. .
Page 1 of 2 12 LastLast
  1. #1
    Hi,

    I'm looking for a couple of answers to some, what I hope are, basic questions.

    1. What is the maximum cutting area I can expect to have if I don't want to have a Y axis that has dual steppers? I hope that's the correct way to phrase the question, from my basic understanding once you get past a certain size I thought the Y axis needs two linked/synced steppers?

    2. What size profiles would I likely be looking at if I wanted to build a machine chassis to the above requirements... 4080, 4590, 5050 etc, etc.

    I appreciate that the last question might be quantified by other design considerations, but again just wonder what people would consider the minimum sized profile to guarantee a decent base level of rigidity.

    Thanks in advance.

    Chris

  2. #2
    Quote Originally Posted by joe.ninety View Post
    1. What is the maximum cutting area I can expect to have if I don't want to have a Y axis that has dual steppers? I hope that's the correct way to phrase the question, from my basic understanding once you get past a certain size I thought the Y axis needs two linked/synced steppers?
    For a router cutting mostly wood, plastics and the occasional bit of light aluminum work then wouldn't go past 700mm cutting width with a single screw. However, the gantry design comes into play as well and needs to be built a little stronger as you get wider.


    Quote Originally Posted by joe.ninety View Post
    2. What size profiles would I likely be looking at if I wanted to build a machine chassis to the above requirements... 4080, 4590, 5050 etc, etc.

    I appreciate that the last question might be quantified by other design considerations, but again just wonder what people would consider the minimum sized profile to guarantee a decent base level of rigidity.
    45x90 or 40x80 is a minimum I would use and again depends on the machine size and design. To give you some idea this machine design I build use's only 45x90 and it will happily cut everything up to aluminium.

    The machine in the picture uses a single screw and as a cutting area of about 600 x 1000 if I recall correctly. However, I've built lots of machines with this design up to 700 x 1250 cutting area using single screws. If you wanted stronger machine at the same width/length say for cutting mostly aluminum or Hardwoods with heavy cuts then go with twin motors every time.

    Click image for larger version. 

Name:	IMAG0916.jpg 
Views:	88 
Size:	460.2 KB 
ID:	27146

  3. The Following User Says Thank You to JAZZCNC For This Useful Post:


  4. #3
    Quote Originally Posted by JAZZCNC View Post
    The machine in the picture uses a single screw and as a cutting area of about 600 x 1000 if I recall correctly. However, I've built lots of machines with this design up to 700 x 1250 cutting area using single screws. If you wanted stronger machine at the same width/length say for cutting mostly aluminum or Hardwoods with heavy cuts then go with twin motors every time.

    Click image for larger version. 

Name:	IMAG0916.jpg 
Views:	88 
Size:	460.2 KB 
ID:	27146
    What about the raised gantry for the machine in the picture? It would become way stiffer with raised Y-axis, e.g. with profiles and then then X-axis would me mounted straight onto the frame. This would require 2 ballscrews on the Y-axis too.


    Skickat från min SM-A530F via Tapatalk

  5. #4
    Hi Jazz,

    I realise I have made what must be a schoolboy error and mixed up my axes.

    I had assumed that Y axis is the largest one, running front to back if you were standing in front of the machine, but from what I can tell having read further and from your reply, this is in fact the X axis. I was further confused by the fact that Fusion360 comes set with the default of the the Y axis being 'up'.

    So just for clarity... The axes are defined as if you were standing to the side of the machine and not the front and are... X for left right, Y for front to back, and Z for up and down? Is that correct? So on a rectangular machine the X would be the longest followed by the Y then the Z?

    Cheers

  6. #5
    The axes are defined with you standing how you would actually use the machine.

    Side to side is X. X+ is the cutter moving to the right. Towards you and away from you is Y. Y+ is the cutter moving away from you. Up and down is Z. Z+ is cutter moving up.

    This is a simple convention from drawing. The same as graphs. It is used in virtually all drawing/CAD/machines.

    Unfortunately a lot of hobbyists can't understand the convention and insist on called the axis across the gantry Y or some other variation.

    For instance on my machine:
    Working area 1300x675mm.
    Gantry is the long axis.
    X runs across the gantry, 1300mm.

    X is not necessarily the longest axis. X is not necessarily the lowest/bottom axis. E.g. X is on top of Y in my machine.

  7. The Following User Says Thank You to pippin88 For This Useful Post:


  8. #6
    Neale's Avatar
    Lives in Plymouth, United Kingdom. Last Activity: 5 Hours Ago Has been a member for 7-8 years. Has a total post count of 1,464. Received thanks 274 times, giving thanks to others 9 times.
    Frankly, what you call the axes doesn't really matter that much but you must obey the convention that the axes of the machine in front of you match the way that the axies fo conventional drawing work. As the last post said, imagine a sheet of graph paper in front of you. X coordinates then run from left to right and Y increases as the tool moves away from you. Z coordinates must then increase as the tool rises. For convenience, a lot of people put X=0 and Y=0 in the bottom (i.e. nearest you) LH corner, and Z=0 at the top of travel (so when working, Z coordinates are negative). However, as long as the axes have these relationships, whether X goes across or front to back rather depends on where you stand and what you consider the front of the machine to be!

