My CNC Engraver (Part 1)

The goal of this project is to design and build a CNC wood router/engraver.This turned out to be a much larger project than I had anticipated.  Bigger both in terms of dollars and hours I spent on it.  It took me about 50 hours to build the mechanical portion of my CNC machine and I still have to do the electrical and software work.  This posting will focus on the parts list and the mechanical systems.

I have done a lot with electronics and with software, but never have I build such a complicated mechanical machine before so I needed to do a lot of research before I started my build.  The best tools I found for this research phase where cnczone and google.  Eventually I decided on a gantry style table because the were the most common and simplest form of table. This thread in particular on cnczone influenced my final build. I didn’t do a very good job at recording the time I spent during this research phase, but it was probably something like 30 hours.

There is no way I’m going to take the time to explain every step of this build procedure, but here is a part list and the price I paid for each one.  I wish this list had existed before I started my build so I would have had an example of the different components you need to build a full CNC router and the approximate cost.

Frame
8020 Garage Sale Series 15 Aluminum Frame, connecting plates, bolts, nuts, … $581.80
CNC Router Parts (6) Linear Carriage with ABEC 7 Bearings $141.00
CNC Router Parts (2) Extended Linear Carriage with ABEC 7 Bearings $67.00
Speedy Metals Cold Rolled steel (2) 0.25x4x36, 0.25x6x32, 0.25x4x16 $89.26
K2 CNC RM-PC892 Porter Cable 690 & 892 Mount $57.95
Local Hardware Store Bolts, angle iron, washers, screws, … $50.00
Electronics
HobbyCNC HobbyCNC PRO Driver Board Packages with 305 oz-in motors $240.00
Mouser Pactec case #DM-4 $37.21
Allied Electronics 24VAC 10A Triad Transformer $52.00
Amazon Porter-Cable 690 LR Router $125.85
XYZ Threaded Axises Go to CNC Router Part List to see how these axises are assembled (note: I did not use the drill that he listed as optional).
CNC Router Parts (6) Bearing Block and Cover for 1/2″ ACME $75.00
CNC Router Parts (3) NEMA 23 Motor Mount $37.50
McMaster (3)5 Start 10 thread/inch 1/2″ Acme Threaded Rods – 3ft $117.51
VXB 10 R8ZZ Bearings (only use 6) $31.34
DumpsterCNC (3)1/2″-10 ACME 5 Start Anti-backlash Nut $73.50
MSC (12)Thrust Washer $10.08
MSC (6)Clamping Collar $9.06
MSC (6)Thrust Bearing $17.52
MSC (3)Spider Lovejoy Connector $5.31
MSC (3)1/4′ Lovejoy Connector $9.90
MSC (3)1/2′ Lovejoy Connector $9.90
Total 1838.69

Some other parts you’ll need are an old PC and the CNC software, but I’ll discuss these in a future post.

The main tools I used were hammer, table saw with aluminum blade, hacksaw, screw drivers, wrenches, hand drill, drill press, threading die (5/16th-18 male), center punch, Allen wrenches, Dremel, and a measuring ruler.

The best way to describe the my machine is with pictures so here we go.

Images of my engraver from different angles.

Images of the threaded axis assembly.

The plate used to attach frame to threads.

Image of the moutned motor.

Image of the rollers on the y-axis.

Image of the y-axis (it’s upside down so you can see the bottom).

Image of the z-axis.

I’ll also haven’t tested it yet, but it feels extremely smooth and sturdy so I’m quite confident that the machine will work great, but complete confidence won’t exist until I’ve used the machine for awhile.  In future posts I’ll cover the electrical systems, software, possibly other add-ons, and the reliability of the machine (after I’ve used it for awhile).

Update: I’ve made some improvements to the engraver here.

54 Comments

  1. floort said,

    August 4, 2008 @ 6:54 am

    Nice machine!
    It looks familiar. Do you live in Zaandam?

    Floor

  2. Glacial Wanderer said,

    August 4, 2008 @ 11:52 am

    Do I live in Zaandam? No. I live near Boston in the US. I didn’t even know where Zaandam was until I googled it. Seems like a nice place though.

