missing collet alignment pin on knee mill

S

slowmotion

Cast Iron

Joined

Mar 31, 2013

Location

Danville Virginia

• Jul 30, 2019

• #1

Friend scored a Clausing/Kondia knee mill with Prototrak MX3. The pin is gone, is this any issue considering that it has a power draw bar?

 

K

kenton

Stainless

Joined

Dec 15, 2015

Location

Illinois

• Jul 30, 2019

• #2

Others would say no, but having had tools spin in my hands when the drawbar catches and does not thread correctly. I would say order the pin and install it to keep blood off the mill table. On a manual drawbar I would just as soon leave it out.

 

K

Krutch

Stainless

Joined

Feb 11, 2010

Location

somewhere in Illinois

• Jul 30, 2019

• #3

Many people hate that pin, I don't. I have replaced bad pins on BPs and clones that I used while working for other shops. My own clones have those pins installed and I have no issue changing out collets and other tools. Once the pin gets mashed by careless operators it is usually removed by those same operators.
One helpful thing is to not have the pin installed too deep into the collet chamber. The pin is a half dog point set screw and uses a second short set screw behind it to lock it in place. The pin is there for a purpose, use it and replace it when it's damaged.
That's my 2 cents worth, use your own judgement and preference.

 

Last edited: Jul 30, 2019

S

slowmotion

Cast Iron

Joined

Mar 31, 2013

Location

Danville Virginia

• Jul 30, 2019

• #4

Thanks for the replies, I'll pass along the wisdom.

 

I

Illinoyance

Stainless

Joined

Aug 24, 2015

• Jul 30, 2019

• #5

When you are trying to hold up a heavy boring head or other heavy attachment while trying to line up the key you learn to despise the pin.

 

J

James H Clark

Stainless

Joined

May 11, 2011

Location

southern in.

• Jul 30, 2019

• #6

Slowmotion: I also agree the pin should be in the spindle, that way I am sure no tool has spun in the spindle. I will probably draw fire for this, but I have been at this work for 50 years and always keep pins in my own machines.

JH

 

S

slowmotion

Cast Iron

Joined

Mar 31, 2013

Location

Danville Virginia

• Jul 31, 2019

• #7

I agree that pins are probably good but having never replaced one, I'm guessing the spindle needs to come out for access to the pin on this mill.

 

K

kenton

Stainless

Joined

Dec 15, 2015

Location

Illinois

• Jul 31, 2019

• #8

Something like this, there are much more in depth videos on line.

YouTube

Just don't over tighten the set screw when you reassemble it or you will deform the quill and it will want to hang up.

 

N

Newman109

Diamond

Joined

Sep 4, 2006

Location

Sacramento County, California, USA California

• Jul 31, 2019

• #9

My Webb Mill needed a new pin when I got it. It was in there but was rounded off. I replaced it with a new 6mm dog bone set screw and a short 6mm backup screw.

I don't know how the one in the Clausing/Kondia is removed but on my mill you just unscrew the nose cap on the spindle and lower the spindle a bit to access the screw hole.

 

C

CarbideBob

Diamond

Joined

Jan 14, 2007

Location

Flushing/Flint, Michigan

• Jul 31, 2019

• #10

IMO not having a pin is OK and I prefer it.
If you have a power drawbar and do a tool change every 20-120 seconds all day long you might like not having a pin.
We used to remove the pin from brand new machines for this reason but not many people do this type work on a manual mill anymore.
Sometimes on lower priced collets the pin will throw off the runout at tool tip but this is a bad slot problem not a pin problem.
Spinning a collet in this style machine with a power drawbar is rare if things are clean. Even with a 6 inch milling cutter.

That said there is on very good reason for a pin as it forces orient. So if you have a touch probe adjusted to a orient to tight numbers you want to put it back in the same.
I grind a little mark on the spindle nose, a matching red sharpie mark on the probe holder and match them.
Gets you very tight but the probe is now matched only to a single machine.
Bob

 

S

slowmotion

Cast Iron

Joined

Mar 31, 2013

Location

Danville Virginia

• Aug 1, 2019

• #11

I'll investigate the pin replacement, now that it might be an easy job. Thanks for all the replies.

 

L

Leadfootin

Cast Iron

Joined

Feb 5, 2009

Location

London

• Aug 1, 2019

• #12

CarbideBob said:

That said there is on very good reason for a pin as it forces orient. So if you have a touch probe adjusted to a orient to tight numbers you want to put it back in the same.
I grind a little mark on the spindle nose, a matching red sharpie mark on the probe holder and match them.
Gets you very tight but the probe is now matched only to a single machine.
Bob

Click to expand...

Like you I marked my spindle. I put a little dab of paint on the spindle as a pin location reference. Makes things a bit easier.