Problem- BP Series 1- Help removing the table after tip-over unloading!

[winegar]

If you want to skip my story and help me on my question... skip down to the red line...

Well guys.... I have a hell of a problem.... Bought my first Bridgeport yesterday... Found me a series 1 with Dro, vise, 12" rotary table and all for good deal and went to get her yesterday... Been planing to get it for over a week and made it a done deal before driving 6.5hrs round trip to pick it up....

Seller loaded my buddy's 3/4ton Cummings with a very big fork truck, truck only sagged 3" and it handled it perfectly on the way home... (2) 2" ratchet straps held it just fine and never moved an inch... completely uneventful!...

I had a friend from work come over with his truck, trailer & Bobcat w/forks to take it off the Dodge.... This is where the story changes!.... This dummy comes over drunk as hell, from tailgating the Michigan game all day... at this point... (you know where this is going right?)... He comes off the back of the trailer like a bat out of hell, up to the side of the Dodge, everything okay at this point.... slips the forks under the ram... I ratchet strap his forks together to keep them from spreading out... He lifts 3" and Dodge get the hell out of Dodge!... Lowers and continues on... He makes it all the up the gravel driveway, to the garage. Now, I was walking beside, using all my weight steady it as much as I could... when he gets to the garage, he just hits a lever just right and my new pretty BP starts taking a very slow fall, column upright & off the ground by1"... I gave it everything I had to keep it from tipping (i'm no little guy!)... unable to keep it from going... I probable slowed the fall some but at about 40deg...I had to let her go, or loose limb... falling of course on the concrete completely unforgiving of the load that of which has been thrown upon her...

At this point, I had a hard time deciding if i need to scrap out my drawers right now or if I should wait till this was all done... I strapped around the ram/turret and righted her... forks now at the bottom just pushing & scooting her 10ft or so into place (instead of letting him try again!)... Got it in place and stripping the shrink wrap from it, checking for damage which was inevitable.... My Dro box took some damage and it hit the ground and got slightly distorted... easy fix, and still works!.... However the (standing in front looking at the BP) right side of the table took the fall landing on the end of the table and the handle hit the ground first, then rolling somewhat to the Dro box where it stopped... The handle is bent, but somewhat usable or until I find another... but the table will not screw back and forth, fearing the worst, thinking that the long screw had sheared.... I found that the head of this bolt (circled in photo) sheared off and shot the 2 brass nuts/sleeves out that side preventing any real damage it seems!... Checking it all out... no other damage was really done & I'm really lucky, considering... The knee was rolled all the way down and the head flipped completely over, keeping the weight low...

I rolled the brass nuts all the way left and slid the table right to left by hand and everything still feels nice & tight. I was able to line up the slot on the brass nuts & get one of them to slide back into the bore... now able to screw the table back and forth... It seems like its fine.... However, I can not get to that bolt in order to extract it... There is enough bolt sticking out I can maybe remove with pliers or at least that I should be able to get it out easily if i can just get to it... I need to remove the table to do so... Can anyone give me some advice on doing so??? I check everywhere online and can not find anything on removing the table... even youtube!

Any help with some instructions, a video or maybe a download of a repair manual would be great... I found the downloads from Hardinge- Installation, Operation, Maintenance and Parts List... but it only shows how to tighten that bolt to set backlash...

Thank you guys for anything and everything you can help me with!

[machintek]

This screw holds the brass nuts in the nut bracket.
Remove both end pieces on the table (that has the bearings).
Loosen the X axis gib. Remove the screws holding the X axis DRO reader head.
Now you can slide off the table. You can also slide out the lead screw with brass nuts.
Usually I can use a pick and back out the remainder of the holding screw from the nut bracket.
But usually the side of the nut bracket blows out too when this screw breaks. The wall adds strength to this screw.
If you cannot get it out, you can remove the y axis screw and then remove the nut bracket from the saddle, put it in another Bridgeport, drill it out , etc.

George

[winegar]

George-
I done exactly as you said.... I removed the ends/bearing/handles... slid out the lead screw and brass nuts... and sure enough, there was a piece broken off of the holder of the brass nuts....The smaller screw was still in the broken off piece.... Can this be welded back on, and re-threaded where the smaller screw locks the flat head screw that broke off?....

You said you do this often?... Same situation or is this something that is a flaw?...

Also, When i go to put this back together.... the 2 brass nuts... how close together do they suppose to be when i reinsert them back into the bore?... Just want to make sure I do this right!...

Thank you very much!

[machintek]

The most common way this screw breaks is someone rapids the vice on the table into the quill with a power feed.
This is a casting. Takes skill to weld. I usually replace them since the customer is a company (not a hobby) and can afford the replacement.
Turn the nuts untill they touch then back one off until the keyways lines up. The broken screw keeps the nuts together and this is how backlash is taken out. Measure the lands of the lead screw on the ends and in the center. If there is a difference and you take all the backlash out at the center, you will bind trying to reach the ends of travel. That is why I like chromed screws. With chromed screws, chromed ways and a electric oiler the life of a standard machine can be extended 5 fold before a major rebuild.

George

[winegar]

I see that casting is only $125... I might just replace it.... or use some purple thread lock on the main bolt that broke to assure it will not back off or tighten on its own... as that part of the casting is good....

Any word on where i can get a rebuild manual for this machine?... Maybe a free download?....

Thank you very much George!....

[79TigerPilot]

Sorry to hear of you mishap. I know where you are coming from, I have a Logan Lathe that fell over on the compoind dial the day before I went to pick it up.

I have never seen an overhaul manual and not sure if there is such a thing but the parts breakdown and operations manuals are available on line at various places.

In the yoke or dog bone that some like to call it are the brass Acme nut or nuts. In my BP there was one nut with a saw cut almost all the way through the nut others were supplie with two nuts. I think your broken screw it is the compression screw that forces the two nuts together or closes the gap in the single nut to control backlash. There is a second screw that clamps on this screw's head screw to lock its positon once you have the main screw set correctly for drag vs backlash. I was told the two nut solution was a better way to go and gave better backlash control so I cut my single nut in two. In my opinion this was a mistake and my backlash got worse. With the single nut, not only is it compressed across the saw cut but the nut also bends a little. I had more rotational slop between the two nuts and the dog bone than I did with the single nut. I believe this is due to the shorter effective lenght of keyway for each of the nuts and the lack of nut bending which may bind the key way in its slot. You can buy the nuts as a singe piece or two piece assembly. I would go with the single nut assembly.

NOTE! The key that's between the dog bone and the brass nuts is pinned to the inside bore of the dog bone is a tiny pin -- don't shear it off trying to remove the key.

Before I did my ball screw upgrade I had built an alternate means to compress the brass nuts other than that screw. It consisted of an aluminum ring that impinged on the brass part and had three 10-32 cap screws tightening the ring down compressing the brass nuts. Thought it would give me better backlash conrol. It worked but the main problem it couldn't solve was the wear in the lead screw. Adjusted for low backlash the screw was too tight other places.

[winegar]

I found this.... Bridgeport Series 1 1J Mill Repair & Service Manual

Thinking about buying it....