View Full Version : Adjustment screw on top of housing ?

08-26-2004, 08:35 PM
I'm not quite sure what the adjusting screw is for on top the pulley housing with the lock down nut, this screw is just in front of the motor. I am wondering if anyone knows until I get a operators manual.

08-26-2004, 08:45 PM
Is this on a concrete mixer? http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif

[This message has been edited by zl1byz (edited 08-26-2004).]

08-26-2004, 10:07 PM
Are you talking about a Bridgeport again?
If so, if it's the one that disappears from view when you lower the quill, then it's the top of the drawbar that pulls the collet up into the taper in the spindle to clamp onto an endmill. Sounds like that's what you're referring to. It's the only thing directly in front of my motor. Pardon me if I'm misunderstanding.

08-26-2004, 10:55 PM
I disassembled the top end and found it be an adjuster for the variable speed control, Fine tuner or to take up slack on the speed control.


THis is a bridgeport early variable speed head.

That was pretty funny about the cement mixer.

08-26-2004, 11:14 PM
Yeah, I would have guessed it to be a washing machine, since this is a homeshop board.
David from jax

08-26-2004, 11:48 PM
I'm glad you took the mixer comment the right way. When I posted it I hadn't connected this question to your other post so was wondering what you were on about.
I have a bridgeport with a 2J2 head, sounds like what you have. At first I thought Lynnl was on to it as I couldn't think of any other screw there, till I went and looked and yes I see what you are refering ro. Looking at an exploded parts veiw it seems to give some adjustment to the speed change plate but I have no specs on how it should be adjusted. It would apear to mainly affect the range of speed adjustment available, I wouldn't think being badly adjusted would prevent machine operation completely.
Just a thought there is a spindle brake on the left side. Is this operating properly?

Cheers, John.

Peter S
08-27-2004, 12:08 AM
Here is a site with some parts drawings


08-27-2004, 02:24 AM

If it is of any help, and assuming both of us have original screws. There is about 19mm or 3/4" of screw above the lock nut on my machine. I would hazard a guess that with speed setting at it's fastest (front pully open max) there should be a small amount or no clearance between the bearing housing and plate, but I haven't any reference to conferm this. I'm sure there is someone around with the correct information about the adjustment procedure. Worst case that the plate travel wont match the available pully (speed) adjustment. I can't see this preventing the machine from operating.

Just a comment on something that has caught out newbe's with these machines. That is make sure the motor speed selection matches the high low gear setting as the motor direction changes there for the spindle direction changes. Cutters don't work very well run backwards.

Cheers, John.

08-27-2004, 03:46 AM
I think that the screw was adjusted improperly and was stopping the machine but taking it apart gave me an opportunity to get aquanted with the machine, so much simpler then I had though and takes the mystery out to boot!