Series I CNC head rebuild

I am in the middle of a top-end rebuild on my R2E4. It was making
excessive noise, and it turns out that a pulley bushing failed, galling
the motor shaft, and chipping out the key slot in the pulley.
Both the motor shaft and movable pulley half on the Vari-Speed drive
element must be replaced.
I have obtained the proper parts, and have the machine apart. In the
midst of this, I developed some "tricks" or strategies to get the motor
off without removing the head -- at least not removing it "completely".
Since this is (according to Hardinge) "impossible", I'm putting together
a photo-essay on how to do the whole thing without removing the head, and
FWIW, under an 8-foot ceiling. It's been tricky, but a little luck and
some ingenuity have panned out.
Lloyd
Reply to
Lloyd E. Sponenburgh
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Lloyd, where did you get the parts?
i
Reply to
Ignoramus7592
Ignoramus7592 fired this volley in news:prKdnaqNXYWSUUbSnZ2dnUVZ snipped-for-privacy@giganews.com:
HandWtools.com
Barry the owner, Nicole the office/sales woman, and Heather the tech (who rebuilds mills herself... no comments, guys) are extremely helpful, friendly, and ready to answer calls.
They'd not encountered some of the problems I have, because most of their business is mostly rebuilding Series I and Series II manual machines. But they had all the right parts ready, and shipped them for quick delivery.
The only thing they didn't have was a method of removing the motor without removing the head -- which, is, after all, "impossible". Got past that!
LLoyd
Reply to
Lloyd E. Sponenburgh
"Lloyd E. Sponenburgh" fired this volley in news:XnsA073CE87F5C17lloydspmindspringcom@216.168.3.70:
Sorry, Ig. That's part of one of their email addresses, not the web site.
this is the site!
formatting link
Lloyd
Reply to
Lloyd E. Sponenburgh
Their prices are pretty good, I am impressed.
i
Reply to
Ignoramus7592
Impossible just takes a little longer.
Reply to
Karl Townsend
This is the one which has the motor under the extension of the head, instead of on top of it? Easier to get *off* with poor clearance, but really nasty to get back in place.
One of the tricks which I remember is to take some channel and drill it for one of the bolts which hold the halves of the housing together (which happens to also fit a tapped hole in the end of the motor shaft) and use the screw and channel to depress the sliding pulley so the C-clip on the motor shaft can be removed -- to allow the sliding half of the pulley to be removed.
I'll be interested in seeing that when you have it done.
I remember finding a place which would happily sell me things like the pulley halves, the motor rotor with shaft (with the old one going to them as a core charge) the bushings, and various other things. However -- it has been perhaps fifteen years since I got them, so I'm not sure that the company is still around. (I'm also not sure who they were, but they had a nice exploded view of the heads.)
Good Luck, DoN.
Reply to
DoN. Nichols
"DoN. Nichols" fired this volley in news: snipped-for-privacy@Katana.d-and-d.com:
IF not the same company (they were around 15 years ago), Machinerypartsdepot.com now provides the same services, with the same happy, helping style and documentation.
I knew about the channel/bolt in the motor shaft, but it was easier to just put a scissor jack between ceiling and shaft (rather than making another tool!), and use a large socket as a pressing arbor. Once jacked down a fraction of an inch, there's a locking screw one can tighten to prevent the pulley from pushing back against the snap ring.
BTW, Don, the motor is NOT "easier to get out" -- it's WAY harder. On the "pointing down" manual series I and series II heads, the motor just lifts up. If you have the clearance (you need about 4"), you can get it out. On the CNC "pointing up" machines, you have to partially or completely remove the head and spindle assembly to get the motor out. Otherwise, it's trapped between the housing pan and the ram of the machine. Also, the motor shaft is almost twice as long on the CNCs as on the manual machines, making you have to "snake it out" rather than just pull it clear. That's why I had to figure the strategy to tip the head forward without craning it off.
FWIW, I think a head removal "jack" that mounts on the table would have done OK, too, but then you have to remove two or three lines and cables that pass through the ram. They are a MF to re-thread. My forearm won't even pass through the draughts in the ram, so I have to use a long-reach gripper to get those lines in and out. With my method, nothing needs to be disconnected except the big AMP-connector cables and air lines to the brake and spindle speed control motor.
Lloyd
Reply to
Lloyd E. Sponenburgh
By the way, the head is not that hard to remove, I have taken it off twice already.
i
Reply to
Ignoramus29003
Ignoramus29003 fired this volley in news:s6SdnaTHYKtBfUDSnZ2dnUVZ snipped-for-privacy@giganews.com:
Then you have a smaller arm than do I. I have "removed" the head, but kept it captive. I cannot reach inside the ram more than about six inches to thread things through the holes. I have to use a "reacher" tool, and that's cumbersome and chancy.
I have no doubt that removing the head would have proved as effective as what I did, but I (at least) eliminated the removal of the connections that prove so hard for me to re-route.
Lloyd
Reply to
Lloyd E. Sponenburgh
Our mills are indeed different. And I hated taking the head off, I hope that I never have to do it again.
Yes, it is great to avoid that risky step.
i
Reply to
Ignoramus30761
Well ... when I got my machine, the motor was in a box packed alongside it, along with two pulley halves.
The keyway on the motor shaft was badly damaged by the Delrin jacket on the key in the pulley half having work out along with the bushing.
I had to figure out how it went together. I used a lab jack between the motor and the ram, which provided support.
Mine must have had more clearance. It was a very early CNC (BOSS-3, with a serial number below "CNC 110", and I was told that they started with "CNC 100". The logic boards were wire wrapped instead of full printed circuit boards.
O.K. Different from what I remember.
The only thing which passed through the ram was the oiling line from the BiJur oiler. The motor power was some oiltight spiral flex jacket which went into the top of the transformer housing on the back of the machine, and the FWD/STOP/REV switch and the panic switch were a different cable which went into the computer box on the side (down low, IIRC).
I never even thought of running them that way. Maybe worth considering. Was this the dovetail ram, or the rigid ram -- I know that both types were used in these machines.
Mine also was too old to have the air motors for the speed control, and the solenoid for the brake. I plan to have the CNC talking directly to the VFD to control motor speed, and most of the time can just leave the variable speed set at one point. (I'm also going to add a switch to sense the back-gear lever to reverse the FWD and REV controls on the VFD when it is in back gear, so I don't have to remember to switch it when changing to back gear.
I'm currently making a replacement motor mount for the Y-axis motor -- since I am replacing the steppers with servo motors, and the servo motors are a lot longer, and don't fit in the cavity in the knee made for the steppers.
Enjoy, DoN.
Reply to
DoN. Nichols

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