584,833 active members*
5,304 visitors online*
Register for free
Login
Page 2 of 2 12
Results 21 to 40 of 40
  1. #21
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by bhurts View Post
    I would leave the electronics alone for now and look at the machines mechanical components instead. Check everything for good lubrication. Unhook your motors and turn the screws by hand thru the travels. Check all pulley setscrews. Check your bearings for end play and adjust or replace as needed. If you perform your measurements tests by hand do the problems still exist?

    Ben

    Sent from my HTC6525LVW using Tapatalk
    Yeah, I'm pretty sure it's mechanical. The control system seems to be working just fine. While it is connected through a parallel port I've not seen anything that leads me to believe it is electrical/electronic.

    One shot oiler system seems to be pumping oil to all of the ways effectively. I can see it on the ways and where it drips off of things and onto the base of the mill in various places. Just lime my manual knee mill.

    With the motor drives off the X axis moves freely using the knob on the end of the shaft. The other axes don't have anything to turn other than a bit of the end of the shaft that exits the encoder housing.

    The set screws on the pulleys seem tight. That was one thing I checked on the Z axis earlier since I can get to that easily and couldn't figure out how it would have this significant asymmetric backlash problem like the X axis with the weight of the head loading the ball screw.

    To check the other axes for freedom of movement I'll have to pull the motors and the belts to turn the pulley itself.

    I will have to get someone to assist me to pull things apart since I can't take get table off unassisted.

  2. #22
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    Mark,

    Before taking everything apart check the lead screw retaining bearings (thrust bearings) remember the magic word "LOGIC" that way you will identify the exact issue or issues which will aid in future troubleshooting endeavors.

    Jeff...
    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  3. #23
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by bhurts View Post
    I would leave the electronics alone for now and look at the machines mechanical components instead. Check everything for good lubrication. Unhook your motors and turn the screws by hand thru the travels. Check all pulley setscrews. Check your bearings for end play and adjust or replace as needed. If you perform your measurements tests by hand do the problems still exist?

    Ben

    Sent from my HTC6525LVW using Tapatalk
    Ben,

    Yeah, I think the electronics are OK. Anything/everything I've checked seems to be normal and nothing about electronics explains the strange behavior I'm seeing.

    Everything that I can get at without pulling the table seems just fine. Pulleys, belts, X-axis screw turns freely. I can't turn Y manually as there is nothing to to turn.
    Unless or until I can get someone to help I'm pretty well stopped out on this. I can't get the table off unassisted and the X Motor will have to be removed to get the table off the end of the screw and the rails due to the enclosure.

    I have often wondered about the long time frames of the CNC projects that people talk about on the forum and now I'm beginning to see why nothing gets done quickly. ;-(

    I'm not sure exactly what you mean "by hand"?

  4. #24
    Join Date
    Jun 2013
    Posts
    1041

    Re: Is Charter Oak still in business?

    When you turn the screws by hand while indicating the table can you tell if there is rotation of the screw before motion starts.

    Ben

    Sent from my HTC6525LVW using Tapatalk

  5. #25
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by bhurts View Post
    When you turn the screws by hand while indicating the table can you tell if there is rotation of the screw before motion starts.

    Ben

    Sent from my HTC6525LVW using Tapatalk
    Ben,

    The same backlash exists when operating the table manually, at least in X, since that is the only axis with any means of turning the shaft by hand. The X-Axis is reporting ~.002-.003 in one direction and less than .001 in the other.

    The Y-axis is well under .001 in both directions.

    I did find that one of the X-Axis gib locks(?) was cranked down really tight. They were both locked with the lock nut but when I loosened the lock nut, one was was really cranked down and the other not tightened nearly so much. Loosening them equally did seem to make everything smoother but the backlash remains and it still asymmetric.

    The screws that hold the pulley to the shaft will not turn and there is no way to get the pulley off the shaft to disassemble things any further than removing the motor and the associated mounting block.

    The problem seems like it might be related to the thrust bearings and that they may allow movement on one direction more easily than the other? That can't be disassembled since I can't take the pulley off so I don't know exactly how they work. This also prevents removing the table completely.

    Charter Oak seems to be closed for business so they aren't a source of any information or parts and I've never seen anything like a manual posted anywhere.

  6. #26
    Join Date
    Jun 2013
    Posts
    1041

    Re: Is Charter Oak still in business?

