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Doc Nickel
11-20-2016, 04:01 PM
I am currently contemplating a short-run production project in wood. It's a fairly simple part, but needs a bit of contouring, and if all goes well (always a tricky thing) I hope to have need of 100 to 200 parts.

I may farm it out, if I can find a shop that can do it cheap enough (although there would still be quite a bit of shipping involved if they're not right here in town) but I also started thinking of picking up one of the now-popular home-shop sized 3-axis CNC wood routers.

I know that as I was looking around for parts for my Logan CNC conversion, I ran across several models of various capacities and costs. I'm not personally familiar with any of them, however, nor do I know anyone who has had one, used one or built one.

So what I'm looking for, is a pretty well-built 3-axis CNC wood router/wood mill. I need a minimum working area of about 18" (I could stand 18" x 12", but I need to be able to cut a part at least 14"-15" long.) I don't need particularly amazing accuracy, but it does need to be rigid enough and have enough HP to be able to rough a fair-sized slab of wood without requiring a 6 or 8 hour cycle time.

And, if possible, available for $2K to $2,500.

NOT really looking for a DIY solution, unless it's simply an assemble-it-yourself kit. The last thing I need right now is another long-term build project. :)

There's a bunch of options listed on eBay, virtually all of which I'm sure are of Chinese origin, but there's several that (at least superficially) look promising at only $800-$1200.

Anybody have the insider's take on this? Any and all information welcome.

Doc.

iMisspell
11-20-2016, 07:01 PM
Got one of these a few months ago:
http://www.ebay.com/itm/1-5kw-CNC-4axis-Router-Engraver-Machine-CNC-Milling-Engraving-Desktop-SHIP-USA-/272145408161

Have not used it a whole lot but no real complaints yet.
It was packaged well for shipping.
Everything assembled with out a problem.
Worked out of the box with only one issue, M3 didnt turn on spindle, had to change a parameter on the control box (dont have info infront me right now).
(edit) found info, adding incase someone finds this thread through a search
Changed VFD parameter 32 to equal 0 and now the VFD is talking with Mach3.
Spindle only works CW, but for wood working thats fine for now.
The 'PC' and 'Manually' switch are working.
FWD and REV are not working.
While in PC mode, i must press the RUN button once and then Mach3 has control, spindle speeds, M3 and M5 work correctly.
(end edit)

As of now, if i was to do it again the only thing i would do different is get a bigger motor just for the bigger collets (dont remember the ER size, but max shank is 1/4 and the next size motor max size is 1/2).

The bed is kind of crap, not flat or square to the machine, i havenít measured it (havnt really done anything which would require anything closer then +- .025 of parallelness (to the bed)) and it was little flimsy/bounce in the middle which i didnt care for and bolted a peice of 3/4 plywood as a sub plate and it worked for me. When i got the machine i was not expecting much and was alittle surprised at how well it works.

The "directions/manual" which came with it was a joke.

It came with a cd with Mach3 on it which i didnt use, i whent strait to the Mach website and downloaded from there (ohh.. and had to use the NEXT to last version/release of the download, the latest had issue at the time, dont know if they released any fix the issues.)

With a 4 day weekend coming up, if you want me to run some tests or measurements just ask and ill post the results.

Heres some things which it cut...

The bord and "fixture":
http://i1284.photobucket.com/albums/a570/iMisspell/Engraving/Flags/th_IMG_20160514_220943_zpsjdk3l6tj.jpg (http://s1284.photobucket.com/user/iMisspell/media/Engraving/Flags/IMG_20160514_220943_zpsjdk3l6tj.jpg.html)


http://i1284.photobucket.com/albums/a570/iMisspell/Engraving/Flags/th_IMG_20160522_164548_zps1c7jwcen.jpg (http://s1284.photobucket.com/user/iMisspell/media/Engraving/Flags/IMG_20160522_164548_zps1c7jwcen.jpg.html)

Plexi Glass...
http://i1284.photobucket.com/albums/a570/iMisspell/Engraving/Flags/th_0716161600_zpsbhef3o0j.jpg (http://s1284.photobucket.com/user/iMisspell/media/Engraving/Flags/0716161600_zpsbhef3o0j.jpg.html)


Plexi Glass...
http://i1284.photobucket.com/albums/a570/iMisspell/Engraving/Flags/th_IMG_20160618_220709_zpspcukx8ju.jpg (http://s1284.photobucket.com/user/iMisspell/media/Engraving/Flags/IMG_20160618_220709_zpspcukx8ju.jpg.html)



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Doc Nickel
11-21-2016, 02:56 AM
Thanks! That's more or less one of the models I was looking at- maybe not that exact one, but one of those flavors anyway.

