Thanks Thanks:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Page 9 of 23 FirstFirst ... 456789101112131419 ... LastLast
Results 121 to 135 of 336
  1. #121
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    A little more....




    I'll have a go at milling the bracket to hold the spindle in place next. Im using 20mm alumimium for the bottom bracket and 12mm for the top.

    Brad.

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #122
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    One 20mm thick bracket.



    And I need to thank Greg... about 60% of the way through making this my Kress cuts out. Good thing I was close by. I quickly stopped Mach3 and moved the mill back to 0. Greg was kind enough to lend me his grinder, so I swapped them over and picked up where I left off. Milling this was a VERY slow process with a 1/8 bit.

    The Kress seems to turn on briefly then cuts out. The speed variable control doesnt seem to work and it just tries to run flat out before cutting out. Anyone here had the same problem with their Kress grinder?

    Brad.

  4. #123
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    More pics.... CNC ... yeah!!!!!!!!



    And a video.... I love my tech crap....lol.



    I've placed the Z axis in the blocks and extended it to the full depth and there's slop... so my great big 600mm Z axis will be a little sloppy when working at full depth. It might stiffen up a bit when I mount the ballscrew but Im not hold my breath. I've 4 spare 12mm blocks so Im thinking adding another set of blocks may add to the stablity.. maybe... can't hurt to try.. just adds another 8 holes to the aluminium plate.

    Brad.

  5. #124
    Join Date
    May 2003
    Location
    Perth WA
    Posts
    3,784

    Default

    Aaaah push the gantry game - only a CNC machine builder understands that.

    Those bearing blocks on your Z axis are adjustable. I have been playing with a set of 12mm rails for my next machine and the bearing blocks have grub screws that can be tightened to take out the slack. One in the top of the block which is hidden because you have mounted them on your plate and sometimes one in the side of the block. Gently does it and you will find the slop disappears. If it doesn't send me a PM and I will give you another option.

    The ballscrew will do nothing so don't rely on that to stiffen the axis. A third set in the middle of those will not do much either as it will pivot around the middle. You need to get the outer bearings adjusted properly.
    Cheers,
    Rod

  6. #125
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    Ahh.. I had noticed the grub screw, just didnt know it's purpose...

    Brad.

  7. #126
    Join Date
    Mar 2006
    Location
    Brisbane
    Age
    52
    Posts
    923

    Default

    Quote Originally Posted by spidey4fun View Post
    Ahh.. I had noticed the grub screw, just didnt know it's purpose...

    Brad.
    lol my wife pointed that out on my rails said does that do anything I said na just holds them in place until I played with it and got the slop out never owned up to her though
    I like to move it move it, I like to move it.

  8. #127
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    I've yet to adjust those grub screws.... but I did mill the other spindle bracket today.



    Brad.

  9. #128
    Join Date
    May 2003
    Location
    Perth WA
    Posts
    3,784

    Default

    Hi Brad,
    Looking good.

    You might want to consider putting spring washers under your cap screws. It will save you some trouble as the high speed spindles can create a bit of vibration.

    Also next time around you might want to try counterboring the cap screws so they are flush. It is neater, gives you more clearance with adjoining components and they don't catch on anything like wiring.
    Here is a link if you don't know what I am talking about.
    McJing sell them individually for around $10 but their site is down at the moment so I can't link.
    Cheers,
    Rod

  10. #129
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    Rod, Are you suggesting spring washers for every bolt?

    Here's another pic. Mounted the Z-axis stepper today.



    I was planning on using the same style plastic bearing support on the Z-axis but I had to slim it down to fit between the rails and the method I used to mount it via the angle frame just doesnt work. I guess I should have drawn it up first.. If I mount the plastic support straight to the front plate Im thinking it might break/split at the tap holes due to the ever so slight flex that occurs when the axis is at it's lowest position..so I'll mill an aluminium bearing mount to be sure. I attempted this today but my 1/8 bit seems to flex a little when milling aluminium and cut the hole a little too big. I recently bought a 1/4 inch bit so I'll have another go shortly. ... just need to borrow Greg's 1/4inch collet for his grinder.



    My Kress Grinder has a serial number 2009 4 which Im guessing is the date of manufacture and Damem CNC (the guy I purchased it from) is looking at getting the replacement variable speed control from Kress, hopefully at no cost.

    With any luck I'll have all the axis's up and running shortly. Next I'll need to think about the table. I had this crazy idea of using 4 lengths of all thread and a chain and sproket connecting the four to raise and lower the table but Im thinking that might be just asking for problems. Most of the time I'd have the table fully raised any way.... not sure how Im going to do this yet. Greg suggested just make it full depth and have a table that simply sits on the base table to raise it to a more conventional depth. This sounds the most logical thing to do.... but the all thread method does sound like fun to attempt. However, something keeps telling me dont do it!!! ... lol....

    Brad.

  11. #130
    Join Date
    May 2003
    Location
    Perth WA
    Posts
    3,784

    Default

    I use spring washers under everything and also a flat washer where I can. The flat washer is overkill unless it is acrylic that you are attaching.

    I have a lot more luck with 4mm bits cutting ally but if it is critical such as a bearing housing I use a 1/4 inch bit. A lot less flex especially if you have a deep cut.

    I like Greg's idea especially if you want to use the machine this year.
    You have invested in accurate leadscrews so wise not to introduce less accurate allthread into the design.
    Cheers,
    Rod

  12. #131
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    Yeah.. best to stick with a solid table Im thinking. Good advise Greg and Rod. I milled / drilled the Y and Z nut bracket today so thought a do a test run... oh.. I purchased a bunch of spring washers also So some of it has washers now!!

    This test run is a circle. Actually it's a bit of G-code for a rubber seal of a vac chamber I made on my smaller CNC.



    Next I'll start on the table and then finally do the tuning as I'm sure it's going to have unwanted movement somewhere.

    Brad.

  13. #132
    Join Date
    May 2003
    Location
    Perth WA
    Posts
    3,784

    Default

    Top stuff Brad.

    My first impression was why the huge Z axis travel with so little clearance under the gantry beam but the penny clicked and you can drop your table. Doh.

    In your video I call the noises the CNC Orchestra and there are some fellows that made Gcode to simulate tunes. I used to have one but can't find it on my computer.
    When I run my mill I can hear the steppers above the cutting noise which is much more pleasant than the gantry router screaming away.

    Keep the posts coming this has been an interesting journey.
    Cheers,
    Rod

  14. #133
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    Yep.. I figured there'd be some flex in the Z axis at full depth so if I had an adjustable table height I could raise or lower the table prior to cutting a job depending on what depth I need during set up. I'd imagine I'll have it at the heightest point most of the time. This is why I wasnt so concerned about the use of all thread. The height of the table would only be adjusted during the set-up.

    I was thinking once I'd set the table to highest position I'd simply mill the table surface so it would be level. However, Im guessing if I were to wind the table down it wouldnt remain level?.. and then if I wound it back up again it wouldnt return to the same position??? But I dont see why not. If your winding systems are tight I dont see it wouldnt....

    Am I missing something? I've not used all thread before. Sorry if the questions are dumb this is the first CNC I've made.

    Brad.

  15. #134
    Join Date
    May 2003
    Location
    Perth WA
    Posts
    3,784

    Default

    Hi Brad,
    It is to do with the accuracy of allthread along it's length. It should return to the same position as the weight of the table will push downwards negating backlash.

    What you will probably find is as it is lowered it gets out of level due to the tolerance along the length of each allthread. It won't be much but it will be noticeable in CNC.

    You will still have to have guides for the table (linear rails or slots) as it will wobble about a bit just supported on threads.

    Perhaps if you created a datum around the table on each corner in your upper position and then used gauge rods to set the table in a lower position.
    Cheers,
    Rod

  16. #135
    Join Date
    May 2008
    Location
    Geelong
    Posts
    264

    Default

    yep.. got some spare rails.



    Not sure what a datum is... best I do some reading.

    Here's some more pics. The Y and Z axis nut brackets were pretty cool to make. Drilled and taped holes and everything lined up perfectly.



    This pic shows the end bearing mount... fits between the rails few a 1mm or so to spare.



    Brad.

Page 9 of 23 FirstFirst ... 456789101112131419 ... LastLast

Similar Threads

  1. Gecko G540 CNC Kits now available
    By phomann in forum CNC Machines
    Replies: 46
    Last Post: 17th January 2010, 06:25 PM
  2. G540 Matched Motors
    By seafurymike in forum CNC Machines
    Replies: 4
    Last Post: 25th September 2009, 02:47 PM
  3. Trailer - to build or not to build
    By motegi in forum TRAILERS & OTHER FABRICATED STUFF
    Replies: 17
    Last Post: 6th May 2009, 03:07 PM
  4. Mach 3 & G540 Motor tuning
    By seafurymike in forum CNC Machines
    Replies: 13
    Last Post: 20th April 2009, 04:24 PM
  5. Gecko G540 - special offer
    By snowyskiesau in forum CNC Machines
    Replies: 13
    Last Post: 13th February 2009, 01:50 PM

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
  •