Page 8 of 9 FirstFirst ... 6789 LastLast
  1. #71
    Quote Originally Posted by irving2008 View Post
    IMHO the purpose of the theoretical calculations, recognising they can't model every real-world situation (but can get very close if you can identify all the 'gotchas') is to see if you're in the right ballpark...
    Yep I agree can be ok for a rough ballpark (Thou yours did seem a bit off base.!!) . . . You only have to look to the BIG BOYS in theoretical design and performance like F1 teams and see that even they can't predict and 100% confidently model every outcome.!


    Quote Originally Posted by irving2008 View Post
    Hey, no offence taken Jazz,
    Good now give us a hug.!!. .

  2. #72
    Ok thats good but bring the screw to the front, will be much stronger having the ball-nut close the Z Axis back plate.

    Have you got the 20mm steel plate.? If not I think you'll maybe change your mind when you see the price.!! It's not really needed either and I'd use ali for easy working.

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


  4. #73
    Ok thats good but bring the screw to the front, will be much stronger having the ball-nut close the Z Axis back plate.
    Ok, thats no problem, i will do that. Is this to prevent racking etc

    Have you got the 20mm steel plate.? If not I think you'll maybe change your mind when you see the price.!! It's not really needed either and I'd use ali for easy working.
    No i haven't got any steel plate and a quick google has made me change my mind, but if i use ali how would I join this to the steel gantry?

  5. #74
    Quote Originally Posted by deannos View Post
    Also now confused after reading comments on the other post about the "effect of forces on gantry cross sections" and the following was mentioned-

    Am i going round in circles
    Dean don't worry about it your only cutting wood the box section will easily handle it. The box can resonate but cutting wood it won't really matter or show.
    There are also ways around this if it does by filling with sand. So long has the resonance doesn't affect the motors then you won't have problem and because your using belts then this won't happen and why it's good idea to use belts.

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


  7. #75
    Quote Originally Posted by deannos View Post
    No i haven't got any steel plate and a quick google has made me change my mind, but if i use ali how would I join this to the steel gantry?
    Bolt or weld Angle brackets to box then bolt thru Ali plate into brackets.

  8. #76
    Bolt or weld Angle brackets to box then bolt thru Ali plate into brackets.
    Excellent, an easy solution i didn't even think of.
    cheers Dean

  9. #77
    I have moved the ballscrew to the front of the gantry and will be using 20mm ali instead of steel plate, too costly. Have added some steel angle to corners to connect gantry to end plates.Click image for larger version. 

Name:	final with box section and corner plates front corner.jpg 
Views:	372 
Size:	263.2 KB 
ID:	6533Click image for larger version. 

Name:	final with box section and corner plates front.jpg 
Views:	1054 
Size:	226.4 KB 
ID:	6534

  10. #78
    Would this design be ok, i thought i would use some 100x60 box section as bearing plates. I would have some left over from the gantry and it saves on the Ali plate. The extra height would help with the bed, bit more room to play with. This box section is only 3mm thick, is that ok. I have used 300mm, 2 x 800mm and 1400 SBR20mm rails. The ball screws are 350mm, 2 x 800mm and a 1450mm length.

    Click image for larger version. 

Name:	final with box section and corner plates and rsj(160x90) front.jpg 
Views:	532 
Size:	334.8 KB 
ID:	6582Click image for larger version. 

Name:	final with box section and corner plates and rsj(160x90) rear.jpg 
Views:	416 
Size:	296.1 KB 
ID:	6583

  11. #79
    2 questions for me that dont mean much to your build sorry :D firstly is that still an RSJ you got across the Y if so your second picture doesnt make it look like that... petty i know..

    EDIT: oh scrap that i just read it's box section... my misunderastanding eek... either way second question applies

    secondly how do you plan on fixing the box section to what i think is the RSJ?

  12. #80
    secondly how do you plan on fixing the box section to what i think is the RSJ?
    The gantry is box section and this will be bolted/welded to the bearing plates. I have put some steel angle holding the Gantry ends to the end plates as well, but the plates will also be bolted to the bearing plates. Rsj is only used on the base "X"

    A couple more pics, it might helpClick image for larger version. 

Name:	final with box section and corner plates and rsj(160x90) fronta.jpg 
Views:	1297 
Size:	249.5 KB 
ID:	6584Click image for larger version. 

Name:	final with box section and corner plates and rsj(160x90) frontb.jpg 
Views:	477 
Size:	207.9 KB 
ID:	6585Click image for larger version. 

Name:	final with box section and corner plates and rsj(160x90) frontclose up.jpg 
Views:	547 
Size:	388.2 KB 
ID:	6586
    Last edited by deannos; 12-08-2012 at 11:30 PM.

Page 8 of 9 FirstFirst ... 6789 LastLast

Similar Threads

  1. Plasma Attempt #2
    By Robin Hewitt in forum DIY Plasma Build Logs
    Replies: 21
    Last Post: 02-09-2012, 08:05 PM
  2. BUILD LOG: My first attempt.... 8 x 4
    By trounce in forum DIY Router Build Logs
    Replies: 0
    Last Post: 18-10-2011, 11:31 AM
  3. BUILD LOG: My First Attempt Of A CNC
    By AdCNC in forum DIY Router Build Logs
    Replies: 61
    Last Post: 21-10-2010, 03:55 PM
  4. help please with first attempt
    By phill05 in forum Machine Discussion
    Replies: 13
    Last Post: 01-06-2010, 05:42 PM
  5. FeatureCam - first attempt
    By HiltonSteve in forum CAD & CAM Software
    Replies: 0
    Last Post: 01-09-2009, 07:46 PM

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
  •