New VMC coming. I need your input, please.

[Dan_AKA_ROY]

Our company is set on buying a FALCON-2040MV made by Chevalier. I need help in here. I know routers O.K., but never ran a vertical mill. Is this a good machine? I'm concerned about a few things:

 

1. The table size is 54" x 13" I got molds they want to machine that are as much as 76" x 24". They said, "They do it at their shop." "They machine one half and flip it around to complete the other half." But I need length AND height adjustments! Do I 'flip' the workpiece around 4 times?

 

2. The feed rate range is 0.1 - 150 IPM. But I noticed most newer mills can feed at 300 IPM.

 

3. It has an automatic tool changer. But I want an automatic tool length sensor. Could I get by just fine without one? I'm machining contoured surfaces. Spoilers or wings for cars.

 

4. The block processing time is 5ms. Does that mean it can process 200 blocks of code in 1 second? I've read where newer machines can process 1,000-2,000 bps. I'm machining large surfaced molds. Can I expect possible data starvation machining large surfaces on a 200 bps machine?

 

5. I'm a novice with VMC's. Is Chevalier a good brand? Can't find much info on FALCON mills. Any opinions on this?

 

Thanks for your input.

 

[ 07-14-2003, 11:20 PM: Message edited by: Dan2uok ]

[Rekd™]

I haven't seen one. But if you're doing mold work with it, you want more rpm, feed and table size, 'cuz flippin' a biatch on cavities/cores and getting a good blend isn't easy.

 

If that "150 IPM" is actual high speed machining, you might get starvation, but I'm guessing from what you said that it won't be able to feed accurately at those speeds. So I doubt starvation would be an issue, unless you're talking about starvation 'cuz it might take 5 times longer to machine on that VMC than on a regular HSM and you won't be able to afford food...

 

Seriously, if you're gonna be doing mold work, you should think about spending $80,000 to $100,000 OR MORE to get a machine that is actually built for surfacing at high speeds.

 

'Rekd teh $.03

[Brendan P]

Yes I have used one.

quote:

---

Is this a good machine?

---

If you consider "Made In China" good. This is a question that you have to answer.

The machine I used was this exact one.It came with a Fanuc OM control.(basic control)

Cat 40 holders.(small but work)

It is great for machining softer metals,but did not have a lotta balls drilling 1.125 dia. on crap steel.Or milling steel.

It is a belt driving machine (not geared head).

So if you are not looking to "RIP CHIPS" then

it is ok.

This is just MY opinion,and others may differ.

I am used to working in aerospace enviroment where we need machines with balls to cut high temp metals.

 

Have you seen the machine yet?

If not I can send you some pic's

[Dan_AKA_ROY]

Thanks Bucket Head. I got a brochure with pictures so I'm ok.

 

Do you know how old the machine is? They envision spoiler molds to be machined. Aluminum, yes, but also steel down the road. The wings you see on the backs of cars, that's how big the molds will be. That's one of my main concerns - it's x axis length of travel is 40"... 20" y axis travel I probably can manage. 24" z axis should suffice. But these are fairly large surfaced molds. I'm skeptical on blending the surfaces after having to flip the part, as Rekd had replied.

 

Also, what about 200 bps? Problems machining large surfaces?

[Rick Damiani]

200 blocks per second may or may not be limiting. It depends on:

 

- The toolpath in question.

 

- Your cut/filter tolerance.

 

- The feedrate you hope to maintain.

 

If the toolpath you are using puts out lots of blocks that are .001 or so in length, the maximum feed rate you can maintain without suffering from data starvation with a 200 bps control is:

 

block size X blocks per second X 60 = feed

 

or

 

.001 X 200 X 60 = 12 inches per minute.

 

Note that if you program such a toolpath for 12 IPM feed, you may still suffer from intermittent starvation issues, as some blocks will be smaller than the 'nominal' size.

 

A larger tolerance, more aggressive filtering, or a different toolpath might alow for 'larger' blocks, but with a corrisponding decrease in surface quality and/or increase in cycle time.

[Greg Williams]

I cant speak for The VMC,

However I once worked in aplace that had a Chevalier CNC grinder. Basically it was a waste of floor space!

[Brendan P]

quote:

---

They envision spoiler molds to be machined.

---

Dan,

I don't think the machine will be big enough without having to do some manuvering.

Don't worry,when "they" are kicking themselves in the a$$es for not buying a big enough machine.

[Tony]

quote:

---

However I once worked in aplace that had a Chevalier CNC grinder. Basically it was a waste of floor space!

---

We found a use for ours..... "Chop Saw"

 

Spinning the mold around.

Hopefully the table is Hardened and ground

(Some imports are)

Other wise you will gouge the table

and have .060 deep "Crop circles"

[Harryman]

Priority list for your molds in aluminum.

1) Size

2) Speed

3) Accuracy

 

If you make them in steel,

1) Size

2) Weight capacity

3) Speed

4) Acurracy

 

The first two priorities are the cheapest. Cost rises exponentially as you add priorities.

 

Find a machine that is big enough to reach your whole job, or it will suck to be you. It's one thing to make a part now and then that hangs over the table, but planning to buy a machine that you know ahead of time will require you to make multiple repositions in surfacing...Perhaps your boss should be running a nice insurance agency or hair salon somewhere.