I don't really need the 4th axis, but I have a buddy with a little Grizzly mill conversion that wanted one... How big is it? Probably a 4" chuck?

Just as a ballpark figure, say you had a workpiece where you had a slab of wood, and had to mill a dinner plate out of it (- both sides, as a rough idea of how much material is to be removed.) Roughly how long would something like that take, including enough finishing passes that it would only take relatively minimal sanding to make it ready for stain and clear?

Is that something that might take 20 minutes a side, or would you be looking at 2-3 hours per side.

Doc.

Doc Nickel
11-21-2016, 01:14 PM
Anyone else? I keep running across mentions of the Shapeoko unit, which is apparently rigid enough people have been cutting aluminum with it...

Doc.

DR
11-21-2016, 08:25 PM
Something to consider on the low end units is the controller software. Shark, Axiom and other systems sold at the woodworking stores like Rockler and Woodcraft, etc have odd ball, proprietary controllers. These controllers make hand coding difficult, the machines are usually supplied with Vectric software to program, but that's odd ball itself. Why they don't use Mach 3 which well supported is a mystery.

browne92
11-22-2016, 10:46 AM
I bought something similar to this a few years back straight out of China, without the water cooled spindle motor.

http://www.ebay.com/itm/3-AXIS-Router-Engraver-Engraving-Drilling-Milling-Machine-Desktop-CNC6040-1-5KW-/142147114880?hash=item2118a0d780:g:rLMAAOSwgQ9V48s C

It has a dc spindle motor with a speed control knob in the cnc controller. No changing spindle speeds in software. Uses an older PC with Linux CNC software.

Not long after I got it, one of the logic chips in the controller died. Moved that axis to another channel. Then the couplers between the motors and lead screws started breaking. Replaced them all with solid ones. Then had to grind flat spots on the motor shafts and torque the crap out of the set screws or the couplers would slip. Then the x axis quit. Turns out there was a break in one of the wires from the controller to the motor. Ran an external wire. Then when I tried to speed things up, found that the x axis would get lost. Turns out the driver board for that axis would work fine at slower speeds, but didn't like 750mm/min. Replaced the driver board. Started having trouble turning it on and off. Had to replace the power switch. A lighted rocker switch that was rated at 20 amps that arced itself to death. I think if you actually ran 20 amps through it, it would had exploded. Most recently the z axis started getting lost. Another broken wire in the cable to the z axis. Apparently the Chinese can't make brown wire.

If you buy one, don't expect anything akin to tech support, documentation, or even return emails. And don't think the term "USA Seller" is going to help you. That just means they shipped it to one of their relatives in California to resell, and they don't want to talk to you either.

Best of luck.

Doc Nickel
11-22-2016, 01:57 PM
Things like that was essentially what I was worried about with the cheap eBay offerings. Some of those start looking "suspiciously" cheap, which made me start thinking of all the corners that got cut- undersized steppers, counterfeit power supplies, etc.

I'm starting to lean towards the Shapeoko setup. Support seems decent, quality seems pretty good, they have an active forum, etc.

Doc.

nc5a
11-22-2016, 02:26 PM
Doc

If this is a test run to see if the product is marketable or a one of production run I suggest you take advantage of one of the rental shops available up here. This particular shop has 2 CNC routers available along with other machines and probably expertise to help you get started in the CNC world. Plus you get hands on experience to see if you want to actually buy a CNC router or farm the job out.

http://anchorage.craigslist.org/off/5833281096.html

Since I haven't heard from you I assume the grinding project isn't going to happen anytime soon.

MrSleepy
11-22-2016, 03:20 PM
Boxford in the UK made a series of routers for schools , that may have made it out to Canada.

I have an ex school Boxford HSR500 as below,and its a heck of a machine for the price,and a very easy conversion to mach3 with a Lpt1 break out board, as it already has all the stepper drivers and power supply in the side cabinet.

https://www.gandmtools.co.uk/shop/boxford-500hsr-high-speed-cnc-router-cabinet-stand-1ph-80203821/
(ignore the security issue FF flags up.)

Doc Nickel
11-22-2016, 04:16 PM
If this is a test run to see if the product is marketable or a one of production run I suggest you take advantage of one of the rental shops available up here.

