Jake's 4x8 CNC Build - Page 2


Page 2 of 2 FirstFirst 12
Results 13 to 24 of 24

Thread: Jake's 4x8 CNC Build

  1. #13
    Member
    Join Date
    Oct 2009
    Location
    United States
    Posts
    489
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Quote Originally Posted by JakeInCharlotte View Post
    I too think that plate is too long and thin.
    For this size of machine, you might maybe consider a H or U style steel "slider"?

    As a side note, would you mind to share where you got the "ball_screw_documentation.pdf" from?



  2. #14
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    321
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Hi Jake -Its a killer machine for timber. Minimise your Z travel and make the tool plate a U section. Webs either side of the spindle. Once you redesign I can do some numbers for the stiffness. Your gantry is mega stiff and it would be good to match the Z axis stiffness to this component. Peter



  3. #15
    Member Ntl's Avatar
    Join Date
    Aug 2018
    Posts
    521
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    To me it looks like the spindle mount would add a lot of rigidity to the z mounting plate if it's going to be made like the drawing. It looks like the spindle is making full contact with the back plate so it's not 1/2 inch material anymore, it's 1/2" plus the spindle and mounting bracket. Maybe I'm way off in what I'm seeing?

    Dan



  4. #16
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    321
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Hi NTL - The spindle mount only stiffens the bottom of the plate. Once the Z axis moves down past a certain point its only 1/2" thick plus the rails in stiffness. Thats why people are recommending reducing the Z axis travel or adding outside webs to the Z plate or sled as Jake is calling it. If the Z axis can be organised to take advantage of the spindle stiffness then that's very good. Peter



  5. #17
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    321
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Hi Jake - Did a quick calc on the plate. I have used the Maximus tool plate as a benchmark. Its equivalent thickness is 79mm. Your gantry is stiffer then maximus as well. If you use 4" or 100mm webs (using 1/2" plate) on the outside of the plate you get an equivalent thickness of 70mm I think this is about you need to do. Peter

    Attached Thumbnails Attached Thumbnails Jake's 4x8 CNC Build-jake-z-jpg  


  6. #18
    Member
    Join Date
    Jan 2015
    Posts
    18
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Quote Originally Posted by davida1234 View Post
    For this size of machine, you might maybe consider a H or U style steel "slider"?

    As a side note, would you mind to share where you got the "ball_screw_documentation.pdf" from?
    Automation Overstock, surplus automation equipment, overstock automation devices, manufacturer overruns, linear bearings, variable speed drives, circuit breakers, contactors, starters, relays

    They are a NC company. I am also planning to get my slides from them.

    I think the Z plate will be a U shape when done.

    Quote Originally Posted by Ntl View Post
    To me it looks like the spindle mount would add a lot of rigidity to the z mounting plate if it's going to be made like the drawing. It looks like the spindle is making full contact with the back plate so it's not 1/2 inch material anymore, it's 1/2" plus the spindle and mounting bracket. Maybe I'm way off in what I'm seeing?

    Dan
    It will be 1/2" steel as well, but I plan to add some support on the sides for good measure.

    Quote Originally Posted by wizard View Post
    The one thing that bothers me a bit is that you apparently intend to use 3 rails on the gantry beam with one mounted 90° out from the other two. .
    The gantry will have only two rails. The top profile will accept the gear rack. The model I downloaded was giving Fusion a lot of troubles so I deleted it for now.

    I am looking for a good supplier for the rack. 20mm+ high?

    Quote Originally Posted by wizard View Post
    Jake which Charlotte are we talking about here. There are shops in the Buffalo NY area that can stress relieve just about anything.
    Don’t make the Z any higher than required for the intended usage plus a bit of clearance for usability. If the goal is to machine sheet goods having 20” of S capability just leads to an expensive machine. Given that there is no perfect value for Z axis capability.
    Charlotte NC, you know, the place all your neighbors moved to. Every fall the sports bars jockey for who can be called the the official Bill's headquarters on billboards and sports radio. Oh, and thanks for the wings idea!

    Right now the Z and gantry clear about 10" (255mm). 9-10" seemed pretty common so I went for that. Also I wanted to give myself enough room for for a gearbox if I have to go that way.

    You can tell form this pic that I still need shorten the Z Plate. I will probably add a Lip to the outside edge of the leg so its not unsupported. Maybe 1" wide.

    Peter--- Right now I have 65mm between the faces of the plates. I was thinking ribs about 1/4 - 3/8 x 1-1/2" wide on the outside edges.

    Steel yard called this afternoon. Tuesday turned into "We'll call you early next week" 2500lbs of steel this order. Thats one heck of a boat anchor.

    Jake's 4x8 CNC Build-side-gantry-jpg

    Attached Thumbnails Attached Thumbnails Jake's 4x8 CNC Build-side-gantry-jpg  


  7. #19
    Member Ntl's Avatar
    Join Date
    Aug 2018
    Posts
    521
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Quote Originally Posted by peteeng View Post
    Hi NTL - The spindle mount only stiffens the bottom of the plate. Once the Z axis moves down past a certain point its only 1/2" thick plus the rails in stiffness. Thats why people are recommending reducing the Z axis travel or adding outside webs to the Z plate or sled as Jake is calling it. If the Z axis can be organised to take advantage of the spindle stiffness then that's very good. Peter
    I see it now, I didn't realize that the rails were mounted to the moving side of the z. It looks like he does have bar's mounted to the backside plus the rails. If the plate is 1/2" the rails and bar's appear to be maybe 1.5"? So he does have some bracing, but I have no idea if it would be enough.

    It's a interesting design, I don't think I've seen one that the rails move and the blocks are stationary. What are the advantages of this design vs the other way around?



  8. #20
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    321
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Quote Originally Posted by JakeInCharlotte View Post
    Automation Overstock, surplus automation equipment, overstock automation devices, manufacturer overruns, linear bearings, variable speed drives, circuit breakers, contactors, starters, relays

    Peter--- Right now I have 65mm between the faces of the plates. I was thinking ribs about 1/4 - 3/8 x 1-1/2" wide on the outside edges.

    Jake's 4x8 CNC Build-side-gantry-jpg
    Hi Jake - Sorry not big enough. 1/2" thick and 4" high minimum. The Z Axis cantilever is the critical part of the machine don't skimp on it. It's the coal face. It's the thing that will vibrate if under stiff, it's the thing that will deflect from your huge motors and drives etc etc. Plus these webs are in free air so there is no reason not to go big. Plus it will give you something to hang the dust collection and other things that you will hang on this area over time. You have a mega machine with a wimpy Z at the moment. Need to add some steroids to it. Peter

    Thks for the ball screw catalogue very good.

    Just a thought you can screw these webs on from the sides (or screw them to the small webs you are thinking of) so you can take them off to modify them without taking the Z axis off. You will have dust collection and other things to add, so this area needs a bit of ease and flexibility to it.

    Last edited by peteeng; 05-16-2019 at 07:15 PM.


  9. #21
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    321
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Hi NTL - The main reason is that it allows a longer travel. Peter



  10. #22
    Member
    Join Date
    Jun 2011
    Location
    US
    Posts
    669
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    That Z axis plate won't need to be nearly that long. Keep in mind that tool holders have some minimum length (usually at least 60mm flange distance on 30 taper/HSK63 I think,) the spindle nose has some length, and there will be some tool stickout. Should be able to cut 120-150mm off the bottom of that thing, may look a little less floppy then.



  11. #23
    Member
    Join Date
    Jan 2015
    Posts
    18
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    It's finally happening!!!! Picked up the first order of steel today. The plan is to build some long saw horses that are level to get work at a height easy to weld. I'm still struggling to save the drive motors so any help in that area is greatly appreciated!

    Jake's 4x8 CNC Build-img_1444-jpg

    Attached Thumbnails Attached Thumbnails Jake's 4x8 CNC Build-img_1444-jpg  
    Attached Files Attached Files


  12. #24
    Gold Member RCjunkie's Avatar
    Join Date
    Apr 2003
    Location
    United States
    Posts
    26
    Downloads
    0
    Uploads
    0

    Default Re: Jake's 4x8 CNC Build

    Looks great keep up the great job, Love to keep watching this!!!!

    2 wrongs don't make a right
    But 2 Wrights makes a Airplane
    Kevin Matney
    www.Matneymodels.com
    734 - 848 - 8195
    "IN GOD WE 'TRUST "
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


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

Jake's 4x8 CNC Build

Jake's 4x8 CNC Build