584,858 active members*
4,422 visitors online*
Register for free
Login

Thread: Spindle Idea

Page 3 of 20 1234513
Results 41 to 60 of 383
  1. #41
    Join Date
    Sep 2004
    Posts
    369
    Quote Originally Posted by gcz
    i've been following this thread about spindles and googling all over to learn about it myself.
    what i seem to get is that the worst problem will be heat induced elongation of the shaft and consequent excessive loading of the bearings.
    ? - if the spindle chassis and the shaft are made of identical material, will this not obviate the problem entirely?
    ? - if each end of the spindle is in a roller bearing only, and a thin disk on the lower end of the shaft is captured between thrust bearings, then will not the thin-ness of the disk obviate any problem of elongation just simply because it's not very long?

    obviously the smaller the diameter of the shaft, the faster it will max because the bearing travel will be proportionately shorter each rev than on larger diameter.

    these look like good clues to start making a test spindle - anybody see flaws or something i overlook?
    Hi gcz,

    Now we really get into the meat of the problem/solution.

    If you had a company that hired the engineers, did the research, the countless hours of testing various metal alloy expansion rates, developing theories, testing theoritical solutions, etc. and could manufacture a quality spindle that is stable and stays within tolerances required at say 1,000 -- 30,000 rpm then run sweetly for years with continuous heavy/light/no load cycles without a rebuild. Would that be worth something? Would you be able to sell it inepensively to a limited market? Would you share the information with the world? I think not. ebay really does rock!

    The rest of us mortals must learn to live with compromise.

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

  2. #42
    Join Date
    Jun 2005
    Posts
    65
    won't know til i get a testable model done...have to get a friend or someone to turn some parts, but sure, i'll share the notion - here's a stupid bmp done in paint to suggest the design
    er...lemme jpg that first...
    well, lemme make a note or 2 on it first...
    but i think it sort of makes the problems i've learned of go away.
    this would be only 1/4 shaft - that's gonna maximize rpm - i don't care if there's a bigger chuck on the end - plz keep in mind, though, that this is for high speed laptop mills - not your 10 ton hog !
    Attached Thumbnails Attached Thumbnails spindle.gif  

  3. #43
    Join Date
    Sep 2004
    Posts
    369
    Quote Originally Posted by gcz
    won't know til i get a testable model done...have to get a friend or someone to turn some parts, but sure, i'll share the notion - here's a stupid bmp done in paint to suggest the design
    er...lemme jpg that first...
    well, lemme make a note or 2 on it first...
    but i think it sort of makes the problems i've learned of go away.
    this would be only 1/4 shaft - that's gonna maximize rpm - i don't care if there's a bigger chuck on the end - plz keep in mind, though, that this is for high speed laptop mills - not your 10 ton hog !
    gcz;

    Check these out:
    http://www.vxb.com/page/bearings/PRO...ONTACT/Kit6930
    http://www.vxb.com/page/bearings/PROD/12mm/6201ZZ10-1

    How about $13.00 + shipping for bearings that will go 15K+ rpm.

    Your drawing is cool

    Make the housing out of 1.5" watter hardening drill rod, 3" to 4" long.
    Bore and ream a hole in one end to 32mm +0,-.001" (press-fit) 15.9mm deep.
    Bore and ream a hole in the other end to 32mm +.0,-.001" (use same reamer for press-fit) 10mm deep.

    Make the spindle shaft out of .5" --- all the way up to 1.5" watter hardening drill rod 4" to 5" long. This depends on the type of spindle taper you desire.
    Turn the shaft down to 12mm +.001" (press-fit) at the business end for the double row angular contact bearing.
    Turn the other end of the shaft down to 12mm +.0, - .001" (slip-fit).
    Assemble with arbor press.

    This configuration would allow the spindle shaft to grow in length as it heats.
    It will get longer as the larger housing must be clamped/held to the Z axis in some manner and the housing will be exposed to air and coolant in some cases, the spindle shaft will not.

    This level of precision is beyond most hobbyists, including me!

    I may try to make one anyway!

