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Making progress on CNC parts... http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10106&t=13361	Page 1 of 2

Author:	Don Williams [ Thu Aug 23, 2007 10:22 pm ]
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Well, it's been several months since I first started planning a cnc. In that time, I have acquired the following items: (2) 20mm 59" THK linear rails (2) 15mm 39" linear rails (1) 8" travel THK linear actuator for t he Z axis. (1) K2 spindle mount for my PC router. (?) Tons of 8020 aluminum extrusions for the frame (?) bunches of socket head cap screws (?) enough T-nuts to attach all the linear rails to the aluminum extrusion slots. (?) bunches of aluminum plate (?) tons of T-nuts to attach aluminum plates to the extrusions (4) Gecko G203V stepper motor drivers. (2) sets of arcade buttons and joysticks for controlling movement and moving gantry around manually. Currently, I'm working on getting a power supply. Still to buy: 1.) I'll be getting the Gecko G100 G-Rex, which will allow me to run Mach3 from the same laptop as my CAD/CAM software, due to running the electronics via ethernet instead of parallel port. In short...it should absolutely fly. 2.) I've picked out some 600 oz/in stepper motors that will be plenty of speed & torque for anything I'll ever do. 3.) I need to get a computer to run all this stuff, and am leaning toward a Mac iBook, with Win XP Pro loaded. 4.) Software. I'm settled on Mach3, but as to whether I'll get Rhino CAD/CAM or something else is yet to be determined. BobCAD has a new package out that is pretty nice, if not a little buggy still, and over-priced at present. The price is coming down, but not to where I want it. I can get an education version (full) of Rhino for a very low price, so that is tempting. Hopefully, I'll start cutting aluminum and assembling some time before Winter rolls around, but I have a lot of wood cutting and selling to do in the meanwhile. I also have to get my butt back in school to finish my degree. Don

Author:	Parser [ Fri Aug 24, 2007 8:45 am ]
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The Rhino CAD/CAM package is much closer as far as look and feel as more industry standard stuff as AutoCAD and MasterCAM. I've been very happy with both of them. I'd be willing to bet that Rhino has much more design capability than BobCAD as well! Good luck with whatever you chose, and don't forget to post some pics! By the way...I never gave you stepper motor sizes from my K2, did I? The steppers are 60 Watt x 24VDC x 2800 RPM x 3.5Amp. They are made by DAE (in Korea) and the serial number is D860-30B7-TC9. I have the KG3925-G Machine...and the steppers provide plenty of strength to push the router...I can also hold about .002" or better on most cuts. The limitation of my machine is the flexibility of the gantry - if you run it too aggressively (either too deep of cut, or too fast) you will get a little vibration in the gantry. Long story short, you just have to take smaller bites than you would with larger equipment. If you figure out a way to stiffen up the gantry without adding a lot of weight, that might be a good thing..!

Author:	Don Williams [ Fri Aug 24, 2007 11:24 am ]
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Hey Parser, (do you have a real name??) I have to agree that Rhino is a great package. Where I work is very closely tied to the sailboat industry, and we have a couple guys who measure boats for racing. They're also really good at boat design, as one is a naval architect. Anyway, one of the guys will teach me to use Rhino if I buy it. The nice thing is the cost due to me being in school, or my wife being a teacher is minimal, so I'm leaning heavily in that direction. I have to admit that the whole nerbs thing throws me for a loop. I picked up BobCAD/CAM's V2007 CAD part pretty quickly. It's pretty easy and fairly intuitive, but I experienced a lot of bugs with the demo version. Rhino seems to work very fluidly, with very few hitches that I came across.

Author:	Don Williams [ Fri Aug 24, 2007 11:26 am ]
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Parts update! I just scored two power supplies on eBay for $19+shipping. Shipping was more than the product. It will have more than enough power to run everything. Tomorrow, after I sign up for this semester's college class, I'm going to buy my new MacBook Pro laptop. Yippee!!!