    When I built my machine, I anticipated standing at one of the long sides and so configured it so that X ran along the long axis and Y along the gantry. In practice, I always stand at the short side of the machine. Think of your usual bit of graph paper in front of you on the desk, label X and Y accordingly, and then turn it through 90 degrees anticlockwise. Means that the reference point (0,0) is now at the bottom RH corner. However, as long as you remember which axis is which and which way they go (which I do almost all the time...) then it still works fine because the important thing is the relation of the axes to each other that matters. The reason that this is so important is that any CAD/CAM package is going to assume this relationship between the axes and if you configure the machine differently then you are really, really, going to struggle.

    But if you like to think of your gantry as being X and the long axis Y, or the other way around, then as long as the coordinates run the right way with respect to each other, it's your choice. I get confused by people talking about "front" and "side", and who assume that everyone has the same layout of X and Y. It ain't necessarily so!
    Last edited by Neale; 27-01-2020 at 04:05 PM.

  9. The Following User Says Thank You to Neale For This Useful Post:


  10. #7
    Quote Originally Posted by NordicCnc View Post
    What about the raised gantry for the machine in the picture? It would become way stiffer with raised Y-axis, e.g. with profiles and then then X-axis would me mounted straight onto the frame. This would require 2 ballscrews on the Y-axis too.
    Yes, your correct it would be stronger and I build that type of machine as well. If you look back far enough you'll find I was one, if not the first build a router in this way and with an adjustable height bed also. However, this machine was built with specific needs and to work within a confined space so raised sides and the extra size that comes with it did not suit. The machine in the picture was designed solely to cut woods but it easily handles light to medium aluminum work also.

    End of the day it's horses for courses and if you want a machine to cut Aluminium and steel then you shouldn't be building a moving gantry-type machine unless it's built like a tank, and even then it will always be inferior to a fixed gantry-type machine.

  11. #8
    Kitwn's Avatar
    Lives in Exmouth, Australia. Last Activity: 12 Hours Ago Has been a member for 2-3 years. Has a total post count of 619. Received thanks 80 times, giving thanks to others 15 times.
    Quote Originally Posted by Neale View Post
    Frankly, what you call the axes doesn't really matter...
    Quite right, but one thing to consider is the common layout for drawing packages on computers is with X horizontal and Y vertical on the screen. This makes the visible drawing area 'landscape' rather than 'portrait' and it makes sense to match this to your machine for those times when you are drawing layouts that are the full size of the machine bed.
    Engineering is the art of doing for ten shillings what any fool can do for a pound.
    Wellington.

  12. #9
    Neale's Avatar
    Lives in Plymouth, United Kingdom. Last Activity: 5 Hours Ago Has been a member for 7-8 years. Has a total post count of 1,464. Received thanks 274 times, giving thanks to others 9 times.
    Quote Originally Posted by Kitwn View Post
    Quite right, but one thing to consider is the common layout for drawing packages on computers is with X horizontal and Y vertical on the screen. This makes the visible drawing area 'landscape' rather than 'portrait' and it makes sense to match this to your machine for those times when you are drawing layouts that are the full size of the machine bed.
    Interesting point. If I'm using something like Vectric Vcarve (which I do from time to time - great for text/signboard type applications) then it makes sense to align the landscape screen and the landscape machine orientation. However, using Fusion 360 (which I do a lot these days) then I'm often building up an assembly as part of the 3D model on screen, but picking out individual components for CAM/toolpath generation. It might well be that the alignment of an individual component is not naturally laid out appropriately. For example, the base of the component which would sit on the bed of the machine might not even be in the XY plane in the model. F360 allows you to easily select axes for CAM independently of the original model axes so you can just, in effect, rotate the component in 3D to best fit the machine.

    If I knew then what I know now, I might well have configured my own machine to have X running left to right in front of me - the conventional XY layout - even though the machine would then be portrait rather than landscape. Main thing is to understand what you are doing!

  13. #10
    Quote Originally Posted by Neale View Post
    If I knew then what I know now, I might well have configured my own machine to have X running left to right in front of me - the conventional XY layout - even though the machine would then be portrait rather than landscape. Main thing is to understand what you are doing!
    It's always better to have it setup up in the direction you view the machine. It doesn't really matter whether X runs across gantry or down machines length but it should always run left to right as you view machine and in a positive direction like the cartesian coordinate system does. Y should always run away and towards you, again positive direction moving away from you. Otherwise, it gets confusing quickly.

  14. The Following 2 Users Say Thank You to JAZZCNC For This Useful Post:


Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. NEW MEMBER: Hi and a couple of questions.
    By TheBoltonian in forum New Member Introductions
    Replies: 4
    Last Post: 08-01-2017, 04:58 PM
  2. Replies: 0
    Last Post: 29-11-2016, 01:16 PM
  3. hi all, new to cnc building,couple of questions if anyone can help. TIA
    By universally in forum Gantry/Router Machines & Building
    Replies: 14
    Last Post: 18-01-2015, 03:12 PM
  4. Beginner MYCNCDIY Mill Build questions
    By suraj1793 in forum Gantry/Router Machines & Building
    Replies: 35
    Last Post: 15-11-2014, 05:28 PM
  5. NEW MEMBER: Hi there, a new member from Mid-Wales with a couple of daft questions.
    By m0nk3hjam in forum New Member Introductions
    Replies: 6
    Last Post: 17-08-2010, 01:32 AM

Bookmarks

Posting Permissions

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