Vertical mills

[TheJDWorkmen]

I would like to by a used vertical mill but I am not sure of what I should be looking for as far as condition. Here are some of my questions.

1. How much back lash is to much before it considered time for a rebuild?

2. I have only operated Bridgeport mills are there other decent brands/models to look for?

3. What is a fair price for a used mill?

4. I plan on using this mill to cut a few engine heads down. Is power feed on the y axis recommend for this?

5. What are other things to looks for when considering condition.

In advance thanks for any help.

 

[shawnspeed3]

Well first off, there are several mills that would work including a bridgeport..but how big are the heads you are planning to re-surface??? I have a BP series 2with a 9x42 table...I have to be creative to do a SB chev head...a machine with backlash, is a sign of wear, depending on what the machne was used for(production runs vs alot of one offs ) will determine HOW it is wore. Avoid machines that had 1 set up operation for long periods of time, the ways ware out in these areas, and is easy to check , by moving the axis to one end of it's travel , and lightly tighten the gib lock so the axis will move with a little drag. move that axis through it's travel, if it frees up there is some wear on the ways. back lash wont steer me away from a machine as long as the gibs are good, and the lash is repeatable& consistant.Also check the quill & it's bearings for loosenes. I have used some off brand machines that were wore badly, but once I learned there glitches, was able to make good parts. Also , the mill is just the tip of the iceberg.....you can spend as much on tooling as you did the mill. Good vices, clamp kits, an indicol & Good indicator to tram the mill head & do set -ups with , alond with a good set of mic's, oh yes ,and cutting toolsthe cheapest would be HSS tool bits in a fly cutter , but these are slow, and a little perticular on set -up, a face mill is great but a 4-6" one will start at around 300 bucks & go over a grand for a good one with arbor & inserts. I have seen mills from 600-3800 bucks...So how much does the local shop charge to re-serface a head??Good luck , Shawn

 

[Eric in IL]

Alliant mills seem as good quality wise as the Bridgeports to me.

Power feed is on x axis on the mills of the size I think you are interested in. I would shy away from one that had power feed installed. They have most likely spent their life doing roughing work with heavy cuts involved. If you want power feed, add it later.

See if the Bijur (hand-operated oiler) is intact and functional. Many times the oil lines get crushed or get holes in them and the oil doesn't get to where it is supposed to.

Table surface is a fair indicator of how a mill has been treated. If the operator doesn't have time to check if he has drilled through the work and into the table, they surely don't have time to pump the oiler once in a while.

Good luck in your pursuit.

 

[leej]

I have a vertical mill Table 36x9 3 phase.Manual controls. Power controls have been removed and rebuilt. Since then in a factory as a repairmill. I have used it for small repairing jobs. Have had no problems with accuracy, No back lash. Also have a large lathe "belt drive" rebuilt for high school metal class. Used very little since,rebuild.62"X 8" or 9" throw. Located north central Illinois. Require you to see both items before given a price. Pictures can be sent. ggp email should be open .

 

[Gun guru]

Here is what to look for:

I have only ever ran a "bridgeport" brand, series 1 and series 2.
The backlash that I am know is normal is about .040". Check for the following:

Will the head move, up, down, back, forth, and swivel. Will the head "tram" in to .001" over a 9" area? With the spindle running does it sound like a bucket of bolts, or smooth like a fine tuned Deere? I am speaking of the 2J head, the step pulley style are the older ones. To get the V-belt pulleys replaced with bearings is several hundred dollars, this is with the labor to do it too. (I am referring to the 2J head)
I highly recommend bringing an indicator and an indicol holder to check head repeatability against the table and also bring an angle plate to check table to head squareness. Move the machine table to the full extreme, X and Y. Does it have a one shot oiler? This is important. I oil mine once per day, Way oil is cheap. Be sure all mechanisms work, the auto down feed for boring, does the quill have a smooth feel? A new drawbar is $18, Does it come with a set of R8 collets? A machining vise too? Digital readout? This should be a good start for a list of stuff to check.

 

[Gun guru]

I forgot to say that money wise,
A good condition Bridgeport mill is $3000, 2J head that runs good. (no readout) A new readout is $1500. An excellent condition bridgeport with power feed on the x with a good readout is likely $5K plus.

