robodrill time..help please.. - Practical Machinist - Largest Manufacturing Technology Forum on the Web

Seekins · #1 10-24-2009, 12:26 AM

Before you say it, i have searched and read everything i could find...

I am dumping the Haas this week and want a kick butt 4th axis aluminum rip'n machine. I cannot afford to screw up again like i did with the Haas, so i nee some serious answers from users. I am looking at the long bed with DDR 4th axis, 24k rpm and whatever other bells and whistles i need to make it a blur inside.

For those that have one, What kind of cuts can i expect with a half inch endmil in aluminum? Im going for the 24k spindle option, but want to hear some numbers from machinists. Light and fast is good, but how fast? and how light? Also, the cuts are going to be short line segments and the cutter will be switching direction every inch or so at best. Its not going to do me any good to outrun my code. Whats the look ahead like? how fast do they accelerate to feed rate? How is the chip evacuation? anything i need to really look at before jumping in?

I have watched all the you tube videos, but i don't see any in aluminum and only a couple of them are actually taking cuts, most are cutting air for demo's and that doesn't excite me too much. The stainless video is neat, but doesn't apply to me.

BTW...If someone wants to steal a 09' VF2SS with everything i know where there is one looking for a home.

StreetSpeed · #2 10-24-2009, 02:31 AM

Can't help you on the Robodrill, but are you getting rid of the Haas because you could never sort out the vibration and finish issues? I don't know that a 30 taper (7hp?) Robodrill is gonna remove material any where near as fast as a Haas (or I should say, that Haas) but if the Haas isn't making your parts to your standards, then I guess a couple minutes here and there isn't gonna make too much difference.

ARB · #3 10-24-2009, 04:06 AM

The Robo is badass for sure. And support is great but don't forget the Brother with the high speed rotary and built in pallet changer. Either way your getting some speed.

barbter · #4 10-24-2009, 04:47 AM

http://www.practicalmachinist.com/vb...ight=robodrill

This says a bit about doc's and feed. But ours is a 10k spindle.
When I looked, the 24k is way down on torque.
What do you want to do? If you want to run a facemill or 14mm ripper, I'm sure 10k will be a better option.
Also, I'm assured that the life on the 10k spindle is years, where the 24k is about 2-3 years.
3t3d on here has a 24k spindle and is v helpful. Squirt him a mail and I'm sure he'll help you.

Are you going new? If you are, have a word with methods ref control/lookahead.
We have a standard 31iA5 control with no lookahead options except G05.1.
I can't see you'll ever outrun the code with 1/2" movements.
We run G05.1 as default all the time with no probs, but don't do mold work (small ark moves).
It's programmable upto 30m/min, and the most we run ours at is 8 (40mm facemill 1mm doc).

DEFINATELY spec a face and taper contact (dual contact). If you don't, then the machine is a light milling machine.
If you have face and taper, you can cut as per the link.

Swarf evacuation works well. We're just rigging up a wash to make it better though.

Swarf on the taper is a pita, but I changed the airblow on ours to 1.5 seconds and we've never had a problem since (knock on wood).

Never cut steel yet. I would assume that 8 to 10mm dia cutters would be ok, and that 1/2" would have to tickle somewhat.

HTH

Tonytn36 · #5 10-24-2009, 05:35 AM

Check your PM Seekins...

Seekins · #6 10-24-2009, 08:47 AM

Thanks guys,

Your 4000mm/min @6mm doc is about 5.5hp cut.

they are telling me with the 24k option, i can do .15doc at 624 ipm. Thats a 12hp cut assuming i did the math properly. If it can do this, not much would touch it for my parts. I will be using lots of 1/4 and 3/8 em's. At most i might use a 1.5" shear hog for light facing. The one i am looking at has the dual contact spindle.

mori also has a new DDR 4th and if the price gets close to a dura with a DDR i will most likely go that way because IMO they are bomb proof. Will also be looking at a Brother next week.

The haas makes nice parts when the spindle is new. Im on my 3rd spindle in less than 300hrs and its going again. its just not going to be reliable enough for production work. Unfortunately, i had to get a machine on the floor to cut parts and this was all that was in stock. It cost me more $$ in job loss than a vertical of your dreams. Monday i almost drug it outside. Im sick of polishing parts that should not have to and also sick of the downtime. Lemon or not, i wont play with another.

fpworks · #7 10-24-2009, 09:33 AM

Glen,
As them what the spindle load is at that "12hp cut." I think they avoid aluminum hogging demos because of the horsepower requirements.

I saw one at IMTS working a descent size part in aluminum with a 3" facemill...real light cuts and the spindle load was in the stratosphere. What they did in 10-12 passes, I would do in 1 or 2 on my Mazaks.

