Removing the tool in the milling machine

What spindle type is your mill -- R8 or MT? If it has an MT style taper it's important to not over-tighten the drawbar. If you do it can take a pretty good whack to loosen it. I know this from experience - we had a little Sherline desktop mill at work and one of my co-workers cranked the drawbar down really good when he installed a drill chuck. As a result it became very difficult to extract the chuck.
 
Thanks for your answers. I´ll try all this weekend and i´ll tell you kno the result.

The spindle is MT.
 
I have seen comments regarding lubricating oil w/regard to MT style tool holders, as something to avoid in order to keep the holder from spinning or losing its grip in the taper.

What's the consensus here? My mill has an R8 spindle so my question is more of an "inquiring minds want to know" thing.
 
mmmm I have tried and it seems that maybe I tight too much the tool. And the mill is very cheap, 1400$ so the quality it isn´t the best
 
homebrewed said:
I have seen comments regarding lubricating oil w/regard to MT style tool holders, as something to avoid in order to keep the holder from spinning or losing its grip in the taper.

What's the consensus here? My mill has an R8 spindle so my question is more of an "inquiring minds want to know" thing.
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AFAIK, there's a small peg-like feature in the mill spindle that engages the groove in the R8 collet and keeps it from spinning. On the other hand, I've seen a few posts on the forum where mill owners removed the peg. YMMV. I removed the peg in my mill spindle and haven't had any trouble. No opinion with regard to MT3 spindles.
 
hman said:
AFAIK, there's a small peg-like feature in the mill spindle that engages the groove in the R8 collet and keeps it from spinning. On the other hand, I've seen a few posts on the forum where mill owners removed the peg. YMMV. I removed the peg in my mill spindle and haven't had any trouble. No opinion with regard to MT3 spindles.
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There are some different situations that have a bearing on the issue. From what I've learned, MT style tapers are designed to be self-holding in some, but not all, situations. For instance, my tailstock quill has an MT2 taper. Tooling like drill chucks and dead/live centers are installed by smacking them into the taper. No drawbar needed. I have never had one spin under load. Many drill press chucks are installed the same way. They are fine when used to drill holes but if someone applies a lot of side-load (like trying to use the drill press as a mill), the alternating side load can work the chuck loose -- with subsequent "problematic" results.

On the other hand, I have a set of 5C collets designed to fit into the MT3 taper of my mini lathe. They come with a drawbar, which can be pulled in with enough force that it can be a tussle to get them to release. But they aren't going to be worked loose if you're using them to mill something installed on your cross slide.

I've seen reports of folks removing the stop in a mill's R8-style spindle without having a problem. From personal experience I know that R8 tapers can "grab" somewhat, but the grip isn't nearly as strong as that produced by an MT style taper. Simply because it always is pretty easy to release tool holders from my R8 spindle. I wouldn't use an R8 style toolholder without a drawbar, even if it did happen to stay in place; but it certainly is possible that an R8 taper with a drawbar would work OK without that stop....under most conditions. I don't know what conditions might be required to cause problems in that situation: but I tend to be on the conservative side when it comes to modifying things on my machines that _might_ cause problems, while leaving them in place only imposes a small penalty. If any. I really don't want any tool holders to spin in my mill's spindle, seems like cheap insurance to me......
 
The pin (radial set screw) in an R8 spindle is for a couple things: to stop the collet spinning before the taper engages, and to consistently locate the collet’s rotation. I removed mine, as many do, because I found it more annoying than helpful. It does not support torque of an installed collet. And I would never use an R8 without a draw bar; I believe the taper angle is not self locking.
 
Drawbar Wrench

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I have an old LC-30 (MT3 taper), and it requires a few good blows to come loose, perhaps I'm over torquing the drawbar?
 
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