[mhackney]

Does anyone know if a commercially available power draw bar for the G0704 is available? I did a quick search and didn't turn up anything but it doesn't hurt to ask. I don't have a lot of time to fabricate the great PDB Hoss developed so I thought I'd see if one is available.

[mhackney]

For several years I have struggled with variable backlash on my Y axis. I've torn apart, rebuilt, replaced ballbearings in the nut, extended, moved the stepper to the rear and many other mods thinking that eventually I'd come across a combination of mods that would stabilize my Y. Most recently I finished the Y extension mod and moved the stepper to the rear. Things seemed pretty good but slowly backlash started creeping in: 0.010" backlash. I tried adjusting the gib but no amount of adjustment (basically a full turn of the front and back gib adjusting screws) even made a difference. So I finally decided to tear things down and figure out what the heck is going on. It didn't take too long to figure out as you can see by the attached photos. Even though I machined the ball nut mount to Hoss' Phase 2 specs (the mount is 2.00" tall) I've always had this situation where the mount sits lower in the saddle slot and the lock screws are actually exposed. It's always been like this and I really never thought much about it - stupid me! As you can see, the lock screws have distorted the top of the mount so I can imagine that it is not held anywhere near as secure as it should. It also explains - I think - the variability and degeneration I've experienced. Ironically, tightening the gib would probably make things worse as more force would be required to move the saddle/table and that would result in "flex" of the ball nut mount.

So I'm machining a new mount on my X2 now and I'll make it about 2-3/16" tall so it reaches to the top of the slot and provides enough meat for the set screws to lock it into place. I'm really hoping this has been my nemesis these past couple of years! At least it seems like a smoking gun.

[mhackney]

Well the new mount is all done. It is almost 1/4" longer than the original and a little tighter fit in the slot too. I have high hopes!

[mhackney]

I haven't had a chance to install the new ball nut mount yet - I did a 750 mile round trip driving my son back to college. But I did want to add something here...

Several weeks ago my Windows XP control machine started acting up. It is nearly impossible to find working machines with parallel ports and even if I did, DropBox is no longer supporting XP and I use it to move gcode files around. Using the web version is a pain. So I posted on the Mach 3 forum hear and got some good feedback on the UC-100 USB to parallel port interface. Since I was in a hurry and don't really have time to rebuild my control electronics, I went for it. I bought a good used windows box and upgraded to Windows 10. I then transferred my Mach3 directory to the new machine and installed the UC-100 driver according to their instructions. It took an hour to upgrade windows 10, 15 minutes to copy Mach3 and 5 minutes to install the UC-100 driver. Plugged the UC-100 into my parallel port BOB and the other end into a USB port and booted up. It works fantastically. I've had a couple of lengthy production runs and it's been several weeks and everything is working great.

[paul3112]

I haven't had a chance to install the new ball nut mount yet - I did a 750 mile round trip driving my son back to college. But I did want to add something here...

Several weeks ago my Windows XP control machine started acting up. It is nearly impossible to find working machines with parallel ports and even if I did, DropBox is no longer supporting XP and I use it to move gcode files around. Using the web version is a pain. So I posted on the Mach 3 forum hear and got some good feedback on the UC-100 USB to parallel port interface. Since I was in a hurry and don't really have time to rebuild my control electronics, I went for it. I bought a good used windows box and upgraded to Windows 10. I then transferred my Mach3 directory to the new machine and installed the UC-100 driver according to their instructions. It took an hour to upgrade windows 10, 15 minutes to copy Mach3 and 5 minutes to install the UC-100 driver. Plugged the UC-100 into my parallel port BOB and the other end into a USB port and booted up. It works fantastically. I've had a couple of lengthy production runs and it's been several weeks and everything is working great.

Ya gottta luvit when a plan comes together

[mhackney]

Every once in a while the stars align!

[louis_mielke]

In the pic you posted here
http://www.cnczone.com/forums/1061316-post246.html
The bearing on the right looks to be in the proper orientation to go on the spindle as it sits,
notice the difference in thickness of the outer race.
Hoss

I know I'm quoting a very old post but am I understanding correctly that when installing these angular contact bearings the correct orientation is the side with the smaller gap between the inner and outer race face toward each other or towards the inside of the cavity?forgive me for digging up old topics.

[wizard]

I know I'm quoting a very old post but am I understanding correctly that when installing these angular contact bearings the correct orientation is the side with the smaller gap between the inner and outer race face toward each other or towards the inside of the cavity?forgive me for digging up old topics.

It depends upon the design of the spindle and its housing. There are a few ways to install angular contact bearings and as such you need to understand how they work with respect to the spindle design. I suggest downloading some PDF's, from the bearing manufactures, to get drawings of back to back and front to front mounting. Also you need to understand the part numbering scheme for these bearings. Not all angular contact bearings are sold with a built in preload so that affects assembly technique. Often a spindle design will require back to back installation with a nut on the spindle shaft taking up or bringing together the inner races.

[louis_mielke]

100% good advice you've passed along and yes I should totally dig up some manufacturers info and do my research. That being said, I guess I should have mentioned I've bought the same exact bearings that the OP has and I'm replacing them on the spindle of a nearly identical machine (PM-25mv vs the G0704) and thus was looking to glean information/experience from someone who has already traveled the same path.

It depends upon the design of the spindle and its housing. There are a few ways to install angular contact bearings and as such you need to understand how they work with respect to the spindle design. I suggest downloading some PDF's, from the bearing manufactures, to get drawings of back to back and front to front mounting. Also you need to understand the part numbering scheme for these bearings. Not all angular contact bearings are sold with a built in preload so that affects assembly technique. Often a spindle design will require back to back installation with a nut on the spindle shaft taking up or bringing together the inner races.

[louis_mielke]

I've done some more searching using different search keywords and found the answer to my question. So another situation of a newb not searching hard enough. My apologies!

[MiniSoCalCNC]

OMG !!! read all 51 pages and ... No updates on the AC motor / VFD conversion ?

So the NEW treadmill motor is just fine with new speeds and feeds ? No longer a need for the motor conversion ? Was really hoping to see a sub $500 Brushless motor + controller upgrade solution ... thats proven to work

[mhackney]

Nope, I left the treadmill motor on. I use this machine to produce the parts for the fly fishing reels I manufacture so I have to keep it operational. I can't afford "time".

[mhackney]

Ok, still plugging away with the G0704 and Phase 2 conversion but after 8 years I feel like my X and Y backlash is just getting a little sloppy (.003" Y, .004" X) and I'm considering converting to double ball nut C7s. Has anyone done a Phase 2 to Phase 3 conversion? Any gotchas to be concerned with? I don't want to do any more machining on my base/Y if possible so I don't have to muck with Z (which is fine). I have a Phase 2 with rear stepper and drive belt with Y extension. I know I'll lose more Y with the double nuts but I can live with that. Is any more machining required on the base and/or X saddle for the Phase 2 to 3 conversion?