Welcome to Our Community

Some features disabled for guests. Register Today.

OpenBuilds OX CNC Machine

Discussion in 'CNC Mills/Routers' started by Mark Carew, Dec 15, 2013.

  1. GrayUK

    GrayUK Openbuilds Team Elder
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    1,668
    Likes Received:
    627
    Jonathan T
    If you take a close look at ours, you will see there is in fact, a V slot, cut into the edges of the slot to enable the wheels to sit in it and be more precise. :thumbsup:
    Gray
     
  2. Jonathan Trinity

    Builder

    Joined:
    Aug 7, 2014
    Messages:
    11
    Likes Received:
    0
    vtrak.gif

    What do you mean?
     
  3. asb_79

    asb_79 Well-Known
    Builder

    Joined:
    Feb 19, 2014
    Messages:
    78
    Likes Received:
    30
    Everything you say is true, but it is still a case of mistaking stiffness for strength. When bending/molding a material to permanently deform it you are pushing it beyond it's yield strength thus you see a clear difference between the alloys at condition O and T6. If you flexed the two alloys to just before the point of bending (of the 6061-O) they would deflect about the same amount, the 6061-T6 will require more force to bend because of the higher yield strength.

    To try and visualise this, if you had two gantry plates (@6mm) clamped in a vise at the base, one 6061-O and one 6061-T6 and applied a load at the top (in a way to try and fold it over) the T6 part will undoubtedly require a higher force to bend (permanently deform) compared to the one at condition O, but, the force required to bend the part at Condition O would still be significantly higher that the force the OX would be able to exert on them. Also, upto the load where the 6061-O gives way, both materials would deflect the same amount. I think this is similar concept to what Rick 2.0 was saying above.

    The short story is, use whatever you can get hold of but thickness should take priority over the material strength. A 6mm 5083 (or whatever) would perform better than a 5mm 6061-T6.

    Chris, your formed parts look very nice, very impressive.
     
    #1203 asb_79, Aug 23, 2014
    Last edited: Aug 23, 2014
    Chris Laidlaw likes this.
  4. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Dec 20, 2013
    Messages:
    2,852
    Likes Received:
    1,524
    Chris: as asb_79 notes, the difference here is between flexing and bending. Flexing is done within the elastic range of the material and the material goes back to where it started. Modulus of Elasticity controls here. Bending is a permanent deformation, pushing the material beyond its elastic range to the yield point and strength of the material is the controlling factor there.

    As he also notes:
    Agreed. :thumbsup:

    Wow, hadn't seen that before. Robocutters.uk claims it to be "FULLY compatible with V-Slot products" (link) and that it is available in longer lengths than V-slot. There was an article recently about a new European producer of this type of material and this may be from them. It's new so no way of knowing if the quality is the same. Longer lengths would definitely be nice but as Mark has noted, he keeps the length to 1500 as producers have had difficulty achieving straightness within acceptable tolerance for anything longer. The European manufacturer may be better equipped to handle it.
     
  5. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Dec 20, 2013
    Messages:
    2,852
    Likes Received:
    1,524
    Nope. If you'd like to test this theory, laminate up several pieces of lumber and test them against a solid piece of the same size. Assuming your glue is the same strength as the original wood fiber bond, you will get the same results. If the glue is weaker you will get slightly more deflection due to a slight deformation in the joint. (Stronger glue will show no difference in a two-ply. It might make a difference in a multi-ply arrangement but only if it less elastic than the wood fibers in which case it is no longer merely a bonding agent but an strengthening enhancement to the system)

    But it appears we have gotten a bit off track here. It's time to take this thread back to it's intended course. If I recall, it had something to do with an OX...
     
  6. GrayUK

    GrayUK Openbuilds Team Elder
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    1,668
    Likes Received:
    627
    Indeed it was :thumbsup:
     
  7. Jonathan Trinity

    Builder

    Joined:
    Aug 7, 2014
    Messages:
    11
    Likes Received:
    0
    Sorry guys...i think it was my fault. :oops:
     
  8. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Dec 20, 2013
    Messages:
    2,852
    Likes Received:
    1,524
    Nope. You had a valid question. :thumbsup:

    That's why the forum exists.
     
