584,879 active members*
5,293 visitors online*
Register for free
Login
Page 1 of 2 12
Results 1 to 20 of 26
  1. #1
    Join Date
    Jan 2007
    Posts
    317

    Progress at last

    Well, I started this process last October and finally have a mill that responds to my commands. I wanted to add the IH cnc kit as I didn't have the knowledge in October to build my own, but things happen and today I'm a lot smarter about cnc conversions than I was then. I've had the mill for over 3 years running it in manual mode. That's soon to change

    One thing I wanted along with the conversion was a one shot lube system. It's not done today, but only lacks a few pieces of hardware to get to that point. I just pulled the trigger on the license for Mach 3, so after I absorb that expense I'll order up the minor pieces and finish it.

    Of course this is a work in process and who know when I'll be done, but I'm close to making chips with it. Got a friend coming over to hook up his scope to it and tune the motors, but today there are not bad. Had a devil of a time with the Z axis motor, but found by swapping the "+" and "-" cables I could get the drive to lock to it. Pics of the build follow:
    Click image for larger version. 

Name:	PICT1277.jpg 
Views:	146 
Size:	108.3 KB 
ID:	109747 Click image for larger version. 

Name:	PICT1285.jpg 
Views:	127 
Size:	89.9 KB 
ID:	109752
    Click image for larger version. 

Name:	PICT1281.jpg 
Views:	132 
Size:	82.5 KB 
ID:	109750 Click image for larger version. 

Name:	PICT1278.jpg 
Views:	157 
Size:	105.6 KB 
ID:	109748
    Click image for larger version. 

Name:	PICT1284.jpg 
Views:	173 
Size:	104.6 KB 
ID:	109751 Click image for larger version. 

Name:	PICT1279.jpg 
Views:	161 
Size:	110.2 KB 
ID:	109749

  2. #2
    Join Date
    Jan 2007
    Posts
    317
    I ended up with parts of an IH kit and parts from other vendors. I had to make my X and Y axis motor pulley as that seemed to be the easy way out. Motors are Keiling and HomeShop Cnc. Z is the 1125 oz in and the other two are 850's. Made an adapter to mount the smaller Z axis pulley to the 1/2" shaft of the motor.
    Click image for larger version. 

Name:	PICT1288.jpg 
Views:	105 
Size:	107.8 KB 
ID:	109754 Click image for larger version. 

Name:	PICT1291.jpg 
Views:	98 
Size:	89.6 KB 
ID:	109755 Click image for larger version. 

Name:	PICT1303.jpg 
Views:	97 
Size:	69.8 KB 
ID:	109758 Click image for larger version. 

Name:	PICT1301.jpg 
Views:	103 
Size:	73.1 KB 
ID:	109756
    Click image for larger version. 

Name:	PICT1287.jpg 
Views:	100 
Size:	103.6 KB 
ID:	109753 Click image for larger version. 

Name:	PICT1302.jpg 
Views:	102 
Size:	61.8 KB 
ID:	109757

  3. #3
    Join Date
    Jan 2007
    Posts
    317
    I little mod to the end plate to retrieve some X travel and the project as it is now. I have yet to map the ballscrews and am running it to help set in the gibs so I can tighten them up. Seems to have lost some X and Y travel, so I'm looking to modify the pieces to get that back. In the next few months I hope to change out the spindle motor and add a vfd as well.
    Click image for larger version. 

Name:	PICT1303.jpg 
Views:	101 
Size:	69.8 KB 
ID:	109759 Click image for larger version. 

Name:	PICT1312.jpg 
Views:	129 
Size:	101.1 KB 
ID:	109764
    Click image for larger version. 

Name:	PICT1308.jpg 
Views:	124 
Size:	84.1 KB 
ID:	109761 Click image for larger version. 

Name:	PICT1310.jpg 
Views:	119 
Size:	74.4 KB 
ID:	109762
    Click image for larger version. 

Name:	PICT1306.jpg 
Views:	181 
Size:	106.3 KB 
ID:	109763 Click image for larger version. 

Name:	PICT1305.jpg 
Views:	115 
Size:	74.8 KB 
ID:	109760

    Bob

  4. #4
    Join Date
    Jan 2007
    Posts
    317
    Got the ballscrews mapped over the weekend and ended up with very little correction. Of course X axis was the most and Z had none at all. Jogged it a number of times afterward and all was very repeatable to right at .0003" to .0005" on X and less on the other two. I was able to actually measure the whole travel of all axis so my measurements covered the whole milling envelope for the greatest accuracy I could do.

    One thing I wanted to finish was the tuning of the motors, but my friends oscilloscope was too slow. It is a 10 mhz unit and it sounds like at the least a 20 mhz unit is needed. So, that's one thing that may not get done.

    I've still got work to do on the one shot oiling system. Anyone have any idea how to contain that loose tube inside the column? I'm thinking about a steel tube mounted inside to just guide it up and down, but i think pvc would work as well.

