[Walky]

I'm not sure about the proper forum to put this, but since at its roots it is DIY-machine oriented I guess it somehow fits here, even when it's not the usual thread you find here.

I'm sure that, like me, some have gone a long way since they started in this beautiful world of CNC. I started to get interested in CNC almost 3 years ago, and at that point I couldn't imagine where this would take me and how much I would learn in this time. Anyway, my story comes from years before

Back to 2000: Last year of school, first of the class, few friends and still, somehow, a lazy bastard that didn't ever study unless it was the night before a test (relied on just paying attention on class) and still got good grades; decided to study civil engineering the next year (I love math, physics and tinkering in general).

Next year was a nightmare: didn't get a thing, didn't understand how university works (included the damn bureaucracy), wasn't used to actually studying which made things horribly worst. I started feeling lost, couldn't hold an idea in my head. Click! "Pre-schizophrenia", the psychiatrist said. Tried changing to computer engineering next year; I managed to finish last year, this time I lasted two months. Lost again. Next year: electronic engineering. "Click" after a couple of months. A full year to another city under treatment, while under $400 specific drugs, quite an extra burden for someone who already had wasted 3 years of his (and his parents) life. Doctors 1, doctors 2, doctor 3, scan my brain, white spots are no good. Next year: yeah, maybe you're fixed, try again. No good, still can't hold an idea on my head, my memory is not the one it used to be, too. At that point I learned Log (2) with 10 decimals by memory just by seeing it at the calculator once, dunno why (I can still remember it 7 years later), but couldn't remember how to make a simple 2 digit division with pen and paper. Maybe I'm not compatible with the university structure.

Finally... I quit; screw the doctors!, took a year to think about everything, it was one of the smartest things I've ever done. Learned some japanese, asked for some help from friends from university to learn some basic electronic concepts, had some much needed mental rest, and the next year entered the fine arts school. Good grades, warm ambient, quite the opposite to the cold clockwork machine university was for me. Spent 3 years there, met my wife there (the most supportive woman I've ever met), my doctor said I didn't need the damn pills anymore... things were finally getting better.

Then I discovered CNC.

I like to build stuff, I always have. This was like something out of heaven, the merging of every hobby into something unique that covers all. I decided to build my first machine using the electronics basics I got from my friends and the at that time dominant aluminum profile - skate bearing approach. My build (as you can see in the first picture) was a piece of crap but somehow worked: I was so excited! So I decided to get proper drivers and motors and build a bigger one. Then came the rails, new power supply, new machine structure with parts made by the machine itself, then a smaller machine made with it, which sold relatively quickly. I decided this is what I wanted to make for a living, and started trying to refine my designs so I could get to a point of being able to sell an affordable commercial-level hobby machine, and now, August 2011, I finally have a 90% finished prototype (minus drivers, which are on their way) on my worktable, looking beautiful. I must admit at this point I feel like crap, I have spent a lot of money in the process of learning and building and the anguish of having to wait to see how will this project unfold is killing me, but I guess that's the price of dreams.

I must admit I'm not the same as before; I feel more mature, but at the same time I feel my brain isn't what it used to be; more specifically, my short-term memory is incredibly bad, but I think I'm getting used to it and my wife doesn't get angry after I ask her to repeat (again) what did she just said.

I want to say thanks to CNC Zone and its members, since without you I'd have never gotten to the point I'm now. It's thanks to the huge will to help that most people have here, and the amazing experience that some members have proven to have that every single doubt I've gotten in the past three years have been solved. In fact, if it wasn't for CNC Zone, I probably wouldn't even have decided to give it a try. The world of CNC fills me, and it's thanks to this forum that I've come to realize that.

Well, just wanted to share this with you, I hope it wasn't too boring.


Thank you CNC Zone! It's been quite a journey.


I've attached some images of finished and unfinished machines I made, in chronological order (just imagine them with music like those videos some people like to show in their weddings ). Some unfinished crappy machines are missing (not worth showing).

[Ron Dunn]

So which is the best machine, and why?

(great to see so much diversity in what you've built)

[Walky]

The pictures go from worst to best (the last two are a little too different to compare, though).

The steel-aluminum machine (sorry, I don't have an updated picture of it) it the one I'm currently using to cut stuff; it's a little ugly since had to make everything by hand, because I had my previous machine disassembled; I plan to use it to make aluminum parts for itself someday. I cut mostly plastic and wood, but it can do aluminum (it's pretty solid). It uses 10mm pitch ballscrews for high rapids and a SuperPID for RPM control. I used it to cut the parts for the plastic machine (last picture). The plastic machine uses all-thread, but newer revisions will use 12mm ballscrews. The driver will be a G540 on bipolar parallel.

The worst machine (first picture) was probably one of the most rewarding, since it's the only one I've done with self made electronics (including PIC programming for step-dir pulses interpretation) and it was my first approach at CNC. I actually built a controller box with etched pcbs to replace the proboboard you can barely see in the picture, but didn't get to use it since at that time I decided to buy a 3 axis kit.

The red machine was built for sale, I loved that machine!, it had just the right work table size for most thing except signs and machine parts.

I will post some Youtube videos from a few of those machines tomorrow, right now I'm extremely tired (6:15 AM) so good night!

[aarongough]

All the machines look great!

I especially love the design of the last one... What type of plastic is that?

I'm slowly working through the exact same process you went through. I'm looking forward to the end result!

[Med-Pac]

Nice work....congrats.

[Walky]

Thanks for your comments

Looks familiar?
Tabla profesional para picar 60x40x2 cm - Sodimac.com

That's what I used as plastic for the last machine; the next units will be made of proper PP, it just wasn't worth wasting so much money on plastic considering I was likely to redesign some parts in the process (which I did, I actually used a full extra cutting board). I would love to make it all aluminum, but I'm finding it very hard to find decent, straight and shiny material locally (in fact, my big aluminum machine is made with scrapyard aluminum plates that just happened to be the right size).

[Benonymous]

Thanks for the inspiring story Walky. My Grandfather had depression and was taking all sorts of drugs and even had electro shock therapy. One day he said "No more!" and just decided to get on with his life. He never visited another doctor or took another medication. He passed away at the age of 93. I'm glad to see you've recovered and found a rewarding path to take in life. You're a lucky guy

P.S I really like your commercial machine and I think it will be a big success. Look into the educational market with a neat little machine like that.

[RomanLini]

Yes it's a lovely and uplifting story Walky. We all love the machines but it's nice sometimes to learn a little about the man who makes them!

I too like your new machine prototype, its looks professional and also friendly enough, ie people won't be scared to own one as it looks like something easy to understand and easy to service and maintain etc. Good work!

If I could make a suggestion, have you considered using acrylic instead of the softer plastics PP or PE etc? I was thinking acrylic is significantly more rigid and you could get rid of the metal bar end clamps (on the gantry) and just clamp using the acrylic itself. Even if you just used acrylic for the gantry uprights? Anyway it's just a thought.

[Walky]

Hi Roman, thanks for your suggestions.

The gantry sides are actually not that big (22cm high) so at 2cm tickness it really doesn't bend that much. I compared this material with 2cm PP and the latter is way stronger, so the next revision should be fine. Since the end supports keep the rails 90º with the gantry arms, it helps reduce the arm's flexing (and rail flexing too). The main reason I use slightly flexible plastic is because the rails (all 6 of them) are press fit into the plastic with a rubber hammer (impossible to get them in or out by hand); the aluminum supports are something that came to my mind later to prevent any eventual misalignment because of crashes (considering this is an entry level machine, and this revision doesn't have limit switches). The next revision will have aluminum supports on both X and Y, and probably limit switches. Most of the flexing comes from the union between the gantry sides and the X linear bearing supports (they're tapped), I will use aluminum blocks for the next revision to get rid of the problem. I'd love to have transparent gantry sides, but that would mean I'd have to use acrylic on the Z axis too (for aesthetics) and I'm guessing that would be maybe too brittle; besides, Acrylic is really not that cheap locally compared to PP (I bet a 2cm piece can easily be the same price or even more expensive, and probably just extruded instead of cast). I'm afraid of what a hard crash could make to acrylic in different situations, not only on the Y axis but specially the Z axis (e.g. plunging with the router off).