 

[Dick L]

Back lash should not be a worry. You should run the table to both ends of the lead screws with an indicator in the chuck. I just put new lead screws and feed nuts in an old round arm Bridgeport. Not a big cost or did it take a lot of time. I scraped it in while I had it apart. It had ben out of use for 20 years or more when I bought a new mill when my tool guys didn't want to use it. I cleaned it up and it is a nice machine again. I cut my teeth on round arms so it might not be the choice of younger guys but I love it. The round arm mills will be less cost. Most will have the shorter table though.

My fancy read out.

 

[Mike M]

If you plan on doing head gasket surfaces then i'd suspect this is asking for troubles. You need to be able to start your cutter from one side and travel all the way off the face on the other side. You won't have enough travel to do this. I think the machine you want is called a rotary broach ?

 

[Anonymous-0]

I am a little bit like Mike below me if you are going to resurface heads and if they are tractor heads I would go with a grinder or the newer carbide cutters. We used to have a rotaty broach, the grinders, belt sanders and we worked with a man that had a jig made just to do small block Chevie heads. Some industrial engines have heads and blocks made from a much better grade of cast iron than automotive cast iron heads and of course there are the newer aluminum heads

 

[Dick L]

I have milled many heads on a vertical mill without a problem with gaskets not sealing. I have never used a gasket compound on standard head gaskets.

This head was done with an end mill. I have done others with a flycutter. You can see the width of the passes in the picture. In the past I would usually set up and do four or five at a time when I could get an open mill. I have not used it yet but bought a one pass cutter to use with my CNC mill.

 

[Dick L]

If you look at the picture of the wheel mold below you will see the mill marks. When I make parts on that mold I will put up to 1200 pounds per square inch between the two halves and I can not let it leak and there is no gasket. If a milled head blows a head gasket it is not because it was milled. It might be improperly milled. They can also be improperly ground as well. Some people are machinists and others have machines.

A mill that cuts dead nuts will do you just fine.

 

[smallercrawler]

Eric, bought several Alliant mills for toolroom use in the 70/80"s. IIRC they were spinoff of Bridgeport, 3 year casting age before building, numerous parts interchanged with Bridgeport, and about 60% price of like equipped Bridgeport. We always had very good service with ours. Generally bought optics as older hands (eyes) appreciated them, and shortened "learning curve" for new men. Usually bought 9x48 P.F. tables, 2J heads, (and neck risers) for maximum flexability.

 

[Spook]

I've used Bridgeports, Index and Tree mills, all basically the same design. If you watch CL you can find good buys sometimes. A round ram Bridgeport dates from maybe late 50's? I saw one years ago, and the guy told me that he bought it in 58? I've milled heads on Bridgeports, worked fine. I've seen machines for auto repair shops, that were designed to mill heads, but I'd rather have the bridgeport, it's much more useful.

 

[Fred Martin]

A Cincinnati #1 Tool Master has an adjustment to take the backlash out of the X table movement. Mine has less than .005"
The Cincinnati is a heavier duty mill than the Bridgeports and the clones.
These mills run from $1000 to $5000. I bought one for $1000 and was surprised how much better built they are and heavier and still accurate after being built in 1955, (I have owned a Bridgeport) bought it from a father/son operation. Their shop was as clean as a house so, I didn't have to go all through the machine to see what shape it was in. I figured they kept their machines just like they kept the floor. You can buy a parts book/operation book from ebay, $30 to $40.
You can use power feed on the X axis only for $300 to $600 or make one from a variable speed electric drill or use your imagination and a DC motor with Vee belts for feeding the table.
Put a dial indicator in the spindle and see how much the table is out from front to rear.(called droop)
The Cincinnati mills are hard to find collets for, they go from anywhere from $30 to $50 bucks each on ebay. There is a way around this problem though, you can buy a set of the Chinese ER collets that can run up to about an inch...so, you buy a 1" Cinci collet and one of these collet sets with a one inch straight shank and you have all the collets from 1/32" to depending on what set you buy as to how large the largest collet is. They will run you about $100 or so for the whole set. I bought the ER-16 set that runs from 1/32" to 3/8ths" size. I bought mine from a fellow in Hong Kong for around $55. I have all the rest of the sizes. The Cinci has a 11/16" tee slot and a set of hold down clamps will cost you around $50 plus shipping. My shipping was around $22 if I recall correctly. The first thing most machinists that walk into my shop do is go to the mill and start talking and asking questions about it. They can be had with variable speed and power feed on X and Y axis'.Just between you and I, I think B'port took Cincy's idea and added a few extras to it and made the most versatile user friendly machine. But, I think the Cincinnati is top dog. ohfred