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Hello Nelson,

The hf type spindles such as Colombo can be controlled for rpm by using a vfd, which you will likely have to have to run the spindle anyway. I have used Porter Cable 3.25hp routers for my spindles for years and have endured the same torture you mention. On a good note, I was in the Onsrud factory looking at one of their fine machines years ago and stood within two ft of a 12 hp Colombo running at 22k rpm and I could talk with the sales rep in a normal speaking voice while we watched this machine cut the last cut of a 2" thick piece of oak for a church pew.....at 1000ipm with a nickle standing on it's edge on the frame of the machine!

Needless to say, I was impressed.......still broke, but impressed!

I am either going to move up to a larger atc Colombo or similar spindle, or buy something that has one on it. One of my customers said he will be offering me a Fadal 2040 this summer for 5k and if that happens, I will get it!

Mike

Hi Mike, good to hear from you.
I suspect that there would be more noise from the cutter against the wood rather than the Columbo spindle.
That's why I was wondering about slowing it down as much as possible and reducing the feedrate accordingly.
The techno machine is quite a bit less massive than an Onsrud and I suspect a lot of the noise is a result of that also.
Again the slower spindle speed might reduce the noise level?
Thanks
Nelson

http://www.youtube.com/watch?v=nj7WHut8NNo
This would be the kind of noise I would hope to avoid.

I'm not sure if it's the toolpath or the machine rigidity, but that noise isn't the cutter's fault. If you listen to cutters running long enough you can separate out the pitches of the spindle, the cutting action, the chatter, and the vibration.

Full width slots are pretty much expected to be noisy unless you use an odd number of flutes (three flute cutters are much quieter and chatter less in slots), but those pockets have all kinds of noisy vibrations going on that shouldn't be there.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Good points all, Bob.
I'm being overly particular here as I run my CNC in the basement and you can understand the noise issue.
I have a very understanding spouse but I don't particularly like having to wear a headset.
Cutting speed is not an issue for me as I'm usually doing another job when the Techno is running.
If I had my wishes, the noise level would be no more than if I was running the endmill at 500 RPM in a vertical mill.
I realize that is impossible with a router as it depends on high RPM to make up for lack of machine rigidity.
But with VFD on a Columbo type spindle could I drop the RPM to, say, 10,000 and reduce the noise level and pitch considerably?
Thanks
Nelson

I can say with a certain degree of certainty that you can get by on 10,000 RPM

You actually need a certain amount of RPM just to get the cutting edge moving fast enough to cut rather than sort of pushing aside the work, but 10K is definitely above that. 500, maybe not . I have a lot of the same considerations you have for my future, as I'd like to start building full instruments again in a smaller, quieter section of my shop and keep the production elsewhere. The actual cutting noise of a properly done wood-cutting toolpath sounds like ripping paper with a medium-pitch hum in the background (or the other way around, depending on material removal rate).

I think you can get it pretty quiet at 8-10K RPM and your intuition as a machinist should let you know what's making the noise and how to correct it once the router isn't the primary noisemaker.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

The actual cutting noise of a properly done wood-cutting toolpath sounds like ripping paper with a medium-pitch hum in the background (or the other way around, depending on material removal rate).
Now that right there is what I'm talkin' bout!

http://www.cnczone.com/forums/showthread.php?t=76069
I've been looking at these Columbos, probably the 3 HP -2 with double row bearings.
I think the electric fan model is a couple hundred more but might be worth it.
The standard is the shaft driven cooling fan.

If I run my Colombo down to 3k rpm it's the same volume as my drill press running at 3k rpm. At 18k rpm, it's closer to a hair dryer because of the shaft driven fan. If you get the electric fan, you can run it at 6k and everything will be much quieter. That is, until you start cutting, and then it doesn't matter what you've got, it's going to be loud. Also, bear in mind, that fan needs it's own single phase 220v line. It can't share with the spindle.

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John Watkins
CNC Guitar Parts

What is the advantage of the electric fan over the shaft mounted?
More cooling at lower RPM?

The advantage is that the fan can run at a low speed while the spindle runs at a high speed, creating much less noise.

