Newbie- Bridgeport-I, quill question...

[winegar]

Hey guys, got my first BP up and running with my rotary phase converter... everything seems fine and smooth now... except for.... when i pull the quill handle it is perfectly smooth until about 1/3 of the way down... then it gets tighter and harder to pull as it goes down....

I have made sure to unlock the quill lock... I even removed the lock bolt and took the two wedge shaped locks completely out and still has exact same effect.... Any ideas???

also, while i have you here... Any tips on installing a One Shot system on an old BP that did not come with it???... I'm good on everything but the saddle!

Thanks guys!

[winegar]

Power feed works fine though... and feed stop works as well.... everything seems fine on here and no odd noise either..... just take a little too much effort to bring the quill down past 60% or so....

[machintek]

The spindle spline may be twisted. Remove the spindle and see if it still behaves the same.
About a 10 minute job.

George

[winegar]

George, I'm willing to give it a try... Can you give me any incite to how it is done???... I do not see that in the manual that I downloaded... Any tips or maybe a link to some instructions would be great!... Thanks a bunch!

Edit:... Found that you remove the cap cover on the bottom of the quill.... I done this last week to replace the collet locating pin/screw (it was doing this before that!)... but how does it come out... It does not look like it bolts into place... does it just pull out?... I almost hope not as it was murder getting that locating screw out/in with the spindle in place!!!...

[winegar]

Okay, I removed the cap & drawbar... knocked the spindle out the bottom.... it is all straight and I still have the same problem even with it out... I have also removed the clock spring and quill lock nuts/wedges and still the same problem.....

Is there something else I can take apart to check???

[winegar]

Looking closely at the quill, it does not seem to be damaged or dragging really... Should I or should I not remove the quill and check it... I'm uncertain of get that stuff back together correctly.....

[machintek]

You may not have a choice. You have already done most of the work.
The whole top of the head can come off leaving the quill housing. Just remove the three nuts.
Remove the quill stop nut rod. Ball lever up top and lever on the bottom and snap ring.
Remove the stop nut by removing the screw holding it to the quill.
Remove the quill skirt (2 screws on top of the quill. Remove the cradle that has the brass gear. It has a set screw holding it that is accessed by removing the feed per rev selector cover.
Now you can use a block of wood and move the quill up or down.

George

[winegar]

I will check that out further tomorrow... Thank you for the fast reply!.... I am familiar with everything you are talking about except for the quill skirt 2 bolts... where do I access them from?.... And the "cradle with brass gear" what and where is that?..... I had already removed the quill stop screw assembly to clean all that up.... so that will be easy to take back apart!....

should the quill come out the top or bottom?.... thanks again!

[machintek]

There are 2 flat head screws that hold the quill skirt to the top of the quill. this would prevent the quill from coming out the bottom.
The cradle that moves against the worm of the splined gear hub drives the quill down feed.
It would prevent the quill from coming out the quill housing in the up direction. It is in the top of the quill housing.

George

[winegar]

Well stripped the head all the way down to being able to remove the Quill..... I found that even with all parts clean and nothing look abnormal the quill is tight without reason that I can find!...

The front most part of it that has the bolt hole... the drag starts when that bolt hole is right in the middle of the window that is cutout for it to slide up and down through.... the drag occurs until the TOP of the quill is about 1" lower than the center of the window cutout..... I checked for more shiny/worn areas in the quill bore and on the quill itself... I found that it looks like the area with the teeth cut for the quill handle is shiny in the center of the teeth... and in the bore right below the quill feed sprocket toward the rear of the head.... So, it seems that is where my drag is coming from... Now what to do with what I found!!??...

I threw the bolt back in it from the front and reinserted the quill feed and handle... and worked it about 150 times up and down in the tight area... not really noticing it getting any better!... Looks like i'm just going to have to live with it!....

Any ideas guys?...

[machintek]

I have seen a lot in my career. Example: rocket scientists. Received a Bridgeport head to rebuild from the Marshall Space Flight Center in Huntsville. They had mounted it to a robotic arm. The quill would not move. I will explain.
The quill is held to the knuckle by 4 T nuts with stand off and nuts. On the two top ones, the nuts press on the quill housing at the front. The casting is thick here. But look at the two bottom ones. This is where the quill is machined for the stop nut etc and is thin. Here spacers are used so the nuts press on the casting at the back of the quill. What the MSFC did was HARD PRESS in bushings into the quill so they would not fall out but this egged out the quill housing and grabbed the quill TIGHT. Had to bore these out to release the forces and get the quill to move.
2nd possibility. The quill and housing are mismatched. There are numbers stamped on the top of the quill and on the quill housing. The clearance is .0004 inches in theory.
Who knows what this machine has been through in its lifetime.
Get some bluing used by machine builders and polish the high spots. It may not take a lot.
Try loosing the 4 bolts holding the quill housing and retighten to 40 Ft Lbs.

George

[winegar]

I checked the # stamped into the Quill and the top of the machined surface of the main casting... they are both stamped with #37... so they match...

Should I paint it with some bluing, make sure where it is a little too tight and use something like emory cloth to take a little off that area?... If so, what grit?... Or what do you guys think?.... I'm at a point where I have about 4-5 days until I really need to get this all back together... Thanks a bunch guys!