Inside Doc's Machine Shop

[DocsMachine]

I, ladies and gentlemen, am an idiot. I know this doesn't exactly come as a surprise to many of you.

In this particular case, as has happened all too many times in the past, I got too focused on one "solution". Focused on trying to execute that one idea, I didn't bother thinking of other options.

My problem was I needed a way to hold my parting tool further out than my basic tool post could. I had an extension, that didn't work. I had a different tool holder entirely- that turned out to be slightly too short, and oriented the tool in the wrong direction. I hit upon making an extended tool block to fit my existing tool post, and as already recorded for posterity, was stopped by a lack of suitable tooling.

This morning, in the sober light of noon or so, I realized that yes, indeed, I was an idiot. There was a way I could do it right and do it fast.

So, I went to my metal supplier, and bought 5" of 1-1/2" (38mm) square steel stock.



After a quick deburr in the belt grinder, I clamped it end up in the vise, and gingerly cut a 1/2" square notch in the end.



That got lightly chamfered for both looks and to reduce blood leakage...



And then drilled and tapped for 5/16"-18:



The soon-to-be underside got a notch and a flat to make a "key"....



And then two carefully-measured and located bolt holes to mate up with the 'key' on the underside.



The bolts wound up just slightly long, so I threw a collet in the little Hardinge and shortened 'em up by about a sixteenth. (21 millifarthings.)



The whole thing bolts on, nice and solidly, like so:



Including the trip to the metal shop, the whole process took roughly three hours. (There was a lot of fiddling, fettling and fitting I didn't show. )

Anyway, I finished up programming the part, and took 'er for a spin:





You can see the "parted" piece falling towards the back, at the bottom center of the frame.

And, since I had the raw stock already cut and ready, I ran the first two pieces, for a total of 24 parts so far.



I'll be able to turn more over the rest of the week, which will put me- at least on this one task- three or four days ahead of where I'd be if I'd just waited for the cutter for the other block.

I'll still finish up the other block- it'll have its uses- but at least I can make a little quicker progress than I'd anticipated.

Doc.

[DocsMachine]

With all the stuff I have going on at the moment, it's time to wrap this little project up, if I can, and get it out of the way. Projects are fun, but there are times when it's better to have a working machine, than to be working on the machine.

In last week's exciting episode, our heroes had just made a new disc to act as the spindle lock. The next step was to bore the pin-receiving holes in it, for which the first step was to mark them. I gutted the locking-pin assembly, and used just the collar and a transfer punch, to lightly mark the OD of the disc.



I then set up the dividing head on the green mill, found the axis center, and located the punchmark as close as I could, with a point turned in a 1/4" steel rod.



The idea here is to try and keep some semblance of balance to the new disc- so I needed an easy way to make sure the two holes are exactly 180° from each other- within the limits of a budget-priced Japanese dividing head, anyway.

A simple set of the quill travel stop also assures that both are the same depth. I pilot drilled them, and then bored them smooth with a 3/8" endmill.



After that, the disc needed a keyway. I'd ordered and received the broach I needed, but I didn't have a guide bushing. So I found a likely-looking section of 3" round 'looneymum (or for you Brits, 'looneyminimum ) and turned it down 'til she fit through the disc.



Swapping back to the mill- which at this point desperately needs a cleaning- I located center and milled a groove of the proper width and depth to accept the broach.



Moving over to the hydraulic press, I carefully broached the keyway, trying to keep it 90° to the two pin holes.



Et Voilá! (Which, I have on good authority, roughly translates to "Hey, check this sh*t out!" )



One last-minute thing: Because the collar is in under a casting, a proper setup is to provide an easy way to remove it- in this case, since you can't get a gear puller in there, a pair of threaded holes lets you grab it with something like a steering-wheel puller.



Again, centered and evenly spaced, to try and maintain a decent balance.

This slips in like so, along with a new key (since the one I'd made before is now too short.)



The original pulley goes over that....



And finally the locknut and it's retainer.



But, we're not done yet!

The locking pin assembly needs to be reworked. It had a spring-loaded detent, that both held it up out of the way, and held it down in the 'locked' position. That meant it was possible to lock it... and then forget to UNlock it. This DC drive setup has a fair bit of low-speed torque, and it's entirely possible that doing so could damage something.

Point in fact, I suspect that's why the factory lock-disc was missing- either some operator kept forgetting it was on, or to keep such an occurrence from happening.

So I set about redesigning it a bit. I found a chunk of 3/8" round stock in my scrap bin, that turned out to be 304 stainless. Not ideal from a machining standpoint, but it was a nice, clean, accurate bar, so I went with it.

It got turned to length, grooved for the snap ring, and one end threaded for the original ball-knob.



