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Need help identifying a thread on a shaper

macgyver

Stainless
Joined
Aug 2, 2012
Location
Pittsburg, KS
I have a customer with an old SCM shaper that goofed and sent the spindle nut with another machine when it was sold. He is not a machine guy and I figured it would be an easy thing to figure out what he needed. He told me he called SCM and they couldn't tell him what he had and weren't any help. I have not called them myself, so just going off what he said.

I took my sae thread gauge over, should have dug out my metric as well, but didn't find it before I went to deliver parts. Anyway, the spindle is using 1.25" cutter heads and I measured with calipers it is 1.250-1.253" OD on the threads. The threads look to me to be normal 60 deg threads. None of the sae threads fit perfectly. A 13 tpi was very very close, but wasn't quite there. When I got back to the shop I found my metric gauge and I think the spindle is a 2.0 thread pitch. So, best guess is that it is a M32x2.0

My problem now is I am not 100% sure that is it and I am not finding any sources for any actual nuts in that size. So far I have only found a chart that shows the thread dimensions, none for sale.

So, could it be a M32x2.0, could it be a 1.25" x 2.0mm? Is the difference between the 1.250" OD and the 32mm (1.260") enough to think it is not a 32mm thread? I'd feel a little more confident about it if there was any nuts in that size.

Lastly, anyone know where to find a M32x2.0 nut?

Thanks,
Jason
 
Might be a regular 32mm thread with a wider land at the crest. Or not, as they would have made the nuts themselves and thus have no need to make the thread standard.

Have to measure it with thread wires to be sure.
 
^^^ What Richard said. I'll check mine and report back, IIRC the thread OD is slightly smaller than 1.25"
The factory item isn't a standard hex nut, simply two flats.
 
It won't be cheap but the nut should be available on partspronto.com. My T130 from the early 2000s uses the same nut for the 1.25" and the 30mm spindle. Knowing SCM, I wouldn't be surprised if it is a bastard thread. Dave
 
^^^ What Richard said. I'll check mine and report back, IIRC the thread OD is slightly smaller than 1.25"
The factory item isn't a standard hex nut, simply two flats.

It's a 1.25"- 7 thread on this machine, early '80s T120c.
From the parts manual, it looks like there were multiple sizes of spindles available with both nut retention and a quick release system and also interchangable spindle options. I'm not suprised the agent wasn't able to assist.
 
Slightly off topic: In my experience, none of the tech support people at SCM USA are familiar with machines made before 2000, as they were not with the company then. I have a 1999 SCM planer and after receiving wrong info from their tech support people three times in a row, I have learned to not call them for that sort of 'support' anymore.

And now they charge around $495/year for tech support, so they've definitely lost my interest.
 
So, could it be a M32x2.0, could it be a 1.25" x 2.0mm?

Jason, as others have noted, either one could be possible with some of the Euro machines.
They were working in metric, but had to accommodate 1.250" bore tooling worldwide, even more so in the US.

My guess would be 1.25" x 2mm.

But really, if no one chimes in with a similar spindle, the best approach would be thread wires like Richard mentioned or thread mic. OTOH the difference is large enough you can probably determine which one it is with the knife edge end of a vernier/dial/digital caliper. It's not copacetic for precise data, but it will probably quickly determine if the minor diameter is close enough to match 1.250", or if it is a bit thicker, and hence 32mm.

I don't know a good way to make a close but smooth fitting nut without a male plug, or better the actual spindle. Can he remove it for your inspection and gaging?

smt
 
Thanks guys, the manual they have said the spindle was 1.375", so not sure if that was meant to be the cutter portion of the spindle or the other end of it.

I have not messed with one of these before so I am not sure how to get the spindle out if it is a quick change spindle. I really didn't have much time to mess with it that day and the spindle wouldn't raise as high as I expected. I think it needs a little love and lube and of course more time. I'll see if he can get his guys to pull the spindle.

I don't have metric threading on any of my lathes and wasn't thinking it would have to go that far. I had hoped I could identify what it is and have him order one. The more I think about it, I am also leaning towards it being a SCM proprietary thread.

I didn't think to try and measure the minor diameter, that might help.
 
Yikes, maybe I opened a can of worms. They might not be able to pull the spindle without a nut.

This shaper is a Griggio, and I made the spindle, the collet chuck came with it.
However, I believe SCM & other Italian makes used similar systems on some/various shapers.

smt_shaperspindle11.jpg


(above photo) motice the collar/flange on the shank just above the MT5. A nut captures this and presses the MT5 down into the spindle socket. See photo below, with nut in place

smt_shaperspindle13.jpg


To pull the spindle, remove any tooling & unscrew the retaining nut with a hook spanner or proprietary wrench until it is somewhat *above* flush with the collar/seat at the base of the straight spindle section (where a cutterhead would seat). Then put a tool body/cutterhead back on, and sufficient spacers. Put the spindle nut on and screw it down against the spacers until the MT breaks free.

There would be no safe way to pull mine AFAICS, without a top spindle nut. There is not hole in the bottom of the quill and no slot for a key unless maybe the quill was removed and the spindle and pulleys partly disassembled.

There's also a chance that the spindle is not removable - there were various options with the Euro makes.

Hope it's easier than that, but the above are things to look out for.

Can't the "other guy" just ask for his nut back? Lot's simpler than what he is trying to put you through. :)

smt
 
That's not the way it was on my old SCM T-100, or my current Schneider shaper. They use a differentially threaded nut.

The nut threads onto both the arbor and the spindle, 2 different pitches, so just unscrewing the nut breaks the arbor free, and then removes it. There was an o-ring between the top of the nut and the shoulder of the arbor, but they can get "extruded" out and then the nut jams onto the arbor. It was necessary to position the nut just right on the arbor before inserting into the spindle to avoid that.

If you get the arbor out, you could just chase it to 13 tpi, whatever diam cleans up, and then make the nut to fit that. Seems like you wouldn't lose much steel. Actually, make 2 nuts so he can run in reverse.

Just found this, he changes arbors at the end of the video - SCMI Shaper Overview and Spindle Change - YouTube
 
I assumed you were talking about the nut for the top of the spindle to attach cutters. The double threaded nut that attaches the spindle to the quill is a whole different deal. Dave
 
He is.

But I suggested having the part in hand to make a nut.

Then we got into a discussion on whether and how to remove the spindle, so Jason can have it for reference.

smt

And Stephen added some photos of a non-SCM spindle on the off chance it might be the same as OP's spindle. Irrespective of whether the spindle is indeed removable, which we don't know.
SCM made fixed spindles in a number of sizes and styles, and likewise interchangable spindles in a range of sizes and styles using at least two systems of retention nut. None of the parts manuals I have access to give any info on the threads used.
As described, measure what is there because that's the gold standard.
 








 
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