    Bob

  5. #5
    Join Date
    Jan 2006
    Posts
    58
    How did you map the ballscrews?

    The Z tubing on my turnkey is just ran up inside the column...it's just longer than needed and runs up then bends and connects to the head (hope that makes sense)

  6. #6
    Join Date
    Jan 2007
    Posts
    317
    Quote Originally Posted by Shev View Post
    How did you map the ballscrews?

    The Z tubing on my turnkey is just ran up inside the column...it's just longer than needed and runs up then bends and connects to the head (hope that makes sense)
    Laser Tracker. I know some guys in the business. Used it to verify level before we started mapping too.

    You used rigid tubing? Mine is nylon and goes everywhere. Wants to wrap up on the ballscrew.

    Bob

  7. #7
    Join Date
    Jun 2005
    Posts
    1015
    I made my oiler tubing into a coil inside the column. the tubing wants to unwind and straighten so it stays pretty much against the walls of the column.

  8. #8
    slightly ot -- what's the benefits/point of a one-shot lube system? I've seen several people say they put these in when they retrofitted t heir mill, but they haven't explained why...

  9. #9
    Join Date
    Jan 2007
    Posts
    317
    One shot lube system is there to provide lube for the ways and ballnuts. Eliminates the need to use the oiler ports built into the castings and provides lube to all points through the pump.

    Bob

  10. #10
    Join Date
    Jan 2007
    Posts
    317
    I made what I consider an improvement to the mill tonight. I got rid of the end of the ballscrew that sticked out of the encoder cover. I never liked those plastic knobs sticking out there turning, but didn't want to leave a hole open to the encoders. I had planned to make new covers sometime, but just decided I didn't want to wait for that. I cut the ballscrews off and covered the hole with Gorilla tape for now. I'll get the new covers modeled up and programmed in the near future.

    What I found inside the covers when I took them off kind of surprised me. They had a pile of black dust inside, I guess from the slight bit of oil I used on the orings and from just a bit of grinding due to slight misalignment. It's only been running a week or so, so that's where the surprise came from. Not surprised that the covers didn't align with the ballscrew.

    While I was at it, I put some 1uf capacitors across the + and - terminals of the encoder to reduce noise per Gecko's recommendation. Now I got a slight problem with the Y drive I need to sort out. That's for tomorrow.

    Bob

  11. #11
    Join Date
    Jan 2007
    Posts
    317
    Man, the Y motor really was having problems. After I thought about it all day at work yesterday, came home and removed the encoder cover to find the encoder wheel was slightly loose. The encoder wheel has #3-48-1/16 long set screws and I never felt like they tightened down very good. I had some 4-48-1/8 long that fit the threads, but were too long. After cutting the threaded end of the ballscrews off so the ballscrew fit inside the encoder cover, modifying the end was easy. I ground a flat across the end deep enough to seat the longer set screws and reinstalled the encoder wheels.

    Motor straightened right out and with the 1uf caps installed across the power wires it was running better that ever. Did the X and Z axis encoders the same tonight and one of the hiccups in the Z straightened right out as well.

    Running so good now I had to make some chips so I started on the X axis spacer so I can get some lost travel back. Ran out of daylight before I got it done, but I'll finish it tomorrow, then the thiner Y axis spacer is up next while I wait on a back ordered end mill to cut the limit switch housings.

    Bob

  12. #12
    Join Date
    Jan 2007
    Posts
    317
    Thought I would add a picture of the encoder mod. I had heard of encoder problems using the encoders from IH, but have to say that, at least today, they weren't an issue at all. I had other problems but they were operator related, not machine related. Here's the pic and one of my new X axis motor spacer. It should get me back to right at 30" travel in X. It's slotted so I don't have to unmount anything off of the ballscrew to install it. First real part off of the mill since the conversion began.

    Bob
    Click image for larger version. 

Name:	PICT1368.jpg 
Views:	79 
Size:	48.0 KB 
ID:	111032 Click image for larger version. 

Name:	PICT1372_2.jpg 
Views:	89 
Size:	95.3 KB 
ID:	111033

  13. #13
    Join Date
    Jan 2007
    Posts
    317
    Been using the mill pretty much weekly now and thought I was noticing some funny movement on the Z axis. I figured it was being caused by the gib being too tight. Felt like the movement was stuttering. So I loosened it up, but then noticed the head would slide down when I turned power off to the motors. Tightened it up some trying to sneak up on the best setting.

    I faced off a tooling plate a couple days ago and knew I had a tram error that needed correcting. Yesterday I got after that and while I had the indicator attached decided to measure the Z movement. What I found is puzzling me. I can tell the head to come down say .100" from a given point and it does exactly .100". Do it again and it moves exactly .100". But now lift it from that position and it moves .0075" shy of .100". But lift it again and it moves exactly .100".

    Change things around and lift it .100" and that's what it moves, but now go from lifting to lowering and the .0075" error is back. If I jog between lowering and raising, the travel is consistent at .0925".

