QC 30 Spindle Nut causing runout, part number/where to find?

[shiver-91vr4]

Finally found the problem with my runout and it's the QC 30 spindle nut which is apparently tightening one side of the 30 taper tool more on one side than another. If I flip the nut around so the teeth engage on the opposite side, the runout moves to that side etc.

Does anyone know where to get one of these in good/new condition? Or have a partnumber that I can reference to find a good part?

Thanks!

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[machintek]

I had a BOSS 9 and the parts book had a diagram and part list for both the QC30 and universal quick switch 200 spindles which included part numbers for the nut you are asking about. Check your maintenance manual.

George

[shiver-91vr4]

Unfortunately I don't have one, doesn anyone around here have the maintinence manual? The only ones I can find online are for the regular bridgeports and not hte boss ones.

[machintek]

Attached are the Bridgeport part lists for the 2 spindles used on the BOSS 3, 4, 5, 6, 8, 9, interacts, etc.

George

[mactec54]

Hi shiver-91vr4

Take some photos of the piece that is inside of the nut you can take it apart to take the photo, the lugs do get broken, but your one may be assembled wrong

The Kennametal part number is ENI-18218-M
it is a QC30QCLN

You can order it at J&L they used to be around $110

I have one new one left but will not part with it at this point as I still have one machine with the QC30 on

[shiver-91vr4]

I took it apart last night and the holding tongs are really bent a bit and you can see they are worn.

On a similar note, it looks like the bottom part was machined nice, but the top tool removal tabs are machined 10-20 thou different height wise. Not sure if this would do anything, but one could butt up against the spindle and cause that side not to torque down anymore.

I'm thinking of cleaning this one up, but not sure if it's worth it and if I should just buy a new one.

Also, in trying to find this problem that was the nut all along, I ended up grinding some high spots out of the spindle taper that I thought were doing it and to no avail there. Then I saw the taper was tight at the top and it was off by .0005 or more in some spots. So I took it on myself to setup a grinder and regrind the whole spindle taper out. It came out VERY nice, and I'm a bit tight on the bottom now, which is much better...but I'm wondering how close I am on the top. So I'm hoping that the spindle is in good enough shape to hold the tool properly, it sure looks like new as before there were gouges and heavy bell mouthing. I measured the runout in the spindle taper after I ground it and it is almost undetectable. I would say < .0001 if that. So it would seem I got a good grind on there, I just hope the taper is at a good enough angle to maintain proper tool contact once I can get the nut fixed.

I've found a new spindle for $100 in supposidly good condition, but I'm worried that it's bearings could have more runout than mine etc, but it does come with the spindle nut.

I'm thinking I may just buy it as a spare just in case the spindle nut does not fix it.

Would anyone be willing to lend me their spindle nut for a day? I can test it and see if that does correct the problem, if not, I can just buy the new spindle.

What do you think about the grinding as well? If I'm a bit tight on the bottom do you think I can still use it? I can regrind it again, but the new (used) spindle is cheaper than my time it would take to regrind.

Thanks again

[shiver-91vr4]

Nevermind, found the part, they want $170 for it now, yuck.

[mactec54]

shiver-91vr4

I don't know what the new one would look like, I don't think they have changed do you have a web link to the new one

Now that you have ground it, it should be easy to lap it with the nut off & the brake on you can lap it with 2 of your holders to get the taper correct or the tool holders will move around in the taper if it is tight at the bottom

This is a photo of what my new QC30 Nut looks like

[shiver-91vr4]

There is a newer version where the ejector tabs are a lot bigger and the adjustment screw is on the bottom face

Also, should I just buy that spindle? Is $100 a good price? I figure if the lock nut is ~$200 and I can get a good used spindle and locknut for $100, why not. If the locknut works, at least I have a spindle in case something is wrong with mine.

[mactec54]

Hi shiver-91vr4

Your nut is messed up it should look like this one, there should be 4 lugs in there

Here is another photo, There should be 4 lugs attached to the locking ring inside this is one piece were the 4 lugs are

[shiver-91vr4]

Look very closely at the nut above, it is a new part, not mine.

The top "lugs" instead of being small, now encompass almost 180 degrees of rotation. There are just cutouts for the keys.