    Try heating the setscrews in the pulley with a soldering iron. They most likely used locktite on the screws. The heat should cause it to break down.

    Ben

    Sent from my HTC6525LVW using Tapatalk

  7. #27
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by bhurts View Post
    Try heating the setscrews in the pulley with a soldering iron. They most likely used locktite on the screws. The heat should cause it to break down.

    Ben

    Sent from my HTC6525LVW using Tapatalk
    I cooked the living **** out of the thing with a heat gun thinking the same thing. No joy. Managed to put a healthy twist in the short end of the hex key though.

    It does occur to me that if this actually has a recirculating ball screw assembly then it should by definition be essentially zero backlash by design shouldn't it? Unless they are actually using some sort of regular lead screws and two spring loaded screw assemblies that are intended to take out the backlash? Or the thing is just worn out.

    I though that was the whole point of a recirculating ball nut and a ground lead screw was to have a zero lash assembly without any other dicking about?

    Of course with no drawings, or other solid information I am clueless what is actually under there and it seems kinda hopeless to even get replacement parts if wear is the issue.

  8. #28
    Join Date
    Feb 2007
    Posts
    4553

    Post Re: Is Charter Oak still in business?

    Mark,

    Removing red threadlocker involves heating the fastener to a temperature of 500°F (250°C).

    Virtually all factory rolled ball screws with a single ball nut have backlash, reballing (hand fitting with oversize balls) will eliminate most of the backlash however a double nut arrangement usually is a far superior solution.

    Once you have taken your mill apart, post images of ballscrews and associated parts. Someone here will be able to help you identify what you have.

    Jeff...
    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  9. #29
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    Mark,

    I neglected to mention>
    If someone built there own spring loaded double ball nut assembly they may have miscalculated the spring tension of the spring pack between the two ball nuts. If the spring tension is too low you will see intermittent and varying degrees of motion loss due to stiction, weight of axis parts, cutting forces etc...

    Jeff..


    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  10. #30
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  11. #31
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by jalessi View Post
    Mark,

    I neglected to mention>
    If someone built there own spring loaded double ball nut assembly they may have miscalculated the spring tension of the spring pack between the two ball nuts. If the spring tension is too low you will see intermittent and varying degrees of motion loss due to stiction, weight of axis parts, cutting forces etc...

    Jeff..


    Thank you Jeff.

    OK, after a bit more investigation into the "ball nuts" in this mill [it is an IH turnkey mill] I find that this mill can't possibly have what I interpret as ball nuts at all!? There seems to be no room for any sort of ball nut assembly (double or otherwise) with any "belleville" washers or anything remotely like that?

    The first two pictures are the X-Axis after I took it apart yesterday down to the pulley and re-assembled it.

    NOTE: The 6 beefy looking cap screws which one might imagine to have the ball nut assembly under it has nothing whatsoever other than lead screw that extends beyond the interface of the white base plate it attaches to and the big aluminum block between it and the table!
    It is as if they put that big aluminum block in there to pretend there is a real ball nut assembly in that area but there isn't.

    Whatever is acting as a "ball nut" is all within the ~1" of the circular housing and the thickness of that white base plate. Beyond that towards the table is nothing but lead screw.
    The other picture is the Y-Axis with its cracked cover and the Z axis which has no cover. They are all essentially the same other than the Z-Axis pulley diameter.




    This is what I think of as a ball screw assembly, and is what is in the other IH mill I have sitting around that has no enclosure, belt drive, limit switches, one shot oiler, functional controller. Notice that the ball nut mechanism to the right of the flange is actually a mechanism which couldn't possibly be what is under that cover.

    I can't read Japanese but this is one of the certification sheets. I can't find these part numbers anywhere (they are about 10 years old) but it looks like they are 650 mm OAL (Y Axis?),850 mm OAL (Z-Axis?), and 1180 mm OAL (X-Axis?) with shorter threaded lengths being the other number.




    I will likely just get this going for rough milling of things where +-.005+ tolerances are suitable and just not try to do anything requiring any real precision. Not at all what I'd hoped for but I can't invest my whole life in it either.
    I suppose the long term answer is to tear it down entirely and replace the lead screws with actual ball screws.
    I'd consider swapping the head and controller to the other mill with the good lead screws but it has no limit switches, one shot oiler, etc. etc. There are no good answers I don't think.

    What a disappointment. :tired:

  12. #32
    Join Date
    Jun 2013
    Posts
    1041

    Re: Is Charter Oak still in business?

