Welcome to Our Community

Some features disabled for guests. Register Today.

C-Beam cnc

Discussion in 'CNC Mills/Routers' started by Kyo, Jun 24, 2016.

  1. Mike Piechowski

    Builder

    Joined:
    Jun 11, 2016
    Messages:
    33
    Likes Received:
    22
    I never even thought of using a BEC to power the Pi, that is a great idea. I think I even have one sitting around in my RC parts. Have you ever looked at how clean the power is coming out of it? I noticed a ferrite on the power leads. Did you connect the BEC to the GPIO (Pins 2 and 6) or are you powering it via the MicroUSB?

    I've got some adjustable buck converters that I'm using with my 24-volt supply to drop the voltage to run the 12V cooling fans. I may use another one on the Pi, but the power coming out of the inexpensive buck converters isn't the "cleanest", I measured about 120 mV of ripple on 5 V. I suppose before I pass judgement on the converter, I should look at the output of the wall-wart I am using and see how clean it is.
     
  2. Barry Danks

    Barry Danks Well-Known
    Builder

    Joined:
    Apr 21, 2016
    Messages:
    113
    Likes Received:
    35
    @Kyo
    Awesome build. I really like the sub frame very ingenious. What steppers did you use?
     
  3. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    It was just by chance I found the bec when looking for pi power supply's. I have not tested the output myself yet. But from the reviews on this unit it should be pretty clean. The gentlemen who gave me the link has been using one to power his Pi based radio for over a year now. I will probably use the pins that way i don't have to worry about the bulk of a usb connector.

    Thanks, I used the new high torque motors from openbuilds "Here"
     
  4. bbirling

    bbirling New
    Builder

    Joined:
    Jul 11, 2016
    Messages:
    3
    Likes Received:
    0
    Awesome build. I am looking to build a version of this. Is there a source for a set of plates for this build.

    Bruce
     
  5. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    Bruce -- I am in the process of getting ready to offer plate sets for this build but not ready quite yet. If you wanted to go ahead and get started on your build shoot @Chris Laidlaw a msg. Don't forget to download and send him revision 2 of the plates if you want dual anti-backlash nuts. He has rev. 1 files on hand already.
     
    Chris Laidlaw likes this.
  6. bbirling

    bbirling New
    Builder

    Joined:
    Jul 11, 2016
    Messages:
    3
    Likes Received:
    0
    Thanks for the info.
     
  7. slm222

    slm222 New
    Builder

    Joined:
    May 17, 2016
    Messages:
    23
    Likes Received:
    2
    I haven't opened the file yet. But looks good. Does the X axis have a 20x40 rail for a cable tray?
     
  8. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    I did not place one in the cad model as everyone does wiring differently. But yes by design it can indeed support one. You can use a 503mm 20x20 two 90 corner brackets and two end caps. To build a support to carry your cable chain on the X-axis. You would use the lower rear x axis nema 23 motor mounting points on the Y-axis side plates.
     

    Attached Files:

    slm222 likes this.
  9. TerryOx

    TerryOx Well-Known
    Builder

    Joined:
    Apr 1, 2016
    Messages:
    90
    Likes Received:
    30
    Thank you for posting this excellent build.

    What are the maximum working dimensions?
     
    #39 TerryOx, Jul 16, 2016
    Last edited: Jul 16, 2016
  10. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    No problem, Happy to share my builds. This is a desktop sized machine and I am building the smaller of the two designs I included in my CAD files. I should end up with a max cutting / travel area of X = 330mm Y = 340mm Z = 45mm ( with 1.5" worth of spoiler board material )..
     
  11. Ronald van Arkel

    Staff Member Builder Resident Builder

    Joined:
    May 7, 2014
    Messages:
    472
    Likes Received:
    242
    You could get a non-HDMI screen, cheaper, smaller (most of the time), a HDMI to VGA is about 10USD and a HDMI to DVI is just the cable. This way you can also use older screens.

    -Ronald
     
  12. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    Your right, older vga monitors are much cheaper then hdmi! I plan to just use the Pi hdmi output via a panel mount cable with a old monitor I have laying around. However I will not be using any of the gpio on the pi so you could also use a resistor ladder to bring out a vga signal no converter needed if you wanted to use a vga monitor instead of hdmi.
     
    #42 Kyo, Jul 17, 2016
    Last edited: Jul 18, 2016
  13. Ronald van Arkel

    Staff Member Builder Resident Builder

    Joined:
    May 7, 2014
    Messages:
    472
    Likes Received:
    242
    Same here, got a lot of laptop screens, some with CCFL, I might look into some VGA to panel cable and tube driver to see if they are still worth something. I never saw the resistor ladder for the Pi, interesting, thank you :). I'm too outdated on electronics so this is why I'll go with out of the box converters ;).

    -Ronald
     
  14. Mike Piechowski

    Builder

    Joined:
    Jun 11, 2016
    Messages:
    33
    Likes Received:
    22
    I am using an inexpensive 19" monitor with my Pi setup, plugged in via a $3 DVI to HDMI cable.