  9. Chris Laidlaw

    Chris Laidlaw Well-Known
    Builder

    Joined:
    Mar 1, 2014
    Messages:
    77
    Likes Received:
    27
    Ahh... the good old days. My very first machine shop class five years ago when they actually let me use the machines.
    It was also my first "customer"... my next door neighbor was put in charge of a new boy scout troop and the boy scout store was out of stock of the tie clips, so he asked me to make some for him after I told him I was taking a machining class. I tied up one of their HAAS machines for 3 full days to machine the dies. Then I had to learn how to operate the 150 ton press to stamp the parts. I remember I had to go to about 140 tons to get a good impression with the 6061-T6 and the brass ones I also made. 6061-0 only took about 70 tons.
     
    #1209 Chris Laidlaw, Aug 23, 2014
    Last edited: Aug 23, 2014
  10. GrayUK

    GrayUK Openbuilds Team Elder
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    1,668
    Likes Received:
    627
    No Jonathan T, it is my claim to fame. :thumbsup:
    I'm always doing it! LOL :ROFL:
    It is the ones, that follow me down the path, who are really to blame. :rolleyes:
    Although my questions are always genuine, just a bit off subject sometimes. :banghead:
     
  11. Chris Laidlaw

    Chris Laidlaw Well-Known
    Builder

    Joined:
    Mar 1, 2014
    Messages:
    77
    Likes Received:
    27
    I stand corrected, thickness is more important the type of aluminum when it comes to rigidity of the OX plates, but if in a bout of frustration you decide to take a sledge hammer to your OX, it would survive a lot better if it was 6061-T6.
     
    #1211 Chris Laidlaw, Aug 23, 2014
    Last edited: Aug 27, 2014
    asb_79 likes this.
  12. Rich C

    Rich C New
    Builder

    Joined:
    Aug 4, 2014
    Messages:
    66
    Likes Received:
    11
    Ok, so question on the electronics if I may.....
    I am just about ready to start getting the electronics portion of my OX going... I bought the gshield and the Seeduino v4 blue that was identified in the BOM. The boards I ordered (I had to order from different locations) did not come with any preinstalled software. I bought BOBCAM-CAD v26 PRO software and will have that running on the tower computer. So here are my questions:
    1) what software will I need (and where can I get it - preferably already configured for the most part) for the gshield
    2) what software will I need (and where can I get it - preferably already configured for the most part) for the Seeduino v4

    This was taken a few days ago..I have since painted the table top, attached the gantry and z-axis. Still awaiting a few parts from OpenBuilds and casters (please disregard the garage mess) DSC_0061resize.jpg

    I will upload a newer pic once I pull the photos from my phone....
     
    Jeferson SImoes likes this.
  13. asb_79

    asb_79 Well-Known
    Builder

    Joined:
    Feb 19, 2014
    Messages:
    78
    Likes Received:
    30
    Here's an idea for running cable chain along the y-axis, I'm going to try and do something similar on the x.

    I used some standoffs and a bit of Aluminium angle to support the chain. I made a simple bracket to fix the chain to the Gantry plate.

    Machine is coming together...Slowwwwly
     

    Attached Files:

  14. Philip UD

    Philip UD New
    Builder

    Joined:
    Aug 13, 2014
    Messages:
    27
    Likes Received:
    22
    No expert, and a Mach person besides but sounds like all you need is Grbl.

    And my question:
    Decided I wanted to build a router table, after much browsing and discovering this forum/OpenBuilds and decided an Ox would be a fun starting point, ordered the parts and am now more or less patiently (or not) waiting on a minor V-rail backup giving me lots of time to review video's, posts, etc...

    Anyway so I started thinking about the Z-axis and wondering why a 4 start-8mm per revolution lead screw? Was it readily available/on-hand, or was there other reasoning for the choice?

    Obviously from the videos it works, and with micro stepping 0.04mm per step should be plenty of resolution, but it seems a bit steep for such a short axis to me so I was wondering if anyone had any thoughts/experiences/ideas???
     
