[TXFred]

Maybe if Bob explains what he means by "effective spindle speed", it would bring a simple conclusion to this topic, because as far as I see, the opposite of what he's saying is true

I read and understood Bob's original post to mean,"doubling the number of flutes has the same effect on the final feedrate as doubling the spindle speed does."

If you switch from HSS to carbide, you increase the spindle speed, and therefore increase the feedrate by the same factor.
If you increase the number of flutes, you can increase the feedrate by the same factor.

To put meaning to Bob's "effective spindle speed" term, and using caps for emphasis. Increasing the number of flutes has the same EFFECT on the feedrate as increasing the SPINDLE SPEED.

I don't know why this is even worth fighting over.

Frederic

[Ashish B]

Hello,

The following things decide the surface finish of any part -
1. Clamping Rigidity
2. Insert grade / Insert material
3. Tool clamping rigidity
4. Feed/Speed
5. Stock kept for finishing pass

Also i suggest that you should check the existing surface finish (by using a surface finish tester) & then check out that what's actually your requirement (specified by ur customer) & compare with what you are achieving.

If you are expecting very high surface finish, then it can't be achieved on Machining centre.

You should think of doing some finishing operations like honning, or mirror polishing. A minimum of 0.02 mm material is removed in such process.

Hope it helps.

Ashish

[latenorgreat]

Ummmm.... No. There is NO dependant relationship between either spindle speed or SPFM and the number of flutes. Ideal SFPM is a function of the material the tool is made of, and the material being cut, NOT the number of flutes. RPM is calculated based on desired SFPM and the tool diameter. The number of flutes is not a factor AT ALL. For a given tool material, and a given work material, and a given cutter geometry, ideal SFPM is constant, regardless of the number of flutes. ONLY feedrate changes as a function of the number of flutes. SFPM and chipload are independant parameters, while RPM is the sole dependant parameter. You can re-arrange the equations to make it appear otherwise, but you will be fooling yourself, and will not end up with ideal cut parameters, while will result in decreased tool life, and/or reduced MRR and/or reduced cut quality.

Regards,
Ray L.

I didn't say that there is a relationship. See where I said "Feed rate is normally just going to be the result of properly choosing/setting the proper SFPM and chip load for the operation"

Hopefully everyone knows that there are ideal ranges for SFPM based on material, tool, cut parameters, tool life expectations, etc. I was just responding to the discussion centered around what parameters would need to change if you were to add/remove flutes.

To that extent though, there can be many effective SFPM numbers depending on the machine, cutter, material, etc. For example, the torque curves on many machines can mean that higher MRR's are achieved at lower RPMs. Since this is a Tormach forum, even the 770 can reach RPM limitations with small carbide cutters. An 1/8" dia carbide cutter is only ~320 SFPM at max RPM on the 770 and ~160 SFPM on the 1100, well below the recommended numbers on something like aluminum.

[latenorgreat]

I read and understood Bob's original post to mean,"doubling the number of flutes has the same effect on the final feedrate as doubling the spindle speed does."

If you switch from HSS to carbide, you increase the spindle speed, and therefore increase the feedrate by the same factor.
If you increase the number of flutes, you can increase the feedrate by the same factor.

To put meaning to Bob's "effective spindle speed" term, and using caps for emphasis. Increasing the number of flutes has the same EFFECT on the feedrate as increasing the SPINDLE SPEED.

I don't know why this is even worth fighting over.

Frederic

Makes a bit more sense looking at it that way, a bit obfuscated though. Seems more intuitive and simple to just say that adding flutes lets you feed faster keeping chip load and SFPM the same. Then that doesn't get you in the trouble of changing an important value. All the same really, but someone following that logic without a full understanding of the implications of changing SFPM may have been thrown for a loop.

[SirDenisNayland]

It is worth fighting over so that people who are just figuring these things out don't go out to their machines thinking they can simply add or remove flutes instead of increasing or decreasing spindle speed.

Yes, perhaps bob does mean that increasing or decreasing one or the other has the same effect on the final feedrate, however if this were the case why wouldn't he have simply said that from the get go when I initially questioned his statement rather than making up a story in an attempt to discredit me?

