Author Topic: My desktop CNC Build (many pictures)  (Read 44153 times)

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #15 on: September 08, 2009, 09:02:28 PM »
Ohhh thats a good way to do it. I'll have to use that..

So right now Im officially hating my Z axis portion haha. Today was terrible... And I hate MDF, well at least I should have used those cross dowels, because the screws that I was using have been backing out and MDF just doesn't like to be held together with screws. So my plan tomorrow is go go buy a sheet of MDF, and rebuild my Z axis using something similar to using cross dowels. Im going to use my CNC to cut out pockets where instead of using a cross dowel, Ill use just 1/4" nuts and bolts. I could just use a large say 3/4" drill bit to make the holes, but then the nuts wont sit flat against the curved face. Today I tried to cut out another gear, and the Y and Z axis were really sloppy.

Edit: Here's a picture of the design Im talking about:


Oh ya and I found out how to vectorize an image. I was reading a bunch at www.cnc4free.org and tried using Inkscape I think its called. Its really simple and you can save the file format into .DXF and open it right up in CamBam and it recognizes the outlines. Then you have to convert to polylines, then join polylines and BAM!... well then do tool paths and such but it works out really well. I also installed Free Mill and opened up a Google SketchUp STL file and made some code for that. Haven't tried running it yet though.

So hopefully.... my cnc will be 97% operational in the next few days. I now realize why nice CNC machines cost so much money! Dang....

Oh ya and I leave for school in 2 weeks! :( Going to have to push the CNC project to the back of my mind so i can focus on school.. Hopefully I wont get distracted haha.
« Last Edit: September 08, 2009, 11:26:57 PM by travis77 »


Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #16 on: September 09, 2009, 01:58:22 PM »
Yes, I hate MDF too. Probably for different reasons than you, but the stuff is most definitely a pain. I'm not really sure why people use it so much.

List of annoying things about MDF

It doesn't hold a screw
It's ugly
Glue doesn't seem to work that well with it
It has a tendency to snap in half fairly easily
Getting it wet absolutely destroys it
The dust created when cutting it is absolutely horrendous.  >:( 

Once my stock of MDF is depleted, I going to avoid using it whenever I can.

OK, that was my rant for the day.  8)

In any case, the picture looks cool. You got to love CAD programs. They make designing stuff sooo much easier. Especially when you're like me and can't even draw a straight line with a ruler.

Have Fun!
Gabriel


travis77

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Re: My desktop CNC Build (many pictures)
« Reply #17 on: September 09, 2009, 09:38:36 PM »
Ya the dust is terrible... Right now since I dont have a shop vac, Im using my CNC in my backyard with a big fan that I have sitting next to it and i just blow all the dust particles away haha. I've been wearing a light dust mask... I imagine inhaling all that sawdust and glue that makes up MDF isn't good to be breathing in. Haha the other day I was doing some cutting with a jigsaw and got some pool goggles out and was wearing those so the flying dust couldn't get in my eyes.

What are you planning on using besides MDF? What else is out there that's works well on cnc machines?

Does that HDPE plastic cut well? Does it melt at all? I haven't tried cutting any except with a hacksaw. I have a sheet sitting in the garage i got from my grandpa. 

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #18 on: September 10, 2009, 10:19:13 PM »
Update: So today I finished rebuilding my Z axis. Its working pretty well and Im amazed at how well it all went together. Yesterday I cut out the pockets for the bolts that you see in the pictures. Using this style connection or similar cross dowel design is much stronger than using screws in the MDF. You can torque down the bolts and the MDF will hold, unlike splitting when using screws. Lesson learned. Im able to adjust the preload on the bearing slides for the Y axis just by tightening the bolts. By the way, I used 1/4" by 1.5" bolts and nylon nuts so they wont back out. Im very happy with this rebuild.





Did I mention I love the copper pipe! I like the color it adds.





Someday I need to post a little thing about how I made my coupling nut holders for the x,y,z axes (shown below). They work really well and allow for some misalignment of the lead screws. And notice how I used two washers on each side to adjust the distance to the Z carriage. Basically its a rectangle with the center cut out to tightly hold a long nut and I drilled two holes for the screw to go through to thread into the nut. I tried directly bolting the nut to the carriage, but it bound up the lead screw really badly. These work well and more DIY cnc'ers should know about this.



Im using the design used on Joe's CNC 2006 for the Z axis bearings slide. The U bolts (with nylon nuts) have been working very well and hold the carriage assembly to the rails nicely. He uses 4 U bolts, and Im only using 2 for now because Im re-using my bearing assemblies from before and they are too short to use 4 U bolts total. But it works, so Im not worried right now.



Notice the giant gaping hole on my deck surface? Ya I was planning to use my CNC to cut out some holes that Im using to mount pieces to the deck so they would all be precise... well the CNC decided the deck tasted delicious and feasted on it.. I then broke out the ruler and pencil and hand drilled the holes... Thinking back on it, I should have just chucked a normal drill bit into the router. This all happened with the old Z axis, so I blame it for eating my deck. Oh well.. it still functions just fine.



I plan on re-building the router holder with some plastic sheet I have laying around... Ill use the CNC to cut it out so it will be perfect and the correct diameter (notice my duc-tape to make the router's diameter fit the holder) ya I made the holes a little too big with the jigsaw.

For now though, Im pretty burnt out on working on this thing. Ive been building and rebuilding and going to the hardware store for two weeks straight it seems.. Tired of spending time and money on it. Time to use it and make some stuff.

« Last Edit: September 10, 2009, 10:38:24 PM by travis77 »

Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #19 on: September 11, 2009, 06:03:31 PM »
That's one heck of a Z-axis. It's pretty sweet that it has gotten to the point where the CNC can make its own parts.

You might want to keep an eye on that copper pipe. I don't know how long it is really going to last because copper is fairly soft as far as metals are concerned.  I would hope that it would take a while to wear out though. You can always just rotate it a few degrees when the skateboard bearings make too deep of a path in it. It should hopefully last long enough for you to be able to make some neat things with it.

Of course, the copper pipe could work perfectly fine for all I know. I've never tried it.

I can't wait to see what you are going to make with your CNC now that you have everything worked out. Do you have any ideas already?

Oh and to answer your question about plastic, its cuts really easily. You could probably cut through 3/4" in one pass if you really wanted to. I don't know if I would recommend that much though. I've never had any trouble with it melting, but, if you were to cut it too slow, it could be an issue. I can't remember exactly, but I think the slowest I've ever cut plastic at was probably around 35 IPM. I don't know how much slower you can go with it.


travis77

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Re: My desktop CNC Build (many pictures)
« Reply #20 on: September 11, 2009, 10:49:09 PM »
I think the copper will actually hold up for a little bit. Its thinker and stronger than I thought it was going to be when I first picked it up. I just couldnt really find any other type of pipe under 20 million feet long at Home Depot. What should I use for my rails? I know Joe's CNC people talk about using drill rod or gas pipe, but where do I find this and what does it look like? Suggestions needed.

Umm.. so far, I dont really have any designs, minus I want to cut out some HDPE plastic pieces for the router mount like I already said. I made a cut out a cat in MDF. I want to cnc this little 3 piece wooden 3D puzzle that I made before on my grandpa's bandsaw. Maybe out of plastic would be cool. Well I guess I just negated what I said earlier and do have some designs. And I want to cut out some more gears to play around with. Gabriel, do you have any ideas I should try? Im kind of limited on my cutting area to 12" by 12" though.

I want to try out this program called FreeMill. I opened up your parabola STL file in it and created some G code with it. So Im eager to see what I can do with some 3D stuff.... I want to engrave a sign for my dad's friend's birthday who's turning 50.. I need to get a V groove router bit... more money ughhhhhh maybe I can talk my dad into buying that instead of his friend a present and give him the plaque. Oh ya and Jamie (Geeks gone bad) showed me this speed control unit thats $20 bucks at harbor freight, I might try one of those out to turn down my router's RPMs.

And I have another update I'll post tomorrow. Hopefully along with something that CNC made...

Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #21 on: September 12, 2009, 07:06:30 PM »

I'm surprised that your Home Depot didn't have anything. Mine has several different kinds of pipes that are only a couple of feet long. I don't know of any online suppliers. I guess that the copper pipe should last long enough for you not to have to worry about it for awhile.



I've always thought that these flies cut out of old CDs looked cool.

http://www.cnc.info.pl/topics68/mucha-vt14889.htm

There's some other stuff on that site too, but its kind of hard to find your way around because it's not in English.

Pretty much all of the interesting CNC projects that I have found have been put onto this page http://www.cerebralmeltdown.com/cncstuff/filesites/index.htm There is a lot to be found on those sites if you search through them.