-I wasn't aware there even was such a thing up there, thanks for the tip.

Unfortunately, a 3-hour drive each way, especially in the winter, is a bit much for regular use of the facilities, and if I did wind up in production, I'd need to carve up between 100 and 200 parts- and I can see each part taking an easy 30 minutes to an hour of profiling. It's not complex, but we'd have to do both sides, and it's a largish piece with a lot of stock removal.

Even just 20 minutes each for 200 parts is still over sixty hours of machine time.

I'm currently leaning towards the Shapeoko unit. I hear good things about it, the support seems decent, and I've heard from a couple of people that have hundreds, if not thousands of hours of production cutting on theirs. The 16" x 16" model is $1,100, and a eBay water-cooled power head kit (ER-ready spindle, VFD, water pump, cables and hoses) can be had for around $400.

That's just $1,500 (plus a PC, which I have) and I can be up and running in my own shop.

Yeah, if I lived in Anchorage, I'd likely be spending a great deal of time at the Maker shop, but for the moment, travel time alone would be a serious issue.


Since I haven't heard from you I assume the grinding project isn't going to happen anytime soon.

-On the contrary, I've made a few calls and will be making a few more shortly. I don't have any hard answers yet since some of the people I've needed to talk to have been either busy or out of the shop, but I'm working on it.

Most of the project is up to you- it's your truck and your trip. I have my preferences, but it'd be easier for me to work around your schedule than the other way around.

Doc.

browne92
11-23-2016, 09:56 AM
-That's just $1,500 (plus a PC, which I have) and I can be up and running in my own shop.

Maybe. If you're looking at using Linux CNC, I suggest downloading it and testing it with your PC. Unless something has changed since my older version, back when it was still called EMC2, it can be very particular about the PC's it will run on, especially the newer stuff.

TOOLZNTHINGS
11-23-2016, 08:05 PM
Vetric is CAM software for programing tool paths, not a machine controller like Mach 3 . Plenty of post processors available.

DR
11-24-2016, 03:27 PM
Vetric is CAM software for programing tool paths, not a machine controller like Mach 3 . Plenty of post processors available.

Exactly. And Vectric supplies post processors for Shark and other low cost routers with proprietary controllers. The problem is Shark does not supply a programming manual if you'd like to know about available Gcodes and Mcodes, etc for programming using methods other than Vectric. Things like G41,42 are nice features to know about, if it does support them.

I was considering a Shark for some very simple parts. When I requested a listing of all Shark Gcodes their tech support sent a program listing for the machine to cut a 1" square. I called back thinking the guy made a mistake, nope, that was the only programming info he had. He seemed surprised I would want to know.

Vectric may be fine if you want to make sign-like things.

DEVILHUNTER
11-24-2016, 03:31 PM
Maybe. If you're looking at using Linux CNC, I suggest downloading it and testing it with your PC. Unless something has changed since my older version, back when it was still called EMC2, it can be very particular about the PC's it will run on, especially the newer stuff.

Since the 2.6 version is way better in terms of compatibility wtih PC's.

Doc Nickel
11-24-2016, 03:41 PM
The Shapeoko I'm looking at comes bundled with what appears to be some kind of proprietary software- they call their design software and control software "Carbide Create" and "Carbide Motion" (the company that makes the Shapeoko is Carbide 3D.com)

I have no idea if those are entirely proprietary, based off Linux, or based off something else. What little reading I've had a chance to do so far (hey, it's been a busy week :) ) nobody seems to be overly concerned with the software, or spending a lot of time complaining about having to convert over to some other software, so I'll assume the bundled stuff is at least reasonably functional.

In any case, the part I need to make is fairly simple- as long as I can make that one part every time I press the "go" button, I'll be happy. :)

Doc.

iMisspell
11-24-2016, 03:43 PM
How big is it? Probably a 4" chuck?

Is that something that might take 20 minutes a side, or would you be looking at 2-3 hours per side.

Didnt get the 4th axis, the machine was $1200 with out and didnt see a need for it.

Have no clue about a cycle time for that, but with a 1/4 endmill i would say closer to an hour. I havnt really played with the machine alot so cant comment on any practical or suitable speeds and feeds the machine. So far spindle speed around 22,000 and feeding about 24 ipm with .187 doc in softwood with no problem, it sounds good (two flute carbide endmill) and no burning wood.

