CNC Build Advice - Thanks!! - Page 2


Page 2 of 2 FirstFirst 12
Results 21 to 26 of 26

Thread: CNC Build Advice - Thanks!!

  1. #21
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: CNC Build Advice - Thanks!!

    Am I going overkill?....

    I think I have settled on a CNCRP Benchtop – deciding between standard or Pro – Do I really need for what I am doing?

    If I go standard, is it worth upgrade the acme screws to ball screws for $400?
    In some ways, there's no such thing as overkill, until things get rediculous.

    If you want to cut aluminum, plain and simple, the better the machine, the better your results will be. A better machine will allow you to cut deeper, faster, and with a better finish. Maybe not all three at the same time, but you have more options.

    Having said that, no, I would not pay $400 to upgrade to ballscrews. At nearly 1/3 the cost to move to the Pro, I'd rather spend more and go for the Pro.


    Do I need a full t slot table or is mdf good enough?
    Everyone's idea of what's "Good Enough" is different. You can always start with an MDF table, and upgrade later if you want. How you actually use it may influence that decision.

    Gecko G540 Stepper Motion Controller package – Is this a solid choice for relative hassle free set up for a new user for the price? I am balancing price/quality/and ease of set up.
    Yes. While it's not as popular as it used to be, it's a solid choice. Gecko's support is excellent, but it's unlikely you'd need it. I think I mentioned before that you can get as good or better performance for less money, but with a more difficult installation.


    If I go Gecho G540, what is the best software I can go considering ease of use and reliably?

    What connector should I use then?
    What motors and drives you use is irrelevant when it comes to choosing software. I already made suggestions earlier in this thread.
    And it's controller, not connector.

    I would not buy 600oz Nema 23 steppers.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  2. #22

    Default Re: CNC Build Advice - Thanks!!

    Quote Originally Posted by ger21 View Post
    In some ways, there's no such thing as overkill, until things get ridiculous.

    If you want to cut aluminum, plain and simple, the better the machine, the better your results will be. A better machine will allow you to cut deeper, faster, and with a better finish. Maybe not all three at the same time, but you have more options.

    Having said that, no, I would not pay $400 to upgrade to ballscrews. At nearly 1/3 the cost to move to the Pro, I'd rather spend more and go for the Pro.
    Ha, I am doing that math in my head, ballscrew upgrade costs, Pro comes with slotted table already, I might just make the jump for this reason. Considering that now.

    Quote Originally Posted by ger21 View Post
    Yes. While it's not as popular as it used to be, it's a solid choice. Gecko's support is excellent, but it's unlikely you'd need it. I think I mentioned before that you can get as good or better performance for less money, but with a more difficult installation.
    Ha, yea, that last part is why I am still leaning this way. I am balancing saving a few bucks and having the support of both Gecko and the individual selling the kit. Plug and play has value to me, just not as much as CNCRPS kits (yikes!!).

    I did notice Gecko is a bit older. Maybe I am bad a looking, but any solid all in one kits out there I am missing with newer/better parts? CNCRPs is $1,600 and the gecko kit I found is half that, so thought a solid option. I am open to any recommendations, and I would be comfortable wiring my own. I just like something that is complete, has good support, and if wired right is on the low end of difficult to work right. There is so much to learn, trying to short cut what I can by buying right.

    Quote Originally Posted by ger21 View Post
    What motors and drives you use is irrelevant when it comes to choosing software. I already made suggestions earlier in this thread.
    And it's controller, not connector.

    I would not buy 600oz Nema 23 steppers.
    Ha, I am a few hours smarter on research and that question looks silly to me now. I was worried that the Gecko was not compatible with some software that would limit my options like mach3 or mach4.

    I am leaning towards using mach4 combined with UC300ETH-5LPT or UC400ETH.

    Thanks so much for more replies!!! Nice afternoon boost



  3. #23
    Member
    Join Date
    May 2005
    Location
    USA
    Posts
    3920
    Downloads
    0
    Uploads
    0

    Default Re: CNC Build Advice - Thanks!!

    I’m a bit late to this thread - work has been hell - but thought I’d add to some of the already good advice. Hopefully this will not confuse you with more options and opinions. The comments are based on your slant to processing lots of aluminum, that is aluminum is the primary material to be machined.

    1. Avoid any design that incorporates wood. This is simply due to the very high likely hood that you will be using a lubricant / coolant. A common problem with Aluminum in a CNC is chip welding and the right machining fluid will help with that.

    2. For a 22 x 22” machine it would be worth considering a moving table design over a moving gantry. For a given amount of effort a moving table design should be easier to build and more rigid for a given outlay in materials. Generally you can get away with just three steppers leaving a channel open for other axis uses. Like all machines architectures moving table designs have their disadvantages, one of those being slightly larger foot prints. You will need to consider the disadvantages vs your needs but at the same time weigh the advantages. A 22” square machine though is very feasible as a moving table design.

    3. If your primary goal is machining lots of aluminum do consider linear profile rails as your linear bearing solution. The additional expense rewards you with a more rigid bearing solution that will enhance surface finish on metals. Understand though that linear bearing rails do nothing for fundamental accuracy. The underlying structure of the machine must be accurate and further assembly must be accurate.