    #1214 Philip UD, Aug 23, 2014
    Last edited: Aug 23, 2014
  15. Rich C

    Rich C New
    Builder

    Joined:
    Aug 4, 2014
    Messages:
    66
    Likes Received:
    11
    Cool. Thanks Philip UD. Is there a modified Grbl out there that is BASICALLY already set up for the OX? I know I will need to make some adjustments....but since I am new, the less I need to modify in the beginning the better.

    Also, Will Arduino Sketch upload it?
     
  16. Philip UD

    Philip UD New
    Builder

    Joined:
    Aug 13, 2014
    Messages:
    27
    Likes Received:
    22
    Sorry that I don't know.

    I use Mach3 for a retrofitted micro-mill pretty easy to drop code into from just about any source with only minor modifications when needed.
    Not sure what I'll finally use for my router build, to start I'll just create a profile on Mach3 for the Ox and use the mills controller.
     
  17. BinaryConstruct

    Builder

    Joined:
    Apr 28, 2014
    Messages:
    19
    Likes Received:
    27
    I'm running the latest version of GRBL from the source on the edge branch.
    https://github.com/grbl/grbl/tree/edge
    I've attached a compiled version from this commit
    https://github.com/grbl/grbl/commit/f298cd925db3c8cce5c8a74fd6f26249773b422d

    Here are the GRBL settings I use. You can (and should) adjust feed rates and max travel to your machine. To upload all settings, I connect to the serial port with Putty and paste them all at once.

    Modify RED values for your machine
    $0=10 (step pulse, usec)
    $1=25 (step idle delay, msec)
    $2=0 (step port invert mask:00000000)
    $3=0 (dir port invert mask:00000000)
    $4=0 (step enable invert, bool)
    $5=0 (limit pins invert, bool)
    $6=1 (probe pin invert, bool)
    $10=3 (status report mask:00000011)
    $11=3.000 (junction deviation, mm)
    $12=10.000 (arc tolerance, mm)
    $13=0 (report inches, bool)
    $14=1 (auto start, bool)
    $20=1 (soft limits, bool)
    $21=1 (hard limits, bool)
    $22=1 (homing cycle, bool)
    $23=0 (homing dir invert mask:00000000)
    $24=20.000 (homing feed, mm/min)

    $25=500.000 (homing seek, mm/min)
    $26=224 (homing debounce, msec)
    $27=1.000 (homing pull-off, mm)
    $100=26.670 (x, step/mm)
    $101=26.670 (y, step/mm)
    $102=50.000 (z, step/mm)

    $110=1000.000 (x max rate, mm/min)
    $111=1000.000 (y max rate, mm/min)
    $112=500.000 (z max rate, mm/min)
    $120=100.000 (x accel, mm/sec^2)
    $121=100.000 (y accel, mm/sec^2)
    $122=30.000 (z accel, mm/sec^2)
    $130=500.000 (x max travel, mm)
    $131=750.000 (y max travel, mm)
    $132=80.000 (z max travel, mm)
    Special note on settings, I am using much higher feedrates, but you should TEST your machine to make sure it can move reliably at these speeds. Heat, belts, motors, bearings and many other things can have an impact on your speed. These speeds should also only be used for SEEKING. I really doubt you could cut anything going this fast, so if your CAM program doesn't have good speed control you should limit your GRBL speed for safety.

    $25=2250.000 (homing seek, mm/min)
    $110=15000.000 (x max rate, mm/min)
    $111=15000.000 (y max rate, mm/min)
    $112=750.000 (z max rate, mm/min)
    $120=125.000 (x accel, mm/sec^2)
    $121=125.000 (y accel, mm/sec^2)
    $122=30.000 (z accel, mm/sec^2)

    For host software I'm using Universal GCode Sender 1.08 compiled with netbeans, as it works with Grbl 0.9. You could also try http://chilipeppr.com/, but I think it is still on GRBL 0.8.