If I somehow manage to find a decent aluminum supplier locally, the machine would go all-aluminum, that would be nice but would add costs, so it might as well be an alternative "pro" version while keeping the original as the "basic" version, or something like that

I want to make a smaller, more affordable machine for light work later (perhaps something with a Dremel and a bunch of Sparkfun's or Pololu's small drivers), maybe acrylic would be a good option then since in that machine the mechanics will be more forgiving.

I appreciate your comments a lot anyway, all suggestions are welcome :cheers:

Expect a build log of Revision 2 in some time

[bill south]

Nice Work Walky!
It appears that you have traveled the CNC path the same as numerous other folks have traveled before you! The Swede once called a cnc machine an aladins lamp. It releases magic from the inside of materials limited only by your imagination. I've been tinkering with this hobby for a few years here on the zone and I never tire of hearing success stories even by troubled beginners. It always amazes me that when a problem is presented, solutions are almost always worked out by those who populate this zone.
You have traveled far my friend and may your journey down the path of learning never cease and welcome home to the zone.
Thanks for the inspiring story.
Bill

[RomanLini]

...
The main reason I use slightly flexible plastic is because the rails (all 6 of them) are press fit into the plastic with a rubber hammer (impossible to get them in or out by hand);

Good point! You can't press fit acrylic like that and i'll bet that press fit makes the machine quite rigid too.

... besides, Acrylic is really not that cheap locally compared to PP (I bet a 2cm piece can easily be the same price or even more expensive, and probably just extruded instead of cast). I'm afraid of what a hard crash could make to acrylic in different situations, not only on the Y axis but specially the Z axis (e.g. plunging with the router off).
...

Interesting! They are a similar price here in Australia; acrylic, PE, HDPE etc.

Re the brittle issue, i've got some acylic plates on my router and it's held up really well although most of the force-bearing parts are aluminium and the acrylic is sandwiched so it's mainly under compression not flexion.

The aluminium machine would be awesome but if you are getting good results with the PE especially on a smaller machine that sounds like the way to go! Good luck with the project!

[Walky]

I decided to turn the plastic design into a full aluminum machine, since the cost between plastic and aluminum is very similar (I get my aluminum quite cheap). I added aluminum bearing blocks and ballscrews to the design, to make it as easy to assemble as possible. The plastic prototype is moving but lacking a router (and mount) so far.



Today I made the first aluminum part, about two and a half hours runtime (longest aluminum job I've made to date), broke the 1/8" bit because feedrate was too high but luckily I was able to keep the XY position and resume at 50% feedrate and higher RPM (broke a 2-flute bit and only had a 1-flute spare at hand). Double sided tape is amazing for this kind of work, it worked flawlessly. Aluminum is 12.7mm thick, and I used some 3-in-1 oil as coolant/lubricant.





Now I have some tapping to do.
I can't wait to make the other gantry side so I can mount the Y rails

I'm considering hijacking my own topic to begin a general build log (machines and other stuff) from this point, but I might as well just create a new topic; what do you think?

[DonFrambach]

No matter where you decide to post your build log, I'll read it with great interest.

[aarggh]

Awesome job! Great to see and very interesting!

One thing I would advise though, I extensively use the double sided tape myself, but at reasonable feedrates the aluminium can heat up very dramatically, and softens the tape. I had this happen myself recently with a mount I was making, it worked beautifully, then it just built up so much on a sideways cut the whole thing slid across and broke my brand new $15 cutter!

The pain ensuing with trying to line it up again to finish machining with a new bit, and clamped was terrible.

Keep up the good work Walky!

cheers,
Ian

[RomanLini]

The way I do aluminium is to put small bolts through it into the table or into a plate screwed into the table. Since you are not surfacing the whole top face that can work fine.

It's going to be an interesting build! Congrats on your cutting finish, it looks quite professional compared to some people's routed aluminium edges that leave munched up tool marks.

I see you have some small supported rails in the photo too, looking at your plastic machine design you could put the screws above the rails and use supported rails with practically no penalty there, apart from needing an L shaped bracket maybe.

[Walky]

Thanks for your comments.

I take very light passes, so the aluminum doesn't really heat much. Also, what I do is to make a 2mm deep pocket in the mdf sacrificial board almost exactly the same width as the aluminum piece (a press fit for it), to prevent side movement (only works from the sides, since they're pieces of extred aluminum and the end cuts are not perfect). Also, I make very thin (less than the tape's thickness, let's say 0.5 mm) pass to create pockets in specific parts of the mdf as reference so I can put the tape there knowing that the cutter won't touch it. Then I clean the MDF, put the tape, put the aluminum and stand on top of it so I get firmly pressed. The part in the pictures is 100mm wide and the extrusion is about 101.5mm wide (biggest I could get), so it must all be carefully planned so the cutter gets to remove material on both sides to get an even finish. I set the Z by using a continuity tester between the router's ground (it has a 2-prong plug plus a convenient ground clamp) and the aluminum piece, and slowly jogging down until it triggers (I plan to make a proper Z probe wiring later, though).

The finish is quite smooth to the touch but not absolutely perfect, so I use some fine sand paper at diferent grains to soften things a bit. At 12.7mm thickness the cutter actually deflects a little, but a ~0.1mm or so difference between the top and lower sides of the material is not really something that will affect the machine's working. I might go with thinner passes for parts that are mounted on their side (like ballscrew mounts) just to be sure, but I don't think it'll be absolutely necessary.

I've had those supported rails for almost a year (the rest of the stuff on the picture is new), but I'm really not very fond of 12mm supported rails, since I've found the 12mm open bearings to be a PITA to adjust correctly (they're not such a nice fit as SBR16 rails/blocks), so I'm saving them for some other project (I'd like to make a motion control rig for stop motion animation sometime in the future, so I might as well use some of them for it).

[Walky]

It's finally starting to look like a gantry



I broke two more bits today (and again managed to keep the position, luckily), I'm finding it very hard to machine this aluminum with 2 flute bits even when trying different rpm and feeds (even tried halving the DOC); the aluminum melts and gets between the flutes very easily. On the other hand, the 1 flute bit works great (but I only have one). I think I'll get a 10-pack of those for aluminum and plastic work (been considering it for some time anyway) and leave the 2-flutes for wood work. I'll still keep trying to find the sweet spot to work this aluminum with the 2-flutes while I wait for the bits to arrive.

[RomanLini]

Sorry to hear about the bits breaking. Were they new (sharp) ie never used on MDF?

I'm no expert on aluminium but I just use 4flute or 3flute metalworking endmills, dry for light cuts or a squirt of WD40 on more serious cuts. Generally they only get build up if they are blunt or something is run way too hot. Actually it might also be something to do with the grade of aluminium too, 6061 cuts pretty good as does marine grade (50xx something). Pure aluminium is nasty to cut and gums up tools.

And congrats! That gantry is lookingvery nice!

[Walky]

They were brand new 1/8" chinese endmills. I use them on MDF for the material leveling I mentioned on a previous post, but that's not really what I'll call extensive MDF work. I remember having used a 3/32" 2-flutes bit on aluminum some time ago with not so different settings and no coolant and it gave me a very clean cut, so it might just be a different grade of aluminum. The 1/8" 2-flutes bit makes an awful sound when cutting at any depth, and at some the SPID shows a dramatic rise in the power drawn, then router starts to go slower until the bif breaks. I'm not sure if it starts gumming and then it causes the problem, or maybe the router it not up to the task (530W) and it starts gumming the material after not being able to keep the pace; I'm leaning more towards the first option, since on the second case I'd expect breakage sooner, and the 1-flute is still behaving very well even after cutting both gantry sides. So far I've been using 3-in-1 oil, but it's a mess to clean the final piece so I might as well do some dry cutting next time (which I know the 1-flute can manage pretty well).

[Bob Adams]

It's finally starting to look like a gantry



I broke two more bits today (and again managed to keep the position, luckily), I'm finding it very hard to machine this aluminum with 2 flute bits even when trying different rpm and feeds (even tried halving the DOC); the aluminum melts and gets between the flutes very easily. On the other hand, the 1 flute bit works great (but I only have one). I think I'll get a 10-pack of those for aluminum and plastic work (been considering it for some time anyway) and leave the 2-flutes for wood work. I'll still keep trying to find the sweet spot to work this aluminum with the 2-flutes while I wait for the bits to arrive.

Looks like a good design. Do you have any DXF you can share? What's the Z axis height? Is it height enough for a 4th Axis? Keep up the good work.:cheers:

Bob A
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