Syil SX3 Quill

[Old Megawatts]

Some of you may be interested in the problem and the fix for the strange noise that my mill has had from new. It wasn't a big noise but when the speed was cranked up it always sounded like there was something rattling in the quill. I also noticed that when milling with a small (.0625) end mill, that the surface had small irregularities like small waves in it. Enough so you could see it in the light reflecting off it. It was starting to drive me batts (Worse than usual.) so I decided to disassemble it. I won't go through what needs to be done to remove the quill feed as one can look at the parts drawing and figure that out. I will mention that the front cover of the mill has to be removed and some of the wires have unplugged to get it out of the way. The digital depth gauge has to be removed to get at the anti-rotation pin that locks the quill body from turning.

In the picture of the spindle here is the bearing lineup from top to bottom: CXWY 6006RS, XUDB 51106, QGG 32907. These are the original bearing numbers.
The strange thing to me was that the thrust bearing under the ball bearing had it's top race a press fit on the shaft and the bottom race was perhaps .010 to .020 oversize on the ID and the OS was a free floating fit inside of the bore of the quill. I had never seen one set up like this. In looking at bearing specifications I found that the ball bearing was capable of around 1700 lb thrust. I decided to try assembling the quill without the thrust bearing and seeing what it sounded like. Boy what a difference, it really ran smooth and quiet. That is how I installed it back in the machine. I also found a size for size angular contact bearing that I could have replaced the standard ball bearing with. The only reason that I didn't do so was that the bearing retails for $127.88. I will try the original one for a while and will replace it if needed. I also took the advise of one of the members here on the forum to drill and tap one of the lock nuts for a set screw rather than using two lock nuts. Put a piece of soft brass under the set screw to protect the threads.
Here are the numbers for the angular contact bearing:
This information is from the Alpine Bearing Co., 1-800-225-4334
Their number: MC-1106SS* These are interchange numbers: The *position is for preload designation. Barden 1206HCRR*, FAFNIR 2MMV9106HXVV*, SNFA HX30-7CE1*, NSK 7006CTRV1V*P4Y, SKF S708CD/P4A*.
That darn spanner wrench with the pins in it always bugged me so while I had everyting apart I milled some spanner wrench groves in the quill.
Afterthought: I found a press fit on the ball bearing of about +.001 to +.0015 pretty tight. I reduced this to just a little more than a two thumbs push on the shaft. Made it a lot easier to adjust the clearence.

[neilw20]

Thanks for pictures. I will eventually see something similar.
Some observations.
1). The spindle needs some spanner flats. I knew that too!
With some collet holders, the two holes for the pinspanner are not accessable.
2). Do you have pictures of the rest of the bits, horizontal shaft etc.
The tapping switch wire. A slip ring used? Is there a proper return for it.
I found you could hold the button down and wiggle the shaft to get reverse.
3). After the quill has been locked for a bit and warms up it is stubborn to unlock. Anything obvious?

[Old Megawatts]

Hi,

I'm sorry that I didn't take some pictures of the horizontal shaft and other parts. I can tell you how the reversing button connects with the wire. There is a brass hub that is insulated from the horizontal shaft with a plastic bushinng. The push button makes contact with this hub. The hub makes contact with the wire through a flat U shaped brass wiper that is about 1/4" wide and about .025 thick. This is insulated from the frame with a plastic oblong plug that is attached to the shaft housing. When I re-assembled the machine I put heat shrink over the end of the wire and left it disconnected as I have never used it. In the instructions that I have it said that the tapping option wasn't activated.
As far as the quill lock goes, I know what the problem is and thought I had corrected it, however, I wasn't as smart as I thought. The problem is that the locking device is placed too far away from the quill. It just barely catches the OD of the quill and wedges in the bore. There are two plungers that make up the clamp. The rear one can be released by tapping on the end of the lock screw but the other one is free floating and won't release. I polished the shoulders of both pieces and gave them more taper. That was the wrong thing to do. It just made the thing wedge tighter. It looks like a nearly square shoulder works better. I don't know if a rather heavy spring could be placed between the two plungers to separate then or not. I don't have a good answer yet.

OM

[neilw20]

OM.

Thanks for reply.
I have seen the spring between on other than X3. Looks like a good idea.
When I have implemented I will send you info.
I am just going out to get a longer custom gas strut. Hope for 40Kg gas load or about 400N in stupid units. I really don't care about gravity using spring scales.
I will gain 83mm in Z+ and hoping for -35 below the original limits.
Bottom limit depend on how much lost travel for piston. (currently 82mm.)
I am raising the upper attach about 50mm with an offset spacer block.
Bottom end of strut will end up on the benchmount part of casting.
They just got this bit so wrong. Strut should be inverted so oil seal works as designed.
I am leaving both upper reference parts on the tower, so I can zero at the lower one when I don't need top put long/mills drills in the machine.
Rapids X and Y are 2500, Z is 1500, 4th axis I haven'nt measured. Requires some unit conversion to get it in radians/second. More brain clogging units!