    I like your enthusiasm; it's contagious.

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

  4. #44
    Join Date
    Sep 2004
    Posts
    369
    By the way, I like the ten ton hogs; I just can't find any more room in my shop for one.
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  5. #45
    Join Date
    Mar 2005
    Posts
    1136
    Quote Originally Posted by MikeAber
    gcz;
    How about $13.00 + shipping for bearings that will go 15K+ rpm.

    Mike
    one thing to consider is the class of bearing - the $12 ones are the lowest and you can easily spend a couple of hundred for the (what is it, class 7?, not sure) same size in a high class. Depending on what you are using the spindle for that might be a consideration - for a pcb mill the $12 are fine, for a grinder, forget it, you need the expensive ones. I don’t know that I’d want to use the $12 ones at 15k though

    I'm also not sure about the double row angular contacts. I think you need to consider separate bearings so you can preload them. Some of the nicer diy spindle designs, such as that used in Quorn, use springs to load the bearings.

    I wouldn't bother using tool steel, just nice free cutting mild steel. Often tool steel or tougher chrome moly steels are used for spindles, but as diy's we don't need this toughness - we'll avoid dings and such by being careful. The reason is that these steels are tougher to work and you don't get the advantage until you heat treat them. When you heat treat, the parts warp slightly and you need to finish by grinding, especially for an accurate part such as a spindle. This is a lot of extra work and requires more specialized equipment.

    Definitely agree with speed comments. In theory, the ability of a machine to remove cubic units of material is a function of horsepower and rigidity. Spinning the cutter 4x as fast as it needs to be doesn't remove materials 4x faster, it just wears the cutter out 4x faster.

    Making spindles is a common home shop endeavor so by all means go for it. Many successful designs have been described in Model Engineer over the years, if you can find some via library or club they will help.

  6. #46
    Join Date
    Sep 2004
    Posts
    369
    Quote Originally Posted by Mcgyver
    Definitely agree with speed comments. In theory, the ability of a machine to remove cubic units of material is a function of horsepower and rigidity. Spinning the cutter 4x as fast as it needs to be doesn't remove materials 4x faster, it just wears the cutter out 4x faster.

    Making spindles is a common home shop endeavor so by all means go for it. Many successful designs have been described in Model Engineer over the years, if you can find some via library or club they will help.
    Mcgyver,

    Your comments are right on target.

    It seems that so many are using sloppy machines and spindles that grinding the material away with a carbide end mill or bur at 30,000 rpm has become the norm. If your machine can move at 200+ ipm to keep the cutting tool climbing this is fine, otherwise you are just polishing the cutting tool's edges until they no longer cut and then they break. "Learn how to make chips, not dust"

    I hope that thru this thread we can collectively explore several spindle designs, and levels of performance. Most important of all, is that we also collectively improve our level of understanding.

    There are many, many Machine and CNC Technology professionals on this website that have forgotten more than I will ever know. Maybe they, like yourself, will share some of that knowledge with the rest of us.

    Thanks

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

  7. #47
    Join Date
    Jun 2005
    Posts
    65
    the point about chips not dust is indisputably good.
    one thing that the numbers show clearly is this:
    if you're using tiny cutters, to get any real tooth travel - to get chip load - you NEED high speeds...but i'm not up for making a table atm to illustrate the point...
    however, plz check out the cutters you CAN get - http://www.pmtnow.com/
    at a certain scale, legitimate chip size is indistinguishable from talc.
    there IS a niche for high speed
    i have a 120 ct ruby i'm dying to carve up with tiny diamond bits completely submerged. for such as this, forget 6000 rpm - i need more like 60,000!

  8. #48
    Join Date
    Jan 2004
    Posts
    668
    I can't find a place for this but I'd like to add a dwg of a spindle idea. What format is uploadable? And how can I convert a dxf file to whatever format is used here>

  9. #49
    Join Date
    May 2005
    Posts
    925
    I've been discusing this idea with a fellow CNCZoner (JRoque):

    What if I take this collet & chuck set:


    This is a ER-type R8 Shank collet chuck

    and machine the shank to do this:






    Opinions & Comments are welcome


    Pablo

  10. #50
    Join Date
    Jun 2003
    Posts
    1365
    Peu, have you taken a look at the different holders they have with ER tapers? they are usually called 'extentions'. They usually have 3/4" shanks and you may be able to use something like that which might end up being a better setup.