    I will hopefully get to testing it soon so then I’ll find out if it just looks good or if it really is good.

  3. SixLima said,

    August 6, 2008 @ 11:57 am

    Very Pretty the machine… but is not very expensive? an its only the mechanical parts…

    I will like have one. I will be content with two axis, to cut sheets, for example with plasma (i think that it’s a option more expensive….)

  4. pcook911 said,

    August 7, 2008 @ 10:19 am

    Very nice!

    One important question though. Are you married? Because there is no way I could get away with doing that on my dining room table!!

    Some day I hope to at least have the time to build something like that in my garage.

    Paul

  5. timc2246 said,

    August 15, 2008 @ 2:49 pm

    This is cool how you took our 80/20 extrusions to make something neat. Would you e-mail me any other pictures you may have and may we use your pictures to be included in an upcoming application flip book for others to see on our website? Please reply back to me at timcain@8020inc.com. Thanks.

  6. TruckTrash said,

    September 5, 2008 @ 7:22 pm

    GW,

    You could route prototype PCB’s with this beast. Hey you helped me a great deal with the RTC DS1307 chip, so maybe I can help you back. Check out this linux CNC distribution. I ran across it recently and wish I had the money to build even what you built, but this OS package looks pretty useful and interesting, I hope one day I will be able to try it out.

    http://www.linuxcnc.org

  7. 13squared said,

    November 6, 2008 @ 5:41 pm

    Very cool machine!

    Could you post a cut-sheet for what lengths of 8020 stock I need to make this? I am so ready to start building. :)
    It looks like the approximate dimensions are 36 by maybe 32?
    I’ve been buying 15 series 8020 stuff all day in preparation to start building this monster.

    Have you been routing any other stuff yet? Please post pics of some parts/projects.

  8. Glacial Wanderer said,

    November 7, 2008 @ 6:57 am

    The table dimensions are 26″ wide by 36″ long. The gantry dimensions are 31″ wide by 22 high”. I just picked these dimensions. I kind of wished I had drawn the machine in a cad program so I could share full dimension details, but I didn’t and don’t plan to go back and do it now.

    Here is a picture of some new Christmas ornaments I did last night (friend is going to paint them). There are also some pieces for a spinning wheel that I’m working on. http://www.glacialwanderer.com/_blog/blog2008/11_November/cnc_example.jpg

    Here is a link to a video of my machine in action. http://www.glacialwanderer.com/hobbyrobotics/?p=48

  9. 13squared said,

    November 9, 2008 @ 8:21 pm

    Thanks!

    2 more quick questions –
    On the longest axis could you have used 3″ wide steel?
    How did you drill the holes in the steel?

  10. Glacial Wanderer said,

    November 9, 2008 @ 11:20 pm

    Yes, 3″ steel should work as long as as you use don’t use double wide 8020 aluminum there which I didn’t. A high quality drill bit will drill through the steel. I have a drill press which made lining everything up easier, but probably isn’t required. It takes awhile to drill all those holes so don’t hurry. Also you will want to use a drill punch to dent the metal so you can control where the center of the hole starts.

  11. 13squared said,

    November 12, 2008 @ 2:18 pm

    One more quick questions — how much ‘wiggle’ would there be if you didn’t double up the rollers on the gantry with an extended plus a normal length one? i.e. could I get away with only 2 bearing trucks on the gantry if i’m looking to save?

  12. Glacial Wanderer said,

    November 12, 2008 @ 4:13 pm

    It could work, but racketing might be a problem. I just went with the four rollers to support the gantry because I didn’t want to hit a potential problem. You could always try it with two and if you get racketing add two more.

  13. 13squared said,

    November 19, 2008 @ 6:22 pm

    Last question — maybe. What is the distance from the motor mount to the first bearing block? 3inches? Are double bearing blocks required to build each axis or is that more optional?

  14. Glacial Wanderer said,

    November 19, 2008 @ 11:15 pm

    The distance between the motor mount and the first bearing block is 2.5 inches. I’ve just finished doing some improvements to the machine and will post an these improvements after some testing. One of the improvements was using these acme couplers instead of the lovejoy connectors (http://www.dumpstercnc.com/acme_couplers.html). With these it should be possible to make the distance about 1 inch and they are cheaper than lovejoy.

