Help a noob get started out.

[wonder squirrel]

Heya fellas, this is going to be a long read and pardon my ignorance I'm learning as I go, I've been lurking around this site for a little while now doing reading here and there. I'm a bit of a noob (apprentice Machinist/ Toolmaker)and thought you guys might be able to help me out with some problems I'm having.

I've got this Bridgeport mill that has been sitting (indoors) for an unknown period of time, probably about a year, but no one can say for sure.

Series I, 2 Hp
model number 7347/A11L275RO21F
Frame # 145TY-4
Type # IVY TE
Design # B
Code # J

Hopefully thats enough info for you guys to know what mill I'm working with. This mill has been fit with "Servo II" motors (X, Y, and Z axes) and "Servo II" Controller(?) that runs through a 9 pin serial connection to a PC running DOS 6.22 and "Servo CNC 3.24" software from http://servoproductsco.com/

I was asked by my employeer to get this machine back up and running because the original PC had died (SCSI hdd failure)and I am computer literate. Unfortunately, I know little to nothing about DOS and even less about CNC software. I told them I would have a look at it, but at the time, knew nothing about it- what software it ran, or even what OS it ran under.

After alot of research, I was basically able to get this setup operational except for a few (hopefully) small problems. I was able to output G-code from a program called "DeskEngraver" that I learned about here (I don't yet know G-code, but again, I'm learning as I go). I just edited out all the Z axis travel moves, the X and Y seem to run without a hitch. I've also ran a "Sample" program from the CNC 3.24 software. Although I've only ran this in the air, it could be completly f'd up once I start cutting matierial.

#1 problem. The Z axis is stuck mid travel. The Servo motor is mounted to the Quill drive assembly, not the table. I can physically move the Servos motor wheel, and the manual hand crank (these operate together- turn the wheel, the handle moves, move the handle, the wheel turns) but the spindle does not extend downward or retract upward as normal.

I'm able to control the motor through software aswell, but it sets off a "Limit" alarm and ceases movement. The software reads about 1.5" of travel. I don't yet know how to set the travel limits, but I'm working on that. I can feel a small clunk that sometimes hangs up the handle/ motor that feels like there may possibly be a chipped/ broken gear inside or something just not meshing correctly.

I've looked at exploded view pictures of the head, but theres far too much going on there for me to comprehend without tearing the head down myself and taking a peak inside.


I've been looking around at other CNC software mentioned here on these boards (Mach3, TurboCNC, etc.) I don't know if these would be better than whats currently on here. I've found no one using this software. The only reason I went with it, is because I searched for "Servo II" on google and found the manufacturer of the drives/ controller and asked them what software they run. It was this, and some other that ran under XP Pro. I don't know if the software would even control this setup.

I've got access to a P3 733Mhz (SCSI hdd) machine that I could run almost any OS on at my disposal if theres something better out there. The current PC is an ancient Compaq AT setup. This goes beyond my knowledge of hardware, I started out around 1998/1999 on a windows 98 machine ATX style

[wonder squirrel]

Anyone got any advice on what I can do to figure things out?

[machintek]

I talked to a guy in Memphis that had a S1STD Bridgeport that was retrofitted with a SERVO control. This is an after-market retrofit and I do not know anything about it. Perhaps someone else does. That is probably why no one else is answering.

George

[wonder squirrel]

Well after some tinkering around with it, I've found out how to set soft limit stops for Z and how to disengage the servo motor from the machine, but the spindle still will not retract back up.

I've noticed on the other mills here, I can just push and pull the spindle in and out with my hand, but this one won't budge, and the handle just goes in circles when turned, so I'm pretty sure somethings (gear maybe?) broken or out of mesh somewhere in there.

[wonder squirrel]

Alright, well after pulling the Z axis motor/ adaptor and manual handle off, I found a broken "quill pinion gear" in there.

Unfortunately, theres still no movement from the quill/ spindle. Theres a small piece of broken off gear in there somewhere. That may be whats causing the jammed up quill/ spindle. I'm leaning towards a lack of lubrication/ junk caught between the quill/ spindle and the head housing though.

[DameCore]

I have little or no comprehension of computer programming, although I am learning as I go as well (I'm a noob, too! ) I'm an electrician of 14 years and more recently I have moved on as a technician/mechanic, and my current job needs me to know some programming. But, as for your issue here...

From a mechanical stand point, it sounds like you're on the right track. My experience so far has been that 9 times out of 10, CNC failures are a result of electrical/mechanical faults. A broken gear piece can certainly cause all that!

I would also check all hydraulic and pneumatic levels and lines, as well as any limit, pressure and proximity switches (as well as any solenoids) for proper function. Once these physical elements are eliminated as suspects, the problem likely lies in broken parts, loose belts or housings, gear alignment, or even faulty grounding. Beyond that, it could be a parameter issue or miscalculation elsewhere in the internal program.