    Jon

  11. #51
    Join Date
    May 2005
    Posts
    925
    JRoque suggested this too, I said that I choosed this set because saw its picture first but yes an extender uses the same concept and maybe its better because there is no need to machine the hardened body.

    Also maybe you can find bearings with the same ID as the diameter of the extender.


    Pablo

  12. #52
    Join Date
    Sep 2004
    Posts
    369
    Quote Originally Posted by peu
    I've been discusing this idea with a fellow CNCZoner (JRoque):

    What if I take this collet & chuck set:
    This is a ER-type R8 Shank collet chuck
    and machine the shank to do this:

    Opinions & Comments are welcome Pablo
    Peu, What a great set of drawings! They are outstanding! How did you do that?

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

  13. #53
    Join Date
    Jun 2005
    Posts
    65

    looks BrIlLi@nT, PEU!

    can you get a housing of identical material as the shank too?
    and maybe seal bottom and an oil zert at top to let you keep it half full or so?
    locking bearings in- how?

  14. #54
    Join Date
    Sep 2004
    Posts
    369

    Quote Originally Posted by JFettig
    Peu, have you taken a look at the different holders they have with ER tapers? they are usually called 'extentions'. They usually have 3/4" shanks and you may be able to use something like that which might end up being a better setup.

    Jon
    Jon, what an excellent idea! Very practical, these are available in almost any size between ER11 and ER32 with shank diameters from .5" to 1.5" and spring collets are available in metric and inch sizes. Bearings would be no problem at all.

    mike
    Attached Thumbnails Attached Thumbnails ER11 Collet Chuck.bmp   ER16 Collet Chuck.bmp  
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  15. #55
    Join Date
    Sep 2004
    Posts
    369

    Lightbulb

    Quote Originally Posted by gcz
    the point about chips not dust is indisputably good.
    one thing that the numbers show clearly is this:
    if you're using tiny cutters, to get any real tooth travel - to get chip load - you NEED high speeds...but i'm not up for making a table atm to illustrate the point...
    however, plz check out the cutters you CAN get - http://www.pmtnow.com/
    at a certain scale, legitimate chip size is indistinguishable from talc.
    there IS a niche for high speed
    i have a 120 ct ruby i'm dying to carve up with tiny diamond bits completely submerged. for such as this, forget 6000 rpm - i need more like 60,000!
    gcz, you have opened my eyes to another dimension of CNC. I thought PCB work was small with .014 endmills spinning at 30,000 rpm and up. If you were using a diamond dust covered tool to work on that HUGE ruby you are precision grinding. (and making beautiful ruby dust. Save me some.)

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

  16. #56
    Join Date
    Sep 2004
    Posts
    369

    R8 Spindle

    This is a Mini Mill Spindle Box Assembly R8, Little Machine Shop.com sells for $99.95 US. If you made a set of sheaves and installed them in place of the top bearing spacer as Jfettig did on his mini-mill you could have an R8 spindle on your gantry or bench mill. Ask JFettig for the details --- more pictures in his gallery.

    I purchased one of these last week and plan to take a good look at it for use on my mini gantry mill. I really prefer R8 tooling as I have lots of it. This is not good for any speed over 5-6,000 rpm. The runout on the one I received is .0001" -- EXCELLENT!

    mike
    Attached Thumbnails Attached Thumbnails 1906.jpg   Jfettig2.jpg  
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  17. #57
    Join Date
    May 2005
    Posts
    925
    Quote Originally Posted by gcz
    can you get a housing of identical material as the shank too?
    and maybe seal bottom and an oil zert at top to let you keep it half full or so?
    locking bearings in- how?
    The bearings are hold in place by the external case and retaining rings (green barely visible in the cut view)

    If you find an extender and matching internal diameter bearings , the only part you need to machine is the cilindrical case (you can make it from a rectangular block too )

    Now is time to find not expensive extenders

    One thing I don't know is if this spindle needs lubrication and what is the better way to do it.

