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Mike Amick
12-12-2014, 02:26 PM
Didn't want to steal the Jig Borer thread.

But I do want to say that before that thread, I had only heard the name
Jig Borer and really didn't understand what it was. Now knowing that it
is a beefie machine with a rigid head that is dead on with a solid table that
has no backlash. Well .. threads like that are why I come here. I get it now.

Anyways it got me thinking ... why don't mill makers (or even mill modders )
index the head .. kindof like a turret lathe. I can't count the number of threads
devoted to tramming your head. Just think if it could just click into position,
how cool would that be.

And the pro's that are going to tell me they can do it "blah quick" can talk to
the hand. I am just talking about a convenience that the rest of us non pro's
would love.

The indexing system could be adjustable to compensate for wear etc.

Just thinkin .. .

Mike A

MotorradMike
12-12-2014, 03:04 PM
The indexing system could be adjustable to compensate for wear etc.

Mike A

Wouldn't this part be like tramming?

Mike Amick
12-12-2014, 05:11 PM
I'm just talking about an indexing feature that .. you could disengage and move the head
to a 45 or whatever angle and it would "click" in. When done you move it to normal and
it would "click" in.

You would/could occasionally tram the indexing system .. but .. baring any little crashes, you
could trust it to be accurate. It would only be as good as the indexer .. but .. there are lots
of things in the machinist world that are indexed. The turret lathe tailstock as an example.

Besides .. you could make the darn thing "NOT" adjustable. I'll be honest, I never used a
turret tail stock, can you fine tune those ?

MIke A

mattthemuppet
12-12-2014, 05:44 PM
I think the issue is likely that any potential error in the indexing system, and there probably will be some in order to use it, is going to be magnified by the long lever/ distance between the knuckle and the cutting edge. Think of using a sprung indexing bolt that is captive in one half and can pop in or out of the other half. For that bolt to move in the captive half, there has to be clearance in the bore, and for it to pop into the other half, there has to be clearance in that bore too. So when you add (multiply?) those two clearances, a smidge of wiggle at the knuckle = a noticeable tilt at the end mill.

Just my guess at least.

Wayne Sippola
12-12-2014, 06:36 PM
I have a Beaver vertical mill that uses two taper pins to square up the head. One for nod and one for - well the other direction - clockwise / CCW tilt. The manual actually states it is for normal alignment - normal tramming methods may be required for higher precision.

Of course the taper pins for my mill are long lost...

oldtiffie
12-12-2014, 06:42 PM
Didn't want to steal the Jig Borer thread.

But I do want to say that before that thread, I had only heard the name
Jig Borer and really didn't understand what it was. Now knowing that it
is a beefie machine with a rigid head that is dead on with a solid table that
has no backlash. Well .. threads like that are why I come here. I get it now.

Anyways it got me thinking ... why don't mill makers (or even mill modders )
index the head .. kindof like a turret lathe. I can't count the number of threads
devoted to tramming your head. Just think if it could just click into position,
how cool would that be.

And the pro's that are going to tell me they can do it "blah quick" can talk to
the hand. I am just talking about a convenience that the rest of us non pro's
would love.

The indexing system could be adjustable to compensate for wear etc.

Just thinkin .. .

Mike A

Mike.

This may help you get a feel for what a jig borer is and what is for and what it can do:

https://www.google.com.au/search?q=jig+borer&biw=1920&bih=883&tbm=isch&tbo=u&source=univ&sa=X&ei=XXyLVI7FD6W7mQXYtoGIAg&sqi=2&ved=0CCMQsAQ

http://en.wikipedia.org/wiki/Jig_borer

https://www.google.com.au/?gws_rd=ssl#q=jig+borer

justanengineer
12-12-2014, 10:39 PM
One of the shops I worked in previously had an M-head on the opposite end of a J-head's ram where an E (shaping) head normally sits. You still needed to tram the J if you swiveled the turret to use the M, but it was already fairly close and contorting the M-head at crazy angles was easy-peezy compared to J's IMO due to the lighter weight.