R8 pin dropped

[Winegrower]

The pin is there for repeatability.

I don't think I have anything that needs that kind of repeatability. Please explain?

Edit: I removed my pin several years ago...everything works fine, maybe better since I don't have to fumble around searching for pin alignment.

 

[Christianstark]

I don't think I have anything that needs that kind of repeatability. Please explain?

Edit: I removed my pin several years ago...everything works fine, maybe better since I don't have to fumble around searching for pin alignment.

IMO the pin just helps in closing the collet.

 

[verbotenwhisky]

After fighting with some R8 tapers, I decided to remove the locating pin in my PM-833TV mill spindle.

Unfortunately, I goofed up and the pin dropped off inside the quill. Feel free to abuse me for being foolish enough to drop this piece. I've had it out before with no issues, but I obviously didn't exercise sufficient care. DOH!

A picture of the quill opening that provides access:
View attachment 496790
Two questions:

1) Any suggestions on how to extract it w/o taking everything apart? I thought about putting a small magnet down to grab it, but with all the spindle being steel, it seems unlikely to work.

2) Is there any risk to using the mill with the very small set screw loose in there.

The small magnet will work, if you do not have a magnet on a stick use a stiff wire, it will stick to the quill but the loose piece will come out.

 

[verbotenwhisky]

I don't think I have anything that needs that kind of repeatability. Please explain?

Edit: I removed my pin several years ago...everything works fine, maybe better since I don't have to fumble around searching for pin alignment.

I agree with Dabbler, I have a bag full of those in case I need to replace it, only happened once though.

 

[Dabbler]

I don't think I have anything that needs that kind of repeatability. Please explain?

sure!

When using slitting saws, some of the runout is in the collet engagement. If you have Hardinge R8 collets,it is hard to measure the runout. But with many lesser quality collets it can pay to be consistent.

When doing precise slots, having runout in your end mill can lead to vee walls, and the cut diameter being noticeably bigger than the end mill diameter, say .002 in some cases. It all adds up.

-- but I was referring to the original intent of the R8 system and the purported requirement for a pin.

I've never minded feeling for the pin when inserting the collet.

 

[rronald]

It turns out that the vacuum method does work. In fact, it worked so well that I continued to try and extract the pin that was already removed.

When I wrote my intermediate email about 4 hours ago, I'd sighted what I thought was the set screw and tried to suck it out. I must have been very lucky. But there was nothing in the hose and the phone that could use the bore-scope was out of juice.

I just went back out and looked for quite a while with the bore-scope. Couldn't find the set screw. So I pulled the top par off the vacuum pump and and gave it a shake. Perhaps the tiniest bit of rattle. So, I removed the pipe fitting for the inlet and shook it out. Behold!

So, for anyone in the future who finds themselves to be a similar knucklehead.....vacuum can definitely suck the pin out. However, you absolutely need a pin trap of some sort because the pin is too small to notice moving thru any tubing and liable to get past a course filter.

Thanks for all the suggestions.

And whew

 

[RJSakowski]

The pin on my RF30 clone is located below the slot in the quill so the only way to remove it would be to disassemble the spindle assembly. The pin on my Tormach PCNC770 is buried inside the spindle cartridge and Tormach expressly states that the cartridge should not be disassembled as it is balanced for high speed operation. However, I have lived with the pin in the RF30 clone for 40 years and the Tormach mill for 13 years with no problems regarding the pin. I did have two collets out of a set that I bought from Enco many years ago where the keyway in the collet wasn't deep enough but with a little effort, I was able to correct that.

At work, we had a Grizzly G0755 mill where the set screw pin advanced inward after a while preventing collets from seating. I removed the set screw and made a dog point socket head screw so the dog point had the correct clearance when the screw was fully seated.