Question for Atlas Horizontal Mill Owners

I am likely tightening the arbor nut too much. When removing the nut I could use a spanner wrench on the arbor driver to resist rotation but the spanner wrench I have is only about 4 inches long - not enough leverage.

My morse taper socket has always been problematic. If I don't tighten the draw bar snug it will slip, but if I do tighten the draw bar that much then it becomes difficult to remove - taking much more than a few taps with a lead mallet. I suppose I should get a MT2 reamer and try to dress the socket.
 
Bi11Hudson said:
The pins on an OEM arbor were put there as a "drive" clamp. They also serve to secure the arbor for tightening and loosening the clamping nut. A retrofit arbor may or may not have them included. An OEM arbor may have had them removed for some reason. As with lathes, engaging the back gears to lock the shaft is a bad idea. Broken teeth is a difficult repair on the MF-C. The nut should be loose enough to tighten by hand. The last little jerk with a wrench is just to make sure it stays where it was set. A key in the tooling does the driving. Same for loosening it, a wrench to break it loose then remove by hand.

From the above post while I was writing, it sounds like the nut is too tight. It should spin on by hand and the wrench just to make sure it stays. And the same for removing it.

.
Click to expand...

My arbor does not have pins - it has half-round sockets that engage with the pins on the arbor driver. This agrees with the Atlas OEM drawings. I made the arbor driver following an Atlas drawing.
 
It has been a while since I have swapped out the arbor for a tool holder. My memory isn't too pretty good either. The locations of the notches and the pins falls into that memory hole. Which ever one has which, the pins fit into the notches and hold things tight.

.
 
Thinking about this some more, I stumbled on an obvious solution - so obvious that now I feel stupid. The spanner wrench will lock into the base casting very nicely. works like a charm.
 

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JPMacG said:
Thanks Bill.

What prevents the arbor from rotating when you use your open end wrench to loosen the nut? If not the morse taper, then what?
Click to expand...
a spanner wrench on the front spindle collar will keep the arbor from turning when loosening the nut.
Dave
 
JPMacG said:
Thinking about this some more, I stumbled on an obvious solution - so obvious that now I feel stupid. The spanner wrench will lock into the base casting very nicely. works like a charm.
Click to expand...
in your picture, the hole in the spindle arbor driver is for the spanner wrench to be used in, not the pins. Dave
 
Sometimes asking a question will put things in a different light and you can see better what you're asking about. You're lucky that you thought of your solution before someone else did.

.
 
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The photo shows a spanner wrench engaging the rear hole in the arbor driver.
 
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