I'm about to give up on fixing the ball screws on my Bridgeport and now thinking of just getting a new ball screw retrofit kit or new acme screw setup. Both will end up costing about the same based on prices at H&W Machine. I realize experienced machinist are split on which is better but for a novice such as myself is one more appropriate than another? If it makes any difference my Bridgeport has a 9" x 42" table and was manufactured in 2007. I don't have a power feed except for the Lyman MK7 that came with the machine and there is no DRO but would like to eventually have both.
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Ball or Acme Screws for Bridgeport Mill?
- Thread starter beeser
- Start date
- Replies 14
- Views 8,731
JohnEvans
Titanium
- Joined
- Sep 23, 2009
- Location
- Phoenix,AZ
Manual machine use the Acme.
hitandmiss
Titanium
- Joined
- Jul 31, 2010
- Location
- Rochester, NY USA
X2 on using Acme screws on manual machines.
Years ago I used a mill that had the servos taken off and cranks put on. It was a real treat trying to keep the axis from drifting on light cuts. Needed to use table and crossfeed locks for nearly everything.
Bill
Years ago I used a mill that had the servos taken off and cranks put on. It was a real treat trying to keep the axis from drifting on light cuts. Needed to use table and crossfeed locks for nearly everything.
Bill
triumph406
Diamond
- Joined
- Sep 14, 2008
- Location
- ca
Ball screws. You can take much heavier climb cuts when roughing with ball screws than with ACME screws. If your in the business to make money I'd go for ball screws.
CarbideBob
Diamond
- Joined
- Jan 14, 2007
- Location
- Flushing/Flint, Michigan
For a manual machine and 2-5 tenths work I'm firmly in the camp of acme but opinions will vary.
Ball for sure on a cnc as the computer has no intelligence and it can't play with the gib locks.
Ball screws make the machine too "slippery" to me for lack of a better term.
There is no servo holding the screw on a manual and creeping up on a number is easier with the built in inefficiency of the acme.
I did think it a great idea once, threw the ball-screws away and went back. Everyone on the floor hated it so dumpster bound.
Your mileage and work will be different and many do like such an arrangement.
Just did not work well for my shop which was mostly making pockets in toolholders.
Was nice at cutting out shanks.........
Maybe depends on usage.
Bob
Ball for sure on a cnc as the computer has no intelligence and it can't play with the gib locks.
Ball screws make the machine too "slippery" to me for lack of a better term.
There is no servo holding the screw on a manual and creeping up on a number is easier with the built in inefficiency of the acme.
I did think it a great idea once, threw the ball-screws away and went back. Everyone on the floor hated it so dumpster bound.
Your mileage and work will be different and many do like such an arrangement.
Just did not work well for my shop which was mostly making pockets in toolholders.
Was nice at cutting out shanks.........
Maybe depends on usage.
Bob
talvare
Aluminum
- Joined
- Oct 19, 2010
- Location
- Sacramento, Ca.
Since you already own a mill that has ball screws and was originally a CNC machine, and you say you want to add power feeds and a DRO, it may be worth looking into one of the various CNC retrofit packages available. Then you would have the features you want plus CNC capability. I own a BP EZ Trak 2-axis machine, and even though it is antiquated by todays standards, it is still very capable and makes many machining operations so much faster and easier than trying to accomplish the same things manually. Think about things like machining arcs, curves, circles, bolt hole patterns, etc, etc, etc. that you will likely want to do in the future, and think of how you would accomplish the task with a manual machine. Just some food for thought.
Ted
Good idea Ted but I'm afraid the cost of a CNC setup is beyond my reach at the moment. It would especially be nice if I could find the EZPlus equipment that originally came with the Bridgeport. I wonder, does this ever pop up for sale?
triumph406
Diamond
- Joined
- Sep 14, 2008
- Location
- ca
I seem to be in the minority, my main BP has ACME's, I do use somebody else's BP with ballscrews, which I prefer, on the other hand I wouldn't pay the money to update mine, unless i won the lottery.
taiwanluthiers
Cast Iron
- Joined
- Dec 6, 2016
- Location
- Xinjhuan District, New Taipei City
I wonder is it possible to have some kind of a clutch that locks the rotation of the handwheel unless you touch it (or push a button on the wheel)? So you could use ball screws manually without worrying about the wheel rotating during cuts.
Scottl
Diamond
- Joined
- Nov 3, 2013
- Location
- Eastern Massachusetts, USA
I don't see why that couldn't work. When you use a CNC Bridgeport in DRO mode the holding force doesn't prevent you from turning the hand wheel and it doesn't seem to change as you turn the wheel. I've long suspected that adding something like a Prony brake (a band over a disc tensioned by a weight or spring) could serve the same function as holding torque on a servo motor. This is the same mechanism used on many pieces of manually adjustable exercise equipment to set resistance level.
taiwanluthiers
Cast Iron
- Joined
- Dec 6, 2016
- Location
- Xinjhuan District, New Taipei City
I think easiest is just some kind of O rings or something to add tension to the handwheel so it does not turn unless you turn it. It may make things more tedious to turn but it would prevent accidents.
Perhaps another way is to tighten the gibs.
Perhaps another way is to tighten the gibs.
Why do you need to change?If i were to do anything i would add a DRO.
I have a Bridgeport probably made in the 60's that has no power feed and about a half turn slop that we hold .002
all day doing production work . The only time that I will climb cut is for a clean up cut and then I will snug the table lock and always keep the gibs adjusted properly.
I have a Bridgeport probably made in the 60's that has no power feed and about a half turn slop that we hold .002
all day doing production work . The only time that I will climb cut is for a clean up cut and then I will snug the table lock and always keep the gibs adjusted properly.
Phil in Montana
Stainless
- Joined
- Jul 31, 2007
- Location
- Missoula Mt
Use acme, ball screws will free wheel with out brakes...Phil
Mr Bridgeport
Stainless
- Joined
- Nov 27, 2002
- Location
- Burlington, NJ
If you do any climb milling with ballscrews on a manual machine be prepared for the axis to try and self feed. Ballscrews were never an option for manual machines made by Bridgeport.
Mr Bridgeport
Mr Bridgeport
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