Mt2 Reamer

[ogberi]

Thanks to Tony, I have been able to move on with this project. Been out of town awhile, but I'm back now, and have some shop time.

I rotated the chuck by hand to cut the taper, using the reamers Tony sent me. They worked perfectly!

I have a really nice MT2 taper on the workpiece. I needed to make a lathe dog to turn it between centers. For that, I dug out an HSS tool, sharpened it up, and literally plowed it through the work. It was cutting, not screeching, right at the edge of chatter. Dark, dark, dark chips, and the reek of sulphur based cutting oil.

Who don't love the sight of a lathe workpiece smoking like crazy? Here's the lathe porn.



Just because.

Many, many, many thanks to Tony for loaning me the MT2 reamers. They worked perfectly. I reamed the taper by hand, taking my time. Once it fit well, I faced off the workpiece until it had the same stickout as the MT2 of the tailstock. Just eyeballed it. Then I flipped the workpiece, faced the end, and drilled it through. I then turned a cylinder so I could make a lathe dog to turn the workpiece between centers, an that's where I'm at now. Tomorrow I'll disassemble the Atlas spindle, and start turning the workpiece between centers to rough dimensions. I'll need to make a toolpost grinder to get it right where I want to be as far as dimensions go.

All in all, it's been a dang enjoyable day in the shop. Coffee, a good cigar, a touch of vodka (after everything was done), and plenty of smoke from the workpiece. That SB9A is working to earn it's keep.

More pics as the job progresses. Again, Thanks Tony! You've really helped this project along!

 

[ogberi]

Taking a step back (finally got the pictures off my phone), here's rough-reaming the MT2 socket in my piece of stock. Supported by the tailstock, wrench is resting on the compound, turning the chuck by hand.


The process was continued until I had a deep enough socket, then it was finished up with the finishing reamer. The result is a dang nice MT2 socket.


The pictures in the previous post were making a lathe dog so I could turn this between centers. I did a lot of checking, and ended up using an MT2 to MT1 adapter in the workpiece, as that centers very nicely on either the dead or live center. Turning the workpiece between centers helps ensure concentricity. I removed the spindle from the Atlas, so that I could get dimensions and have the original right in front of me. I'll need to re-assemble the MFC's spindle to cut the woodruff key seats, and drill some blind holes in the workpiece the same as the original.

One thing I want to change is to add some meat between the threaded nose and the shoulder the front bearings ride on. I want to either mill some flats, or slots so that I can use a spanner on the spindle nose to help tighten and loosen the drawbar. It may only add a quarter inch to the overall length of the spindle, but the convenience will be worth it.

Here's an action shot for everybody:


Using a tangential tool, about .030 DOC, happy RPM, happy feed rate. Sulfur based cutting oil reeks, gets into your skin and stinks, gets into your clothes and stinks, and it smokes pretty good too. But, it leaves a good finish, it's relatively inexpensive, and it cleans up pretty easily. As is always the case when turning between centers and using a lathe dog - *NEVER* get your hands close to the headstock. Short sleeves, no jewelry, no rings, safety glasses on, and keep the chips under control! Use pliers and a chip hook to keep the chips clear, because if one gets snagged by the lathe dog, you can end up with a big spinning ball of razor sharp metal. On my South Bend 9A, the drum switch is mounted on top of the headstock. I regularly shoved the chips down underneath the lathe and off onto the floor. Still, reducing a 1.25" shaft to .8749" produces quite a lot of chips.


After getting pretty close on the OD, I took a break and painted the chicken coop while the workpiece cooled. It was pretty dang toasty, and chasing zeroes on a hot workpiece is an exercise in frustration.

My wife will paint the sign for the coop this weekend, 'The Egg Plant' She said she wanted a purple chicken coop with green trim. And she got it.



Once I snuck up pretty close on the final OD, I switched to a vertical shear tool. Left the RPM the same, but changed to the finest feed rate, and let 'er rip. The finish doesn't look fantastic in the picture, but it really is smooth as silk. You can see the fine, wispy shavings produced by the shear tool. Nasty little buggers.


I forgot to mention - having so much material to remove, I took advantage of the process to dial in my tailstock. I'd cut, then mic the shaft, adjust the tailstock, and repeat until I got about half a thou taper on the part. I called the adjustment good enough at that point. The SB9A has two adjusting screws for the tailstock, which makes it cake to align it.

I also used a $3 magnet from Tractor Supply, ring magnet in a nice chrome housing and a center hole, a 3" 10x32 screw, a couple of nuts, and the vice (to bend the screw) to make a magnetic base dial indicator holder that I can slap right on the ways. Cheap, easy, and handy as heck! I'll get pics of it tomorrow.

That's the progress for today. Tomorrow I'll thread the small end of the spindle for the preload adjusting nut (may make another one), and turn down the next portion of the workpiece. It's a seriously enjoyable project. And with luck I'll end up with less runout than my existing MFC spindle....

 

[T Bredehoft]

She said she wanted a purple chicken coop with green trim. And she got it.

I am IN AWE of your wife's humor. Aubergine indeed!

 

[ogberi]

She can't remember where she saw that sign on a coop, but she liked the idea, and decided that adding color was a good idea. I can't complain, except that it'll be months before we get any fresh eggs from our chickens.

Got a bunch done today. Started around 8:30-ish AM.



Turning down the 1" diameter section that the front spindle bearing rides on, along with the bull gear. I've been using the heck out of the vertical shear tool, because it leaves a gorgeous finish that requires only a quick touch with 600 grit wet-dry, if that.

I threaded the end of the spindle 7/8 x 14 tpi to fit the spindle adjusting ring. Ground a threading tool from a 1/4" HSS blank, took maybe 10 minutes. While I don't recommend you cram the tool blank into the wheel like a maniac, HSS definitely cuts better if you grind it with some authority. Babying it only tends to overheat it. I grind it hard and fast, until my fingers get toasty, then give it a swish in the water cup. I've not had any trouble with chipping, the tool blank loosing it's temper, or anything like that. I've heard that dipping hot HSS into water can cause tiny fractures, but I've yet to see any failures that weren't a result of my own incompetence. (IE, forgetting about a drilled hole while turning a shaft aggressively, and chipping the tool. Not on this project, thankfully!)

After threading the spindle's end, I flipped it end for end, using a more traditional lathe dog. There's a scrap of aluminum pop can under the screw to prevent marring up that pretty finish. The right hand side of the spindle is supported by an MT2 to MT1 adapter in the workpiece, riding on a live center in the tailstock. I didn't notice any issues with runout when I measured prior to starting the next turning operations. The far left end of the spindle shown below is just for workholding, and will be turned off prior to installing the spindle.




I increased the thickness of the shoulder that the front bearing rides against, so that I could mill some flats in it for a wrench. It added maybe 3/8" extra to the length of the spindle sticking out from the headstock. Nothing major. After turning down the right hand side of the workpiece, I used the same HSS threading tool I ground earlier to cut the 1" x 10 TPI threads for the drive arbor. I snuck up on it, and the drive arbor fits great. Unlike the original, which looks to have been threaded with a threading head or a die, I let the threading tool cut a bit of a relief at the ends of the thread. The shoulder that the arbor locates on is still there, though, and works fine.

There's still the woodruff key seats to cut, plus a couple of blind holes to drill. But I have to re-assemble the mill with the old spindle in order to do this. And grind some old drill bits down to cut the seats.

But, here's the semi-finished product. The end is in sight. The new spindle looking smaller than the old one is due to my not-so-fantastic phone camera and it's horrible depth of field. The threads on the right end are in the same location as the lower spindle, even if it doesn't look like it.



More to come!

 

[4GSR]

I have a couple of new old stock Collis drill extensions that have more taper socket and outside diameters large enough to make replacement spindles out of for a tailstock or two. I have them saved to use when I rebuild the tailstock on my Sheldon lathe some day.
Just another thought on making a new spindle out of.

BTW- You did a nice fine job there on your spindle.