It's because that's not what he meant. He has said several times that increasing/decreasing the number of flutes is the same as increasing/decreasing the spindle speed. He has used terms like tantamount to, effectively, and even outright said that changing one is exactly like changing the other, leaving no room for interpretation. In his mind increasing the number of flutes is exactly like increasing the spindle speed and vice versa.

This is even further evidenced by his belief that the single flute cutter was designed for router people wishing to cut harder materials where they can't get the router to spin slow enough. LOL!

As I said, if it were a simple misunderstanding why not just elaborate on what he meant? I wasn't rude or aggressive at first, I simply disagreed. He chose the path which the conversation spiraled down.

I apologize for mucking up the entire thread. But if there is one thing I cannot stand more than someone making up bs to discredit me and completely ignoring my sound coherent logic rather than backing up their claims, its the spreading of false knowledge as fact. This is something I would have never expected a man who created a tool such as G-wizard to say, someone who by very nature of his business should be an authority you can count on for factual information, and even more so I would have never expected the way which he has chosen to address me as if there is no way in hell he is wrong and I'm just some dumb kid who isn't worth his time of day.

If I were any of his customers I would now be very weary of his software and the potential flaws in its calculations. Nevermind that, I would never want to do business with anyone who responds in such a childish manner to someone disagreeing with their statements.

I'm done with this thread. I've proven my point enough times and my example about the 10 insert facemill speaks for itself. Funny how he responded to that by calling me a troll.

Cheers everyone.

[Steve Seebold]

It is worth fighting over so that people who are just figuring these things out don't go out to their machines thinking they can simply add or remove flutes instead of increasing or decreasing spindle speed.

Yes, perhaps bob does mean that increasing or decreasing one or the other has the same effect on the final feedrate, however if this were the case why wouldn't he have simply said that from the get go when I initially questioned his statement rather than making up a story in an attempt to discredit me?

It's because that's not what he meant. He has said several times that increasing/decreasing the number of flutes is the same as increasing/decreasing the spindle speed. He has used terms like tantamount to, effectively, and even outright said that changing one is exactly like changing the other, leaving no room for interpretation. In his mind increasing the number of flutes is exactly like increasing the spindle speed and vice versa.

This is even further evidenced by his belief that the single flute cutter was designed for router people wishing to cut harder materials where they can't get the router to spin slow enough. LOL!

As I said, if it were a simple misunderstanding why not just elaborate on what he meant? I wasn't rude or aggressive at first, I simply disagreed. He chose the path which the conversation spiraled down.

I apologize for mucking up the entire thread. But if there is one thing I cannot stand more than someone making up bs to discredit me and completely ignoring my sound coherent logic rather than backing up their claims, its the spreading of false knowledge as fact. This is something I would have never expected a man who created a tool such as G-wizard to say, someone who by very nature of his business should be an authority you can count on for factual information, and even more so I would have never expected the way which he has chosen to address me as if there is no way in hell he is wrong and I'm just some dumb kid who isn't worth his time of day.

If I were any of his customers I would now be very weary of his software and the potential flaws in its calculations. Nevermind that, I would never want to do business with anyone who responds in such a childish manner to someone disagreeing with their statements.

I'm done with this thread. I've proven my point enough times and my example about the 10 insert facemill speaks for itself. Funny how he responded to that by calling me a troll.

Cheers everyone.

Adding flutes without changing spindle speed would have the same effect as reducing the feed rate.

If you are currently using a 5/16 2 flute end mill, running 4,000 RPM and 24 IPM and you change only the end mill, you would still be running at 4,000 RPM with the effective feed rate of 16 IPM.

[SCzEngrgGroup]

"If you are currently using a 5/16 2 flute end mill, running 4,000 RPM and 24 IPM and you change only the end mill, you would still be running at 4,000 RPM with the effective feed rate of 16 IPM." - No, you'd still be running a 24IPM "effective feedrate". What you've done is reduced the Chipload, which is in no way, shape or form the same thing as feedrate! Or is feedrate now to be specified as normalized for a 2-flute endmill?

This is really getting silly now. "Effective RPM" and "effective feedrate" are completely meaningless and nonsensical terms!

Regards,
Ray L.