You can see the top lugs right below the new style circlip (it has two tabs to extract it easier, mine has just angled cuts on the edges that make it hard to remove.

[mactec54]

Hi shiver-91vr4

I posted another photo so you could see the inside of the nut better
How old is your machine, as I have never seen a nut like yours, I have done a lot of these spindles.

The 4 lugs are all on the same part,

I think somebody messed your nut up, because the one I have in the photo has always been made like this, it is not a new design

[shiver-91vr4]

Yes, that is how mine looks right now with the 4 pieces, except mine is messed up.

The picture I'm posting is of Kennametal part number 30SLQC, it's a good part.

[Sparky_NY]

Having recently got a bridgeport with this spindle/nut I have a question. Somewhere I read about these nuts having "locator" pins or something of the sort to limit rotation and make lining up things easier for tool changes.

My nut has no such pins but there are 2 threaded holes on the nut OD where I imagine they belong. I have found that when removing the tool after opening the nut that the tool is still wedged tight into the taper and requires a tap to unseat it before it will drop out.

I imagine this is wrong and hope the missing pins are they key to easier operation. Any info or pics on these pins and how the nut is supposed to operate would be most appreciated.

I am hoping this isn't considered a hijack.

[shiver-91vr4]

Many times I've had to tap the tool holder with a rubber hammer to unseat it.

There are supposed to be the tabs on the top that help remove the tool, and those tabs do help locate in-between the keys on teh spindle, but they're really not that huge of a deal.

Theoretically you could really crank the nut and have those tabs eject the tool, but I've found sometimes when that happens the teeth are lined up in the same orientation as the keys and your tool will come crashing to the table....not a nice thing to do...

So I've just resorted to tapping it with a rubber mallet if it gets stuck.

I would say if it's holding your tools properly you're in good shape. Unfortunately I can't get that far yet, I should have my new (used) spindle and nut in today, I'm hoping they're in good enough condition to use.

[mactec54]

Hi Sparky_NY
If you look at the first photo I posted you will see a button head cap screw that has a polished head that screw is just long enough to stop the rotation of the lock unlock disc
inside the nut I will try & give more detail in another post

[Sparky_NY]

Hi Sparky_NY
If you look at the first photo I posted you will see a button head cap screw that has a polished head that screw is just long enough to stop the rotation of the lock unlock disc
inside the nut I will try & give more detail in another post

Thanks, I think replacing those missing screws will make toolchanges a lot easier. Now, aligning it is very picky, same with removing.

[mactec54]

Sparky_NY

Only one screw hole is used with a long screw just enough to catch the disc inside the nut, the other one is just for a different position when setting it up, the screw is turned down on the end I will take a photo & give you how long it should be

The screw length from under the head should be .225/.230 long the turned down part is.063 long X .125 dia

In the other hole the screw if you use one is very short, just enough to screw it in ,you can just put a rubber/plastic plug in there if you want

[shiver-91vr4]

Alright, tried the new spindle lock nut and to no avail, same runout. I think it's a problem with the taper itself and is in need of a professional regrind.

Luckily I had the extra spindle here I bought to throw in.

Threw that in and I'm getting .0005 or less inside the tool holders now, so I'm pretty happy. I wish it was less, but I'm not sure if I could ask for more.

What does everyone else have in their toolholders?

I had some measuring .0005 and the best one was around .0004 or so. This is measuring the inside of it.

I didn't have time to throw a tool in and measure the runout on the tool itself yet.

Can you really get better than .0005 on a bridgeport without having it professionally reground? By that I mean from the factory were they any better than that even?

[Sparky_NY]

Thanks so much! You did everything but make the screw and install it for me!

I'm curious, you mention the other hole is for a different position when steeing it up, what is that all about?

Sparky_NY

Only one screw hole is used with a long screw just enough to catch the disc inside the nut, the other one is just for a different position when setting it up, the screw is turned down on the end I will take a photo & give you how long it should be

The screw length from under the head should be .225/.230 long the turned down part is.063 long X .125 dia

In the other hole the screw if you use one is very short, just enough to screw it in ,you can just put a rubber/plastic plug in there if you want