None of this junk may even apply to your machine, but I just thought the insight might help you somewhere down the road. I know this forum has helped me out at times.

Good luck!

PS. Please don't take offense at the smiley guy with the sign!

[wonder squirrel]

Any advice is welcomed advice. I was told yesterday the machine will need the plastic bushings in the drive pulleys replaced. I had never turned the machine on untill that point- and ofcoarse it was noisey as hell. The manual brake feelslike its out of adjustment aswell. Seems to just stick in place throughout its travel. I'm sure everything that can be lubricated, should and will need to be before this thing sees any operation.

I've monkied around with it, but still am not sure why the spindle/ quill won't retract back to normal. There may be a small piece of broken gear in there, but I can't see anything, and can't get a magnet to pick it up. If its jammed tightly into the gear that moves the spindle assembly, that could explain things.

I've LIGHTLY tapped the spindle upwards with a rubber mallet, but got no results.

Theres an aluminum spacer/ drive on the shaft on the left hand side of the machine that the motor drives for Z axis, I'm not sure how that comes off though. It looks to be pressed on, but thats a best guess.

Anyone know if the other gears behind that spacer that are floating on the shaft with keys, or if they are pressed on?

The broken part is number 146 on this exploded view. The part I'm stuck at would normally be number 68. I can see the tip of the shaft through the aluminum drive pulley. The shaft has a keyway cut into it, and theres a shearpin? in there, so theres no way of turning it off. I don't want to damage the shaft removing it though

[wonder squirrel]

Still no luck getting the quill moving up or down. I've dripped some wd-40 down from the top draw bar and the oil cups, tapped on it some more with a rubber mallot, adjusted the quill brake to make sure it wasn't hanging up.

Now that the broken gear is out, everything should move freely no?


The other gear that the quill pinion gear rides on, is that just a rack style gear thats attached to the back of the quill? The exploded view above doesn't show it. Or am I missing something?

[SORCHEROR]

i have a couple of questions,what is the servo motor on the z axis mounted too,most of the time they use a ballscrew in stead of the quill stop screw and make brackets in front,is this one mounted to the boring down feed?try to disengage the down feed knob,its the round knob labeled 23 and the handle is 22 on your views,disengage it and spindle might move,i bet someone left it engaged and than moved the z aixs and broke something,check it out,can you post a pick of the z,would help,i have a servo II machine,1997 vintage,but mine is a bed type mill
steve

[wonder squirrel]

Originally Posted by SORCHEROR i have a couple of questions,what is the servo motor on the z axis mounted too,most of the time they use a ballscrew in stead of the quill stop screw and make brackets in front,is this one mounted to the boring down feed?try to disengage the down feed knob,its the round knob labeled 23 and the handle is 22 on your views,disengage it and spindle might move,i bet someone left it engaged and than moved the z aixs and broke something,check it out,can you post a pick of the z,would help,i have a servo II machine,1997 vintage,but mine is a bed type mill steve

This isn't my machine in the picture, but heres a picture of the Servo motor and the "Zachar" gearbox. My setup is identical to this. Incidently, I've just recently met the man who help engineer and build the gearbox.



As you can see from the picture, the quill feed built into the machine is basically closed off. The "Engage/ Disengage" handle on the top right handside of the machine can still be moved back fourth, but the quill feed rate handle and clutch setup have been removed.

You could be right about the machine being left engaged and then the Z axis motor breaking the quill pinion gear. Although I've gotten the broken gear out, and I've reaasembled the gear, it looks like all the broken pieces are accounted for yet theres still no quill movement. I've also tried like you said with engage/ disengaging it, but there was no effect.

It was my understanding that once the quill pinion gear was removed, it should slide up and down with out any problems

[wonder squirrel]

Just figured I'd post an update. Finally got the handle assembly pulled out. The clutchworm ring shows heavy signs of wear around the entire diameter, but only on the inside edge of the teeth.

The quill is still stuck. With a piece of 2x4 inbetween the table and the quill I can lift it using the table. I can't move it back down though, so I haven't pushed it too far into the head. My guess now is that years of sludge and whatever else has slowly sunk down the quill sides and is creating heavy friction.

Had this been my own personal machine, I'd begin a teardown and cleaning of the head. But this is a company machine that recieves very little care as far as maintence goes, and very little use aswell. The company naturally doesn't want to invest too much into and older machine when we have two new CNC mills.

So I guess my next question would be, how long would a new pinion gear last before breaking again? At this point, what would you say this machine is worth? The company may be more interested in replacing the two old bridgeports with a newer/ faster/ more accurate Haas.

Inwhich case I'd be personally interested in buying this for a fair price.

Everything seems functional except for the sticking quill.

The motor and vari-drive assembly are working- but the plastic bushings on the pulleys are in need of replacement.

The Servo motors are all operational, so I'd say the controller is fully functional aswell.

Likely that it won't come with any tooling/ vice though.