[Steve Seebold]

"If you are currently using a 5/16 2 flute end mill, running 4,000 RPM and 24 IPM and you change only the end mill, you would still be running at 4,000 RPM with the effective feed rate of 16 IPM." - No, you'd still be running a 24IPM "effective feedrate". What you've done is reduced the Chipload, which is in no way, shape or form the same thing as feedrate! Or is feedrate now to be specified as normalized for a 2-flute endmill?

This is really getting silly now. "Effective RPM" and "effective feedrate" are completely meaningless and nonsensical terms!

Regards,
Ray L.

(chair)What's the difference? Effective feedrate or chip load. If you slow the feedrate down, you'll have a lighter chip load. If you leave the feedrate the same and add a flute, you'll have a lighter chipload.

A 5/16 "2" flute endlill turning 4,000 RPM with a .002 chip is a 16 IPM feed rate, so it stands to reason that the same size end mill with 3 flutes would have a smaller chip load at the same feed rate, thus effectively reducing the effective (not actual) feed rate. A 5/16 "3" flute end mill at 4,000 RPM, .002 chip load would be traveling at 24 IPM. So by changing ONLY the number of flutes, you can change the "EFFECTIVE" feed rate.(chair)

[Spinnetti]

< Pulls up chair, eats popcorn, watches in facination people's unwillingness to just let it go >.

I started the thread, and I'm a big boy with a working brain... We don't have to decide who's right. I can make up my own mind on that. Thanks for the show though!

[SCzEngrgGroup]

"What's the difference?" - The difference, as I already said, is that "effective feedrate" is a meaningless, made-up term that NOBODY outside of this goofy thread, would ever use with a straight face. Why use a meaningless, made-up term that will leave even the most experienced machinist with a blank stare on his face, wondering WTF you're talking about, when there is already a correct, accepted, perfectly understood term that that is used by everyone who understands this field? You are reducing chipload, plain and simple. THAT is the CORRECT term, and the one that everyone will understand instantly. If you don't believe me, go talk to any 10 machinists, and use the term "effective feedrate" to describe the effect of changing the number of flutes, and see how many simply shake their head, turn, and walk away....

I guess if I put larger diameter wheels on my car, I've reduced the "effective RPM" of the engine?

Regards,
Ray L.

[SirDenisNayland]

No Ray, you've got it all wrong. You can only increase the effective rpm of your engine by taking a heat gun and adding more tread to your tires. If you remove treads you decrease the effective rpm - its why when your tires are getting bald you can't go as fast in the rain.

Cheers

[Spinnetti]

No Ray, you've got it all wrong. You can only increase the effective rpm of your engine by taking a heat gun and adding more tread to your tires. If you remove treads you decrease the effective rpm - its why when your tires are getting bald you can't go as fast in the rain.

Cheers

Now we're talking! I build and race cars too, so this is right up my alley. In this example, the analogy would be effectively changing the final drive ratio.. bigger tires means "effective" lower relative RPM for a given road speed

its kinda like tag team big time wrastlin' Dennis taps out, Ray is in with the chair!

<gobbles more popcorn>

:nono:

[SirDenisNayland]

It's why back in the late 70s when lemans cars became far too powerful for their subframes they had to develop the single tread tire - or if you can believe it, the zero tread tire to slow things down. This stands true to this day.

[BIG IGG]

< Pulls up chair, eats popcorn, watches in facination people's unwillingness to just let it go >.

I started the thread, and I'm a big boy with a working brain... We don't have to decide who's right. I can make up my own mind on that. Thanks for the show though!

Now we're talking! I build and race cars too, so this is right up my alley. In this example, the analogy would be effectively changing the final drive ratio.. bigger tires means "effective" lower relative RPM for a given road speed

its kinda like tag team big time wrastlin' Dennis taps out, Ray is in with the chair!

<gobbles more popcorn>

:nono:

That is pretty FUNNY Spinnetti LOL

[BobWarfield]

I read and understood Bob's original post to mean,"doubling the number of flutes has the same effect on the final feedrate as doubling the spindle speed does."

If you switch from HSS to carbide, you increase the spindle speed, and therefore increase the feedrate by the same factor.
If you increase the number of flutes, you can increase the feedrate by the same factor.