    The monitors I have are used Dells, they're older, with CCFL, but they're good panels. Best part? They cost $45 each from Ebay, shipped. Just need to make sure that the monitors have a DVI input. Everything just worked when I plugged it in, no fiddling with settings or anything. These monitors also have an integrated USB hub, so I only need to connect the DVI to HDMI and one USB cable to the Pi, then I can plug the keyboard and mouse into the monitor and position the console a bit further away from the machine.

    BTW, I'm running Raspbian and BCNC on my Pi3 to control my C-Beam with a Protoneer shield, it all seems to work well so far, but I am just getting started.

    @Kyo: I picked up a 5V/12V BEC and Power Distribution board meant for quadcopters (an ARRIS CC3D Naze32, $12 @ Amazon) the other day and tried it out. Voltages are spot-on, 5.00 and 12.00, they only dip a little bit under load too. Fairly clean power, not perfect, but there was only about 20mV of ripple on the 5V according to my scope after I looped the power out wire through a ferrite and put a load onto it. The Pi seems to run just fine with it, I plugged the power in via GPIO pins 1 and 3. As soon as I can get some sort of case or cover printed out for the board, I will install it on the C-Beam. The 5V output is rated to 3A, plenty for the Pi. The 12V output is limited to half an amp, but that is plenty to spin a few fans, which I all I need the 12V for. The steppers run @ 24V.
     
    Kyo and snokid like this.
  15. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    Hey Bob, Indeed I do. I am still learning the software and have not gotten to the cam side of things as of yet. I have been using Sketchucam for my cutting needs. Right now my work flow is like this.
    Fusion 360 > export dxf > Sktechup > import dxf > Sketchucam > save g-code file > bCNC.

    When using Fusion 360 as your cad and cam for the c-beam machine your in luck. The Uno and protoneer hat run GRBL ! Fusion 360 has a GRBL Post processor built in and ready to go.
     

    Attached Files:

  16. Metalguru

    Metalguru Veteran
    Builder

    Joined:
    Dec 29, 2015
    Messages:
    740
    Likes Received:
    533
    Kyo, you might take a cue from Mark Carew in the way he designed the XL Gantry Plates for the c-beam. Rather than messing around with trying to get the lead nut bolt spacing exactly right, he just slotted the mounting holes for the lead nuts parallel to the lead screw. This allows you to adjust the position a bit to make up for any issues.

    As an aside note, I discovered that this setup also makes the use of anti-backlash nuts irrelevant. Since you have a bit of adjustment on the nut position, you can use the regular non backlash nuts and compensate for backlash by adjusting the position of the two regular nuts. Just put in the leadscrew, and squeeze the nuts together while tightening the mounting screws.
     
  17. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    Done and Done. :thumbsup: I left a bit of slop in the slot to allow you to mount the nuts without issue. Rev2. plates have also been posted if you want a precise position for your lead screw nuts. This gives you some options.

    Here are the files for the slotted nut mounting points. All other files from the original build zip file are still good to go. The changes only effect the plates a lead screw nut mounts to.
     

    Attached Files:

    Chris Laidlaw and silopolis like this.
  18. darkshady1

    Builder

    Joined:
    Jul 12, 2016
    Messages:
    2
    Likes Received:
    1
    I love the design and I think this might be what I go with for my machine.

    Two questions:

    1. On the BOM it lists http://openbuildspartstore.com/belt-reduction-mount-nema-23-high-torque-series/ but it appears as though OpenBuilds no longer sells them (or they renamed them and I can't find it on their website). Is this a suitable replacement: Threaded Rod Plate - NEMA 23 Stepper Motor

    2. I plan on scaling this build to 1000x1000. Looking at the Y axis end plates it has the bearings on the inside of the C-Beam. After reading a lot about screw whip and methods to eliminate it I saw about removing compression on the screw by tightening the lock collar up against the bearing (Video R7v7 Build Videos - SMW3D R7). I'm considering moving the bearing recess to the outside of the plate and using this method. Any thoughts or opinions on that?

    EDIT: I guess number 2 would apply to X end plates also.
     
  19. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    @darkshady1
    Nice, Happy to see more builds. I know Chris has had a few plate orders I hope they all come back and post their builds. :thumbsup:

    A 1: Yes, I started to collect parts before the plate was pulled. The OB team is working on a redesign but for now go ahead and supplement the belt reduction plate for the following.
    : (x1) 1/4" - 8mm Coupler
    : (x2) 40mm Spacers

    This will allow you to mount the Z-axis motor as it is mounted on @Mark Carew Plate Maker The Z-axis belt reduction can always be a later upgrade for your build.

    A 2: You bring up one of the major design considerations I made when designing this machine. As reviewed in my build video. You can do either one! both have pro's and con' s. With this in mind the plates have been designed to give the end user the choice of putting his leadscrews in tension or compression. If you want to assemble your build with the screws in tension instead of compression as I have done. It is a simple matter of flipping the plates left to right and not trimming the leadscrews down.
     
