Subject: Re: Q's about large shaper and heads on vertical mills

From: [email-masked] (Paul Amaranth)
Date: 11 Apr 1994 02:10:06 GMT

In article <[email-masked]> [email-masked] (Stuart Friedberg) writes:
>
>I have a couple of questions about machinery that's larger than I've
>played with.  Your knowledgeable advice would be appreciated.
>   I've also read references to M- and J-heads for Bridgeport machines.
>   Which is which?  Is there a more general classification for head types
>   on mills of this class?
>
>Stu Friedberg ([email-masked])

I think that an M head has no power feed on the quill.  

A J head has a stepped pulley drive  for 8 spindle speeds (80, 135,
210, 325, 660, 1115, 1725 and 2720 rpm) and 3 quill feed speeds (.0015,
.003, .006).  I get the impression that Bridgeport has been making J
heads since around 1930.  You can still buy a new one for around $3700.
A quote in one of my catalogs syas "The 'J' Head was the first head
produced by Bridgeport". Since it's remained virtually unchanged for 60
years you might say that the engineering was pretty good.  J heads
usually have 1 or 1.5 HP motors.   In fact, you can buy a brand new
Series I J head mill for around $9400.

A 2J head has the identical quill body, but with a continously variable
speed control on the motor for a speed range of 60 to 4200 RPM with a
2HP motor.

Actually, after working with electronics, where you're not sure you can
get a chip next year, it really blows me away to be able to get parts
off the shelf for my 60 year old mill.  

-- 
Paul Amaranth  Manager User Services - office: (313) 370 4541 (also voicemail)
(internet)     [email-masked]  |Best error message that wasn't
(bitnet)       amaranth@oakland               |supposed to show up: HODIE
(uucp)         ...!uunet!umich!vela!amaranth  |NATUS EST RADICI FRATER