Author:	Parser [ Sat Aug 25, 2007 2:24 am ]
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Cool! MacBook? Argh! I don't think you can run Rhino on a Mac..(?) I'm not sure about MachIII or BobCAD.

Author:	Sprockett [ Sat Aug 25, 2007 6:37 am ]
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Don... Rhino is a great software package, but I strongly suggest that you also attend one of their training classes. They aren't that expensive and it makes all the difference in the world with the package, they have always been very responsive to my questions and issues but after the class I felt I had the skills to do anything I wanted. The coolest part was our instructor had done manufacturing CAD work for years, once he found out I was making guitar parts he had all kinds of advice and we still converse on issues when I get stuck. Same with Rhino-Cam, they have great support which is important when you are running into issues (and you will, trust me), though I didn't need a training class for them. I have learned a ton about their stuff over the last year. MachIII is a good choice, three suggestions about the package... 1. Read the manual AND watch the video's, there is stuff in video's that is not in the manuals and vice versa. 2. Learn to make macro's and use the script language, it makes a huge difference when you are running stuff all the time (I have my tool change macro's customized to do what I need). 3. Use lock collars on your bits to set their length (or you could go with a collet system) and then learn to use the offsets in the tools table, once you set tool 1, the rest will adjust their offset during a tool change. It makes more complicated pieces SOOOO much easier. The Mach guys make a great product, support can be a little frustrating sometimes because you will not always get a response to 'obvious' questions. Expect to spend a good deal of time just tinkering to learn what it can do. I'm still tweaking my Mach setup... Also Parser's right you can't run Rhino on a Mac and I can assure you %100 you want to run MachIII on a dedicated machine, I have a machine in the shop just for mach that has a totally stripped version of XP running. -Paul-

Author:	Don Williams [ Sat Aug 25, 2007 7:35 am ]
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[Quote=Paul] Also Parser's right you can't run Rhino on a Mac [/quote] I was just looking at the Rhino Support Site, and they've had folks running Rhino on a Mac using XP Pro run in Parallels or by a couple other methods. I'm going with a Mac because they seem to be so much better built than most of the PC's out there, and running XP Pro on a great machine like that still gets you very good performance. Plus, it gets me some great tools that I'd like to have, plus a free iPod, and a couple hundred bucks off the MacBook Pro. Not only that, BUT...Rhino is deep into the development of their OSX Version. So in the not-too-distant future, it will run on a Mac without the need for XP Pro. So you'll be able to run Rhino in OSX, and Mach3 from XP Pro. [Quote=Paul]and I can assure you %100 you want to run MachIII on a dedicated machine, I have a machine in the shop just for mach that has a totally stripped version of XP running. [/quote] Dedicated machine? Not anymore! The Gecko G-100 is a device which replaces break-out boards and such, and allows you to run Mach3 et. al. via Ethernet rather than a parallel port. In short, it screams. I know a couple folks who are running the Gecko G203V's with the G-100 and steppers at 500 Oz/in and smaller that go blazingly fast, beyond 240ipm, and the motors hardly make a sound and move extremely fluidly. In short, you can take steppers where they once couldn't go. One of those guys runs Mach3 and Turbocad and cam at the same time, and it still flies. Coincidently, on a MacBook Pro in Parallels running XP Pro... Don's been doing his homework, eh?

Author:	Sprockett [ Sat Aug 25, 2007 9:12 am ]
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Yes you have, I'm very impressed :) I've been making too many parts and not tinkering enough obviously!! , I'll have to look at the Gecko device, I got a full control unit from K2 when I bought my CNC machine so I'm not sure what would be involved in changing it out, but it sounds like I need to do a good deal of research. I was looking at upgrading from MachIII for a time but if Gecko has something that does what the other vendors are doing I may just stay and upgrade my controller, since I've invested a ton of time in making MachIII fit my needs. Right now the machine is running 3 G320's on a breakout box, I've tuned the machine to the point where I can run it without missing any steps. But I'd love to get off the parallel port and add more options like vacuum on/off and motor control... Looking at the G100 it's cheap as well, the other solution I was looking at was well over $3K so I could upgrade to the G100, get bigger motors, G340's and still be wayyyy under what I was looking at before. I still suggest taking the Rhino class, it was very well done, there was a great amount of knowledge transfer and it made understanding the tool SOOOO much easier. -Paul-

Author:	Don Williams [ Sat Aug 25, 2007 10:07 am ]
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A Rhino class is a great idea. BTW, if you email Mariss the engineer at Gecko, he will tell you exactly how much more performance you'll get out of your servos. I'm guessing you may not be able to see them move! The G-100 is only $400, and just the fact that you go from parallel port to ethernet will give "4,000,000 steps per second vs 45,000 max from a parallel port.". Check out the thread here. I'm guessing that should make things a tad more efficient, eh?

Author:	Sprockett [ Sat Aug 25, 2007 10:42 am ]
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I emailed him a number of questions about converting, I've known for a while that moving to a hardware solution would be much much better but up until now it was just too expensive. I poked around the Mach forums to see who has it running, I'm going to post a message there and get a head count. I have so much going on with the CNC that I really can't afford to simply take it offline for a couple of weeks while I tinker, I'm supposing it will make Mach run faster as well without bogging out my machine. The machine is great, I've had very few issues, it's always been the connection to Mach that's been the single biggest issue. For $400 to solve that is actually a steal in my opinion, PLUS I can automate all the other stuff as well like dust collection.... It's too good to be true right now :) I'll let you know what Mariss has to say.... -Paul-

Author:	Don Williams [ Sat Aug 25, 2007 12:38 pm ]
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Too good? Nah, great things had to happen eventually. It's a killer product. Plus, as you know you can turn the spindle on and off and turn on the dust collector, etc... I'm going to post a pic of a guy's G203V's and the G-100, along with a host of buttons for moving things around manually, all done simply with the G-100 in a new thread...it's too cool not to post it here.

Author:	Sprockett [ Sat Aug 25, 2007 1:29 pm ]
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Brett over at Mach is going to run some tests for me and report back, they have been updating the drivers pretty consistently and the only thing that he said doesn't work is a probe. I don't use one anyway, I have a digital arm to do my point clouds, I prefer that to using the machine which has no finesse :) I'll know more when Gecko gets back to me, but this is looking like something I'm going to do here pretty quickly. I know for fact that machine will go MUCH faster, I just can't set Mach that high without the machine having issues. Good Stuff ;) -Paul-

Author:	Bob Garrish [ Sun Aug 26, 2007 7:22 am ]
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The deal with the motion controller is more complicated than the theoretical statistics companies quote would make it seem, but it's a pretty decent solution for a hobby machine. Every dedicated processor in the chain is good, but every communication link added to the chain is bad. As for the Mac thing, the hardware and the OS have now been decoupled. I bought a MacBook Pro last year as it was the best notebook I could find with a Dual-DVI port. I've been running XP on it since I bought it. I've run Rhino in XP natively as well as in Parallels. If you're not doing any really serious work (this isn't your job) or you really like having MacOS available at all times, then Parallels works just fine and is fast enough. The graphics on Parallels are coming along as well, and I guess the new version performs rather well for those who really want MacOS as their main OS for whatever reason.

Author:	Don Williams [ Sun Aug 26, 2007 7:39 am ]
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[QUOTE=Bob Garrish]As for the Mac thing, the hardware and the OS have now been decoupled. I bought a MacBook Pro last year as it was the best notebook I could find with a Dual-DVI port. I've been running XP on it since I bought it. I've run Rhino in XP natively as well as in Parallels. If you're not doing any really serious work (this isn't your job) or you really like having MacOS available at all times, then Parallels works just fine and is fast enough. The graphics on Parallels are coming along as well, and I guess the new version performs rather well for those who really want MacOS as their main OS for whatever reason.[/QUOTE] Hey Bob, what do you mean that the OS and the hardware have been decoupled? My guess is that when I'm doing hard core CAD/CAM in Rhino and Mach, that I won't be using Parallels, but just boot up in XP Pro. It would be more on the rare side for me to run Parallels unless the Rhino-OSX version comes out soon. Then I'll probably get that version instead of the WinXP version. In that case, when I'm moving the motors around, I'll run Mach in XP via Parallels and Rhino CAD/CAM in OSX.

Author:	Tim McKnight [ Sun Aug 26, 2007 1:16 pm ]
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Man you guys are making me reeeeeely jealous. I have been lusting after a CNC router for several years now and it is closer to becoming a reality ... I have seen some of the cool stuff that Mike Baranik is doing with his K2 and it is some fine work. If you guys had it to do over again what pre-built unit(s) would be on your radar? in the sub $10K range with beds and travel large enough to do necks.

Author:	Don Williams [ Mon Aug 27, 2007 2:10 am ]
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You want to BUY one???? What fun is that?!?!?! There are lots of options. ShopBot, K2, Techno, and there are some Chinese imports that are cheap, but I'm pissed enough about all the crap coming here from over there, like food that poisons us and our pets. Grrr... ...so don't buy one of those! Actually, talk to Brock. I sent him a link to one that was very reasonably priced, and big enough to do a neck. Don

Author:	Parser [ Mon Aug 27, 2007 4:01 am ]
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I got my K2 (with 39" x 25" x 8" cutting envelope and servo controls) with Rhino CAD/CAM and Mach III for about 9k. I think that is the best thing going for under 10k. I did not like the proprietary language that the shopbots run with. Also, If I remember correctly, the shopbots were stepper driven and not servo controlled. A machine like a techno will give you a much more powerful spindle which will allow you to take heavier passes. The accuracy of a techno is comparable to the accuracy of the K2's. K2's are a lot cheaper but you will have to cut a lot slower. The best thing you can do if you are really interested in CNC is to start using CAD (you can download Rhino for free). If you are new to CAD...do yourself a favor and take a class. While it is certainly possible to learn it on your own...it will take much longer! Also, if you get into and you find that you just aren't that into drawing everything on the PC..then you've minimized your investment. It is really cool stuff...but don't let anyone tell you it is easy!!

Author:	Don Williams [ Mon Aug 27, 2007 5:36 am ]
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Easy? Nadda. No way. Big learning curve, especially if you're not trained in CAD at all. Fortunately for me I used to use CAD professionally. It was a long time ago, but not so long that the basics were gone from my head.

Author:	Bob Garrish [ Mon Aug 27, 2007 9:28 am ]
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[QUOTE=Don Williams] Hey Bob, what do you mean that the OS and the hardware have been decoupled? My guess is that when I'm doing hard core CAD/CAM in Rhino and Mach, that I won't be using Parallels, but just boot up in XP Pro. It would be more on the rare side for me to run Parallels unless the Rhino-OSX version comes out soon. Then I'll probably get that version instead of the WinXP version. In that case, when I'm moving the motors around, I'll run Mach in XP via Parallels and Rhino CAD/CAM in OSX. [/QUOTE] Macs used to use their own PowerPC chips, which were different from the x86 chips used on Windows computers. Now Macs also use x86 chips and so the hardware is identical to that used on Windows computers. For what it's worth, I really didn't like OSX based on reliability criteria, so you might just want to run XP straight on it in the end. The suggestion about running mach in Parallels is a good one. If you've got to be running your controller that far out of the loop to begin with (over a comm link) then you want it responding as fast as it possibly can and that means nothing else distracting it.

Author:	Don Williams [ Mon Aug 27, 2007 9:38 am ]
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From the FWIW Dept... I've been interviewing Mac users and employees today, and there seems to be a concensus that the program Fusion is actually much better than Parallels for running the two OS's simultaneously. Thought you guys would like to know. My MacBook Pro purchase has been delayed due to lack of inventory, and now I'm hearing that the new OS X Leopard is due out in October...seems to make sense perhaps to wait, but it's all a big head game to me. Trying to guess what configuration is best for me now and in the future etc. Ick.

Author:	Sprockett [ Tue Aug 28, 2007 5:54 am ]
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Tim... I have essentially the same machine Parser has, it's a good reliable machine and it works very well. I spent about the same as he did to start with but then I added in Rhino training and a ton of bits and pieces. If I had to do it again starting from scratch I would do some things differently but your not going to like my answer ... I would still get a K2 3925 like I have now but I would upgrade to a spindle instead of a router, i would also demand that they either use the G100 as opposed to the serial port OR I would look for a better controller solution. Parallel ports just aren't designed for controlling servos, I run MachIII at the lowest setting because any faster and the machine becomes unresponsive while running parts (the CNC machine is faster though). Now I know some people do that and have no problems, today I can cut anything I want but if the machine so much as burps I can lose work, or worse yet do major damage. Looking back this is the one thing I wish I knew before going in, I found out too late in my case :) All of this costs more, a spindle is an extra $3k but it's worth every penny, they also offer upgraded ballscrews and I would do those as well (mine has them). The G100 is $400 extra and right now you have to wire it in, it does give you more control options but it's extra work. I would also invest in a good Cam program, I use Rhino-Cam and it works very well but I constantly wish I had upgraded to the pro version (which I may do yet). It works today but I'd like some of the other features the upgraded version gives. If you want to get started I would get RhinoCad and learn to use it first (I took classes), it's the biggest hurdle out of the gate. And expect at least a year to come up to speed (maybe more), CNC is simple in concept and difficult to execute flawlessly. It's a learning process, much like building guitars, just with a machine that can do lot's of damage. To be honest if I really was going to do it over, I would save up and buy a used Fadal which you can find pretty cheap (in CNC terms). And I would not build a machine, no offense to Don who's schooled me on the latest stuff, but I have enough to worry about as it is, let someone else sort out the machine :) -Paul-

Author:	Don Williams [ Tue Aug 28, 2007 6:32 am ]
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I agree with Paul on pretty much everything there. A spindle is a great thing to have, and offers better accuracy and a wider array of operations that it can perform. You can't really machine aluminum at 16K rpm, you have to go a lot slower, or the bit and the aluminum will become one. A spindle can slow way down and give you that ability. I think the only reason I'm building one is the challenge and the ego-trip of telling someone "I built that". Similar to building a guitar, when you see someone's face when you tell them, it's a big kick. As you can probably tell, I also enjoy making jigs and stuff myself. Just wait until I figure out how to probe a guitar and use the cnc to cut the binding channels! From there....the next step will be cutting them with a laser.

Author:	Bob Garrish [ Wed Aug 29, 2007 1:31 am ]
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I machine aluminum at 65000 RPM all the time... I run my spindle at full RPMs probably 95% of the time. The main advantage, for your type of machine, would be that a spindle is made to run a heavy duty cycle and the runout is much, much less than that of a consumer router.

Author:	Don Williams [ Wed Aug 29, 2007 1:54 am ]
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Interesting Bob...I was told that if you have high rpm's you also have to have an equally high feed rate to keep the aluminum from welding to the bit?

Author:	Parser [ Wed Aug 29, 2007 2:22 am ]
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65000...whew....how large of a bit can you run? I'm assuming that's an air driven spindle? That would be awesome for inlay cutting. The Fadal's seem to really only want to run up to about 400 ipm though from what I have seen..unless you are tweaking the machine settings from the norm? Don - read up on "chip load" or "feed per tooth". This is basically the chip thickness coming out of your cutter. You'll find that there is a linear relationship between RPM and feed rate...i.e., if you run at 50% higher RPM then you can theoretically run at a 50% greater feed rate. The Onsrud cutter site has some good info on feed rates & chip load for cutting wood. The real rule of thumb though is to run as fast as you can while still getting a good quality cut (and not pulling your part off it's fixture!). You can tell a lot about the cut by the way it sounds when it is cutting.

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