    I think you need the double bearing blocks. Without them I think the acme screw would wiggle.

  15. Plank said,

    January 5, 2009 @ 7:10 pm

    I’m impressed not only with the machine but the photos as well. Nice details, very clear shots. Obviously great care was taken in making those beautiful photos.

    Congratulations!

  16. raygun said,

    January 16, 2009 @ 7:51 am

    What a solid looking beast! I hope I day I’ll be able to build one close to your beauty…

    I have one question though, looking at the second picture I can see that the router + Z axis assembly is kinda over-hanging in front of the of the Y axis linear rails, something like this:
    |
    |—-|
    | |
    |
    |
    —-
    Doesn’t that throw the balance of the Z & X frame forward & stress the front rollers more? Maybe if the rails are longer like this it would be better?
    |
    |—-|
    | |
    |
    |
    ——–

    I hope you understand what I mean…

    I hope you post some vids of that beauty milling some stuff. Good job!

  17. raygun said,

    January 16, 2009 @ 7:55 am

    Oops, the artwork got jumbled up after I post. Sorry : P

  18. Glacial Wanderer said,

    January 16, 2009 @ 8:10 am

    You want to make sure the machine handles the worst case. In the worst case the router is pressing down on the work surface and that counters some of the overhang forces you mentioned. I didn’t run any calculations for this because I was pretty sure my machine could handle it and it can. I agree reducing some of the overhang might be nice, but in the real world I don’t think it affects the machine because the rails can more than handle the overhang forces. It also is not obvious to me how I could easily reduce this overhang.

    I have tested the machine by putting large forces (50+ lbs) in every direction on the router and it continues to work fine.

  19. jonh said,

    January 17, 2009 @ 6:15 pm

    Dear Glacial Wanderer.
    I like hve some information.
    1º What is the precision of this cnc machine.
    2º What is the cutting speeds per minute from this cnc machine.
    3º What is the step resolution of ” from this cnc machine.
    4º What is the positional accuracy of +/- ” from this cnc machine.
    5º What is the control system software to run this cnc machine.
    6 What is the year warranty from this cnc machine

  20. Glacial Wanderer said,

    January 18, 2009 @ 11:22 am

    1) I believe accuracy probably more important and it should be within 1.5 steps. The precision is mostly a function of deflection and backlash. These variables are influenced by material harness and cut speed. Getting an accurate precision measurement seems difficult to me so I don’t have not do that. I believe the precision is good and have never noticed a problem with it during my work.

    2) I cut lots of 1/4″ plywood at 60 ipm (inches per minute). During bringup I found the machine maxes out at around 300 ipm.

    3) I currently have the hobbyCNC stepper controller to do whole steps. This gives me 0.005 inch per step resolution. If I wanted smaller steps I could set the motor controller to 1/16th steps which would give me 0.0003125 inch per step resolution. I think the deflection and backlash mentioned in #1 would likely become issues if you did this. But you could lessen the backlash with software.

    4) I think this was addressed in #1

    5) I posted some about the software I use here: http://www.glacialwanderer.com/hobbyrobotics/?p=48
    If you haven’t looked at improvements I made to this machine look here: http://www.glacialwanderer.com/hobbyrobotics/?p=53

    In addition to the software mentioned in that post I now use Cut2D from Vectric which is awesome. Today my workflow is usually inkscape, cut2d, mach3d.

    6) Since I built it myself, each part has a different warranty. If any part breaks I’d just replace the broken part. I think the only parts that are likely to every break are the stepper motors/control board, router, and the anti-backlash nuts. So far none of those have broken for me.

  21. jonh said,

    January 18, 2009 @ 6:49 pm

    Thank you Glacial Wanderer for your last information.
    If is possible and is not probleme to you I like to have your email adress for send some pictures of the machine I wanted build.

  22. Glacial Wanderer said,

    January 19, 2009 @ 8:25 pm

    You can email me at: ribblem “at” yahoo “dot” com.

