Tool Library for High Speed Machining

[bstall]

Does anyone have a tool library for highspeed machinging that they would like to share or know of any documentation on speeds and feeds for highspeed machining?

[Greg McKay]

I do not have any libraries myself. I would think that tool manufacturers would have this information

[Lucky]

The best high speed machining data I have found is published by FRAISA. They are a European cutting tool mfg. with offices and distribution in the U.S.

[Quickmike]

If you are new to highspeed machining there is a magazine called Modern Machine Shop they have published several articles on it. They also have a very nice website with lots of information on different machining methods.They also have forums on machining, and they have an area on their site called The Highspeed Machining Zone with lots of technical information.There web address is mmsonline.com.

[Guest CNC Apps Guy 1]

Greg, where you been? Long time no "see"!

[Elad]

Hi,

Can someone explain me what is high speed machining??

Thanks,

[ 12-22-2001: Message edited by: elad ]

[Guest CNC Apps Guy 1]

HSM is not a certain speed or feed. It is a strategy. Old school says "Take Deep Heavy Cuts Low Speeds, Slow Feeds", New School says "Take Lighter Depths Of Cut at higher Feeed Rates and faster speeds". Old School "ways" require big heavy Box Way Machinery, new school "ways" can do well on box way machinery but really is not dependant on the vibration dampening characteristics of the Box Way machine.

Machining in the realm in excess of 1000 IPM requires certain control characteristics like look ahead AICC, or HPCC (on Fanuc).

JM2C

[gcode]

quote:

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Machining in the realm in excess of 1000 IPM requires certain control characteristics like look ahead AICC, or HPCC (on Fanuc).

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It also requires an certain amount a fearlessness when you hit Cycle Start for the first time

[gmenzies]

we use fraisa tools also . take a look at belmag.com there web page has alot of info for hardmilling. the Dixi section has a good starting

area for speeds and feeds.

the frasia tools last and last . and there cheaper than sandvick .

[GREG]

What sort of rpm do you have.

Weve been HSM for some time (Aluminium) and find

that no 2 Machines are the same , even though they are. We start of at a safe speed and feed and crank it up after programs are proven .

Most tool manufacturers offer safe starting values

then its a matter of finding your own preferances.

[Guest CNC Apps Guy 1]

quote:

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....no 2 Machines are the same....

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This is very important. While I was an AE for a Machine Tool Builder we had one customer that had 2 machines that were the same model, size, HP, their s/n's were even sequential. The used this one tool for a particular job that was not very efficient and thus pretty much put spindle load around 100%, on one machine, on the other one, it was at 105%. Most all the spindle loads were different by about 5% and they were pissed. I was able to tweek the servos a bit and get it closer but it still varied a couple of %. They just could not get it.

[Lucky]

"High Speed Machining" is light cuts at very high spindle speeds and feedrates. On a capable machine the metal removal rates are impressive. I can rough out a pocket with a 1/2" Ball cutter using HSM techniques faster than a 1 1/2" insert cutter using conventional methods. The roughed out cavity is much closer to finished shape since the smaller cutter fits into more tight areas (reducing the amount of semi-finishing).

A good starting point for roughing in hardened steel is 5% depth of cut and 5% stepover with spindle speeds ranging from 15,000 (1/2" cutter) to 40,000 (1/8" cutter). Feedrates around 350 ipm.

Finishing stepovers of .001 to .003 at 30-40k RPM at 200-500 ipm work well. Mirror finish - no handwork - .0002" accuracy.

Machines designed to do this kind of work well have heavy stationary bases, lightweight moving members, and powerful drives. They are capable of very high accelerations. The best machines can accelerate at 1 to 2 g's. Acceleration specs. are an indication of how much time the machine will spend at the high programmed feedrate rather than the slow feedrates the machine will use to maintain cornering accuracy.

[limitless creativity]

This is really a process, you need many functions for high speed machining.

1. spindle rpm, hp. 15,000 rpm, 15 hp to start.

2. control processing and feedback, 500 bps to 1000 bps at .1 to 2 ms, also at least 180 block look ahead. Especially if you are doing 3axis cutting,(molds).

3. automatic thermal compensation, with faster rapids and processing the machine will generate heat. Chilled ballsrews, sensors in castings, oil, air to the ball nut, ect.

4. machine rigidity, weight, weight, weight,. Move a table and fixuring at 2000IPM rapids and tell me weight does not matter. A machine that weighs 2 times as much as another with stay in place, and absorb much vibration.

5. balanced tooling, at high rpm,s out of balanced tooling will whip and will damage spindles and make unacceptable finishes. also keep runout to within .0004.

6. programming. depending what your doing will require a different approach to machining. example

thin walls, thin floors, molds. troichoidal machining,ect.

SME has High Speed Machining seminars throughout the year. But like I said it is a Process, do your homework. you really can not have one without the other.

This is just my perspective on the matter.

Have a Merry Christmas all.

Lets hope for a good New Year also.

Mike