For bigger aluminum parts, it will give up some time in roughing, although it makes up crazy time in the finishing and detail work. I'm sure I'll end up with one someday.

Seekins · #8 10-24-2009, 09:51 AM

Direct quote from email

"Using a good .500 end mill (SGS SkiCarb 2Flt)at 24K you can achieve .013 chip load or 624 IPM at .1 to .15 depth of cut."

If it will indeed do this without killing itself im all over it.

psychomill · #9 10-24-2009, 10:08 AM

Careful with the HP calculations these days because the cut force constant is not the same with all endmills like the "old" days.... improved coatings, coolant and most of tool geometry changes these aspects. Sheer speed capalities and acceleration of machines can raise the MRR into very respectable numbers even for the small machine class. You also have to consider elasticity points which HP calcs don't have this in the equation.

Use to have T14i with a 24k spindle and that thing hauled ass and did great work for a little guy. 3" FM (although it ran) was a bit overkill... I liked a 2" or 2-1/2 better and it ran better rates. Although, switching to an aluminum bodied 3" FM showed improved ability as well.

With the Robodrill or rather any little ones, don't forget Brother (as ARB mentioned) and also Kitamura. Tough choices IMO because I like all three...

Tonytn36 · #10 10-24-2009, 10:28 AM

Interesting.......
The spec sheet I have for the AlphaT-14iF with the 10k spindle shows the following spindle rating:
1 minute = 16.5 hp (12.5kw)
10 minutes = 7.5 hp (5.5kw)
continuous = 5.0 hp (3.7kw)
I don't have any specs on the 24k spindle.

When evaluating machine tools, I prefer to look at the continuous ratings.

Perry Harrington · #11 10-24-2009, 11:55 AM

Glen, I know of what you speak. I gain a lot of success by hand drawing the toolpaths and puting a generous radius between direction changes. The machine didn't rock n' roll after that. My little 1993 VF-0 was happily rouging .5 WOC, .125 DOC, 90ipm at 7500rpm and direction changes were frequent.

Repeat with me, a spindle chiller is your friend. What I've learned from a little research is this:

Greased spindle, 4krpm continuous, long life
Air blow spindle with oil (older Haas like mine) 7500rpm okay
8krpm continuous over 5HP and you need a spindle chiller

Your haas is a 12krpm over 5hp and no spindle chiller.

I would not look at ANY machine without a spindle chiller. Matsuura was shipping spindle chillers on their 15k spindles 20 years ago, and the lifespan was quite good on a greased ceramic bearing spindle.

psychomill · #12 10-24-2009, 12:54 PM

Agreed Tony...
Of course I find spindle HP to be an interesting rating... even odd at times given the things I can get away with...

I also should've noted that I didn't have the machine for long. It was only here for testing. I pushed/pulled, drilled, faced, different endmills paths, high speed, low speed, HP coolant stuff, 3D work, Nurb interpolation tests, etc. Fed them the data back and and the machine was out of here. Looking back, I have parts that are well suited for that thing... maybe should've asked if I could buy it... Of course, if I had the machine longer under my roof would my thoughts be different? Hmmm

Correction: Machine was a T21i with a long bed

mwarren1999 · #13 10-24-2009, 01:41 PM

Quote:

Originally Posted by Tonytn36

Interesting.......
The spec sheet I have for the AlphaT-14iF with the 10k spindle shows the following spindle rating:
1 minute = 16.5 hp (12.5kw)
10 minutes = 7.5 hp (5.5kw)
continuous = 5.0 hp (3.7kw)
I don't have any specs on the 24k spindle.

When evaluating machine tools, I prefer to look at the continuous ratings.

The continuous rating should be the only one you look at if this is to be a
production machine.

Seekins,
Why are you looing at the 24K spindle? Would this mainly be for finish purposes, or are you looking at some samller stainless or titanium medical parts?

In aluminum with a 1/2 inch endmill, and if you are wanting to look at a powerfull 30 taper machine. The Brother TC-22B-O is the most powerfull on the market.

Here is a 4th axis Video on Youtube:
http://www.youtube.com/watch?v=NsYR8X6fndc

* Notice how the machine can position the pallet, rotate the 4th axis and change tools at the same time to reduce noncutting time.

Perry Harrington · #14 10-24-2009, 01:51 PM

My newsed machine has a 15HP continuous rating and 20hp 30min rating. That's a far cry from the 20HP Haas claims. Downside is that this machine has greased bearings and not much of a method for cooling it. I was told they got a new spindle under warranty 1yr after they bought it, running 8krpm in Al. This is a Tree 1050 BTW.