That little fixture for holding the circuit board blank is aluminum and was cut with the router. Used small .032 doc (i forget the speeds and feeds) and it worked, sounded horrible but i think the machines bed had alot to do with that (didnt use any sub plate for stiffening),

Gonna assume that these parts are too big for your cnc lathe conversion ? With the convex and concave features of a dish/plate, its an ideal part for a cnc lathe. You could machine the back side of the plate first, then hook up a vacuum chuck and use the dish/plates "foot" for centering/consentricity.

When i bought this cnc router, it was for a basement hobbie toy kind of thing, not sure i would buy the same if i was gonna depend on it to make money, I am suprized on how well it works, but it is a hobbie machine in my opinion.


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GEP
11-24-2016, 04:58 PM
Things like that was essentially what I was worried about with the cheap eBay offerings. Some of those start looking "suspiciously" cheap, which made me start thinking of all the corners that got cut- undersized steppers, counterfeit power supplies, etc.

I'm starting to lean towards the Shapeoko setup. Support seems decent, quality seems pretty good, they have an active forum, etc.

Doc.

Look at this Doc
http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/

DR
11-24-2016, 05:02 PM
With a bit of Googling on "carbide motion" it looks like they might use an Aduino and GRBL as their controller. If that's correct, another puzzle why they don't use something more mainstream like Mach 3.

GRBL is not exactly a full featured controller.

DR
11-24-2016, 05:13 PM
I have no knowledge of Shapeoko. But in the world of "real" CNC's manufacturers have no hesitation about evaluating parts and giving time estimates to run the part. Wouldn't hurt to ask them, huh?

garyhlucas
11-24-2016, 05:49 PM
http://s811.photobucket.com/user/garyhlucas/library/Sampler?sort=3&page=1

Doc,
I've been following this thread and thought I might give some ideas. I hope the picture link works, its pictures of a Chinese CNC3020 I just purchased. I am not using it for machining, it's being used to place liquid samples in test tubes and the 4th axis runs a peristaltic pump. This seemed like a cheap way to get the task done. However it has been more of an adventure than I had hoped.

This machine must run standalone for weeks and possibly months. So I really didn't want to use Mach 3 on a PC to run it, even though I have another machine I built using Mach 3 which works very well. If you are interested the dropbox link has photos and video of that machine too. So I found this little TOPCNC TC55H controller that looked perfect for the job, and bought a CNC machine that used a parallel port control to connect to a PC. However my electronics knowledge was not up to the task of figuring out a connection scheme that would work. Also in looking at the driver box that came with the machine and not having any drawings means it is completely un-serviceable if it fails. Then it became apparent I really needed some things like automatic current reduction drivers so the motors don't overheat sitting powered for weeks at a time.

So I grabbed an enclosure out of a previous project, and some terminal blocks, a 24 vdc power supply, then went on Ebay and got 4 Leadshine DM422 drives, and a surplus American made 36vdc linear power supply. I used open wire only for the DC power, and used 4 conductor shielded cable for the motor cables and the connections between the CNC control and the drives. The Leadshine drives are the best of the chinese drives in my book. I am microstepping the drives at 3200 steps per revolution for smoothness and the motors are fairly quiet. The box you see took me two days to mount all the components and wire it, so this was quick and dirty. However all the wiring is properly shielded and all terminations have ferrules. It works! Rang out the connectors on the CNC3020 with an ohmmeter and every wire was right and all the motors went the right direction on the first try. I've been building industrial control panels for over 50 years because my dad started me out at 11, so I would hope that would be the case.

I saw mention in this thread of speeds above 750mm/min being a problem on one of these chinese machines. Probably due to the high quality drives and the 36 vdc power supply this one runs smoothly at 1500mm/min. The drive box easily runs it at 3000mm/min but at that speed the acme screw and ball bushings on the long Y axis sound terrible! Just for comparison, my homebuilt CNC Mill operating on Mach 3 with THK linear ball bearing ways and 20mm x 5mm pitch ball screws rapids at 7500mm/min, and I often cut plastics and such at 3000mm/min. Mach 3 works well but you can't reach these speeds unless you use a USB or Ethernet motion control board. The one in my mill is a Xiulifeng 4 axis board that has been much better than I expected, never giving me a single glitch. The one downside is there are no drivers for Mach 4, so I haven't been able to make that move.

The shapeoko has a couple of shortcomings I can see right off. One is the control system software is GRBL (pronounced Gerbil) and the name is appropriate as in really under powered. The second is the driver board, compare that and the power supply to what I just built! The performance is going to be really mediocre at best. The frame design is quite clever but you must realize the axis are plastic V-wheels on hard anodized aluminum, so I'd purchase spare wheels right out of the gate.

It really is the controls that make a CNC perform. So I'd see if I could get the Shapeoko machine and motors without the electronics, then buy a surplus enclosure off EBay, some drives (Leadshine DM422 4.2 amp not the 2.1 amp, $60 each), there were a couple more of the 36 volt power supplies I got ($50), a Xulifeng ($180)or other USB motion board, Mach 3 ($149) and CamBam Cam software ($149 use it 40 sessions for free), some fuse blocks and terminal strips from AutomationDirect.com and a cheap computer desktop or laptop with a USB port. Get an enclosure a lot bigger than you need, it will still be too small but thats just how it goes! You'll likely want a bigger or simply more robust machine at some point. If the box is big enough you can upgrade the drives, power supply, motors, or even the machine etc. and flip them on Ebay continuing to use your control package and keep the future cost low.

Happy to help you pull this off.

Doc Nickel
11-25-2016, 02:24 AM
Gonna assume that these parts are too big for your cnc lathe conversion ? [snip] You could machine the back side of the plate first, then hook up a vacuum chuck and use the dish/plates "foot" for centering/consentricity.

-Sorry, I wasn't clear. I was just using the "dinner plate" shape as an example of a common size and shape, with a rough idea of how much material would need to be removed. The actual part in question is more of a tapered rectangle, with lots of rounded edges.


When i bought this cnc router, it was for a basement hobbie toy kind of thing, not sure i would buy the same if i was gonna depend on it to make money, I am suprized on how well it works, but it is a hobbie machine in my opinion.

-Oh, I fully understand these are little more than toys, as far as production machine tools are concerned. But I'm having to look up options here. I hope to need upwards of 200 parts. If I pay another shop to produce them... well, as you say, they might well take an hour or more each. I spoke with one local shop and their rate is $60 an hour. With material, I might then have $65-$75 in each part. That's $14K in product right there.

Even just $20 in shop time would be about $30 each, or $6K for the lot.

If I bought the Shapeoko AND the water-cooled head, for a total of around $1500, even if it's fully used up and ready to throw away after 200 parts, that's still something like $7-$8 per part, plus the same $5-$10 for material.

Hell, I could buy two and still be ahead of the game.

Doc.

Doc Nickel
11-25-2016, 02:31 AM
Look at this Doc
http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/

-Thank you for the link, but I've seen more than a few articles like that already. At the moment, I don't have the time or, really, the interest to start yet another major project. I still have no fewer than four machine tools to finish rebuilding, I need to finish prototyping the project I'm needing the router for (I figure two more generations of prototypes before I expect I'll be happy with it enough to start ordering thousands of dollars worth of parts and materials) and all that is in addition to the countless small projects, customer projects and so on I'm currently working on.

If I had more time, yeah, I'd probably jump on something like that. :)

Doc.

iMisspell
11-27-2016, 12:27 PM
The actual part in question is more of a tapered rectangle, with lots of rounded edges.
Read too many threads and posts to keep track of which member has what experience and machining they have done, so please don't take offence to this if you have already been there, done that and have experience or knowledge with this.

When dealing with convex, concave and tapered shapes/features of a part (in/with Z axis/plane) on a mill, finishes become time consuming cause you have to use a ball endmill so the leading and trailing edge of the cutter does not dig into the feature being cut and you have to make very small step over passes cause the cutting end/tip of the ball endmill is so small.
But if you are talking about a tapper in the X/Y plane and corner radius also in the X/Y plane then the finishing time is reduced drasticly cause your step over passes are larger. Depending on the feature you might beable to use a form tool to cut down on the finishing cut time. If you need a 1/8 radius on the top edge of the part you can use a 1/8 round over cutter and run the perminitor.

1/4 endmill will make 5 finishing passess with a step-over of .235 and cover alittle over 1-1/8 wide part (just face milling).
1/4 ball endmill will take over 100 passess with a .010 step-over to cover the same surface area, hence the long finishing cycle time.

Hope that all made sense if your not familiar with it.

Some CAM software will give you an estimate of the cycle time, pretty sure ive seen people talk about it for Fusion 360, i know Alpha CAM and HSMWorks does.

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