B'port Clone Spindle Depth Feed Trip Mechanism, Help

[Lowell K]

The machine is a manual Super Max B'port clone.

The spindle down feed works but I have a problem with the depth feed trip mechanism. It has started tripping before depth is reached and recently even before the cut has started. I have a users manual for the machine at the shop but apart from a parts list it is useless for figuring out how/what's wrong.

I spent some time fooling with it and found some things that might be clues.
The actuating lever doesn't seem a solid when in is engaged or crisp when I disengage it manually.
The 1/2-2o rod that controls the feed depth doesn't have as much up and down play as I remember. In fact it has very little vertical movement.

I fiddled with things, removed the large headed screw on the head that is above the afore mentioned depth control rod, behind it was a small rod that moves up when the spindle is up all the way and down by the action of gravity. It seemed to be stuck as it didn't drop by it's own weight. I put some penetrating oil in with it an it seemed to fix it but started acting up after while. I gave it another dose and decided to let it sit overnight.

Has anyone else encountered a similar problem?

Can anyone point me to an explanation of how the depth control mechanism works? Not how to set it but how it works.

Thanks

Lowell

 

[chevydyl]

There's a clutch that is set for down feed pressure, maybe yours is worn, get an actual Bridgeport manual, it tells how to adjust it, can download from www.kneemills.com

 

[JimDawson]

Normally this is caused by the pin not pushing the plunger down in the trip mechanism, This can be cause by crud in the system. If you remove the scale from the head, you can see how the system works. The plunger may be sticky and needing a bath and some oil. There may also be other sticky parts in the system.

It is also possible that the adjusting screw is out of adjustment. You can remove the hinge screw and the plunger and rocker should just fall out in your hand.



Part 121 is what pushes the plunger down, 123 is the bushing in the top of the plunger housing.


124 is the plunger.

 

[Lowell K]

I was just figuring that out. I think I had an adjusting screw problem. There was audible strain before the down feed released and the circlip snap ring had been moved from it's groove by the force of the down feed. I figured there was a down feed limit adjustment mechanism and I get it now.

Thanks

LwL