I then found a suitable spring in my Suitable-Springs Stashes®, and assembled it like so:



And that assembly simply tightens into place just as the original did:



Where it, of course, works like a champ.

The spindle is now back up to 100%. We just need a motor. And the collet closer. And the turret still needs some fiddling, and...!

Doc.

[Cal440]

Nice work as always Doc,the finish line must be close, you can make it!

[DocsMachine]

NOW we're getting somewhere!

I rolled into the shop about two in the afternoon, having had some prior engagements on my schedule, but with the intention to finally get the motor back into place and wired.

I'd gotten the motor back from the shop last Friday, but was unable to clear enough time to do much with it. They did a great job, and while it was a tad more than I was hoping to spend, they gave it a full workover, including new bearings.

But before I could attend that, I needed to patch up the flexy conduit, and double-check the wires in there were okay.



Turns out the only real damage was to the outer plastic sleeve- which was old enough it cracked when bent too far. The inner steel armor held up nicely, and the wires were fine.

The ends are older, and likely obsolete, fittings, but I was able to extract the sealing ring from the bad end, bandsaw off the 3" or so of damage, and carefully resinstall everything.

But first, the motor!



New bearings, dipped and baked rotor, new field and armature wires, and they checked the comm and brushes. I didn't know paint was on the agenda, but I ain't complainin'.

I cleaned the junction box, and snipped a sort of "gasket" from some of the leftover tool-drawer liner...



And fixed it in place with fresh bolts and washers.



Bolted on the pivot/hanger...



And with remarkably little cursing, got it hung up, the belt installed, and the tension adjuster bolted in place.



Since the spindle pulley was now in it's final resting place, I was able to slide on the jackshaft pulley, and with the aid of a piece of string and a weight, align it to the spindle and lock it down.



This one's a taper-lock pulley, likely an aftermarket, as the few diagrams I've seen online- including the paper one glued inside the door- show a stepped pulley. Two sets of two pulleys, to give two different speed ranges- one normal and one slower, for more torque.

I had again used a buddy's heat-shrink printer thingy, and made a new set of ID tags for the new wires.



The shop had put their tags out at the end of the long wires- not unreasonably- but in my case, I wanted to snip about 4" off each one, so they'd fit better inside the junction box. Anyway, simple matter of double-checking, sliding, shrinking and snipping.

I similarly relabeled the wires in the conduit, slid that into place, and got it connected up at both ends.



With the wires wire-nutted in place and in proper order... it was time to test this puppy!



And it works like a champ! There's a touch of vibration, probably from the big iron step pulleys, but plenty smooth enough, and at this point, with just the motor and jackshaft, damn near silent. The motor-generator pair makes more noise.

Throw the two spindle belts on...



And take that for a spin:



Smooth, quiet.... A significant difference from the as-delivered sound level. The original setup didn't "howl", but as noted earlier, it made more noise than I thought it should.

All this was a nontrivial extra expense and expenditure of time, but it was worth every penny. I'm actually wondering now, if the motor-generator pair couldn't stand a set of bearings...

All the way up to top speed- in this range, about 1600 RPM- and still nearly no noise save for the M-G setup. I mean, it's not library-silent, but the fans on the VFDs on some of my other machines, make more noise than this spindle and drive.



And finally, the back covers can go back on, more or less for good at this point.



Over the course of the day, I snuck in a few other little fiddly bits as well. One item was the electrical enclosure had no latch- it used two bolts to hold the door shut. I'd imagine that's in part to keep operators from poking around in there, but in my case, I didn't like having to get a wrench when I wanted to fiddle with it.

So I found a hunk of 1" 'looneymum, gouged a curvy bit into it, drilled and tapped it...



Gave it a quick knurl with a handheld knurling tool...



Parted it off, faced and chamfered it...



And somehow ended up with two of them.



These simply go in place of the bolts, and let you open the enclosure, if necessary, by hand. There's a gasket on the door, to give some 'crush', so the knobs are unlikely to vibrate out.



I also bolted the back cover... er, back on, including adding a middle bolt at the top edge, as the cover tended to "oil can' a little, and rumble slightly under vibration. I had to use the large washer there, as there wasn't enough depth to the cabinet edge to put a screw through both.



I may wind up putting a screw or two at the bottom, too.

And finally- finally!- I remembered to cap the sump drain.



I'm still not sure if I'll ever use flood coolant or oil- this thing doesn't have enough splash guarding- but I figured if I ever do, it'd be just my luck I'd have forgotten I'd never capped it.... after I dumped two gallons of oil into it.

Stand by, we're nearin' the end!

Doc.

[superman]

but did you use the new lathe to make the screws for itself?