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John Watkins
CNC Guitar Parts

So it sounds like the fan is sized to provide adequate cooling under load at low RPM.
That makes sense.
What happens, John, if you reduce the air supply going into the fan at high speed to reduce noise?
I'm thinking of a situation where a guy might be running a 1/32" dia. endmill at max RPM.

Anyone have thoughts on the Chinese water cooled VFD spindles on the market?
One of the claims I see is quieter operation than fan cooled.

Note sure about the water coolers on the VFDs, but the spindle motor fan on the Fadal is waaaaaay louder than the spindle chiller (and it's a pretty big chiller).

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Those Ironman routers look like a really smart design. I've often wondered how you could utilize laser-cut steel components in a design.

Regarding the Chinese spindles. I've read surprizingly good reviews of them. I guess for the price, you could buy a spare to keep on hand. A Colombo or HSD would be simpler to mount and easier to source parts for though.

I too thought the Ironman to be an interesting design. I does look, however, like the gantry ends could use some type of stiffeners against side deflection of the gantry.
As for ease of mounting, it does seem like the Columbo style spindles would require just a simple adapter plate.
The mounting for the Chinese spindles with their round bodies would be similar to most router mountings.
The easy height adjustability of the round housing is a plus.
I was thinking, however, in terms of a mount that would be somewhat like a turret in the spindle could be tilted side to side.
This might be useful in machining necks or some type of workpiece where an undercut is needed or to eliminate the need for a long cutter.
I haven't given up either on the idea of a ball nose cutter doing a better job is tilted slightly off vertical.

Hi Guys,

Just to jump in with my 2c,

i run an SCM Machine weighing in at 19000lbs and a small pacer machine weighing 1000lbs with a colombo spindle.

I can tell you now that the spindles on both machines run whisper quiet at low RPMs and with slight hum at full tilt. the noises that will drive you mad are either the sound of the compressed air for cooling the colombo, it sounds like someone leaving an airhose blowing all day long......and really drives you nuts!! or maybe the sound of the dust extractor for this machine, which is a shopvac...........or perhaps even the 5hp vacuum blower....thats a real doosie after a few hours......on the SCM it gets worse.......the spindle is cooled by the dust extractor, which in this case is a 10hp 16 filter beast.... or maybe the total racket created by becker vf250 vacuum pump.................


i guess what i'm trying to say is, the noise the spindle makes is probably the least of your concerns, as one of the other ancillary systems will probably create 10 times as much noise!!!

adios

Paddy

Paddy, do you notice a difference in cut quality between the two machines?

I rebuilt most of my machine frame adding mass and stiffness and the cut quality has noticeably improved.

Hey Sheldon,

Thats a bit like comparing Apples to Melons!!

The Smaller machine produces a great quality of cut, but it is limited to a maximum speed of 5m/min,

Big beast can do 60m/min, but obviously that depends on the material, and cutter choice etc..... it can take much heavier cuts. or you can even mount a spindle moulder head in it and really make some chips!!

basically they can both produce excellent finishes, but with the big machine it can more tweaking as you have such a greater range of speeds available to you.

Paddy

PS, i love your basses man !!!

Thanks Paddy.

I realize that this thread is a little old now, but I've been looking at investing in a CNC Machine, and have had a price quote from the local distributor whom is based in New Zealand. I'm in Australia. I was quoted around the $22,000 AUD range for a LC 3024 machine. The exchange rate was quoted at $0.88 AUD to the US dollar.

This was landed in Brisbane, but taxes and freight extra. Software also on top of that. Machine included spindle etc. and ready to run expect for the aforementioned software and computer. Tooling would also need to be purchased.

For those of you in the know of what these things go for, is this an appropriate price, or has there been some padding to the bottom line as was suggested about the Canadian distributors of these machines.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

It costs a lot to get a piece of machinery to Oz. You can do what I did: call a distributor in the US and get a price, and then figure out what it would cost to get something that heavy across the Pacific.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I'm estimating that shipping is in the $1,000 range. Thanks Bob,

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

Allen why don't you consider building your own cnc machine?

I have no doubt this would save you a considerable amount of money, but might take more time than you want. Prices from compontents have come donw from when I first started in cnc and the quality has come up. You can get all the help you need to build one on CNCZone plus there is a group of builders there in Aus.

Mike