# Trueing Bridgeport Mill table



## binnaway

Has anyone used a flycutter to clean and true up Bridgeport mill table???


Garry


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## Richard King

That is not advised as the table dovetails are no doubt  worn and top of knee is worn, as the table move from left to right it rocks and the top of table will get high and ends apear low.  Get a staright edge and lay on top and see how much the tabele is bent.  Also the tablle top is peaned and stretched where the tee slots have been stretched over the years.  I am late for work and will write more later.  I am a professional machine rebuilder and have repaired and rebuilt thousands of Bridgeports in my career and can help later.  Rich


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## GK1918

I aggree with Richard.  For the most part our shop machines are my living. Id say being affordable, be
prepaired for atleast something not 100%.   So, myself Id just work around it.  Seeing a high percentage
of milling is done with a vise.  Me Id just shim and tram the vise.  And then it was not stated what the
actual problem is.  Cosmetics?  has scratches and drill marks? Not flat?  Maybe not correctly trammed?
No clue, we can get a better handle on this > what is the actual problem.  Richard is the machine M.D.
just like a vet. doctor, the patients dont speak.  
sam; not a wise guy just trying to help.........


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## binnaway

I am just trying to clean up some milling and drilling marks, I will ckeck with straight and dial indicator edge as Richard said. Just as easiy to live with the marks and make sure that the vise is spot on.

Will check over the next few days, many thanks for the advice.

Garry


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## 8ntsane

binnaway said:


> I am just trying to clean up some milling and drilling marks, I will ckeck with straight and dial indicator edge as Richard said. Just as easiy to live with the marks and make sure that the vise is spot on.
> 
> Will check over the next few days, many thanks for the advice.
> 
> Garry



If that's the only reason, I would suggest just leaving it be. Consider any table top damage as part of machining.
It would not be worth trying to repair this, and chance screwing it up. Unless this table has some major sag on the outer ends, I would not advise trying to machine the table top for cosmetic purposes .Even if your table does have some sag at the outer ends, are you machining long items, using multiple vises?

Im sure Richard will chime in on the ins and outs of doing this, as Im sure there is many things that could cause a other wise good machine to turn into a inaccurate machine. I wouldn't let the wounds bother you.


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## Tom Griffin

Yeah, that's a really bad idea. Even if the table is full of marks, at least you can assume that it's flat. Cleaning it up with a fly cutter may make it pretty, but any wear on the ways will be transferred to the table and it will be flat no more. Just clean it up with a stone to remove any high spots and Scotch Brite the crud off. It'll be fine.

Tom


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## Jeff in Pa

binnaway said:


> I am just trying to clean up some milling and drilling marks, I will ckeck with straight and dial indicator edge as Richard said. Just as easiy to live with the marks and make sure that the vise is spot on.
> 
> Will check over the next few days, many thanks for the advice.
> 
> Garry



  I would suggest stoning the table with a 2" x 8" flat stone ( I use WD-40 as a lubricant ) to remove the high spots.  Anything that is lower won't matter.


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## Bill C.

8ntsane said:


> If that's the only reason, I would suggest just leaving it be. Consider any table top damage as part of machining.
> It would not be worth trying to repair this, and chance screwing it up. Unless this table has some major sag on the outer ends, I would not advise trying to machine the table top for cosmetic purposes .Even if your table does have some sag at the outer ends, are you machining long items, using multiple vises?
> 
> Im sure Richard will chime in on the ins and outs of doing this, as Im sure there is many things that could cause a other wise good machine to turn into a inaccurate machine. I wouldn't let the wounds bother you.



I would use a 10-12 inch long flat file and go over the entire table top to knock off any bumps.


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## radial1951

Jeff in Pa said:


> I would suggest stoning the table with a 2" x 8" flat stone ( I use WD-40 as a lubricant ) to remove the high spots.  Anything that is lower won't matter.



Garry

Most of the above posts are good advice, although I wouldn't be keen on using a file, unless you really know what you are doing. If you really _must_ reface the table, the only way is to have it surface ground, using its own ways as the datum. Not a big job for the right machine, depending on how deep the marks are. Might be worth it if the rest of the machine is _really good_, just to dress it up. (and then don't add your own scars)

You can measure the thickness of the table, from the top of the table to the flat slideway surface underneath, at all end corners and close to the middle without taking it off the machine. If the four end corners are equal, which would normally be the case, the top could be re-ground. Most of the wear is usually on the top ways of the saddle, due to the load of the table when it's hanging out at the extremities of its travel.

About the only people doing machine rebuilding in Sydney are Hardwick and Tatum at Mona Vale, (02) 9979 5666. I have heard they are always heavily booked in advance...

Might be worth a call. Good luck.

Regards, RossG
radial1951
_____________


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## onecut jimmy

binnaway said:


> Has anyone used a flycutter to clean and true up Bridgeport mill table???
> 
> 
> Garry



You can not be serious.  I am not being nasty I am just telling you how that question sounds to a Machinist. 
Groves gouges drill marks are blemishes like a pimple on the Mona Lisa. Unless they affect the machines accuracy forget it. lay a flat bar on it see how much it rocks. 
I have seen people drill holes in them, mill slots in them,  Another machinist friend of mine got a brand new Bridgeport back in 1979. He was doing his first job on it and a lady friend of his wife came into the shop wearing shorts and a halter. and she was HOT! He was watching her and milled a 3/8' slot 1/4" deep by 7" long.
I LMAO. He deburred the edges and kept on going like nothing happened.  If it don't affect your work forget it.


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## binnaway

Thanks for all the replies, I will leave well enough alone and just check for flatness and remove high spots with an oil stone.

Garry


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## george wilson

No one seems to have mentioned that recutting or grinding the top of the table can stress relieve it and cause the table to warp.


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## Richard King

George is correct.  A friend of mine, Axel Fors of Fors Machine Rebuilding in Ogden UTah runs a T-Slot cutter down the peaned T-Stots on all the table before he grinds them.  Archie the professor who writes on my forum says the table bends from peening and stretching the metal.  I have also heard of rebuilders who flip the table over and peen the bottom and it straightens out.  I tried that once on an old 36" table to see if it would bend back. It did, but it was on a machine we scraped.  I would never do that to a customers machine.  But George is correct, you could pull the table and have it ground and it will straighten up.  A friend of mine up here in MN will grind the top and fly cut the bottom from $750.00 - 1000.00.  Rich


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## george wilson

I once had to have the table of a little Burke #4 recut. It had warped pretty badly from tightening stuff in the T slot. Had to have both the table and the underside and dovetail recut.


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