Newbie and the Thread Cutting OOPS

[Foozer]

While ago I snapped the lathe spindle, being a tad to aggressive with this little hobbly lathe (AA109)

Not being the first time I've bent or broke a part I set out to see if the lathe was big enough to make its own spindle. Just enough room, so down goes a hunk of 1144 to resemble a spindle shaft.

This thing is only .550 in dia and the 109 is awfull about tapers so much tapping on the tailstock was in order till the point was reached to which this last skim left me with a shaft that measured .550 along its length.

A little 600 grit paper polish and it fit just fine in the headstock. Now to cut the threads for the chuck itself. Brought to size the nose at 0.750", set the change gears for the 16tpi required and made a scratch cut to ensure clearance. So far so good,

Somewhere the mind went on vacation. Rather than feed the bit in a little, make the cut, stop machine, back out cutter, reverse machine (not enough room to use Thread Dial) I made a cut, stopped machine and just flipped the tumbler reverse. Well . . . just doesnt work that way to well

Glad I got a 3 foot hunk of that 1144.

Robert

 

[dsquire]

Robert

OUCH! ???

Not a lot more that can be said except your not the first to do something like that and you you won't be the last. I hope when you make the next one things go according to plan.

Cheers

Don

 

[ileed]

I HATE learning from mistakes. I would rather learn from a book or mentor. But, it seems doing is the manner in which it is done. Committing errors in this manner keep many industries in business, and suppliers working.

 

[Mo deller]

Ha, just done the same thing. Thought I could use the tumbler reverse instead of switching on and off.

I feel your pain Robert :big:

Peter

 

[kendo]

Hi Robert
we all make mistakes, and that's all part of the learning curve. A man
who has never made a mistake has not been born yet. But do feel
your pain fella. Hope all goes well next time. Good luck Rob
Ken

 

[Foozer]

kendo, Mo deller, ileed, dsquire

Thanks for the words, yes sir, errors happen and to salvage some of the work, plan is to just cut a 60 degree point on the spindle remains to use as the headstock center (centre) for cutting the new one.

Just another day in paridise , another piece for the
"Wall Hangings of Educational Endeavours"

Robert

 

[ieezitin]

Foozer.

I like your attitude, keep it up.

Try making two of the parts this time, as if it ever goes again you have a spare. Think about it your already set up for it. Good use of your time.



All the best Anthony.

 

[Foozer]

So rather than start from scratch making a new spindle figured a rework may do the deed.

Cut the hosed up threaded portion down to a shaft dia of 0.501. From another piece of the same 1144 about an inch plus or so long, bored and reamed a 0.499 (cause thats the size I had)

Used the press to push the repair piece onto the spindle shaft. Heated the repair piece with the old propane torch, but ya know that flame wont change the pieces colour but what the heck, some heat better than no heat.

Little pressure to place it but not bad. Seated and in place. One thing i havent used before are those already made carbide bits. So nice, they just chew the stock off. Once it was near size switched cutter to a HSS one to get the better finish, finer cuts..

Took my time and remembered the sequence this time. Machine cut the threads untill a nut would just begin to start and finished it off with a die to leave a clean and usable end.

Still have to turn the nose down to a point for a center. Get the chucks re-registered and perhaps can make more than parts to make parts.

Robert

 

[Blogwitch]

Very nice rescue Robert. A man after my own heart.

Blogs

 

[Deanofid]

Way to go, Robert!
I have a feeling that 1144 solid will be a bit more stout than the original that had that 0MT cut into the end. Not to mention, they put a 1/4" hole down the middle of a 1/2" shaft. Not much left to hold things together after that.

This should be better than what you had.

Dean

 

[Twmaster]

Sweet. I'm a kooky sort of fellow and for whatever reason like the old Craftsman Dunlap 109 lathe. Nice job fixing the old gal.

 

[Foozer]

Twmaster, Deanofid, Blogwitch, Thanks for the kind words.


She all better now, did the trim and fitting with the center point cut in place.

My favorite chuck in place and the tip of the center point is just behind the chucks face.

Know its not a big deal to most, but for this newbie the exercise kept me busy for 'round 5 hours. Got to practice cutting to specific size, threading and well, threading again. Plus it saved me the price of a new part, which having bent up 2 already at 95 bucks US each is something I was getting tired of.

Lesson learned. Keep track of what is doing when cutting threads. I was lucky in that the OOPS was fixable.

Robert

 

[Twmaster]

Good job. That Taig chuck fits on there nicely.

 

[Blogwitch]

Robert,

Know its not a big deal to most, but for this newbie the exercise kept me busy for 'round 5 hours. Got to practice cutting to specific size, threading and well, threading again.

That is a very noble way at looking at things, you will go a long way in this machining game. Thm:

Mine is that I will attempt to learn one at least one new thing each day. Most of it nowadays falls out of my ears in quick time, but some of it still sticks.

Also, if the end result is what you were aiming for, there were never any mistakes made. You were modifying as the job progressed.


Blogs

 

[lee9966]

Ooooh, I think I need to make a sign for my shop wall

"Also, if the end result is what you were aiming for, there were never any mistakes made. You were modifying as the job progressed."

That made my day. Well, that and figuring out how to fix modify this cylinder head.

 

[Twmaster]

Robert, A couple of questions if you'll indulge me.

1. Did you cut a slot for the key on the pulley/back gears?

2. How long of a hunk of 1144 did you use for your blank.

3. Could you share some photos of your Craftsman lathe?

4. What model number is your lathe?

Thanks.

 

[Foozer]

Robert, A couple of questions if you'll indulge me.

1. Did you cut a slot for the key on the pulley/back gears?

2. How long of a hunk of 1144 did you use for your blank.

3. Could you share some photos of your Craftsman lathe?

4. What model number is your lathe?

Thanks.

No keyway cut on this spindle. Cut a flat near center of spindle 'bout as deep as the one on the aft end for the spindle gear set screw. Backgear pulley assembly has that oil hole down the center pully already tapped for a 1/4 set screw. Just slipped a piece of 3/16 brass rod bout half inch long down the hole and snugged up with the set screw. Haven't used the back gears since the DC motor change over. Now that lathe is back in order I can cut keyway on the soon to be made backup spindle.

Hunk of 1144 was 10 inch or so, Wanted plenty of extra each end for the mounting tween centers.

Photos? Here's some from the motor changover
http://www.homemodelenginemachinist.com/index.php?topic=4210.msg43722#msg43722

Model number, its a 109 20630


Robert

 

[Twmaster]

Robert,

Thank you for the info. That's a nice old 20630 you have there. Of course with that DC drive you don't need that awfully noisy backgear setup.

Nice job!