[NC Cams]

Life was moving along sort of nicely when all of a sudden SPROING, the "clock return spring" (P/N 11192020) for the quill on my 2J head on my EXTRAK mill broke and the quill dropped.

Got the spring out and the housing et al appart OKl.

However, to reload the spring thingie and wind it back up, it seems we need to remove the "Quill Pinion shaft" (P/N 28007063). It won't slide out and seems to be held up internally by something deep and complicated-like sounding inside the head. AARGH.

Several questions:

Question 1: are the manual mill springs the same as EXTRAK (Spring P/N for "trak is 11192020) Number is from parts manual supplied with machine.

Question 2: how do you replace the spring and rewind it (IE: number of turns, special tricks,etc)???

Would appreciate excruciating details. Send via P/M if it is too comlex for the M/B.

We're down and hurting so ANY reply ASAP is appreciated....

Thanx

Dennis
aka "NC Cams"

[wms]

Dennis,

Try these guys: http://www.hqtinc.com/index.asp

They will have a replacement clock spring..

You don't need to remove the shaft..If I remember right..been a day or two..you put the spring in the cup and then place the end of the spring into the slot in the pinion shaft..then wind the cup back wards a couple of times..then install the screws..might have to try it several time to get the right amount of pre load on the spring..

Anyway if you call High Quality they can tell you exactly..nice people..

[One of Many]

Life was moving along sort of nicely when all of a sudden SPROING, the "clock return spring" (P/N 11192020) for the quill on my 2J head on my EXTRAK mill broke and the quill dropped.

Got the spring out and the housing et al appart OKl.

However, to reload the spring thingie and wind it back up, it seems we need to remove the "Quill Pinion shaft" (P/N 28007063). It won't slide out and seems to be held up internally by something deep and complicated-like sounding inside the head. AARGH.

Several questions:

Question 1: are the manual mill springs the same as EXTRAK (Spring P/N for "trak is 11192020) Number is from parts manual supplied with machine.

Question 2: how do you replace the spring and rewind it (IE: number of turns, special tricks,etc)???

Would appreciate excruciating details. Send via P/M if it is too comlex for the M/B.

We're down and hurting so ANY reply ASAP is appreciated....

Thanx

Dennis
aka "NC Cams"

More than likely the springs are the same. Same head at least. This is a counterbalance spring and should not be set as a return spring as in a drill press. They break if set to tight at the extreme quill extention....like you have found?

First, I have made a simple spanner to wind it. Some of these spring cups have 4 screw holes and some only 2. Just put a 3/16 pin in the face of a 1/4" x 1" x 6-8" length of aluminum bar. About a 1/4" from the end and edge. Use the shaft to ride the spanner on during the wind with the pin in one of the cup holes. Keep the spanner pin short enough only to catch the cup and not fall into the screw holes on the head itself.

I have repaired the spring ends to look like the original. Basically a key hole that catches the head on the quill shaft or the inside of the cup. It will get you by until a replacement is available. Just reload the spring in the cup and verify the outer end that connects to the cup is coupled correctly.

Now, the trick is to get the catch head on the quill shaft in the key hole. The cup is not so bad although some were just bent into a slot. Regardless, reform it to work as original. Always turn in the correct rotation or it may disconnect the cup end of the spring.

When re-installing, rotate the cup with the spring inside in the wind up direction until the shaft end key hole lines up with the catch head on the quill shaft. It may take a slim screwdriver to manipulate it to engage. Once it has engaged. Using the spanner, only wind it enough to keep the quill from drifting down, then maybe add a 1/2 turn. Don't let go of the spring yet! Line up the hole that is open to the closest screw hole in the head casting. Replace the screws to hold it and return the quill handle parts.

It's not too tough, it just gets frustrating if the angle of the dangle on the spring end pops off during the wind, you let go of the cup or you find the spring is too short and slips out of the cup slot from over tightening.

If anything else, you will know how to do it the next time it happens.

DC

[NC Cams]

OEM manual shows same part number for manual head vs "TRAK's. However, aftermarket has "early" and "late" versions.

Early is same for manual and 'TRAK but "late" is supposedly heavier (price and load) for "TRAK and other "power quill" applications.

Ours is 2 hole, may add 2 more to prevent overtightening the spring.

Never thought of repunching the hole in remaining spring to get by with. How would you do it??? Spring steel is pretty hard and annealing it isn't something I'd feel comfortable doing

(DUH... it is only to get by with but that could be for years if the fix works well enough...).

Thanx for the advice.

[One of Many]

You can drill through it with a cobalt, carbide drill or end mill. I just drilled the large hole and milled the slot to suit. It is not all that hard. Fatigue is its worst enemy, but it does still have some ductility.

If you had to anneal it, use a propane torch and get it to the blue stage in the area of interest. I've had to do that on the cup end to reform it a few times. Less chances of it cracking while cold working it into submission.

You may need to reform the end of the spring anyway. The end should wrap around the shaft snug and match the shaft radius as it goes around to the key hole or a little past it. This will prevent a void as the second wrap holds it to the shaft. A void at the catch head/first wrap can allow the spring key hole to slip off of the head and Boing goes the spring again! Dho!

DC

[NC Cams]

OofM = can't seem to get the ID of spring out to do ANYTHING with it. Wrapped WAY too tight. Sadly, is was the ID that broke, not OD. Had it been OD, it would have been a piece of cake.

New one is only $35 at Production Tool and is in stock - contains spring and housing. Life is too short to spend time doing some things. Mostly do not feel like sproinging my fingers.

Sproinging, for the newbies, is a highly technical term for bodily harm that preceeds the infamous "you piece of $#%!!" expletive after the spring snaps loose and darn near kills you. Feeling comes back in a day or so....or after the bleeding stops....

[machintek]

I have only once returned a spring into its case and that was at a school to save them some money. NEVER AGAIN!
Buy a replacement counterbalance spring assembly. Per the book, the preload with the quill up is one and a half turns.
I find it easier to remove the quill downfeed can (clutch) on the left side of the head, remove the little snap ring and slide the quill pinion shaft out the right side of the head.
Install the spring on the shaft spring pin and slide it all back in. Put the snap ring back on and install the can, preload the spring (I use a pin punch to wind it up and hold it in one of the holes while putting a screw in the other hole).
This also gives you a chance to grease the shaft and gear.

George

[NC Cams]

Thought about the downfeed clutch deal but came to conclusion that messing here is something I'm not in a mood to do. MOREOVER, this is also an early model EZTRAK with the servo drive mounted to the outrigger arm mounted to the snout of the quill.

IT has to be removed FIRST to do the clutch deal. AARGH.

Will try to install and wind up the spring FIRST (until I get horribly P/O'd) - do not want to mess with R&R'ing the Z servo until/unless I have to.

EDIT: located a spring/housing at Production Tool. Will take machinetek's advice re: replacing the whole deal instead of screwing with spring - life and my patience are too short.....

Thanks all for the advice. The gang came through again and in the nick of time... Indebted to you all....

[One of Many]

I am surprised with the older quill drive that it even needs a counter balance spring. Could be that one is a bit heavier than the stock head due to the drive?

Oh, well. You can't beat $35. The only reason I repaired the ones I did was for returning to production when no spares were in stock. Down time was worth more than my little bit of labor to get it back on line. As long as one does not make a habit out of cobbling. It can come back to bite you down the road. Pretty soon you're cobbling your old cobbles!

As always, George's advise takes the professional route.

DC