  23. Jordan Stark said,

    January 20, 2009 @ 12:47 pm

    Looks great, one question though, how thick of material are you able to cut with no extension on your z-axis? It doesn’t look like it can machine deeper than about 0.5″ plus the bit extension. It also looks like the whole z carriage needs to drop about 4 inches to even get close to the table top. Forgive my ignorance if everything you are machining is that thick, and only that deep, I just wondered from the pictures. Otherwise, it looks like a terrific machine!

  24. Glacial Wanderer said,

    January 23, 2009 @ 2:24 pm

    If you look at my update link at the end of the article you’ll see I reworked the z axis. Now I think I have about 3 inches of useful z travel. That doesn’t matter much though since my router bits can only handle about 1/2 to 1 inch of z travel. This is fine with me though since most of what I work on is 1/2 inch or less.

  25. Wolfspaw said,

    January 29, 2009 @ 11:39 am

    Great machine…

    Were you able to order the 8020 cut to length? If not, what did you use to cut it? It appears that the cut needs to be pretty accurate.

  26. Glacial Wanderer said,

    January 29, 2009 @ 5:38 pm

    I did not order the 8020 to length. I cut it with my table saw and am very happy with the results. I think a band saw would also work great. Power hand saws would probably work. It is nice if you can get accurate cuts, but I don’t think it’s critical. Most of my joints were with plates so everything just fits together.

  27. That Guy said,

    February 19, 2009 @ 3:47 am

    Out of curiosity, what is the purpose of the thrust bearing on your Z-axis?

  28. Glacial Wanderer said,

    February 20, 2009 @ 6:58 am

    They help deal with any lateral thrust. In the case of the z axis since the router is pretty heavy most of the time this thrust will be in a downwards direction. The system might work without them, but this reduces friction and they are cheap.

  29. That Guy said,

    February 20, 2009 @ 1:52 pm

    Did you only use them on that axis? I assumed the Dumpster CNC couplers would be enough to do the job. I’ve never built a CNC, but i’m about to using bearings from CNCrouterparts. your build is the most detailed one I have found using this system.

  30. Glacial Wanderer said,

    February 20, 2009 @ 2:45 pm

    I used them on all 3 axises. The couplers hold the axis in place. These bearings just reduce the friction. Like I said, I’m not sure if they are needed, but for a few bucks they help ensure everything runs smoothly. If I were to build another machine I wouldn’t think twice about it and include them just because I know this method works.

    If you want to try it without them and think it would work then go for it. As long as you leave 1/4 inch of space you can add these later.

  31. Sparky said,

    April 5, 2009 @ 11:01 pm

    I enjoyed your machine so much a built my own. Mine has a 26inch x, 52inch Y, and 20 inch Z. I built one machine out of MDF. It was kind of flimsy. When I saw yours, I knew I had to build it.

    On my old machine, I had the X axis motor on the left side. On my new machine, I put the motor on the right. This has reversed my positive and negative X moves. On my old machine, when I would jog postive the machine would move the z to the right. Now when I move the X positive,the machin moves the Z a to the left.

    Is there a way to go into Mach 3 and reverse the settings. This would save me from teatring the machine apart and switching my motor to the left side.

    I hope this is clear, and I hope you can help me figure this out.

    Thanks
    Sparky

  32. Maurice Ribble said,

    April 6, 2009 @ 5:21 am

    Under Config > Homing/Limits you want to check “reversed”.

  33. Sparky said,

    April 6, 2009 @ 5:43 pm

    Maurice,

    Thanks you were right on the money. You saved me alot of time.

  34. imageorg said,

    September 22, 2009 @ 3:18 pm

    Хотел бы задать деликатный вопрос. Могли бы Вы более подробно расписать эту информацию?

  35. Ed said,

    October 27, 2009 @ 12:15 pm

    Great looking machine and I am seriously looking at building one. I have one question. Would the machine be accurate enough to engrave lettering onto perspex or brass plate . The lettering would be approx 3/16″

  36. Maurice Ribble said,

    December 27, 2009 @ 10:20 pm

    Above I mention that I have a resolution of 0.005 inches. This is more than accurate for 3/16″ lettering.

