom lathe post benefit, thinking 

And then looked at all its replies and Bwahahaha, I've reached peak interweb as I'm now arguing with a bot!

 

On 4/22/2023 at 8:23 AM, Skylar Roberts said:

VC is a type of private equity investment. Investors give money to companies that have been backed by venture capital in exchange for a piece of the company. VC usually means giving money to new businesses or companies in their early stages of growth. 

SFM is a more standard way of managing investments, with the main goal being to reach long-term financial goals. SFM is a way to manage a portfolio of investments by making a plan that takes into account the investor's risk tolerance, financial goals, and time horizon.

VC is the acronym for "vulture capitalist" .

Change my mind.

[SlaveCam]

SFM = imperial unit. You don't see it in metric literature (at least hope so)

[kssboat]

VC is cutter velocity. It has the units of measure of SFM. RPM = 3.82(Vc\dia) for a mill spindle. Lathe can use SFM straight up in CSS mode.

[jpatry]

On 7/21/2022 at 11:35 AM, [email protected] said:

I would like to know the difference between VC and SFM. I am used to seeing SFM and using it like this: 35 SFM for Stainless Steel drilling with 1/8 dia. HSS drill. I would do 35 x 3.82=133.7 and then divide 133.7 by .125(dia. of drill) to get 1069.6 for my spindle speed. I was trying to find a clear explanation but seemed to find some odd looking stuff on Mitsubishi's website and others... just looking for a quick explanation or a link to one.

They're the same thing, VC is the ISO standard abbreviation for the speed at which the metal is going by the tool or vice versa, same as DC (cutting diameter), APMX (max depth of cut), and Fz (feed per tooth).

[Maclaw]

Both Vc and SFM are a measure of linear peripheral speed of a tool in reference to the material it cuts. Both are proportional to the RPM which is the angular speed. So RPM causes Vc (and SFM) and the latter is the speed at which the tool cuts (rips off) a layer of material. This cut layer has a mean thikness equal to the mean thickness of the chip (hm) and depends on fz - feed per tooth.

Vc is in metric units while SFM is in Imperial units. Vc is the cutting speed in meters/min, SFM is the cutting speed in feet/min.

Common formulas in a nutshell:

 

Vc = Dc * PI * RPM / 1000

where Vc is in [meters/min] ; Dc is in [mm] ; RPM is in [1/min] ; Dc is the cutter diameter

 

SFM = Dc * PI * RPM / 12

where SFM is in [feet/min] ; Dc is in [inches] ; RPM is in [1/min] ; Dc is the cutter diameter

 

To switch between them use these formulas : { Vc = 0,305 * SFM } or { SFM = 3,28 * Vc }

Hope this helps. Take care!