Small CNC mill recomendations?

[Miles]

I was thinking of getting one of these, to play with: http://www.syilamerica.com/product_X5.asp I can always upgrade it later.

I'd rather be designing and prototyping than building machines. Had enough of that with my manual mill.....

 

[TPA]

It does have ball screws!!

but it is $3200

 

[Miles]

but it is $3200

Yes, quite cheap for a ready-to-run

 

[jag]

I was thinking of getting one of these, to play with: http://www.syilamerica.com/product_X5.asp

That little mill certainly looks like it could be the center piece of someone's model workshop. It is nice to have both motors and hand crank ability. It looks like one would crank it though the steppers. How does that feel? I was afraid that it may make hand cranking less smooth due to the magnetic poles of the motor. The big Bridgeport's I used in school would mechanically completely disengage motors when hand cranking.

I thought I had overcome my machine-shop-at-home desire/addiction about a year ago... Maybe not. Problem is that once I start with one machine I will want more until I have the same capabilities as a real shop. Now that would maybe be ok if metalworking was my only longing, but there is so much else exciting out there, e.g. composites. So I also have to restrain myself from acquiring a vacuum bagging outfit... Better stick to woodworking. Woodframe electric car anyone?

 

[liveforphysics]

http://seattle.craigslist.org/see/tls/1445853950.html


This says it's a CNC router table.

I'm not too interested in doing anything with wood. I would be mainly cutting aluminum. Everytime I see this style of machine design, it always looks so flexy. Would a machine like this be able to do good work in aluminum?

Would that Joes 2006 machine (which looks similar to this one) be able to do decent aluminum work? I noticed the kit was up in the woodworking area, and that all I had ever seen anyone using it for was wood.

 

[liveforphysics]

I just had a 20min talk with the guy in the listing i linked above.

He said it has very find pitch 10tpi ball lead screws with zero backlash nuts. He also said he has a control for slowing down the spindle, and it lets it make good cuts in aluminum or thin sheet steel. He sent some pics of some very fine circuit board work that it did, and it looks pretty good to me!

Much bigger table than I wanted, cutting area of the table is about 55”x27"x6”. But I guess that's not such a bad thing in the event that someday I want to cut some bigger stuff.

He said he will give me the cut-code for every piece of the router, so if I'm worried about it being made of MDF, I can use the router to replicate itself out of 1/2" aluminum sheet.

I've got the cash in my pocket, and I'm going to meet with this guy tonight.

If this sounds like a good deal to you folks who know what you're doing, please let me know! If there is some critical design flaw in this thing, please also let me know before 8pm this evening, because I'm likely going to buy it if nobody can see any problem.


Things I'm personally afraid of, are MDF as a structural material. It just seems so weak and flexy for something cutting metal.

It also just uses little sealed roller bearings riding on aluminum channel to function as linear bearings. That seems pretty cheesy compared to looking at the linear bearings I've seen that slide onto 1" centerless ground steel rods, but maybe it's good enough?

Give me some advise here guys! Seem like a good machine for doing aluminum? Seem like a flexy wooden waste of time?

 

[AussieJester]

My mill is MDF Luke as are many DIYs when doubled and trippled up it is very solid...sounds like
a pretty typical linear setup too alot use sealed bearings running on rails mate, i have mine running on steel not ali though,
Like the fella said if your not happy with the mdf parts you will have the mill and the codes simply machine it up in aluminium and whack it together ...with bed that size you will find many uses for it IMHO...I would take a serious look at it anywayz...best of luck


KiM

p.s Fella local too me built this CNC Router and it cuts aluminium no probs, he made his from steel though not mdf..

 

[jag]

Give me some advise here guys! Seem like a good machine for doing aluminum? Seem like a flexy wooden waste of time?

I'd think twice. What's your main use? I had the impression that you want to do high precision milling of aluminum and possibly other metals for e.g. building motor components. In that case I think a real metal mill, even a small one like the one Miles pointed to, would be best.

What you describe now sounds like an automatic router table. They have these in the design department at school, but I haven't used one. The most common use they have for it is to make wood 3D models of things they design. However Ken Salisbury, the prof who among things designed the DaVinci surgical robot, the Phantom, our WAM's and many other things, (He's like the Burt Rutan of robotics), makes fully functional cable drive robots out of plywood routed by one of these robots. Load bearing space structures are made much like the wood cores in home built aircraft wings. Very cool. For $5000 he can make a robot from wood, steel wire and servo motors that can do the same stuff a $100,000+ commercial robot. (Probably 95% of the $5000 is in the servos. Good ones for robotics can be $800-1000 a piece.) So if you wanted to get into for instance making aerodynamic bodies with techniques similar to homebuilt aircraft this router would be great. Takes full wood sheets and out comes your parts.

(b.t.w. Need mote speed? Get into airplane racing!)

 

[Kburn77]

Here's a cnc router that I make, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200391105834&ssPageName=STRK:MESOX:IT#ht_4010wt_1165, I'm doing some revisions now but it cuts aluminum really well! I'm making a cnc now that uses NSK ballscrew actuator and it'll have .0003" accuracy and 17"x17"x6" of travel, I'm only making one of these and it's going to be ultra! If you ever have any cnc questions you should hit me up.

Kevin

 

[Kburn77]

Here's a pic of the NSK cnc I'm building now.

 

[greenerwheels]

Hi

I've had my eye on a CNC router, basically a 2D Mill and after reading a review in nuts and volts magazine I think this is the one I'm planning on buying (eventually)
Probotix Fireball V90 CNC router
Here's a link
http://www.probotix.com/FireBall_v90_cnc_router_kit/
http://www.nutsvolts.com/media-files/1014/122008-PersonalRobotics.pdf

The place I used to work bought a MAXNC. I learned to program GCode on it. The DXF to Gcode converter that came with the MaxNC was pretty bad and I found in quicker to write the Gcode for many simple tasks in Notepad.
Otherwise the MAXNC was an ok machine and I did use it almost daily. Set it up, turn it on, go to lunch. It cut aluminum and brass just as long as you took small cuts, I imagine the V90 would be the same

http://www.maxnc.com/maxnc_15_open_loop.htm

The one thing I would suggest is to keep in mind precision requires mass, that's why Bridgeport mills look like tanks, I believe all of the desktop machines pretty much share this same limitation.

Best of luck

Greenerwheels

 

[AussieJester]

Very nice looking mill there Kburn77 looks close to completion, i wish
i had room to have mine 'a work in progress' still but had to pack it away
to make room for latest build...Itching to finish it and get a larger furnace happening still

KiM

 

[Kburn77]

KiM, thanks, if you ever need parts or help with anything, lmk. I have made over 30 cnc's from 4'x4' plasma, to a 4'x8' that I am using now. With a hobby like ebikes this it's a huge help having a cnc make the parts for you. I am still amazed when I set the machine up to mill out multiple pieces out of 1/2" aluminum and a little while later it's done and the parts are pulled off the machine completely ready to use. It's also very cool to have all the holes and parts fit perfectly Half the battle with cnc's is having the need/product for it and the the other half is knowing/learning how to design and program parts to be made.

 

[kfong]

For metal cutting, it's best to have as much cast iron as possible. A heavy solid mill will have very little tool chatter. A wood based CNC will chatter too much on deep cuts. Even my micromill has way too much tool chatter so I have to do shallow cuts to compensate. If you do build one, go with 3amp stepper drivers or higher and at least 300 oz motors. The best setups are servo systems, but they are more costly and more difficult to setup. My website shows how we converted a cheap harbor freight micro mill. I use this to make all my bike parts.

If you did pickup the wood cnc, you will probably need to remake it out of aluminum to be able to cut metals. I've made one out of wood, but would not use it to cut aluminum. One possibility that I have not tried is to use a high speed motor setup from an RC motor. The high speeds 40-60K will allow for less too loading which means a less stiff milling machine. Then the wood CNC might be possible.

 

[AussieJester]

The high speeds 40-60K will allow for less too loading which means a less stiff milling machine. Then the wood CNC might be possible.

You might have missed the fact that the routers used on these mills do spin pretty quick already mines 30 000rpm max speed.
I have seen many of the DIY wood builds mill aluminium no probs at all.

KiM

 

[kfong]

Hi Kim, having a high speed spindle helps a lot. Not a lot of routers go that high or are just too bulky to use. Some have terrible runout and you are limited to the tooling used. What brand is the one you are using? That's why I brought up the idea of a custom RC motor setup. Something I've been wanting to do but have been busy with other projects. You can get very high speeds with outrunners, but the bearings will be the weakest link. High speed spindles in the CNC world are quite expensive. Ususally air driven bearings. I would like to see a video of a wood cnc cutting aluminimum, I'm sure it's being done. Just curious at the depth of the cuts and the cut quality.

 

[Jonathan in Hiram]

I built a CNC router for custom wood carving about ten years ago, used wood for the base, hardened v wheels running on music wire embedded in aluminum bar for the linear bearings, stepper motor drive by rack and pinions.

What I found was that every once in a while the electrical noise from the router brushes arcing would cause random missteps, ruining the piece I was working on. I tried an isolation transformer for the router and the stepper driver, putting all the electronics in Faraday cages, everything I could think of and still got the very occasional misstep while the router was running.

I'm thinking about getting it up again but use a brushless RC motor for the spindle drive, shielded ceramic bearings may stand up to 40krpm, which is about what I'd like to turn..

 

[nicobie]

No matter what, DON'T buy one of these.

I did, but sold it right away. It would work on aluminum (taking shallow cuts) but the problem was that the results weren't repeatable. It just wasn't accurate enough for my needs, even when working wood.

http://www.carvewright.com/

Among other things, I make reproduction totes for old hand planes.

Nick

.

 

[kfong]

I remember Sears selling one of those, thought it was a good idea at first but since the wood is moving back and forth. The repeatability was questionable, there is something similar in the RC world called the phlatprinter. Similar concept, good enough for foam planes and balsa but same problems. You can't count on the material being moved from drifting.

No matter what, DON'T buy one of these.

I did, but sold it right away. It would work on aluminum (taking shallow cuts) but the problem was that the results weren't repeatable. It just wasn't accurate enough for my needs, even when working wood.

http://www.carvewright.com/

Among other things, I make reproduction totes for old hand planes.

Nick

.