    4. This brings us to the next issue assembly of a kit or the build of a DIY machine demands that you have some tools suitable for the job. Here I’m talking precision machine tool mechanics tools like squares, dial test indicators and the associated stands, levels, straight edges and maybe some micrometers. Many people into home shops already have some of these tools but it can be an additional expense that will inflate the cost of a kit or DIY project.

    5. The cost of a few power tools may be offset by savings over a kit or cut charges from a supplier. For example a used table saw with an accurate cross cut sled can be used effectively to cut Aluminum extrusion to length. Likewise chop saws can be had that will cold cut Aluminum extrusions and steel tubing just fine. It may make a lot of sense to invest in more DIY machinery if you can see long term usage.

    6. This depends upon your location but the big extrusion companies like 80/20 have many local distributors / job shops that can take a cut list and supply you with everything to assemble your dream machine with. You would need a proper cut list to get a quote however it might be cheaper than a kit from one of the specialist retailers. Further you can tailor the parts to your exact needs for a machine build. In the end though you are stil paying for a jobber to do the cutting and processing for you.

    7. I’m not really a big fan of Aluminum T -slot extrusions for machine builds. I’d lean towards box section steel builds for any machine where weight isn’t a problem. Frankly mass is an advantage in most machine tools and that is the case here also. However the reasons for leaning wowards steel are broader than just the additional mass you get. One outstanding value is its cost, especially as drops or junk yard finds but even as prime stock steel is still very cheap. Other advantages in Include good screw holding (assuming proper thickness for the screw), weldability with simple processes, strength, and a very wide array of profiles. I tend to urge every one to at least consider steel for parts of their machines, even if that is only the gantry beam.

    8. You seem to be in on the electrical controls side of the machine a bit early. It is better to have your basic machine mechanical design down first. Even though this is a small machine you will want to be sure you have the proper selection of parts for the axises involved. For example you need to make sure the steppers or servos can handle the loads involved, likewise the drives must be able to handle the motors connected. This isn’t a big machine by any means so their is plenty of design experience in this forum.

    9. Software is in a state of flux. Mach based systems have seemingly lost ground to the alternatives. Having little contact with the alternatives I can’t say a lot about them. I would not however dismiss Linuxcnc as a much older but well regarded solution.

    10. Maybe I missed it but nothing about the spindle was mentioned. The primary thing here is that the Z properly supports thes spindle. There is little info on the Z hight but do realize that these are factors in a proper gantry beam design. A very high Z implies significant twisting of the gantry beam. If the machine is focused on one type of work, processing sheet goods, it pays to minimize Z to some extent. Leave room though for spoil boards and fixturing.



  4. #24

    Default Re: CNC Build Advice - Thanks!!

    Quote Originally Posted by wizard View Post
    I’m a bit late to this thread - work has been hell - but thought I’d add to some of the already good advice. Hopefully this will not confuse you with more options and opinions. The comments are based on your slant to processing lots of aluminum, that is aluminum is the primary material to be machined.

    1. Avoid any design that incorporates wood. This is simply due to the very high likely hood that you will be using a lubricant / coolant. A common problem with Aluminum in a CNC is chip welding and the right machining fluid will help with that.

    2. For a 22 x 22” machine it would be worth considering a moving table design over a moving gantry. For a given amount of effort a moving table design should be easier to build and more rigid for a given outlay in materials. Generally you can get away with just three steppers leaving a channel open for other axis uses. Like all machines architectures moving table designs have their disadvantages, one of those being slightly larger foot prints. You will need to consider the disadvantages vs your needs but at the same time weigh the advantages. A 22” square machine though is very feasible as a moving table design.

    3. If your primary goal is machining lots of aluminum do consider linear profile rails as your linear bearing solution. The additional expense rewards you with a more rigid bearing solution that will enhance surface finish on metals. Understand though that linear bearing rails do nothing for fundamental accuracy. The underlying structure of the machine must be accurate and further assembly must be accurate.

    4. This brings us to the next issue assembly of a kit or the build of a DIY machine demands that you have some tools suitable for the job. Here I’m talking precision machine tool mechanics tools like squares, dial test indicators and the associated stands, levels, straight edges and maybe some micrometers. Many people into home shops already have some of these tools but it can be an additional expense that will inflate the cost of a kit or DIY project.

    5. The cost of a few power tools may be offset by savings over a kit or cut charges from a supplier. For example a used table saw with an accurate cross cut sled can be used effectively to cut Aluminum extrusion to length. Likewise chop saws can be had that will cold cut Aluminum extrusions and steel tubing just fine. It may make a lot of sense to invest in more DIY machinery if you can see long term usage.

    6. This depends upon your location but the big extrusion companies like 80/20 have many local distributors / job shops that can take a cut list and supply you with everything to assemble your dream machine with. You would need a proper cut list to get a quote however it might be cheaper than a kit from one of the specialist retailers. Further you can tailor the parts to your exact needs for a machine build. In the end though you are stil paying for a jobber to do the cutting and processing for you.