To put meaning to Bob's "effective spindle speed" term, and using caps for emphasis. Increasing the number of flutes has the same EFFECT on the feedrate as increasing the SPINDLE SPEED.

I don't know why this is even worth fighting over.

Frederic

TXFred and Steve Seebold, thank you. Two machinists that can actually understand the discussion without wanting to graphically describe embedding tools in one's head or creating childish signatures.

I agree, I don't know why this is worth fighting over. I've contacted the moderators and asked them to put a stop to the Trolling.

Best,

BW

[SirDenisNayland]

TXFred and Steve Seebold, thank you. Two machinists that can actually understand the discussion without wanting to graphically describe embedding tools in one's head or creating childish signatures.

I agree, I don't know why this is worth fighting over. I've contacted the moderators and asked them to put a stop to the Trolling.

Best,

BW

Just answer me this,

Why didn't you just address my initial disagreement with a real answer?

Why instead did you make up some bull**** story, putting words into my mouth in an effort to brush me off and make me seem like an idiot to all the other posters?

Its really simple, and the discussion could have ended long ago. I don't see why you felt the need to attempt to slander me because I simply disagreed with your statement which was vague and convoluted, using terms like "effective speed" which do not exist and only serve to confuse the heck out of people. Its as if hell froze over for you the moment someone questioned your almighty know-how.

You've made several erroneous statements. You never outright said said the factor that the flutes are increased or decreased by affects the final feedrate in the same way as if the spindle speed were increased or decreased by the same factor. No, you explicitly said changing the number of flutes IS A SUBSTITUTE for altering the spindle speed where it isnt possible to alter it, hence your (again) erroneous comment about the single flute endmill being used where lower speeds cannot be achieved.

[philbur]

Mr Warfield attempts to discredit a member that disagrees with him by attributing a flawed statement to the other member. He provides no reference for the flawed statement and the subject matter has nothing to do with the current subject. It is clearly designed to antagonise. He then continues with several pages of tit for tat, culminating in an attempt to get the other member reprimanded for Trolling.:bs: There's only one Troll in this thread.

Mr Warfield followed a similar process with me several years ago when I tried to point out his misunderstanding regarding the functions of the drive flange on ISO-30 type taper tooling. Reference supplied on request.

Phil

PS: I assume the moderator response to the request to "put a stop to Trolling" was to reprimand or ban Mr. Warfield

I've contacted the moderators and asked them to put a stop to the Trolling.

[Steve Seebold]

Mr Warfield attempts to discredit a member that disagrees with him by attributing a flawed statement to the other member. He provides no reference for the flawed statement and the subject matter has nothing to do with the current subject. It is clearly designed to antagonise. He then continues with several pages of tit for tat, culminating in an attempt to get the other member reprimanded for Trolling.:bs: There's only one Troll in this thread.

Mr Warfield followed a similar process with me several years ago when I tried to point out his misunderstanding regarding the functions of the drive flange on ISO-30 type taper tooling. Reference supplied on request.

Phil

PS: I assume the moderator response to the request to "put a stop to Trolling" was to reprimand or ban Mr. Warfield

Come on people!!! We're supposed to be grownups here. Do we really need all the mud slinging?

Phil, I have a great idea. You do it your way, and everyone else can do it their way and let's all just get along.

If you're so worried about the finish you get from your machine, maybe you just bought the wrong machine. I have found that with a little fine tuning of the program, I can get almost as good a finish as I could get on my Haas. I'm working on a part now that started out as a 44 minute part with a lousy finish. Now, (after a half dozen rewrites) I have the run time down to about 22 minutes, with a decent finish, and that's with 6 tool changes and no ATC. It's not a Haas quality finish, but it's not a Haas sized payment either.

And while the machine runs, I get to stand outside, drink soda and chat with the neighbors. I drink soda now because I gave up alcohol 25 1/2 years ago.

[philbur]

Steve, you've kinda misunderstood the point of my post, again!

Phil

[BobWarfield]

I assume the moderator response to the request to "put a stop to Trolling" was to reprimand or ban Mr. Warfield

Nope, they some of the posts to be more appropriate and then moved on. You can see their signature on the posts edited. No need to reprimand or ban anyone on this thread. Just need to calm down and stick to helping the OP.

Cheers,

BW