Feed Rates and cutters for wood panels

[Ger21]

Forgetting about tool life and cut quality for a minute.
3500mm/min is painfully slow, and will get old very quickly. Imo, there's really no excuse for a machine to be designed to have a maximum speed of 3.5m/min.

Now, yes, you can cut at 3m/min with a 2 flute cutter, at 10,000-12,000 rpm, and get good results.

Fwiw, I cut 19mm melamine at about 25m/min every day - on a $100,000 machine.

[jimbo_cnc]

It was my mistake to originallly say I only needed a slow machine, that's why I was offered 3500mm/min. When I know what speed I need (not what I want!) I can get a faster spec.

OK, here's the machine (1500mm version).
http://www.alibaba.com/product-detai...981060776.html

The advert for the 1500mm bed machine states up to 8000mm/min working speed. Seller has said 6000mm/min is fine, maybe 7000 for my machine. But as Jazz noted, seller has suggested it will mean going up to 32mm ballscrew.

I'm having a 3kW spindle and square rails at the moment.


edit:
I've forgotten one of my principles: always think about resale value. So an abnormally slow machine doesn't make sense there.

So, I will up the speed to 6000 ish. I need to understand the performance disadvantages of 32mm ballscrew, in case seller offers eg only 5000mm/min with 25mm screw, or 6500 with 32mm.

I guess I'm going to have to download octave unless there's an excel spreadsheet calculator around?

[Clive S]

I think you might need to ask if it has two screws on the x and what pitch and what is on y and z ..Clive

[JAZZCNC]

OK, here's the machine (1500mm version).
http://www.alibaba.com/product-detai...981060776.html

Remember what I said on phone about the Chinese chasing profit which means only one thing, something has to give.!! . . . Look closely at that machine and see if you can spot what is jumping out at me.!! . . (Clue) Sloppy and Baggy needing maintenance ounce a month.! (No it's not a Women) . . . . And that cost cutting can be seen from out side just imagine what's lurking under those covers and in that control box.??

[jimbo_cnc]

Don't worry Jazz, I'm having square profiled rails on mine.

Seller will build to what I want, but his opinion is 32mm screw rather than 25mm. He says 10000mm/min will vibrate with 25mm screw. Thisimplies 2510 ballscrew to me. There is no belt on the drive, so that rules out the simple double the pitch and use pulleys to keep the same motor speeds.

He also susgests that 3kW spindle is not powerful enough for 10000mm/min at 19mm depth anyway.

[JAZZCNC]

Seller will build to what I want, but his opinion is 32mm screw rather than 25mm. He says 10000mm/min will vibrate with 25mm screw. Thisimplies 2510 ballscrew to me.

Argh Probably because he's got a pile of 32mm screws he wants shut of.!! . . . You won't find many other reputable builders recommending 32mm screws with a single central screw at this width and using steppers.!! . . . . . However You will find many machines this size running 20 and 25mm screws without any trouble.

Also 3Kw will easily push cutter thru MFC at 19mm with correct cutter/size but if your in no rush what does it matter if it's done in 2 passes.? Proper spec'd machine will do 2 passes quicker than one only capable of 3500mm/min.!

By the sounds your sold on the machine anyway, so no point saying anymore really other than good luck.!

[jimbo_cnc]

Don't be like that Jazz,

I'm here for help to get what I want. Although all I seem to be doing is pissing of all my potential suppliers :)

Those machines you mention are running 2525 or 2020 I assume ?

...and 1 pass at 6000 is quicker than 2 at 10000 :)
Again, this could be my mistake for mentioning cutting at full depth when that might not be an actual requirement.

[Shinobiwan]

Your going to need a beefy machine to do 19mm in one pass at 6m. I wouldn't fancy doing that with 6mm tool either! Cut quality would be shite with all the chatter and that's if it didn't snap. 10mm would be where I'd want to be at really.

[JAZZCNC]

Don't be like that Jazz,

I'm here for help to get what I want. Although all I seem to be doing is pissing of all my potential suppliers :)

I'm not being or have been anything other than helpful with sound advise.!! You on the other hand appear not to be listening and hell bent on that particular machine so I wished you good luck. Nothing more than that.! . . . . I still wish you good luck.