    7. I’m not really a big fan of Aluminum T -slot extrusions for machine builds. I’d lean towards box section steel builds for any machine where weight isn’t a problem. Frankly mass is an advantage in most machine tools and that is the case here also. However the reasons for leaning wowards steel are broader than just the additional mass you get. One outstanding value is its cost, especially as drops or junk yard finds but even as prime stock steel is still very cheap. Other advantages in Include good screw holding (assuming proper thickness for the screw), weldability with simple processes, strength, and a very wide array of profiles. I tend to urge every one to at least consider steel for parts of their machines, even if that is only the gantry beam.

    8. You seem to be in on the electrical controls side of the machine a bit early. It is better to have your basic machine mechanical design down first. Even though this is a small machine you will want to be sure you have the proper selection of parts for the axises involved. For example you need to make sure the steppers or servos can handle the loads involved, likewise the drives must be able to handle the motors connected. This isn’t a big machine by any means so their is plenty of design experience in this forum.

    9. Software is in a state of flux. Mach based systems have seemingly lost ground to the alternatives. Having little contact with the alternatives I can’t say a lot about them. I would not however dismiss Linuxcnc as a much older but well regarded solution.

    10. Maybe I missed it but nothing about the spindle was mentioned. The primary thing here is that the Z properly supports thes spindle. There is little info on the Z hight but do realize that these are factors in a proper gantry beam design. A very high Z implies significant twisting of the gantry beam. If the machine is focused on one type of work, processing sheet goods, it pays to minimize Z to some extent. Leave room though for spoil boards and fixturing.
    Wow, so much great info. Thank you for taking the time to respond. I should have updated, right now I am leaning towards the CNC router parts benchtop pro or standard, or one of their 4824 Pros.

    1. Noted, I was deciding between a spoil board and the tslot, but as you noted, spoil boards do not work with coolants. So no wood.
    2. The only machines I ever found like this were big boy machines. I would prefer to keep the rig under 400lbs. Can you point me in the direction of one. Budget right in the $5.5k range for the machine alone.
    3. Noted, I am looking at only linear rail stuff with the CNCRPs i noted above.
    4. I have a few of these, will buy a few to ensure the build is aligned well. One thing I like about CNCRPs is that I have noted a couple youtube builds, in them they started off pretty darn square before major alignment. I like that a lot.
    5 - 7, I am leaning away from building my own from scratch. I like leaving that on CNCrps atm.
    8 - Yea, changed my mine on this. With the CNCRPs, i would do their plug and play system to limit the stress of figuring things out myself.
    9 - Yea, this is still up on the air.
    10 - Going with a cheapo HY one for now from ebay. I dont plan to mount very high.

    The question now is, which of the CNCRPs i want to use. What fits my application and space. I actually have another thread asking that question here.

    https://www.cnczone.com/forums/cnc-r...rd-2424-a.html

    Thanks again !!!!!!!



  5. #25
    Member davida1234's Avatar
    Join Date
    Oct 2009
    Location
    United States
    Posts
    733
    Downloads
    0
    Uploads
    0

    Default Re: CNC Build Advice - Thanks!!

    Very solid advise. Thank you.



  6. #26
    Member hanermo's Avatar
    Join Date
    Aug 2004
    Location
    barcelona
    Posts
    780
    Downloads
    0
    Uploads
    0

    Default Re: CNC Build Advice - Thanks!!

    To mithral ..
    You are pretty much right.
    You will get a decent balanced system as proposed.

    It will be *able to* cut alu to pretty high repeatability - but pretty slowly vs anything commercial these days.

    So, with the right adjustments, cutters, etc. You can/will be able to make parts in alu that are feature-accurate to about 0.02 mm over a small area, and look good, and are accurate to maybe 0.05 mm overall in 150 mm cubes of work area.
    It will be possible, if a bit slow and awkward, for You to make parts and assemblies to 0.01 mm local accuracy or feature sizes via endless machining strategies - just like all big boys commercially.

    For the 5.5K budget, it is an overall decent plan.
    You can then later adjust and upgrade, as needed, if your desires and needs (or commercial-hobbiest) goes that way.

    Once You see what is doable, in what time, You are better positioned to make decisions on commercial-competitive stuff.

    E.g.
    You can cut say 10 motor mounts, or model engine frames, of 150x100 mm size, per setup, 5 tools, in 3 hours.
    Boring critical holes, finishing with reaming for size on true cylindrical holes, etc.
    Chamfering all corners.

    You need to charge about 30$ x 3 x 1.2 or hourly hours+1 x time to account for tools, setup etc.
    == 110$ minimum for hobbiest stuff.
    11$ each, zero profit.

    A vmc will cut 40 frames in 20 mins, after a 150$ setup charge, 80$ /hr, 240$ total.
    6$ each.
    Or 400 frames for == 2$ each, no setup charge.
    In about 2-3 hours.



Page 2 of 2 FirstFirst 12

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

CNC Build Advice - Thanks!!

CNC Build Advice - Thanks!!