    The nut is not able too be seen until the table is removed most likely. The part on the end is just the thrust bearing housing. The ballnut would be centered under the table and would require a good bit more work to get to.

    Ben

    Sent from my HTC6525LVW using Tapatalk

  13. #33
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    Mark,

    As Ben pointed out the ballnut or ballnut assemblies are usually attached to the center of the saddle, center of the table and center of the head slide.

    See attached images:


    Review Bob Warfields conversion for details.
    https://www.cnccookbook.com/diy-cnc-...sion-retrofit/

    Jeff...


    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  14. #34
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Jeff, Ben,

    OK, that makes sense since it could be anywhere along the shaft. This picture doesn't have the big aluminum block between the motor and the table so I figured that would be where it was. But I can feel under there and there is nothing.

    Since I can't get the pulley off, I can't take the thrust bearing off and I can't pull the table. I had my heat gun on max temperature for probably 15 minutes and the set screws didn't budge. Smoke from the oil on the shaft but whatever they put those things on there with was ignoring my efforts completely. Nothing needs to be 'welded' on there that tight.

    Ahhh well. Like I said, I will just use this for rough milling of slides that has almost no tolerance requirements [I mostly do that by eye and handle position] and move on.
    While I might try an optics adapter part at some point to see just how bad things are in real use. But I can't possibly trust this for a customer slide and finish work, much less hope to do any threading which was one of the things that I'd hoped for. Tapping holes in hard material and all of the attending problems is another long saga.

    Thanks,
    Mark


  15. #35
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    If it were my machine, a torch would be resolving the loctite setscrew dilemma in a heartbeat. Of course all safety precautions would be in effect including a full fire extinguisher on standby within hands reach.
    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  16. #36
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Quote Originally Posted by jalessi View Post
    If it were my machine, a torch would be resolving the loctite setscrew dilemma in a heartbeat. Of course all safety precautions would be in effect including a full fire extinguisher on standby within hands reach.

    aaaahahahahahahHHAHAHAHAHAHAHAH!!! So much for the "Patience" part eh?

  17. #37
    Join Date
    Jun 2013
    Posts
    1041

    Re: Is Charter Oak still in business?

    That's why I recommend a good soldering iron. It should be able to get 7-800 deg Fahrenheit without the open flame. Not as much fun but less likely you'll melt something else in the process.

    Ben

    Sent from my HTC6525LVW using Tapatalk

  18. #38
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  19. #39
    Join Date
    Feb 2007
    Posts
    4553

    Re: Is Charter Oak still in business?

    The aluminum pulley will dissipate an extremely large amount of heat, you may have to fixture the heat gun in place for an extended period of time before desired temperature is reached.

    Appling Toluene by positioning the pulley with the set screw upright and filling the pocket will soften Loctite.

    Extreme Caution.... Toluene is extremely flammable and also toxic to inhale.


    Jeff...
    Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish.

  20. #40
    Join Date
    Apr 2016
    Posts
    17

    Re: Is Charter Oak still in business?

    Since the answer to the OP question (Is Charter Oak Automation still in business) seems to be trending pretty strongly towards NO. Zero communications by email or phone indicates to me that they have pretty much gone under without bothering to mention it to anyone. Hopefully there were no outstanding orders and customers left in a lurch.


    In view of that, I'm wondering what is the proper thread to discuss technical issues related to the MACH 3/controller interface? Specifically Ethernet connections and the like.
    The ESS that I have installed worked perfectly and transparently right out of the box in all but one critical aspect and I'm at a loss to figure that one out.

Page 2 of 2 12

Similar Threads

  1. New X4 Speedmaster From Charter Oak
    By Bob La Londe in forum Charter Oak Automation Support Forum
    Replies: 14
    Last Post: 06-08-2016, 07:22 PM
  2. WHy Charter Oak CNC MILL?
    By new2cnc4 in forum Charter Oak Automation Support Forum
    Replies: 11
    Last Post: 02-08-2016, 04:46 AM
  3. Syil CNC at Charter Oak
    By tmarks11 in forum Charter Oak Automation Support Forum
    Replies: 0
    Last Post: 03-30-2015, 12:49 AM
  4. Charter Oak Automation
    By saabman in forum Charter Oak Automation Support Forum
    Replies: 8
    Last Post: 04-11-2013, 07:27 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
  •