Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Jennifer on February 21, 2011, 11:36:21 AM
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Hi,
I've spent the last couple of months learning CNC methodology with the help of a small (14"x14") router and an ok CAD/CAM package (V-Carve Pro). The application i am working towards is performing repeatable inlay on stringed musical instruments. I am at the point where i am about to purchase the CNC machine that i will actually use for production. The benchtop machine i am using is a good little router, it is perfect for carving,cuts really smoothly, but is a tad too "sloppy" for highly detailed inlay, I can only hold about .007" over a foot, my X and Y axis are belt driven off stepper motors and i suspect the belts may be the culprit.
An example of my art is creating "tree of life" type inlays on fretboards, personalized head plates as well as the standard embellishments found on stringed instruments.
My dilemma is this: i do not know which type of machine is best for my application, a better built CNC router with all three axis using "ball screws" or a full blown milling machine with a CNC conversion applied?
I like the bang for the buck one gets with a router with regard to addressable size, but also am impressed with the much higher degree of accuracy obtained with a milling machine equipped with a high-speed spindle.
Any opinions about this would be greatly appreciated. I've pasted a couple links below to the machines. I am also welcome for other suggestions, perhaps you have a good used machine or know of one? I am looking to purchase within about the next week.
I am considering the "Vortech" router, the "CNC masters" Jr. and the Microkenitics Mills
http://microkinetics.com/express/
http://www.vortechrouters.com/shortcut-203.html
http://www.cncmasters.com/index.php?page=cnc-jr-table-top-mill
Thanks in advance for taking the time to add you two cents,
Jen
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HI JEN,
NOT SURE IF YOU ARE INTERESTED OR HAVE SEEN THE FIREBALL COMET BUT IT SEEMS NICE. IM USING A V90 I BUILT FOR PRODUCTION.
I HAVE A 30,000 RPM AIR SPINDLE MOUNTED. HOLDS 1/8 IN SOLID CARBIDE BITS. SEEMS PRETTY ACCURATE... CUTS NICE. IM DOING VERY CLOSE WORK.
http://www.probotix.com/FireBall_Comet_cnc_router/
DAVE
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One concern I would have with a mill is the sawdust will get in the ways and clog up the oiling. I refuse to turn wood for the boatyard on my lathes as about 10yrs ago I agreed to make a plug for a boats tube so they could put it down the slipway whilst waiting on the parts arriving. Anyway I did it and was constantly trying to clean the sawdust out and after about 5 yrs I had to strip the whole thing down as the oil ways were totally clogged, still was loads of sawdust under the saddle.
Hood
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Hi Jen,
My 2 cents.....
Routers for wood and plastic, Miling machine for metals (and some plastics).
Ballscrews are best and if the router has a table larger than about 600mm x 600mm then servos are best. Three phase high speed spindle with VFD is best and good dust / fume extraction is essential.
Exact model and where to buy - that's another story.
Tweakie.
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Dave,
I took a look at the probotics offring and do not think it will be enough of an improvment over what i have now to justify the cost. I do like the larger 25x25 cutting area.
The table appears to be made of some kind of composite, that worries me. if the table is out by more than about .005" or so i could wind up with "pockets" that are too deep. That could prove costly with regards to material. The same goes for the male part of the inlay, the abalone.
A 5" x 9"x .050" piece of material (Ablam) costs me about $300. A grade AAA Ebony Fretboard can go for close to $100. So the stiffness of the machine,repeatability, and having a stable "plane"working surface is very important.
I like the idea of an air spindle, 40k rpm is a good increase out of the 25k i am getting now, i could kick up the feed by a good 35%. But i would have to add the complexity and noise of a air supply and the noise of a screamimn turbine. I have found some high speed electrical spindles that run on 220v single phase, that are rated about 2hp and turn 40k as well, but they tend to be bulky.
so, the search continues....
thanks for the feedback
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Forgot,
with regard to material, what i am doing is cutting very fine inlays out of a material called "Ablam" it is basically abaline shell that has be delaminated and re laminated with a plastic compound as a binder. many thin layers of shell. the size i use if .050" thick. it is basically limestone. the amount of wood carvig is equally small. "pockets" that are like very thin vines ("tree of life" designs) about .040" in depth. in very hard woods like ebony, ironwood, rosewood & etc...
thanks for the feedback guys!
