Pm935 R8 Socket - Setscrew As A Key

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Alan H.

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I have seen within some posts the issue that folks couldn't get their collets into the quill shaft socket because there is a set screw in the socket that is maladjusted on some new machines just out of the crate. I searched the site to try to find a reference to that today without success. So I thought I would start a new thread with that as the subject in order that some other person doesnt waste time trying to find it.

Here is a photo of the collar. (BTW, the head of the mill is rotated down for moving.) Notice the collar has a setscrew locking it into place.

collar.jpg


Remove the setscrew and use a spanner to remove the collar. NOTE: It is left hand threads!

spanner on collar.jpg

Once you get the collar off, you can then adjust the R8 setscrew within the depth parameters for your collets or other R8 spindles as needed.
 
That info will save someone a bit of time, Thanks for posting!
 
I have heard/read more complaints about that dog point screw in the last few years than ever. I guess that's another victim of a lack of a thorough inspection. I can give you trouble, which is why so many people simply remove it. There are potential bad consequences to doing so, and I would be more hesitant with a new, budget small mill than I would an older brand name BP, but that shouldn't be the case. It's a shame but true.
 
I had ONE collet, the one attached to my face mill, that wouldn't go in so I had to adjust mine. Just a personal preference, but I won't remove it entirely.
 
Regarding the pros/cons of the R-8 guide pin, it can be an issue and the bigger question is whether it should be removed. There are some variations on R-8 arbors/collets, I had some issues with the guide screw on my original benchtop mill, and it was because the alignment pin was set too deep. I did not have any problems after that point, but it was a manual drawbar system. Now my new knee mill is another tale, I use a Maxi Torque rite drawbar system. Seemed to work just fine with collets, but I had an issue with some arbors not torquing all the way up and trying to turn. When I pulled the arbor out the guide pin had dug into the arbor. Had I not pulled the guide pin out it would have eventually shared and made a mess. The problem was with the draw bar and the design of the arbor (which had worked just fine on my benchtop mill), the threading in the arbor was not deep enough for the drawbar threads and would lock into the arbor and try to turn it. A number of my other arbors, I needed to manually clean the arbor threads with a tap, and I oil the threads when I put it into the machine. The guide pin is removed, I have had no subsequent issues. I tossed one of the arbors that was not threaded deep enough. I check the depth of the threads on any new arbors.

Suggestion is that if you are going to manually use your drawbar, the guide pin seems to be very helpful. If you are using a power drawbar it could be more of a liability and there is less /no need for a guide pin in this type of system. Worthwhile reading this old post on the subject: http://www.hobby-machinist.com/threads/anyone-else-ever-removed-their-r8-drive-pin.19448/
 
Thanks for the link Mark.

Now that I have figured out how to adjust it, I will leave mine in for the time being. It is less than a five minute job to get to the adjustment if need be. Big issue for me was to understand the collar is a "lefty".
 
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