Does an R8 knee mill need the set screw register inside the spindle?

[erikmannie]

For some reason that I have forgotten, I purposely removed this set screw on my R8 collet PM-25MV a few years ago. I have never missed it.

I just bought a *new* Bridgeport clone knee mill. I could feel this set screw with my finger, as you would before you insert an R8 collet (with no power to the machine) in order to know where to index the slot on the collet. If there is power to the machine, I will put in the R8 collet and rotate the collet until I find the set screw.

Anyway, *I don’t see that this set screw is there anymore* on the new machine. Maybe it got sheared off, or maybe it rotated itself back.

I see in the manual that one can get in there and position this set screw exactly how far out they want it.

I am asking here if I even need it. I have been using the milling machine just fine without it.

Don’t a lot of people purposely remove this indexing set screw?

 

[erikmannie]

Only now did I see (and read!) this thread:

R8 Collet Alignment Screw

Just a comment here...As you may recall I just got a Bridgeport and SBL. I'm going through the process of cleaning, sorting, repairing...and more cleaning, you get the idea. So the collet, you could just throw up in the spindle...no collet alignment screw. Stick in your finger and feel the...

www.hobby-machinist.com

I didn’t want to bias any responses that I may get in this thread so I held back the memory of mine from machine shop classes where the (old school!) instructors said that most people remove these set screws because they are a PITA. What is more, it can be easily argued that they are unnecessary.

So does everybody agree that I am good to work without it? I will use the knee mill a lot, and I run my equipment pretty hard.

 

[ErichKeane]

I've been running mine without, it makes inserting a collet WAY easier IMO. At one point I considered a power drawbar, and being able to start the thread from the collet side sounded like a good idea.

 

[erikmannie]

I've been running mine without, it makes inserting a collet WAY easier IMO. At one point I considered a power drawbar, and being able to start the thread from the collet side sounded like a good idea.

What a relief! As far as I’m concerned, this matter is settled.

 

[alloy]

I've got a power draw bar and it's great without the set screw. I've never even missed having the screw and never spun a collet.

 

[BGHansen]

You telling me there's supposed to be a set screw in there? I don't have one in my Jet JVM-830 or Bridgeport. Granted, I'm pretty conservative on my feeds and such. I've never spun an end mill or had tool pull out. But again, I'm really easy on my machines.

Bruce

 

[wachuko]

Wait a minute! I installed a new one when I did the install of the power draw bar.

You mean I could have skipped disassembly of the bottom of the quill to replace that pin!??

I even bought a spare one... 25.90 for both pins.... oh well...

 

[mmcmdl]

I have one to pull out today . It serves absolutely no purpose and can do some real damage . Take the pin out and never look back !

 

[Batmanacw]

I have one to pull out today . It serves absolutely no purpose and can do some real damage . Take the pin out and never look back !

I'm failing to see the damage it can cause but I won't argue its necessary.

 

[Parlo]

I preferred to use the pin, it saved me holding collets across the corners with my fingertips to start the drawbar. I could just pop the collet home and tighten. I've never spun a collet in an R8 spindle - the tool has always slipped first.