Bridgeport Locknut and bolts stripped?

bloomautomatic · Nov 21, 2017

Two of the locking nuts on my Bridgeport J-head are stripped out. The lower left one will tighten up a little, but not completely. The lower right one just spins the stud like there's nothing there. Top two are ok.

Looking at the diagrams for these, it looks like i should be able to remove the head if I take these four nuts off. Am I missing anything here? I will support the head with the overhead crane before loosening them.

As for getting the parts, I'm looking at this manual, page 76. http://www.bluechipmachineshop.com/books/BP_Mill_Series1_Manual.pdf
Looks like the bolt, spacer and nut are items 155,156,157 - but the parts list says it only has 2 of each. Are there two other bolts I need for this? I want to get new parts in before I take this apart.

Thanks

jhruska · Nov 21, 2017

bloomautomatic said:
View attachment 213362

Two of the locking nuts on my Bridgeport J-head are stripped out. The lower left one will tighten up a little, but not completely. The lower right one just spins the stud like there's nothing there. Top two are ok.

Looking at the diagrams for these, it looks like i should be able to remove the head if I take these four nuts off.

Odd that the lower right one spins the stud as it is supposed to be one piece. Not a stud screwed into a T-nut.
Yes, removing the four nuts from the studs allows the head to be pulled forward and clear of the ram bracket.
Balance will be a problem due to motor and upper housing weight.
I used old drawbars with an eye bolt welded to the top end. Screwed it into a solid collet thru the spindle for lifting.
John

bloomautomatic · Nov 21, 2017

jhruska said:
Balance will be a problem due to motor and upper housing weight.
I used old drawbars with an eye bolt welded to the top end. Screwed it into a solid collet thru the spindle for lifting.
John

I'm wondering if someone along the way had replaced it with a piece of all thread or a hex bolt and the corners rounded off.

I was going to sling it with some nylon straps, but the drawbar idea sounds good too.

Thanks!

bloomautomatic · Nov 21, 2017

Head came off without much ado. Wrapped it with a sling and had it hooked on the crane. As it came off it wanted to tilt to the side, so we let it. Took it off sideways and it seemed to balance fairly well that way.

All four bolts are able to turn freely. The square heads all have rounded corners, so they can spin in the slot without catching. The corners look too consistent to be worn out like that. They look like they were like that from the factory.

Are these the correct bolts? At some point before I got it, the base (c. 1964) had the head replaced with a newer J head. I don't know the year on the head, but it's a Bridgeport Textron, so 1968-1986? Did the older machine use a different size bolt head?

Any help is appreciated.

Thanks!

jhruska · Nov 21, 2017

The head bolts should not spin in the slot. That being said the ones you have may be original equipment and look well made.
My photo from the HQT catalog shows the square head without the rounded corners, that is a magnified image.
Your head bolts have the lock washer?
Call this supplier and ask for Barry and or one of his minions
Contact
parts page: H&W Machine Repair & Rebuilding - Parts and Service for the Metalworking Industry
John

moonlight machine · Nov 21, 2017

The easy way to remove the head is put a piece of 3/4 cold finish bar in the collet with about 2" hanging out, then with the quill all the way up clamp the 3/4 bar in your vice. Remove the 4 nuts and move the "Y" axis away from the ram. The vice and bar support the head just fine and it is dead easy to put the head back on as it is all lined up already! I have done it, it works fine.

Richard King · Nov 21, 2017

The older models had curved T nuts that were the same radius of the circular groove. Those bolts look like someone replaced the originals to me. Order new ones and the hard thick washers and new hard nuts H&W or HIgh Quality parts

HWElecRepair · Nov 22, 2017

jhruska said:
The head bolts should not spin in the slot. That being said the ones you have may be original equipment and look well made.
My photo from the HQT catalog shows the square head without the rounded corners, that is a magnified image.
Your head bolts have the lock washer?
Call this supplier and ask for Barry and or one of his minions
Contact
parts page: H&W Machine Repair & Rebuilding - Parts and Service for the Metalworking Industry
John

Being called a minion normally might offend people, but being one of Barry's minions isnt so bad. Maybe its cause I am his son in law too :P

Jon
H&W Machine Repair

HWElecRepair · Nov 22, 2017

Good morning,

The ones we carry in stock don't have rounded edges. Part number is 1431.

That part number comes with the T bolt, washer, and nut. We got a ton in stock. Perhaps not a literal ton... but close. ahhhah

Jon
H&W Machine Repair

@RicharckKing @jhruska, thanks for recommending us. It means alot to us.

gustafson · Nov 22, 2017

Isn't nice when the problem is not something diabolical like broken castings

And a forum member has the right part for the job in stock

Every once in a while......

bloomautomatic · Nov 22, 2017

HWElecRepair said:
Good morning,

The ones we carry in stock don't have rounded edges. Part number is 1431.

That part number comes with the T bolt, washer, and nut. We got a ton in stock. Perhaps not a literal ton... but close. ahhhah

Jon
H&W Machine Repair

Thanks everyone. It appears they are the wrong bolts. I called H&W and placed an order for the correct bolts this morning. Jon was out, but the friendly lady who answered the phone took care of it.

Also, the instructional videos they have on their youtube page are a wealth of Bridgeport knowledge.

H&W Machine Repair and Rebuilding
- YouTube

Thanks again!

HWElecRepair · Nov 22, 2017

bloomautomatic said:
Thanks everyone. It appears they are the wrong bolts. I called H&W and placed an order for the correct bolts this morning. Jon was out, but the friendly lady who answered the phone took care of it.

Also, the instructional videos they have on their youtube page are a wealth of Bridgeport knowledge.

H&W Machine Repair and Rebuilding
- YouTube

Thanks again!

I am glad that she hooked you up, especially since the girls are much faster at taking orders and much better with the parts. I strictly deal with DRO's, powerfeeds, and CNC retrofits (EZ Trak, EZ Path, EZ Surf, Anilams, and Acu-Rites). SO if you need parts, I am not necessarily the smartest guy with those.

I did find out that it was my wife you spoke to, so I am glad she could hook you up.

Jon
H&W Machine Repair

Richard King · Nov 22, 2017

The guys on here recommend H&M a lot...I offer a 5 to 10 % discount on my Cast Iron Straight edges for Practical Machinist members depending on order size. Maybe you could do something like that too. Also possibly you might like to host one of a scraping classes at your plant as I would bet we could fill it in a week, With both our reputation in Machine Rebuilding I bet we could recruit far and near as we do with the You-Tubers and Borne & Koch. We could teach them to scrape their Bridgeport's? Rich

bloomautomatic · Nov 30, 2017

IT'S FIXED!

Bolts arrived and they are installed. The bolts that were in it were definitely wrong. Looks like someone used standard square head bolts which are too small.

I scraped the old dried up grease out of the gear teeth and applied fresh new grease to it. Putting it back on was a bit tricky by myself, but when I grabbed two guys to help it went right on. I supported the head with sling hung from a crane and had them line up the bolts as I slid it back. Went right on that way.

Thanks to everyone who helped on this.

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