Neil

[MIKE JEFFERS]

on my standard x3 the spindle was over size for the top bearing to slip over and allow
adjustment of the play ,set it up in me lathe and turned .1mm off ,fine now
quil lock ,put a spacer in-between thw handle and the outer collet now pulls up in 1/8th a turn so you dont have to keep re-setting the guard (need to disconnect it anyway pita)
mike

[neilw20]

I'm naughty!
My guard's in storage.
How is the top of the chuck ever going to throw anything at you.
Now I have a long strut, the guard would be even more insignificant.
I can put LONG drills in it now, even with a vice.
I new there had to be a use for the top of the tower other than sheetmetal attachment points!

[48racefan]

Since I have my SX3 completley tore down, i would be happy to snap some pictures and post them here...

[fringe]

Hi,

I recently purchased a 2nd hand SX3 that has only seen very light use, and has pretty much been in storage for the last 2 years. I'm currently in the process of stripping it down and cleaning. However, there are two issues which I need to resolve immediately, both referred to above in this thread...

1. Loud clickerty-clickerty-clickerty noise when spindle is rotating. I have isolated it to the pulley wheel on the top of the spindle which seems to have quite a lot of play on the toothed spindle shaft (i.e. the belt pulley visible at the top of the attached photo).

2. Very tight quill. It takes two hands on the adjustment handles to raise and lower the quill. I have loosened the locking bolt and fine adjustment wheel of course, but still very tight.

I haven't found any instructions or photos showning how to remove and disassemble the SX3 head, so am trying to figure it out as I go. Any photos of the process, or the disassembed components would be really helpful.

I have stipped down the head as far as I can...removed the top, front, bottom covers, tachometer display, belt, and motor. Now I am a little stuck. The quill gear "block" seems to be firmly attached to the side of the head casting and I can't free it. Also, I can't work out how to remove the pulley at the top of the spindle. How do you get the spindle out?

Any help with these issues would be very much appreciated

PS. I have limited experience with shafts, bearings, and pulleys so please excuse me if I am being dim.

TIA

[neilw20]

I see you have removed the 4 screws form the top pulley bearing support assembly. With the drawbar removed from the spindle you should be able to lift off the pulley/bearing assembly. The key is probably getting stuck on the end of the spline. Look for burrs at top on splines. It comes off readily.
Tap the end of the quill locking bolt, to free the nut on on the other end.

Unscrew the bolt right out. The front part of the locking part is probably wedging against the quill. Put a good fitting pin up the hole and give it a firm wiggle.

Make sure you motor can't fall off. If it does the wiring to the hall sensors will get damaged. Disconnect if practical, noting all the connections. The 3 hall sensor wires must be correctly phased to match the power wires to the windings. There are also 2 other wires providing power to the hall sensors.

Eight active wires in all excluding any power earth wiring.
Difficult to get going if you get it wrong and don't understand BLDC technology. Document this carefully to save grief later on.

Once the gear is removed the I believe the quill can fall out, once it comes loose. BEWARE. You don't want to drop it on the nice table. Get the cushion off your chair. Better to get a sore backside.

[iGG1e]

Even though it wasn't too long ago I took mine out, it seems a blur now!

I do recall behind the DRO unit a screw you need to take out to final release the spindle. It runs in the machined groove on the front you can see.

The tables do mark easily...the factory kindly supplied my table with two lovely dents by what I can only assume is achieved by hanging off the spanner when bolting the clamps for the 4th axis prior to shipping.

[fringe]

@neilw20
Thank you for your extremely prompt response. Following your suggestions I have now managed to remove the toothed pulley and bearing subassembly. This has revealed the cylindrical bore along which the quill moves - it seemed very dry in there so I have added a thin coat of lithium grease. Unfortunatley quill travel is still extremely tight. At the moment I am not sure whether it's the gearbox mechanism [part 103 in attached parts breakdown] (i.e. the assembly containing the fine feed and quill handles) or the quill itself.

@iGG1e
Thanks for the suggestion regarding the spindle orientation shaft hidden below the DRO. Unfortunately when trying to remove the four bolts that support the DRO, 2 of the philips heads just crubbled so I'm going to have to cut a slot in those with a dremel to get them out (will have to do this later in the week). Whilst I was able to free the other 2 bolts, they were much tighter than necessary.

@neilw20, @iGG1e
So assuming that I can't drop the quill out until I get the DRO off, can I remove the quill gearbox in the meantime? If I could detach the gearbox then that would allow me to determine if the gearbox is causing the resistance. I suspect that the fine feed is not working, so will probably have to disassemble it.

I have removed the spring mechanism on the left side of the head. Also removed the four cap screws [parts 109 and 110] but not sure what to do with the screw lock sleeve [part 108] - is that just an alignment fixture? If I remove the circlip [part 35] should the whole assembly pull out to the right?

TIA

[neilw20]

fringe.

Thanks for the PDF. I never did have a good copy of that exploded view.

CNCzoners !
Feel free to ask for any SX3 documentation from my collection.