By the way, be careful with FreeMill. Unless they've changed something since I last tried it, FreeMill doesn't create a roughing pass. It will happily create a g-code file that will cuts way too deep into the wood. For some things, you can get away without a roughing pass, but a lot of the time you will need it.

You could try either MeshCam or CamBam Plus for 3D work. They both have demos that you can try.

I honestly haven't done a whole lot of 3D work myself. I built my CNC thinking that 3D stuff would be the only thing that I would ever do. I eventually decided that I was too impatient for it. A part that takes two hours to cut out isn't uncommon, so I mostly just work in 2.5D now. Most of the really useful stuff can be done in 2.5D while 3D is generally just used for decoration.

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #22 on: September 13, 2009, 11:46:03 AM »
Maybe I didnt look around my home depot hard enough..

You know you can always have google translate pages for you. http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.cnc.info.pl%2Ftopics68%2Fmucha-vt14889.htm&sl=pl&tl=en&history_state0=

Those flies are awesome! I just need a bit small enough to cut those out. I saw a spider and some other bug someone made on CNC zone. I think they posted the dxf files for it too.. I should look into those. They look interesting.

Very true about the 2.5 vs. 3D stuff. I really doubt Ill be doing much of any 3D, just wanted to try it. You can do a lot in 2.5D really.

Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #23 on: September 13, 2009, 11:49:59 AM »

You know you can always have google translate pages for you.


Oh yeah! duh

lol

Google rocks!

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #24 on: September 13, 2009, 08:11:13 PM »
For some reason when on the translated page, the DXF file doesnt like to be downloaded. But switching back to the original page it downloads just fine if anyone was wondering..

So I have a little update for today. And a video! (hopefully if it uploads) Today I cut 2 router holders out of plastic. The router worked amazingly well and was very impressed. I definitely have to get a shop vac for the plastic snow the machine was blowing everywhere. The picture is only a fraction of the mess. My depths were .12" to a total depth of .6" (the plastic was 1/2") and my feed rate was 10 ipm. These settings are little conservative, I could have run the machine faster but I'd rather have a precise piece that takes a little longer than a sloppy messed up piece that took a minute. Total run time was i think about 15 mins. I sped up the video so its not completely boring.








Watch out for the audio, its really loud...

Plastic Router Holder



My other little update is I now have my dedicated cnc shop computer up and running Linux and EMC2. This dell (tower, monitor, keyboard and mouse) was given to me by someone at my moms work. I took the hard drive out and gave it back because he wanted it, so all I did was buy a cheap $30 one on new egg. Now its working and I used it today to run the code for the plastic pieces. With only 256mb of memory, I thought I was going to have to get some more to run EMC2, but no, it works just fine.



Soon I will make an enclosure for my electronics and computer setup. Im already throwing around ideas for CNC build #2. Its going to be larger, Im thinking around 2' by 4' with a moving gantry. A steel frame stand will be made for the router to be on top and electronics mounted below.
« Last Edit: September 13, 2009, 10:22:53 PM by travis77 »

Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #25 on: September 14, 2009, 03:28:18 PM »
AWWWWSOOOME!!!

I wonder how many hours/days of my life I've spent watching CNC machines do their thing? It is hard to take your eyes off of them isn't it.

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #26 on: September 14, 2009, 10:30:41 PM »
Haha, ya I think its more mesmerizing when its going slower. Check out the other video that I just uploaded on the Thingiverse thread.

Gabriel, have you tried making one of those flies? I need a smaller bit. Or i could jumbo size the fly :)

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #27 on: September 22, 2009, 04:41:55 PM »
So school starts Thursday, and Im officially moved back to school. Things sure have been quiet on here. No one's our tinkering huh?

Gabriel

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Re: My desktop CNC Build (many pictures)
« Reply #28 on: September 22, 2009, 05:13:39 PM »
I might seem quiet to you, but for me it has been a little crazy.  :)

I sent my heliostat project to the Makezine blog earlier, and they posted it about a week ago. Lately, I've been answering questions that people have emailed me about it. It's kind of taken up the time that I normally use to post stuff.

That, and there is that pesky school nonsense that interferes with my tinkering. For the moment, I'm trying to get caught up because I've been procrastinating over the last week. ;D

Once I get ahead again, I will start work on something new.

travis77

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Re: My desktop CNC Build (many pictures)
« Reply #29 on: September 23, 2009, 06:56:31 PM »
Ya I know what you mean about the school thing.. Its difficult. Ill keep checking in though and see what you're building or working on.