Post By averycustom
Post By abarnsley
Post By JRIowa
Difference Between Bridgeport Series 1 J Head and Series 1 2J Head Machines
After a fair amount of searching I've been unable to ascertain the difference between a series 1 J head and series 1 2J head machine; any insight would be much appreciated.
The 1J has step pulleys
the 2J is variable speed.
I was caught on this long ago.. Lathes.co.uk is not exactly right about this...
A Series 1 2J IS a 2 hp Vari speed head, says Series I right on label of head.
A Step pulley J head Mill has a Step pulley Model J head... This is right from old catalogs... NO SERIES marking. NO 1J. Just Model J milling head. There was the Standard 1hp J head and the 1.5 hp high speed J head (went to 5440 rpm) Some catalogs have a generic Series I name for machines, but actual part numbers clearly show just J head or 2J head mills. The column is identical on the more modern machines...
Series II machines (4J head) are 4 hp and a lot heavier... (Except the for seldom seen Series II Special, which had a Vari speed 2hp 2J Head installed on the larger Series II column)
Of course nothing to stop someone from putting a 2J Vari speed housing on Step pulley Quill housing ... This would create an older mill (pre series 1) with a 2J Series 1 head.
A 2J is the variable speed head. The current model is 2J2 (2hp) the early versions were 2J1 1/2 (1.5 hp motors). Not all 2J heads are marked "Series 1". That moniker didn't come out until the Series II was released in 1971, which had a 4J head on it unless you had a Series II special which had a 2J head.
Originally Posted by abarnsley
There really is no "1J" its just a "J" head. One letter like the M, C, R, and T heads.
Abarnsley is correct about Tony's site. A J head was never a Series I.