    I use Xloader to upload to my Arduino UNO. http://russemotto.com/xloader/
    Modify your devices.txt to include UNO if that is what you are using.
    Mega(ATMEGA1280);m1280;stk500;57600;
    Duemilanove/Nano(ATmega328);m328p;stk500;57600;
    Duemilanove/Nano(ATmega168);m168;stk500;19200;
    Uno(ATmega328);m328p;stk500;115200;
    Mega(ATMEGA2560);atmega2560;stk500v2;115200;



    I haven't had any issues with line noise using Grbl 0.9. I'm using inverted logic, so the switches send a GND to the board when they trigger. The UNO has internal pull-up resistors and seems pretty stable. I have had issues with some cheap and or smashed switches giving false triggers on other machines in the past. Occasionally a wire can come lose due to vibration if they aren't connected very well, this can also give false triggers. I don't have an oscope hooked up to the wires, but I use this same setup on a couple RepRaps and they don't have any issues either.

    If you are having issues, you could build filters and debounce circuitry. However, that seems overkill if you aren't having any problems.

    One last note: If anyone is cutting ovals and you can't figure out why, you might check your setscrews and add some threadlock to them. They like to come loose on my machine.
     

    Attached Files:

    #1217 BinaryConstruct, Aug 24, 2014
    Last edited: Aug 24, 2014
    Mark Carew and Rick 2.0 like this.
  18. Chris Laidlaw

    Chris Laidlaw Well-Known
    Builder

    Joined:
    Mar 1, 2014
    Messages:
    77
    Likes Received:
    27
    Very impressive wood working to support your Ox.
     
  19. Jonathan Trinity

    Builder

    Joined:
    Aug 7, 2014
    Messages:
    11
    Likes Received:
    0
    Very impressive indeed. You have a nice working space for your Ox. :thumbsup:
     
  20. Rich C

    Rich C New
    Builder

    Joined:
    Aug 4, 2014
    Messages:
    66
    Likes Received:
    11
    Thanks. here are two more pics. One shows the painted top and the Makita RT0701C mounted, the other is a side/rear shot showing my printed cable-chain and v-slot wire-holders. There will be another cable-chain (which I am currently printing) along the x-axis that will sit atop the silver v-slot. I will have to remove the power cord from the Makita and run it thru the cable-chain because the plug is too large to fit thru the slots. Oh, and the OX will be bolted to the table top.
    DSC_0077.JPG
    One point of note: you notice (or maybe not) that the silver v-slot is only being held with one screw on each end, that is because if I rotate it 180 degrees, the nuts behind the rear z-plate actually set into the v-slot and I didn't like that idea. There isn't going to be any weight on the solver v-slot, so I figured the single screw on each end would suffice (and it is the perfect width for my cable-chain in the orientation that it is in). Also, the red brackets around the NEMA23s may or may not stay....they might be used to attach the cable-chain ends, but I am looking at another option...
    DSC_0078.JPG
    I have 40 feet of stepper motor wire on its way, once that gets here, I will start my wiring task.

    Rich
     
    Chris Laidlaw likes this.
  21. Derwin Palacpac

    Builder

    Joined:
    Jan 22, 2014
    Messages:
    14
    Likes Received:
    5
    image.jpg image.jpg
    Im running a 1/2" lead screw for my z, modified some things to make the ox bit more stronger. Theres alot of force everywhere. I been having an issue with my X skipping steps, and the reason is the GT2 belt keeps slipping loose.. Does anyone have a solution or a trick to keep the belt tight?
     
    Mark Carew likes this.
  22. Gareth

    Gareth New
    Builder

    Joined:
    Jan 23, 2014
    Messages:
    15
    Likes Received:
    8
    This weekend I finally ( finally, when did I start this, February??!!) cut the ALU extrusions and set up my mechanical bits. I still have some more fabrication work to do for the X and Z axes but its almost time for electronics! :D IMG_430633360.JPG
    The table is a torsion box design. It is a bit bigger than 2'x4' so the final cut area will be something like 23"x36" (580x900). This configuration has 4 1/2" of Z travel plus space for a 1" spoilboard. It can be raised another 20mm by going up 1 notch on the angle brackets. I'm a little disappointed with those, they aren't square. o_O I will probably end up bending them into shape.
     