Joe788 · #15 10-24-2009, 06:06 PM

Quote:

Originally Posted by mwarren1999

The continuous rating should be the only one you look at if this is to be a
production machine.

Seekins,
Why are you looing at the 24K spindle? Would this mainly be for finish purposes, or are you looking at some samller stainless or titanium medical parts?

In aluminum with a 1/2 inch endmill, and if you are wanting to look at a powerfull 30 taper machine. The Brother TC-22B-O is the most powerfull on the market.

Here is a 4th axis Video on Youtube:
http://www.youtube.com/watch?v=NsYR8X6fndc

* Notice how the machine can position the pallet, rotate the 4th axis and change tools at the same time to reduce noncutting time.

Every time I click a link to one of those Brother vids, I end up wasting 30 minutes going through ALL of the Brother vids. The toolchanger on the TC32BNQT is just awesome.

psychomill · #16 10-24-2009, 08:00 PM

Just FYI....

There are quite a few machines that have the logic to toolchange and pallet rotate/position at the same time... some of them can pallet change and tool change at the same time... It's nothing new. Simply that most builders aren't willing to setup that way for safety considerations. In fact, it's done so infrequently that's it's "obscure" and most factory guys don't realize it can be done...

Funny, being the speed freak that I am, that's something that I don't do (on purpose). Too many hands in the cookie jar at many places and I've had trouble come up quite a few times from it... especially with large format machines...

Seekins · #17 10-24-2009, 08:22 PM

I will have to check out the brother. That looks like a neat machine. What control is on it?

I am in need of a dedicated 4th axis machine, want it to be super fast, accurate, dependable, smaller footprint and affordable. I will run mainly 3/8 and 1/4" em's, some 1/2" and a small face mill for finish facing. Im all about how long it takes to make the part as i have allot of parts to do and want to minimize machines and maximize my hours in the day. I have all kinds of different parts to do, max length is 15", so i need 17" between my 4th fixture and the tail-stock to be available.

Why 24k rpm's ? because after having 10k, going to 12k, then 14k found that RPM's make a huge difference in aluminum. 3min on a part when you have 1000 to do adds up fast and time is money...Thats 50 hours!!

For the 2 seconds it takes, i can wait for a tool change after a pallet changes. I have almost crashed my horizontal and now have some good safety lines that will prevent catastrophic dumbassness...

vmcman · #18 10-24-2009, 08:43 PM

Quote:

Originally Posted by Seekins

I will have to check out the brother. That looks like a neat machine. What control is on it?

I am in need of a dedicated 4th axis machine, want it to be super fast, accurate, dependable, smaller footprint and affordable. I will run mainly 3/8 and 1/4" em's, some 1/2" and a small face mill for finish facing. Im all about how long it takes to make the part as i have allot of parts to do and want to minimize machines and maximize my hours in the day. I have all kinds of different parts to do, max length is 15", so i need 17" between my 4th fixture and the tail-stock to be available.

Why 24k rpm's ? because after having 10k, going to 12k, then 14k found that RPM's make a huge difference in aluminum. 3min on a part when you have 1000 to do adds up fast and time is money...Thats 50 hours!!

For the 2 seconds it takes, i can wait for a tool change after a pallet changes. I have almost crashed my horizontal and now have some good safety lines that will prevent catastrophic dumbassness...

Sounds like a T-21iF with DDR 4th is the way to go, but I am biased. You are in good hands with Chris. I will sound off and let the discussion take its course.

Seekins · #19 10-24-2009, 08:53 PM

VMCman, your more than welcome to join in!!

Whats your opinion on a 24k machine and feed rates it can handle with a quality 1/2"em? short line segments and all..What can i expect to run at for 12hrs a day??

Im stirring and don't want to bug Bruce or Chris during the weekend

mwarren1999 · #20 10-25-2009, 12:31 PM

Quote:

Originally Posted by Seekins

I am in need of a dedicated 4th axis machine, want it to be super fast, accurate, dependable, smaller footprint and affordable. I will run mainly 3/8 and 1/4" em's, some 1/2" and a small face mill for finish facing. Im all about how long it takes to make the part as i have allot of parts to do and want to minimize machines and maximize my hours in the day. I have all kinds of different parts to do, max length is 15", so i need 17" between my 4th fixture and the tail-stock to be available.

Do you have a program you currently or plan to run?

I would have the machine tool builders run the program. Get a base line for comparison that you know. If you are interested in speed,then make them prove it. Also, do what you can to see the machine when it runs the program. This way you could pick out the better tool changer design and note the casting differences between these small machine designs.