  20. darkshady1

    Builder

    Joined:
    Jul 12, 2016
    Messages:
    2
    Likes Received:
    1
    I went back and looked at the model and realized you're absolutely right. I thought about flipping them earlier but for some reason it didn't work out in my head. Awesome job on having the foresight to design them that way. Just have to decide if I want to make any modifications or not. Awesome job on documenting everything. That makes everything 10000 times easier when someone wants to come along and plan a build. The documentation helped me make my decision on this build as opposed to comparable builds which didn't have as good documentation.
     
    Kyo likes this.
  21. slm222

    slm222 New
    Builder

    Joined:
    May 17, 2016
    Messages:
    23
    Likes Received:
    2
    At what point would the tr8*8 have whip? 1000mm seems to be the max people are pushing them. I'd like to build a bigger machine, but cost is something I'm considering.
     
  22. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    The TR8*8 Have been working great for me. :thumbsup: I have not yet built anything long enough for me to start worrying about whip at those lengths. As such I do not have any hand on experience in that area. If you wanted to up the size to 10mm leadscrews you will need to run MR16105-ZZ bearings and grab the compatible antibacklash nuts online. Anything larger would require a redesign for both the machine and lead screw nuts.
     
    #52 Kyo, Jul 20, 2016
    Last edited: Jul 20, 2016
  23. Metalguru

    Metalguru Veteran
    Builder

    Joined:
    Dec 29, 2015
    Messages:
    740
    Likes Received:
    533
    Kyo, do you have a source for the 10mm leadscrews and nuts? I found a similar type on Ebay in both 10 and 12mm, but lengths not longer than 950mm. Have not found any others. There are lots of Chinese made ball screws out there but nothing compatible with the OpenBuilds nut mounting system.
     
  24. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    @Metalguru I have not run or have any affiliation with the following but I do have them bookmarked.

    You can get a tr10x2 trapezoidal lead screw from Roton up to 144" long just let them know what you need, Motedis offer a tr10x2 antibacklash nut in the same style we use with the same bolt spacing. I wonder if the OB store nut has enough "meat" to be drilled and tapped for tr10x2 the taps are cheap and easy to find. Might be worth a try.
     
  25. Metalguru

    Metalguru Veteran
    Builder

    Joined:
    Dec 29, 2015
    Messages:
    740
    Likes Received:
    533
    Where do you get taps? I recall a thread on the list somewhere where one of the members was making his own lead nuts, using taps he made from the actual lead screw. I'm not sure I have the facilities to do this accurately.

    The TR10x2 is only half the pitch of the OB screws, and would be pretty slow... And Motedis is German and makes no mention of shipping to North AM. Their lead nuts are 13mm thick, 1mm thicker than the OB ones.
     
  26. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    I have a semi local mom and pop style hardware store that has a good selection of metric hardware / taps. Last I checked They ran about 15 bucks or so. Most online shops like amazon would carry the tap as well. Just search for "TR10x2.0mm Right Hand Metric Trapezoidal Tap"

    In comparison a tap like @Giarc made for his 5 start 1/2" - 10 acme run around $100 plus when you find them. Not very cost effective for only one project.

    Yeah, that is why I have never tried running them before. I am happy with the OB tr8x8 in the size of builds I do. They offer a solid mix of speed precision and strength.

    The thickness would not be to much concern, we use spacers to align our nuts as is, just need to change up the sizes. I am not sure if they ship to Canada the website sure does not look like it. You would have to email to be sure.

    On my next OB order I will grab a spare nut and try drilling and tapping it; if you guys really wanted to know. :thumbsup:
     
    #56 Kyo, Jul 20, 2016
    Last edited: Jul 20, 2016
  27. Metalguru

    Metalguru Veteran
    Builder

    Joined:
    Dec 29, 2015
    Messages:
    740
    Likes Received:
    533
  28. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    Looks like they only have a nut for a 1.5mm pitch screw not 2mm. I do not know of a source for 1.5mm pitch 10mm screws that are very long.
     
  29. Metalguru

    Metalguru Veteran
    Builder

    Joined:
    Dec 29, 2015
    Messages:
    740
    Likes Received:
    533
    That's the problem I am having.

    Although, I do not want to run anything much over 1000mm anyway. I've been holding off doing a 1000mm machine for just that reason.

    However, running the lead screw under tension rather than compression seems like it will solve the problem. I already have the thrust bearings, but the 750mm machine I'm building I've already cut the lead screws and they will be too short for a tension mode to test it out. I can do the Z axis, but that's not really a fair test. Hmm, I have not cut the lead screw for the X axis yet. Mebbe I'll try that.

    Thanks a bunch, buddy. Happy building!
     
  30. Kyo

    Kyo Veteran
    Staff Member Builder Resident Builder

    Joined:
    Feb 27, 2014
    Messages:
    670
    Likes Received:
    684
    No Problem, Same to you :thumbsup:
     

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