    #1222 Gareth, Aug 25, 2014
    Last edited: Aug 25, 2014
    Mark Carew likes this.
  23. GrayUK

    GrayUK Openbuilds Team Elder
    Staff Member Moderator Builder

    Joined:
    May 5, 2014
    Messages:
    1,668
    Likes Received:
    627
    Gareth.
    It's looking good. You mentioning the extra 20cm, (or do you mean, 20mm) by moving it up a slot, I'm thinking maybe join the holes into a slot, and then sliding the X axis, up and down, with a built in Spirit level and locking mechanism?
    How many X cross members have you got there? I can't quite see from the picture?
    Just a thought.
    Gray
     
  24. Gareth

    Gareth New
    Builder

    Joined:
    Jan 23, 2014
    Messages:
    15
    Likes Received:
    8
    There should be room for 3 X pieces. The plan is to put one in the middle and then put bolts through all 3 to clamp them together. This is the longest span in the machine so it needs to be super rigid.

    Oh yeah, that 20mm! Moving up one slot on the Y rails.
     
  25. Derwin Palacpac

    Builder

    Joined:
    Jan 22, 2014
    Messages:
    14
    Likes Received:
    5
    @JustinTime the motor pulleys on my Y & (slaved) A dont slip at all and those are a 1000mm long. Im looking for a way to keep the belt taunt. Mach 3 gave me a warning saying that the feedrate is be too fast for the pulley. Alot of builders on youtube show that their machine can go "so fast" and its actually not under any load. There has to be some way to keep the two ends of the belt from slipping away from that "t nut".
     
  26. dddman

    dddman Journeyman
    Builder

    Joined:
    Mar 2, 2014
    Messages:
    468
    Likes Received:
    187
    A bigger pulley (with more teeth) will surely help, add a second t-nut so it will limit the slipping of the other one. I think Mach3 means spindle, not pulley.
     
  27. Rick 2.0

    Rick 2.0 OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Dec 20, 2013
    Messages:
    2,852
    Likes Received:
    1,524
    @Derwin Palacpac, search through the forum for tensioning clips. There are several good examples that may solve your problem. Also check with the OX plate makers to see what they have available.
     
  28. SWAMPER

    SWAMPER New
    Builder

    Joined:
    Aug 25, 2014
    Messages:
    1
    Likes Received:
    0
    Have been looking at the OX build for some time and would like to build a 2'x4' size one and wonder if anyone sells a kit with all the parts at once deal that way i don't have to buy part by part ?

    Thanks :)
     
  29. Frederic Goddeeris

    Builder

    Joined:
    Jul 15, 2014
    Messages:
    39
    Likes Received:
    19
    I did the same exercise. I took pictures that I magnified and printed. My backlash on the X axis seems to be 0.333 mm and 0.188 on the Y axis.


    x.jpg
    y.jpg

    What could we do to improve this? This is a standard build with GT3 belts.

    Frederic
     
    Jeferson SImoes likes this.
  30. Jeferson SImoes

    Builder

    Joined:
    Mar 7, 2014
    Messages:
    16
    Likes Received:
    9
    Thanks a lot @Frederic Goddeeris :thumbsup:

    I was thinking it was some my mistake. I realized that different micro-stepping change the backlash. 1/32 and 1/16 I get about 0,2mm or more. Now, with 1/8, the max backlash I can mensure is 0.13mm.

    Here's a table about the belts backlash: http://www.sdp-si.com/resources/imgs/belts/fig10.jpg

    I will try a reduction system in next weeks and report here about. I don't want to use Mach3. It's the cost of software + PC with DB25. Or "high" cost of a solution to use Mach3 in USB computers. I think the GRBL + some mechanics solution will be cheaper.
    I mean (sorry my english, guys):
    Money to get Mach3 + breakout usb board + belts setup = Arduino + ballscrew setup.
    Even the ballscrew solution would be more expensive, I prefer improve this backlash in mechanics, and keep with GRBL.

    Also, I will figure out how to use this (link below) in Gcode that I need reduce backlash, like PCB.
    https://github.com/Lenbok/NoLash
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice