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  #1  
Old Thu 15 May 2008, 21:34
skypoke
Just call me: Chuck
 
Port Aransas
United States of America
Spindle selection

I'm looking into spindles and associated gear, want as a minimum 5hp. I'd like to go with more like 8 hp but understand this will take a rotary phase converter since single phase in, 3p out seems to only go to 5 hp. I see a source for a Chinese spindle, 4.5 hp, $700.00. Anything know anything about them?

I also see the Eckstrom Carlson spindle which is available with collets, VFD, reactors etc., 5 hp, for around $2500.00 as a package. The spindle alone is about twice the price of the communist version.

A final option might be to buy or build a rotary phase converter, add a balancer, feed it into a 3phase in 3 phase out VFD and drive a higher hp spindle. I had a homemade phase converter (rope start!) driving some industrial woodworking equipment in the past and have mixed feelings about owning another one.

Appears water cooling is used in some spindles. If it cuts down noise that would be nice but is there a downside other than having to deal with piping, pumps, tanks etc.?

I'd appreciate any insights into spindles you guys can provide. Anyone who wants specific company info for quotes on above spindles please p.m., per forum policy won't post this online.

Chuck
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  #2  
Old Fri 16 May 2008, 04:38
Robert M
Just call me: Robert
 
Lac-Brome, Qc
Canada
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Chuck !!

8hp spindle ??!! MMmmm, I’m no expert in CNC as I’m still in the process to be, I’m only at the drawing board stage. But 8hp,outch… by what I’ve read so far, I’d say with some ease you’re a bit to ambitious with horse power needed for the MechMate. Look around, see others set up and you’ll notice that many time 5hp is more than fine. Heck, A LOT of us & other similar set up stay with a 3hp portable router set up for ease of maintenance and it’s simplicity of set up putting aside cost. 3 to 5 hp spindle should be more than enough for your future MechMate.
My opinion, but worth investigating more on this!!
It’s a mater of what you intend to do & cut, expect out of your future CNC & spindle/router set up. Will you need an ATC ( automatic tool changer) for production ?
Things that make you go MMmmmm….
8 hp may be what you will need, just hopping your not suffering from the bigger must be better syndrome !?!
Robert
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  #3  
Old Fri 16 May 2008, 04:49
Robert M
Just call me: Robert
 
Lac-Brome, Qc
Canada
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Oupsss,
I mist again the occasion to pass on my comments… Darn !!
Bigger must be better syndrome is not of your concern. From what I can see, You made the biggest MechMate to date !!!!
Than, sorry for being to fast with my reply !!
Robert
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  #4  
Old Fri 16 May 2008, 06:45
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
Skypoke,

When I build my machine which I hope to start soon, I also plan to use a spindle. If Gerald was not on vacation, I am sure he would mention that their machine uses a HSD spindle. It is a 3,5 KW which is approximately equal to a 4.7 HP.

I have been in touch with the HSD office for the USA which also happens to be in FL. I hope to have a price and more details on the VFD and the exact spindle that I will be buying.

I will be happy to share what I find out and would be interested in what your research finds.
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  #5  
Old Fri 16 May 2008, 07:15
skypoke
Just call me: Chuck
 
Port Aransas
United States of America
I'm eager to see what you find out, Sailfl. The reason I'm looking at a larger than usual spindle is we intend to do some serious aluminum cutting, large parts, thicknesses ranging from 1/8-1/4". I'm not worried about cut speed but need the capability to run the tool at the optimal chip load for specific cutters. From what I'm hearing, 5 hp is somewhat marginal for this job. I realize we're pushing the envelope a bit for the Mech, compared to what has been done in alum cutting so far but am convinced it's a viable proposition. Not really "bigger is better" but I do recognize the downside of driving such a large spindle...cost, electricity, maint.

I see that Drivewarehouse sells a line of 1 phase in, 3 phase out VFD 220V that go up to 10 hp.


Chuck
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  #6  
Old Fri 16 May 2008, 07:27
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
The first thing that you need to look at is what you're going to cut and how you're going to cut it. If you're going to use "standard" 1/4-inch, 3/8-inch and even 1/2-inch straight or spiral cutters, you'll find that even a 3HP spindle will handle that job. On the other hand, if you're using large "stacked" cutters that have to whack off a lot of material in one pass, then a larger spindle might be required.

There are other factors that come into play. In my case, I knew that my two-FEIN vacuum system could not hold the work properly to need even a 5HP spindle. My machine (Shopbot PRT-Alpha) can not be counted on to handle the forces required with a > 5HP spindle. The 1/4-inch and 3/8-inch diameter tooling can only be pushed through the material at a certain rate, after all, the cutting edge has to have time to actually cut away the material instead of just plowing through the material.

The other drawback is the power required. Using a 1-phase to 3-phase converter requires about 50% extra current - depending on its efficiency. Although it's been almost fifteen years since I've used a rotary converter with a vertical mill that I once owned, the power consumption was significant.


-----------
Edited
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Chuck,
You posted while I was writing. Cutting non-wood products, especially metal, changes everything. I've cut some 1/2-inch aluminum for belt-drive transmissions, which took a lot of passes at very shallow depths.

I've only personally seen one large CNC router (Busellato) that actually needed its 12HP spindle. It used stacked cutters to edge-cut cabinet doors. When I was asked to run their CNC department, I was told that one of their goals was to have the two $750 cutters last for a full shift. The 12HP spindle on that machine was not particularly large for its required use, but things fell into perspective in a hurry when I did the math and realized that the tooling costs, just for the two main cutters, would be 2 shifts X 2 cutters X 6 days per week X 750 per cutter, or $18,000 per week. (That made me stop complaining that I had to buy six $18.50 3/8-inch spiral down cutters per week when I was cutting lots of MDF.)

Last edited by Richards; Fri 16 May 2008 at 07:31..
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  #7  
Old Fri 16 May 2008, 22:39
skypoke
Just call me: Chuck
 
Port Aransas
United States of America
Mike and All,

Well let me state right off, I am unsure of what my power requirements are. What I'm wanting to do is cut parts, not small "milled" type parts but things like frames, hull skins and so forth from 5083, 5052 and 5086 aluminum. All these marine series are "gummy" and soft when compared to 6061 making it even more difficult. Not in a hurry to cut the parts, if it's a viable proposition to cut a few 1000ths per pass, no problem. However, what I'm hearing from folks who cut this material is that tool life is going to be maximized, chip rewelding problems minimized when optimal feed loads are used. These optimal loads are, in my understanding, fairly heavy cuts requiring big HP.

My next step is to talk to some cutter mfgs and see what they suggest. My (our) interest is not limited to boat parts. I'm thinking that the strength, efficiency, light weight and "greenness" of alum alloy will find greater application day by day. I want the ability to work with it in an efficient manner.

I appreciate the comments, keep em coming!

Chuck
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  #8  
Old Sat 17 May 2008, 13:01
Alan_c
Just call me: Alan (#11)
 
Cape Town (Western Cape)
South Africa
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Chuck

From my days of running a Multicam, the best advice I can offer is lubrication. Try and get hold of one of those misting lubricators as used on the Multicam, it helps a lot. Also when plunging, ramp into the material especially with an endmill - if you plunge straight in you end up with a small disk under the cutter that can weld to the cutter, ramping avoids this.

There is a company here in Cape Town that does nothing else on their Multicam than cut Aluminium boat parts, I will try and get some more info from them and report back. I see no reason why we cannot achieve similar results on the MechMate. You may need to change the table material for something waterproof such as phenolic (I know its expensive)
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  #9  
Old Sat 17 May 2008, 16:56
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
chuck
check out the onsrud guide at hartlauer bits. They specifically carry bits for the 5000 series alum and list all the cutting suggestions as well.
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  #10  
Old Sat 17 May 2008, 18:22
Corwes
Just call me: Corwes
 
Stouffville ,ON
Canada
Chuck!!!

Good news!!
You can run a "3PH in - 3PH out" VFD on single phase.
First let's look at how a VFD functions. The "AC in" is converted to DC by a Bridge Rectifier . The DC is stored in the capacitor bank . That DC is then pulsed at a very high frequency to more or less simulate a sine curve of a lower frequency. The VFD does not require 3PH or even AC to function properly.

You can either just connect single phase to any 2 of the 3 phases and derate your VFD because the rectifier diodes now have to carry more current for the same load.
Most VFD's only monitor output current and will not fault out with this method. Or you can connect a single phase bridge rectifier directly to the DC buss without derating your VFD. Just make triple sure of the polarity.

You even get VFD's that have a seperate DC input.

Where did you find the Chinese spindles?
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  #11  
Old Thu 22 May 2008, 20:11
skypoke
Just call me: Chuck
 
Port Aransas
United States of America
Corwes, Sean,

That is good news indeed. Makes sense. I wonder why some mfgs have particular models that are rated 1 in 3phase out...could it be that you need to derate the vfd when used in this config? BTW, PM sent.

Thanks for the tip for Hartlauer. Anyone ever taken a look at the book they sell "Your Future in Router Cutting"?

Chuck

Last edited by skypoke; Thu 22 May 2008 at 20:22..
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  #12  
Old Fri 23 May 2008, 04:20
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
Chuck,

I am not an expert here but I have been looking at spindles and VFD. I hope to hear from Delta VFD today.

When you have a small HP motor and the VFD is rated 1 Phase in and 3 Phase out. The unit does not have to be derated. Most motors need 3 phase but most user only have 1 phase power. With this type VFD you can buy a small VFD.

I have been told that all VFDs can be run 1 Phase in and 3 Phase out. But to do that you have to derate the VFD or you have to purchase a VFD that is larger than the motor you are using it with. For example I have been looking at a 4.7 HP spindle. I will have to buy a 10 HP rated VFD that is 3 Phase in and 3 Phase out and derate the VFD.

As I mentioned, I hope to talk to Delta today and I am going to ask them these same questions to confirm my understanding.
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