    Pablo

  18. #58
    Join Date
    Sep 2004
    Posts
    369

    Smile ER Streight Shank Collet Chuck Spindle Idea

    I was doing some research on Jon's idea in the MSC catalog and a few bearing resellers online.
    ER Streight Shank Collet Chucks (extenders) are made out of heat treated alloy steel and available everywhere; MSC, ENCO, etc. and cost $55 to $110 depending on size.
    Sealed bearings contain grease, open bearings would require oil and seals.
    Open bearings have higher rpm limits.
    The smallest bearings have the highest rpm ratings.
    I could not find any angular bearings in inch sizes. I am sure they exist, I just didn't find any.
    I did not find any angular bearing listed for over 27,000 rpm. I am sure they exist, I just didn't find any (I'm not sure I want to $$$$$$).
    ABEC7 bearings can run $400 or more for a matched pair. ebay --ebay --ebay

    I like this concept best so far (for high speed).

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

  19. #59
    Join Date
    Jan 2004
    Posts
    668
    This is exactly where I wanted to go. I mistakingly thought I'd need 30k rpm. . I have a Grizzly mini mill now and have access to R8 tooling. So, I take off the milling head, cut down the casting size, cobble up an adapter plate add pulleys and I'm in, right ?. The motor and speed controls are also salvagable to machine/route aluminum and stuff. When I want to mill wood I switch off to a router. I think I'm on to something. :idea:

  20. #60
    Join Date
    Sep 2004
    Posts
    369

    R8 Spindle

    Quote Originally Posted by SPEEDRE
    This is exactly where I wanted to go. I mistakingly thought I'd need 30k rpm. . I have a Grizzly mini mill now and have access to R8 tooling. So, I take off the milling head, cut down the casting size, cobble up an adapter plate add pulleys and I'm in, right ?. The motor and speed controls are also salvagable to machine/route aluminum and stuff. When I want to mill wood I switch off to a router. I think I'm on to something. :idea:
    Hi SPEEDRE,

    This is your thread, look what you got us into!

    Look in my photo gallery for more pictures.

    This is a Dovetail Spindle mount. There is a 2.5" hole in the mount to hold the spindle. The mount has a dovetail base with adjustable gibb and lock to slide the spindle up or down to adjust for tool, drill chuck, or spindle height and a means of using several different spindles as no single spindle can do everything. This is my solution until I can find a better one.

    I believe the weight of the motor and existing cast iron housing will be too much for my mini gantry mill. I will probably make a new housing for the spindle out of FORTAL, a 7000 series aluminum alloy that machines beautifully and is as strong as mild steel in most applications.

    If your machine can handle the weight you might consider keeping the existing housing and change the motor to a higher speed and/or more powerful motor to give you two speed ranges and higher max rpm for wood and plastic work.

    JFettig has much more experience on this subject, would you comment on this concept Jon?

    Mike
    Attached Thumbnails Attached Thumbnails Dovetail Spindle Mount_1_4_1.JPG   DC Servo Spindle_1_1.JPG  
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

Page 3 of 20 1234513

Similar Threads

  1. DIY Spindle idea
    By puurtsi in forum DIY CNC Router Table Machines
    Replies: 21
    Last Post: 10-02-2010, 05:11 AM
  2. spindle idea
    By HARI_R in forum PCB milling
    Replies: 4
    Last Post: 07-11-2008, 11:13 AM
  3. Floating spindle idea
    By originator in forum MetalWork Discussion
    Replies: 7
    Last Post: 11-19-2006, 03:39 PM
  4. spindle idea
    By truman in forum Open Source CNC Machine Designs
    Replies: 4
    Last Post: 08-18-2006, 11:35 AM
  5. New spindle idea...
    By WilliamD in forum DIY CNC Router Table Machines
    Replies: 6
    Last Post: 12-01-2005, 12:02 AM

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
  •