Jen
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JEN,
IF YOU ARE INTERESTED I COULD BUILD ONE AND DESIGN IT IN 3D SOLIDWORKS. OUR COMPANY IS A FULL METAL FAB & DESIGN SHOP... ALL CNC
WE HAVE LASERS BRAKE PRESSES, VMC'S LATHES AND A FULL STOCK OF FLAT SHEET, RND STOCK, TUBING AND EVERYTHING YOU COULD THINK OF...
I BOUGHT THE V90 SO I COULD LEARN STEPPERS AND CONTROLLERS BETTER AND THEN TAKE THAT KNOWLEDGE AN PUT TO BUILDING OUR OWN PLASMA CUTTER...
NEMA 34 SCALE... THIS LITTLE AIR SPINDLE I AM USING IS SWEET.. I GOT IT FROM NSK AND BUILT AN ATTACHMENT FOR OUR MACHINING CENTER (VMC) NOW ITS TOO BUSY
SO I PUT IT ON THIS V90.. PERFECT SCALE. THE MATERIALS YOU ARE CUTTING I CUT ON OUR 6-AXIS 1500 WATT LASER. IT CUTS THE PEARL AND SHELL GREAT.
IT ONLY TAKES ABOUT 450 WATTS. YOU CAN BUY OFF THE NET A 450WATT LASER AND A FOCAL LENS. YOUR CUT WIDTH WOULD BE ABOUT .005 DIAMETER....
YOU CAN ALSO BUY FOR THE COMET AN ALUMINUM TABLE...
DAVE
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Dave,
that is not a bad idea. i could replace the belt drives with ball screw feeds on the X & Y on the table i have. there is room to bring the travel up to 18 X 32 on the table i have. the Z axis is already a very precise set up. built with ball screws and dovetail rails of hard steel. no slop at all.
i have a budget of 8k for this machine, aren't laser heads much more expensive? could it be made switchable so i could use the spindle i have for wood, and the laser for shell?
Jen
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YES YOU CAN MAKE A UNIVERSAL MOUNT ON YOUR Z AND JUST MAKE INDIVIDUAL LASER MNT AND SPINDLE MNT. ( QUICK CHANGE )
WE CAN BUILD ANYTHING HERE. WE HAVE EVERY MACHINE IN HOUSE TO BUILD MOST ANYTHING.
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Hi Dave,
could you please e-mail me your contact information, so we can take this discussion off line? my address is: jedwards@hanger.com.
Thanks,
Jen
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YES YOU CAN MAKE A UNIVERSAL MOUNT ON YOUR Z AND JUST MAKE INDIVIDUAL LASER MNT AND SPINDLE MNT. ( QUICK CHANGE )
WE CAN BUILD ANYTHING HERE. WE HAVE EVERY MACHINE IN HOUSE TO BUILD MOST ANYTHING.
A quick change laser head ?????
I would really like to see a picture of a 450Watt laser fitted to the Z Axis of a machine.
Do you know the price of a 450 Watt laser ?
Tweakie.
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Hi Tweakie,
I once owned a laser hair removal clinic, an alexanderite laser that output 20 joules of enercy into a 25mm spot over a 3ms pulse cost me about 80,000 dollars a pop. output in watts it was probably about 40. The power supply generated a huge amount of heat, i had to water cool them then air condition the room the machine stood in.
i just have this frankenstein picture of this room full of power equipment tied to a six foot long CO2 laser attached to a six inch mount focused on a tiny piece of .050" thick by 1/4 inch across abalone shell :)
Jen
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;D ;D ;D
Tweakie.
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I have been real busy here at work. Im building fixtures for our Lincoln robotic welding cell.
they are around 800 to 1500 for a 450 watt laser. i will find them on line and post a link when i get some time later today.
you will have to build a mount for the focal lens and will need an assist gas. nitrogen works best for small stuff or you can use an air compressor.
oxygen is for steel only every thing else will catch fire with it. we cut 3/4 marine ply wood at 700watt and use shop air. cutting at 80 ipm
Dave
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Hi,
i am investigating a third alternative, it is a laser system from a company called epilog. they make small lasers that work off of image files from applications like vcarve or corell draw. they have a very high accuracy and lightning speed, on the order of 100 inches per minute cutting materials similar to the "ablam" that i use for my inlay work.
they run in the 40 to 80- watt range and work a lot like a dot matrix printer. the cost is well below 10k for table sizes of 12x12 and 12x18, which is great for the type of work i am doing. they are a CO2 based system and have many advantages over a router or a mill. very thin "kerf" about .001". They are capable of making the sharp corners that inlay artists love, no cutters to wear or break, made in the U.S. real win win stuff.
I am in the process of working with the local sales rep to test one out on the material i use. i will keep you posted. the real concern is how accurately it can hold "depth" on the "pockets" that my inlay work "guzinta" so we will be testing some of the various hardwoods used in musical instruments to see if it is possible to maintain a reasonably even depth.
have a great week!
Jen
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Hi Jen,
The Epilog sounds like a good choice.
Just one point to keep in mind is that organics such as shell, bone, leather etc really stink when you attack them with a laser. I am not sure about the composite 'ablam' because I have never tried it but depending on your location (if you have neighbours) you may need a HEPA filter attached to your air extraction system. They are not that expensive but still a bit of extra cost to factor into the equation.
Tweakie.
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Thanks for the advice tweakie,
Yah the stuff will put up a nice stink when burnt. fortunately the units i am considering have a 4" vent on them, and my dust collecting system uses the same size hoses. It vents outside, and neighbors are a fair distance away, so the odor should not be an issue.
My real concern is weather or not i can get a controllable depth for the pocketing. I would really hate myself for dumping that kind of money on a system that turns out to be unweidly in the z axis. wood does not, by nature, have a consistant density. also if the laser discolors the wood around the edges.
it woould be senseless to have a machine that can cut nice sharp corners on my inlay material only to have to use the router to cut pockets that will be rounded by virtue of the tool's diameter.
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Jen,
You are right about wood's density. Wood's like teak and spruce have a soft growth layer sandwiched between a very hard annual ring - the laser will cut deep into the soft and not so deep into the hard but the overall average should be pretty constant.
As the depth of cut is related to both power and speed as well as the wood itself the exact depth will always be a trial and error thing but once established it will be repeatable, at least for that sample of wood.
There will be some blackening (charring) around the edges but the surface of the work can be protected with paper transfer tape (used with vinyl signs) also there are a number of proprietary cleaners which, I understand, can work wonders.
(Incidentally, the smallest practical beam spot size is around 0.05mm diameter without resorting to beam expanders or extremely short focal length lenses).
Tweakie.
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Tweakie,
That is what we are hoping, that on average we can control the depth, any irregularities should be controllable with the liberal application of adhesive. i am also hoping that sanding the surface willl diminish any blackening of the wood, if it occurs. i'll let you know when i find out.
I am sure i can develope some kind of protocol for testing the timing/intensity needed to control depth on a given sample of wood. after a while it should become routine. perhaps develop a test template, varying the settings programatically between the different test areas so i could push a button, measure the depth of the samples and choose the settings necessary to achieve that depth on that particular sample of material. any thats the plan.
Jen
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LADIES,
IVE HAD PRETTY GOOD LUCK CUTTING WOODS AND SHELLS... *** FOR SURE DO NOT CUT PVC (VINYL) *** IT GIVES OFF CHLORINE GAS, VERY TOXIC EVEN WITH A FUME EVAC..
WE HAVE SOME BIG LASERS HERE AND WHEN WE CUT 1/16TH WOOD LAMINATE IT CUTS VERY PRECISE. PIERCE TIME AT 450 WATTS IS .200 SECONDS. CUT SPEED AT 450 WATTS IS 100 IPM.
USE NITROGEN AS AN ASSIST GAS. OUR BEAM DIAMETER WITH OUR FOCAL LENS VARY FROM .003IN TO .010IN DEPENDING ON FOCAL LENGTH.
http://www.rofin.com/en/products/fiber_lasers/starfiber/starfiber/ <---- CHECK OUT THIS SITE TO GET YOU STARTED ALL YOU HAVE TO DO IS MOUNT THIS ONE....
DAVE
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SORRY TWEAKIE I DIDNT CHECK UR PROFILE BEFORE I SENT LAST POST... I GUESS YOUR AVATAR MADE ME STEREOTYPE YOU ...
DAVE
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Thanks Dave,
I'll check it out.
Jen
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No worries Dave :D
I think we would all appreciate it if you use the caps lock key though.
Thanks,
Tweakie.
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Good Morning,
i wrote to the folks at Rofin, that stuff looks a bit spenny but you never know. i do not think that kind of power will be necessary to cut a thin laminate, but it could not hurt to have extra capacity. If i decide to go with a laser i would prefer a purpose-built machine as opposed to something i cobble on to a router table. In my humble opine, i feel it would be difficult to take advantage of the speed and almost impossible to control the depth for pocketing without a machine designed to do so.
BTW, i stole tweakies avatar, and use it for my Cisco "WebX" company intranet chat avatar. i think it is pretty "Gender Neutral".
Jen
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BTW, i stole tweakies avatar,
Jen
Hi Jen,
You might ask Tweakie for the very fashionable accessory package for "Super Kitty".
There is a "Laser Eye Patch" for first time laser users, as well as seasonal garb including a cool Santa hat.
Cool, :)
Russ
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;D ;D ;D
Tweakie.
btw. The 600W Rofin Fiber laser costs just a little over the price I paid for my house :D
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Hi Tweakie,
please forgive the plagiarism:P
I figured it was not a cheap device. Like i said i owned a laser aesthetic clinic for a few years. we did skin peels (erbium laser), hair removal (alexanderite & NDYag), tattoo removal (ruby, KTP and YAG) and other stuff like spider veins and age spots. each of those machines were high durability fast switching and very fast switching, from about 3ms pulse width to 10ns pulse width anywhere from about 10-400 joules of output. the cheapest one cost me about 80k and the standard 3 year service contracts were similarly priced.
they all had fiber optic delivery systems, every time i broke a fiber it cost me about three mortgage payments!
Jen
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Hi Jen,
After spouting on about it I thought I had better try some inlay work. ;)
This is just wood in wood but it shows that it is easy to do with Mach3 and LazyCam. http://www.machsupport.com/forum/index.php/topic,12444.msg121416.html#msg121416
Tweakie.
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Tweakie, Shoot i replied to the wrong post! see "the laser project" for my comments. :P Jen
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Thanks Everyone!
well the answer to my question Mill or Router has been resolved. the answer is: Laser! :D
i have ordered an Epilog "Zing 24". it can cut abalone like butter, gives me a sharp corner with only a .004" radius, will rip thru the thin woods i use when building a stringed musical instrument and has a bunch of other applications like carving or engraving. A few people in my industry are using them with really nice results. One example can be seen here: http://www.rgmusic.com/gallery.html . it opens up a lot of possibilities for additional aesthetic techniques not normally applied to luthery.
I want to thank everyone who put in their two cents regarding this post. You all made me think about my decision process, regarding what direction to take regarding my next machine purchase and to take a look outside of the box. for this i am grateful.
If any of you are interested you can check out the laser i picked at: http://www.epiloglaser.com/zing_24.htm . The only regret i have is the name of the machine "Zing" sounds pretty tacky. This model can be had for around 10-14k, depending on options, their smaller "starter" model in the 7k range. really not much more than low end industrial router.
some of my decision factors were: table size an nice 16x24 inches, cutting speed measured in dozens of inches per minute as opposed to single digit feeds, accuracy close to a low end milling machine, no tools to break, few wear parts, quiet operation, spot size of .005" and ease of use.
These things just use a modified windows print driver you can "print" any common graphics file, like corell draw, dxf etc..., to this driver and it will interpret fine lines as a cut and thick lines or gray scale as a carve. Gee i should sell these things, i'll get off my soapbox.
i guess you can see i am enthused, we shall see what the reality of this thing is like in a few weeks when i take delivery.
Again, thank you all,
Jen
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Jen,
We expect to see lots of pictures of stuff you make with it even though you won't be using Mach3 :'(
Tweakie.
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That was a quick reply,
No need to fret (luthery humor) Tweakie, i will still be using the router a lot, just not for cutting abalone. you are right i should post some pictures of my art, i am pretty proud of my work.
Jen