    So, I figured it must be hanging on a too tight gib adjustment. I've been loosening the gib little by little and I think it's right on the verge being too loose now, but the problem persists. Just before giving up for the night, I checked the side to side movement at the lower end of the spindle and could only get .001" and that's with the spindle extended all the way down.

    Today I'll loosen the gib enough so I know it's not a problem and go from there. I'll do it before I fire up the motors and loosen it until the head slides down on its own. Then I'll remeasure. I can't come to any other conclusion other than the gib is too tight.

    Bob

  14. #14
    Join Date
    Jun 2005
    Posts
    1015
    I had the exact same problem and did what your doing by trying to readjust the gibb to the point i burnt out the z axis motor. the real problem is the bolt that holds the ball screw nut mounting bracket to the z axis slide is loose. this is a mod that aaron was doing where he added a washer and i believe a 1/2-13 bolt to lock down that connection. my bolt was too short and also the loctite i put on did not hold, so under the vibration, the bolt worked itself loose. i had to pull the head and then redo that connection with cleaning it out, heli coiling it and adding a longer bolt.

  15. #15
    Join Date
    Jun 2004
    Posts
    822
    Sounds like common backlash to me. If so, no amount of fiddling with the gibs will correct it.

  16. #16
    Join Date
    Jan 2007
    Posts
    317
    Quote Originally Posted by Runner4404spd View Post
    I had the exact same problem and did what your doing by trying to readjust the gibb to the point i burnt out the z axis motor. the real problem is the bolt that holds the ball screw nut mounting bracket to the z axis slide is loose. this is a mod that aaron was doing where he added a washer and i believe a 1/2-13 bolt to lock down that connection. my bolt was too short and also the loctite i put on did not hold, so under the vibration, the bolt worked itself loose. i had to pull the head and then redo that connection with cleaning it out, heli coiling it and adding a longer bolt.
    That issue has been in the back of my mind since last night. Seemed that the gib is loose enough now that it shouldn't be a problem. I think I have enough time on the mill where little things are starting to crop up. Funny thing is this problem is very repeatable. .0075" every time makes it seem like backlash, but with that heavy head and gravity I don't see any chance of that.

    My mill is one of the first from IH Connecticut and I believe it has the improved connection there. I had to borrow a 12mm allen wrench when I did the conversion, so now I guess it's time to own my own. Well, I've never been opposed to a trip to the big tool store. I'll loosen the gibs some more just to totally eliminate them, then I guess I'll be pulling the head next.

    Thanks for the advise.

    Bob

  17. #17
    Join Date
    Sep 2008
    Posts
    133
    Hi Bob
    Just read through this thread and configuration on a fine build.
    We have a similar mill and we where getting the weird z axis reading and found it to be in the connection between the ballnut mount and the head. We had a single bolt mount and no matter how tight this was it had movement in it. There a lot of mass hang of it whether you a driving it up or down. We ended up making a total new ridged mount. This has work out for us
    Hope this helps.

    Russell
    www.vapourforge.com ..................I recycle electrons.

  18. #18
    Join Date
    Mar 2009
    Posts
    144
    I've measured about 0.001" backlash and added the appropriate correction in Mach3. It's easy to do under the "Config" tab. I'd set the take-up speed to something a little faster than 20%, but that's just me. It give it a weird little hitch when it changes direction, but should make things more repeatable.

    Ken

  19. #19
    Join Date
    Jun 2005
    Posts
    1015
    my z axis movement was very repeatable as well and once i had redone the connection between the ball nut mount and the head all was good.

    also just as a side note... i just snapped a 1/2 HSS endmill with my IH mill and i never missed a beat, just kept rolling through.

  20. #20
    Join Date
    May 2005
    Posts
    2502
    Quote Originally Posted by Runner4404spd View Post
    also just as a side note... i just snapped a 1/2 HSS endmill with my IH mill and i never missed a beat, just kept rolling through.
    Been there done that!

    Cheers,

    BW
    Try G-Wizard Machinist's Calculator for free:
    http://www.cnccookbook.com/CCGWizard.html

Page 1 of 2 12

Similar Threads

  1. Oodles of progress with new X4 !
    By DAYG in forum Syil Products
    Replies: 7
    Last Post: 06-05-2010, 10:13 AM
  2. BMC-20 Making Progress, More Q's
    By fasto in forum HURCO
    Replies: 7
    Last Post: 03-07-2010, 06:51 AM
  3. My first build in progress...
    By ESP Graphics in forum DIY CNC Router Table Machines
    Replies: 0
    Last Post: 01-04-2010, 11:46 PM
  4. My first CNC... in progress!
    By hi-tech in forum CNC Wood Router Project Log
    Replies: 12
    Last Post: 06-02-2009, 10:45 PM
  5. progress! (pix)
    By anthony in forum Waterjet General Topics
    Replies: 12
    Last Post: 06-03-2005, 10:56 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •