Disaster and Recovery

[John Hart]

Boy did I have a bad night last night.

I was turning a large off balance chunk of cherry...maybe about 700-800 rpm. I lost my focus for just a nanosecond and BLAM!...got a catch of all catches. My toolrest was up close so I had the advantage on leverage...so the lathe lost the battle.:( The spindle wouldn't turn...even by force. It had bent slightly, but there was something internal wrong.

Now this thing is a direct drive, PWM driven lathe, meaning there's a DC motor driving a drive gear mechanism..that, in turn, drives the spindle gearing mechanism. My worst thought were that the gears were shattered or a shaft was destroyed.

First off...with all the financial burden we've had over the past year...a new lathe is out of the question. In fact, buying repair parts is pretty much out of reach for a few months. So I went to the sears website and downloaded the exploded diagram and the parts list, and started to learn what I was up against.

First thing this morning, I went out and took the drive system out of the headstock.
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Then did an inspection of the spindle and bearing. This showed about a 50 thousandths runout on the spindle...but still, the big problem was inside.
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So I got out my diagram and tore it apart
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I was pretty relieved to find that once the gear/spindle box was removed, the motor shaft rotated freely. Also, there were no visible broken gear parts in the gearbox. Plus, once disconnected from the motor, the spindle would rotate...but very rough.
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Continued on next page....

[John Hart]

I removed the drive gear and shaft and saw the problem. The thrust washer at the bottom of the bore had shattered and I later found out that the broken pieces had wedged themselves into the driven gear of the spindle.
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Well, I removed all the grease...cleaned the whole thing out with brake cleaner, and found a suitable washer that fit the bore like a glove. Then put in some super-deluxe mollydewhatchamacallit grease and rebuilt the dang thing.

Once back on the lathe, I fired her up and it sounded good....but the spindle still had that 50 thousandths runout. I chucked up a vase I was working on, to see if I could live with the runout. The verdict? Not a chance.

So....the dilemma remained. Sears no longer supplies replacement spindles for this lathe...and I can't buy a new machine...and I can't use this one as is.
No choice. I got the biggest hammer I could find....a 3 pound Craftsman Mini Sledge. Mounted up an old 4 jaw chuck....rotated the spindle to find the high spot.....reared back and gave it a baseball swing...WHAM! (I wasn't swinging for the fences....but I was certainly trying to drive a liner between 3rd and Short).
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So, with a deep breath, I checked the damage. It ran true. Still a little runout, but definitely less than 5 thousandths....maybe 1 or 2.

I can live with that.

In fact... I turned a little walnut vase just to celebrate.:)

[David Fried]

Disaster and Recovery, nanosecond... hmmm, wonder what you do for a living?;)

Nice save. Good to know I'm not the only hammer mechanic around here.

Root Cause Analysis? Catches are evil too. :D

[Bill Stevener]

Bend to fit, Smash to form. I knew ya had it in ya John.
Hope it holds up well for ya.

[Tim A. Mitchell]

Good work John. Your a brave man with that hammer. Good thing you didnt have a 4#, you might have been going back and forth trying to find the right "tap":rolleyes:. Guess sometimes you have to try the brute force method.

[Bernie Weishapl]

Wow John that was quite the ordeal. Glad you found the washer and got the spindle straightened out. Glad things worked out for ya. I could see months of withdrawal on the horizon.:eek::mad:

[Art Mulder]

To quote an old colleague... "Don't force it! Use a bigger hammer!"


Fortunate ending, John, I was on pins and needles for you.

[Christopher K. Hartley]

John, you remind me of my Dad...that's a good thing and a compliment. It does not mean however that there is any age comparison. Congrats!!:)

[Alex Elias]

nice save there.

[Jim Becker]

So you're saying that the "bigger hammer" theory is, in fact, valid, eh? (Glad you were able to recover from this...being with out a lathe might have forced to you get to know all the horses better...)

[Tom Sherman]

All Right John, alls well that ends well.

[Andy Hoyt]

Aw man - and I thought we had another opportunity for a you know what.

What became of the piece that got catchified?

[Steve Schlumpf]

Glad you are up and running John! Also glad the catch didn't result in any personal injury! Oh, in all my years of working electronics - a hammer was always known as a precision alignment tool!

[Rich Stewart]

One of Murphy's laws: If it jams, force it. If it breaks, it needed replacing anyway. Glad you got it going John. When I get them big catches, my wife can hear me yell all the way in the house. Did you soil yourself?

[Tom Sherman]

Aw man - and I thought we had another opportunity for a you know what.

What became of the piece that got catchified?


UH OH the MOA is getting that old feeling

[Curt Fuller]

Way to go John. If you would have checked the runout on that spindle when it was new out of the box it was probably more crooked than now. Craftsman might want those pics to add to their repair manual. Especially where you used a Craftsman hammer.

[Ken Fitzgerald]

John, you remind me of my Dad...that's a good thing and a compliment. It does not mean however that there is any age comparison. Congrats!!:)

To your advantage Chris......there's no genetic connection either!:D


Nice recovery John!

[Barry Stratton]

Smacked it with a big hammer, eh? Pure sweetness John!:D

[Earl Reid]

Nice recovery John. As they say, theres more than one way to skin a cat.
Earl

[Jim Underwood]

Wow. I'm impressed. From .050" to .002" runout in one whack is a pretty precision hammer "adjustment".

I used to repair cars for a living, and it's not very impressive if you tell the customer that you whacked it with a hammer!

"Adjustment" is the word you use to get paid....:D

[Randy Privett]

Where's there a will, there's a way. Good save, in more ways then one.:D

Randy

[John Hart]

Thanks everyone. I am a little concerned about the washer that I used for the repair...in that it is not the kind of material that should be used for thrust. I'll probably check at the hardware store for something a little more lubricating like brass or something.

But for now...It's doin' ok. I went out to the shop this morning to take a picture of the evil catch.

You can see the catch in the first pic....and the second one shows that the catch also shattered the blank. So....to the woodstove for this bad boy.:D
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And here's a couple of pics of the celebratory walnut vase that's on the lathe now. About 5 minutes after taking this picture, I got out the hollowmaster to make some final smoothing cuts on the inside..and she got away from me. The swan neck of the tool whipped itself around and tore the mouth off the vase. But...no biggie....I parted off the damage and epoxied a really nice cherry burl to it. Should make an attractive glue-up vase.
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[Harvey M. Taylor]

Some of you older ones will remember a few yeas ago in the space program. The astronaughts couldnt get something to work, with all the multiplied millions of dollars involved, someone suggested hitting it. They did, it did and then it worked . Good save. Max

[Tom Hamilton]

Nice save John! My turning instructor calls that at "Percussion Adjustment!"

Happy Thanksgiving, Tom

[robert hainstock]

way to go John. for my twenty years in the navy I frequently heard "Get a bigger hammer!" It was always good ad:rolleyes:vice?

[Brian Weick]

Glad to see you have it up and running, I have a suggestion for you. I had my whole headstock ungraded on my lathe by a machinist and they milled my spindle shaft for me to accept new bearings. If you know of a machinist in your area, you can have them make you a new spindle to match exactly as the OEM that the lathe came with. It's worth looking into if you want to keep the lathe.
Brian

[Bill Wyko]

John, that's great you are able to getterdone. What ever chuck you have must have one heckofa grip. I thought we were gonna have to take up a collection to get you a new lathe. ;)We can't have you leaving again for an extended vacation. Let us know the dimentions of the washer and we can see what we can find. If you can't find what you need, I have access to a machine shop, no charge.:)

[Mike Golka]

John, great save!! As for that "percision hammer adjustment".... I'd go out and buy me a loto ticket before the luck runs out.

[Jim Silva]

Good job on the fix!

Around here we call it "Percussive Maintenance":rolleyes:

[Barry Elder]

So, I guess that sets you up for a "Happy Thanksgiving"! Glad you got everything rolling again, John!

[Paul Engle]

All right John, you discovered how outside machinsts fix the nations war ships. Ya just get a bigger hammer .... actually that'd be pretty close sometimes, when shafting is outa wack , ya just wack it back....:eek:.I hear by make ya an honorairy Machinist ( Marine) ( as past pres of LL1785 Long Beach Navy Yard CA. International Association of Machinists and Aerospace Workers , I think I could do that .... sorta , maybe ...;)) 'course bigger shafting calls for bigger hammer... say 20 lb 'er.

[Ben Gastfriend]

Whew! Good job! Where's the pic of the vase?:D

[Brian McInturff]

Never doubted you fix that dang thing. Some of the things I've heard you do this was a piece of cake. Glad it worked out and you were able to get something turned to verify the fix!!
Brian

[John Hart]

Whew! Good job! Where's the pic of the vase?:D

Why...it's right here..
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Just got back from dinner and the first couple of coats of laquer were dry enough to take some pics. I'm not thrilled with the finish...but it's not done yet. The picture just isn't picking up the figure in the wood very well. Think I have a lighting problem with the new booth setup. All in good time....

I always wanted to be an honorary member of something.....As ex-Navy m'self, I'd be proud to be called HW2 Hart (Hammer Whacker 2nd Class):rolleyes:

Thanks again yous guys....I'll check the dimensions of the washer and see if I can come up with something...Otherwise...I may just take you up on that offer Bill.

Hope everyone had a nice Thanksgiving. I sure did. And I gotta tell ya....You folks sure were a big part of it!! Thanks.:)

[Glenn Hodges]

A man after my own heart.

[TYLER WOOD]

HW2?? Shoooooot....going from 0.05 to 0.02, and making it more precise than when it came out of the box makes you 1st class in my book. Oh wait that's military so it's bass ackwards..... ok 2nd class for you then, I think...maybe.... ahhh heck I don't know. Congrats anyways on getting it back in alignment. Here's hoping/praying you get a big bonus/extra money for something bigger and more in precise alignment without hammer adjustments.:eek::D:cool:

Maybe santa will bring it. Oh wait it's John never mind, you gotta be good to get something from the fat man!!!!:D

[Julie Tanner]

Pretty amazing stuff>> :D

I have a deck that is outta wack, wanna stop over with yer hammer ??

[Mike Ramsey]

Nice save John, but why the hammer? Why not just use "Bertha" to whack it!