  37. aniket said,

    March 14, 2010 @ 9:43 am

    hey man… the hardwork u have done is really impressive… i wish i had seen ur page earlier.! i have built the same machine. but the only difference is tht is it made from company scrap and reject material. its a prototype.! i just want to know how do u analyse the cutting forces and bending forces on those extruded channels u have used! if u could refer any books dat wud also do.
    your reply is eagerly awaited!

  38. Maurice Ribble said,

    March 14, 2010 @ 10:54 am

    I think any college entry level statics and dynamics book would give you the knowledge you need to do these analysis. If you have a rudimentary knowledge of these subjects then the company providing the structure materials you are using will give you the deflection factors you need to do these calculations. It will get a little complicated because most deflection will come from the joints.

    I just built something that would be more than strong enough so I wouldn’t have to do the calculations. Since I haven’t done any calculations like this since college I’m not the person to refer you to a website or book. I think if you did some searching you could find a forum that gives better answers than I am.

  39. aniket said,

    March 15, 2010 @ 3:24 am

    thank u.. !

  40. Luis said,

    May 11, 2010 @ 12:52 pm

    Hi, congrats on a great build, just wanna ask, from where did you get the L shapped parts you use to conect the 8020 extrusions? are they the only thing you use to conect the 8020?

    Thanks and greatings from Costa Rica!

  41. Maurice Ribble said,

    June 7, 2010 @ 4:44 am

    If you go to joining plates on the 8020 site you’ll find these brackets. Yes, I just used these brackets for connections. Here’s a linK: http://stores.ebay.com/8020-Inc-Garage-Sale_Joining-Plates_W0QQ_fsubZ6486515QQ_sidZ129537225QQ_trksidZp4634Q2ec0Q2em322

  42. CNC router said,

    June 15, 2010 @ 9:02 am

    Great looking machine and I am seriously looking at building one.

  43. CNC Machinery said,

    July 10, 2010 @ 6:04 am

    Nice looking machine and I am seriously looking at building one.

  44. Trevor Waldron said,

    July 10, 2010 @ 3:02 pm

    I would like to why you used 1/4′” steel instead of aluminium

  45. Aswan said,

    January 19, 2011 @ 9:20 pm

    Thanks for all the great info. You have really encouraged me to build a CNC of my own. What did you use the the 1/2″ bearings for. I have studied the photos again and again, but still can’t figure it out.

    Thanks again

  46. elbert said,

    March 4, 2011 @ 1:29 pm

    can i ask…what is the mechanical system in cnc machine..?i need to do my assignment….

  47. Adnan said,

    July 1, 2011 @ 2:14 pm

    .I really need help that how can we use our gcode? means to say that how can we interpret our gcode?
    m using microcontroller 8051 how does a microcontroller read gcode and how we can interface our macine with microcontroller?

    my email address
    addirwp@yahoo.com

  48. Maurice Ribble said,

    July 1, 2011 @ 2:22 pm

    I suggest reading this post about using the software to create and run gcode: http://www.glacialwanderer.com/hobbyrobotics/?p=48

  49. Adnan said,

    July 3, 2011 @ 11:01 am

    THANX FOR REPLYING
    i have already read that but not much helpful for me.we load the gcode file in mach3 software but how does mach3 control our machine??
    what does a microcontroller read from mach3 and how?

  50. jim sterling said,

    September 7, 2011 @ 6:32 pm

    I have a 14″ x 14″ router engraver and I would like to change the lenght of the table. I need one threaded rod 60″ and two 60″ shaft rods. please get back as soon as posible. jim sterling

  51. Newbie How to fix the lead screw end? - CNCzone.com-The Largest Machinist Community on the net! said,

    December 8, 2011 @ 7:45 am

    [...] [...]

  52. ghanmi said,

    October 13, 2012 @ 3:38 pm

    Hello
    I found this machine a good work
    I’m a hoppyste CNC
    can you please send me the pdf plans for the mechanical parts of the your CNC

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