[Fast Orange]

This is one for the machinists out there-
I've got access to a old B-port mill,but very limited experience using one.
I'm looking for books or other info on set-up and use of this machine.I need to know how to adjust the play out of the feed screws,how to square the head to the table,etc.Can anyone recommend a source of info that won't require taking a course somewhere?My present schedule precludes going to the local vo-tech for a course.

Thanks,George

[OneMoreTime]

If you get yourself over to www.metalmeet.com there are some old time metal guys over there that may be able to help you out..

OMT

[scholman]

F.O.,

Try "Home Shop Machinist". This is a Magazine for guys that want to do just what you are setting up to do. They might have a web page I am not sure. They have all types of projects and lessons for small lathe work and small milling machines. I figure your mill is on the larger size but I still think this mag. is what you want.

Scholman

[OneMoreTime]

Originally Posted by scholman

F.O.,

Try "Home Shop Machinist". This is a Magazine for guys that want to do just what you are setting up to do. They might have a web page I am not sure. They have all types of projects and lessons for small lathe work and small milling machines. I figure your mill is on the larger size but I still think this mag. is what you want.

Scholman

I checked it out and they do have a web site and a good forum..bet they have what you need..

OMT

[oldred]

www.use-enco.com

use keyword-machine shop reference

These guys have about anything you can think of in machine shop needs from small bolts to major machinery and tools with a big selection of reference and how to books.

[4 Jaw Chuck]

Removing the backlash from the feed screw is accomplished with a backlash eliminator which essentially is two nuts forced apart with a heavy spring, adjusting a bolt on the mechanism will bring this spring into play or not causing a large increase in lead screw torque required to rotate it. Machinists avoid using the backlash eliminator during hand feeding operations because of the heavy load it places on the feed handles, it's primary purpose is to reduce chatter during machine feed operations where the cut is interrupted which could cause the table to jump forward. Most machinists use "conventional milling" as compared to "climb milling" to prevent the tool rotation pulling the tool into the work. For example say you had to create a blind pocket in a large block of metal, to do so you would have to move the milling cutter inside of the pocket in a clockwise rotation inside the pocket to prevent the tool grabbing the material and pulling the table into the tool (this is with regular tooling however, there are left hand cutters available). I might mention not all "bridgeport" style milling machines have backlash eliminators, many of the chinese ripoffs do not for example. To overcome this limitation many machinists will use the table clamps to "preload" the table platen from tool rotation induced movement, it works well if you have experience using it.

Dialing out the head is accomplished by chucking a dial indicator and a long mounting rod to hold it offset from the head, this will allow you to dial out the head against the table, as you can see the longer the offset rod the more accurate your dial in will be. The one I made for myself in my tool box is 12 inches for extreme accuracy. Since the X axis is easier to dial, it is the direction you do first, getting the Y axis dialed in can be troublesome since most bridgeport type mills have a geared offset mount for the head in the Y axis causing the milling head centerline to not lie within the dial indicators centerline. I can dial a head in about two trys because I worked in a shop where moving the head was a daily occurence. You just get good at it with practice and experience with the individual machine.

When using a dial indicator to dial out the head you must lift the indicator spindle inbetween touch downs on the table, any bumping of the spindle will throw out the indicators position on the chucked mounting rod. Always rotate the indicator to another position with the spindle raised and then let the spindle make contact with the surface when you are in the correct position.

It might seem obvious but I've seen some "certifed" machinists just swing the indicator around wildly (hitting the t-slots) while they beat on the head of the machine with a softface hammer trying in vain to dial the head in. Locking the spindle on the mill head to eliminate the plunge feature is necessary to get accurate repeatable results also.

...then again I have a 6 inch disc shaped tool (made on a lathe) that I used in a rough jobber shop that I just chucked up in the drill chuck, I would then just raise the table with the head loose and then with a 0.0005" feeler gauged the disc around it's periphery until it was flat on the table. At that point I would lock the head, it works well if you need the head roughly dialed in a hurry where extreme accuracy is not required or necessary. I've seen it done with a dowel pin in a collet chuck mounted in the milling machine spindle and a lathe 3 jaw chuck clamped to the dowel pin, there are many ways to skin the cat.

Use your common sense and the many methods available to you are limited only by your imagination.

[Fast Orange]

Thanks,guys-
I'm ordering up some of the ref. books from Enco,and I'm going to a used book shop this weekend to see what I can find.I haven't had a chance to get into the "Home Shop Machinist"website in any depth yet,but it looks interesting.
Chuck-your post and directions shook loose some of the cobwebs and got me thinking-I'll probably make the arm for the dial indicator soon and square the head.I've got about 75 degrees of free play in the feed screw on the long axis-just seems excessive-I need to get a better look to see whats under the table.
I'm working with a real B-port-from late 60s from what I can figure out-not that they changed much over the years.
One thing I learned real quick-without power feed, the mill can be bought pretty cheap-the tooling will cost big $.
Thanks Again,George

[Kevin45]

Fast Orange....Check out this site CHECK IT I get their catalog in the mail every so often and for the home machinist, they have some pretty good prices on endmill, etc. You'll grasp the use of the Bridgeport pretty quickly. Just remember to be safe. I've been a tool and die maker for 24 years and all I have ever run is a Bridgeport or Alliant which is identical to the Bridgeport. tramming the head in is one of the first things I try to teach other when they are learning to run a mill. Some grasp it rather quick and others have worked at it for a 1/2 hour or more. Here is a list of sites that can help you out.

http://easyweb.easynet.co.uk/~chrish/techindx.htm
http://bbs.homeshopmachinist.net/ubbs/Ultimate.cgi
http://www.practicalmachinist.com/
http://www.metal-mart.com/Dictionary/dictlist.htm
http://www.metalwebnews.com/
http://www.chaski.com/ubb/ubbthreads.php
http://www.geocities.com/mklotz.geo/#shop
http://www.rossnet.com/gr8solv/LINKPAGE.HTM

Kevin

[Fast Orange]

Thanks for the links and encouragement,K-45
A B-port looks pretty simple,until you start realizing just how much you can do with it.I think that with a lathe,welder and a B-port ,there isn't much you can't make.Of course,learning how to use each machine is the challenge.
I just got the B-port wired for power,and have only had time to play with it enough to make sure that the various speeds and feeds work.
I was lucky that a friend of mine is a machinist and gave me a good start-up set of collets and end mills.Now if I can get him to show me some of the basics and the dos and don'ts,I'll be off to a good start.
Thanks Again,George

[Kevin45]

Also remember and not to contradict what Chuck said, but for a smooth cut, your finish cut should be about .005/.010. Outside of the part = clockwise. Inside of the part = counterclockwise. Sometimes when you conventional cut, depending on the material, it will get fuzzy. You climb cut, it won't. But if you climb cut heavy it will suck a cutter in and have the potential for some damage. And an endmill WILL suck out of a collet if a cut is too heavy. It will pull down and push away. It will take a little time to learn to read the mill, material, and cutters. And just remember....run everything wide open. When it breaks, then back it off a notch. LOL!!! J/K. Don't do that.

Kevin