Thinking of a Bridgeport CNC Conversion

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V8 BUG
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Thinking of a Bridgeport CNC Conversion

Post by V8 BUG »

Hey Guys,

I'm thinking about converting my Bridgeport mill to CNC. My TMC-1000 is a great little machine...but little. With a machine travel of 6" x 12" I have things that I cannot make for my car hobby. I have found that I do not use the BP as much as I did in the past before the CNC. There are conflicting opinions on line about converting a manual machine. I have seen what Jim Glass has done in the Outback Machine shop. That is great retrofit of the Series II. I would love to have a machine like that but don't want to give up my manual machine. I do not have any more room in my small 2 car attached garage for another machine. I feel my only choice is do nothing or give the conversion a shot. I watched some videos from Centroid CNC and Flashcut CNC. Both conversions look great and fairly simple. I have read that its better to save your cash and just buy an old cnc and retrofit. Again no more room. So I figure I will make a pro and con list. Feel free to add to it with past experience or what ever info you have.

PRO
Already have rebuilt machine that runs very well. (re machined ways, dove tails, hand scraped saddle and new rulon on gibs, one shot Bejour lube system, machine is tight)
Already have phase converter (5hp American Rotary) and step up transformer (600v)running for power
Already own Mach 3 license and know how to use it
Already have R8 collets and tooling that I share with the TMC-1000
Can make my own mechanical components and have local suppliers for belts and timing pulleys
Can machine my own ball screw ends an make a new yoke (with help from expert tool makers from the shop I work at)
Will allow me to create parts larger in size and may be some cyl. head porting.
Will allow me to create parts that people have asked me to do but i could not with the current capacity of the TMC-1000
Keling has a kit with 1200oz steppers that should work for under 1000 or servos for a bit more (used Keling with no problems for the TMC retrofit)


Cons
Not as good as a real VMC
No tool changer (not that I need that)
Read its a waste of money to convert a manual machine
I'll have more money in the conversion than i would have had to just buy a broken Series II (one for sale on CL for 2500 but don't know how good it is)
A lot more work than converting a Series II
I will probably spend 2-2500 on the conversion doing as much as I can myself.
In the end not sure it will be as good as I would have hoped for


Again Please feel free to add to the pro and con lists
This project will take some time as I always try and pay for the fun with products sold or traded. Its easier to sell to the Wife that way.

Thanks

Kevin
BUILDING IT IS MORE FUN THAN BUYING IT
JimGlass
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Re: Thinking of a Bridgeport CNC Conversion

Post by JimGlass »

Kevin;

I understand your limited floor space. Sometimes I feel I spend more time juggling my floor space than I do working. I'm constantly finding ways to keep my machine shop a machine shop instead of a machine shop storage area. I have spent over $1000 in the last month on better storage techniques and so far I'm glad I did.
At the same time I look at stuff that has been taking up my valuable floor space. If it has not been used for a couple of years it either gets relocated to my more remote storage areas or it goes in the trash. We all have stuff around not because of the need but more of an emotional attachment. We need to break these emotional attachments.

I would try to find a way to have both, your manual Bridgeport and a full sized CNC milling machine. Is there any way you can put up some kind of storage building in you back yard? All you need is roughly a 5' X 5' footprint for another machine in your garage.

After I got my CNC Bridgeport running I'll never forget my wife asking me if I was going to sell my manual milling machine and I told her no. I still use my manual milling machine more than I use my CNC Bridgeport.
I would be lost without my manual mill.

Kevin, if I were you I would stand back and take a look at your overall garage then ask yourself how much stuff is just taking up space and how much stuff compliments your efforts then make the decision.

I have a three car garage. My machine shop is in the garage and somehow we still get a Ford Taurus and a
Ford Ranger inside and still close the door.
Jim
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Bill Shields
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Re: Thinking of a Bridgeport CNC Conversion

Post by Bill Shields »

Can machine your own Ball Screw?

Wow....

Now there is an art....
Too many things going on to bother listing them.
V8 BUG
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Re: Thinking of a Bridgeport CNC Conversion

Post by V8 BUG »

Bill

The ends not the screw it self. Yes that is an art. We have a company in town that does it though. I work in Windsor Ontario. We have a very large tool shop base here.

Jim,

The way it sits I would not be able to fit the cars in. In my 2 car I have stuffed the Bridgeport, The cnc on a 2.5'x3' rolling table, Atlas 10"x42" lathe, 36 Gallon compressor, 60 Gallon compressor, Kennedy roller with top box, Red roller with top box, work bench with overhead cabinets, mig welder, arc welder, stock shelf, and the beer fridge, Jeep top hoisted to the ceiling. Oh and still need to get the cars in. 76 Corvette project(on a 2 post hoist), VW Bug(under the Vette), and my wife's Miata.
I do have plans to add to the rear shed. If i could do this I would look for a Series II for sure. Plans call for a 26'x40' "addidtion" to the shed out back which is 20'x24'. I keep 3 cars in there during the winter months and it opens up the front garage for the Corvette project and just in case I need to service one of the regular vehicles.
So Jim your saying bad idea on the BP conversion?
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Re: Thinking of a Bridgeport CNC Conversion

Post by JimGlass »

V8 BUG wrote: So Jim your saying bad idea on the BP conversion?
WOW.....You got a lot of stuff.

I don't find the BP conversion very attractive but that is just me. How will you get the third axis on your exiting machine? Maybe you should consider selling the Bridgeport and buying a project CNC mill. You would probably be time and money ahead going that way. Once I got my project CNC mill home and inside the garage
it took one week and $1000 to get it running.

Here it is, 2006, my Series 1 Bridgeport still on the trailer parked behind my house and out of sight from most of
the neighbors. After sun down a tow truck arrived to hoist the machine off the trailer and set it in front of the garage.
Image

The way it looks today except for the computer upgrade. I'm running Mach3 now. Only a few feet away is the rest of the shop

Image
Jim
Last edited by JimGlass on Fri Nov 08, 2013 9:46 am, edited 2 times in total.
Tool & Die Maker/Electrician, Retired 2007

So much to learn and so little time.

www.outbackmachineshop.com
V8 BUG
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Re: Thinking of a Bridgeport CNC Conversion

Post by V8 BUG »

Jim,

I was thinking of using the quill for the Z axis. Elrod cnc conversions use Centroid control. They have a good video on youtube. Link below.
http://www.youtube.com/watch?v=AVlxLDNv-Tc



There are some machines on sale like your Series I on Craigslist but I just wish I had more room. I guess I should work on the addition on the shed out back.
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Re: Thinking of a Bridgeport CNC Conversion

Post by JimGlass »

Sometimes we have to take what we already have and make it work.

That old Bridgeport Series I was the only way I going to have a full sized CNC milling machine in my garage.
My wife was not up for spending 25K or 50K on a running CNC mill and neither was I really. I bought that thing in Milwaukee Wisconsin (about 90 miles away) for $1500. It came from a trade school. Paint job almost like new. The chrome ways still had the satin appearance, ways not even shined up.

Even though the machine is 40 years old it is not unusual for me to be on the floor on my knees with a pail of soap and water giving the thing a wash down. Just think, 100K machines don't get care like that.

Let us know how your project turns out.
Jim
Tool & Die Maker/Electrician, Retired 2007

So much to learn and so little time.

www.outbackmachineshop.com
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Re: Thinking of a Bridgeport CNC Conversion

Post by Marty_Escarcega »

What work envelope do you need? How about one of the square column mill drills and convert that? You might be able to shoe horn it in the garage, keep the bridgeport as a manual machine.

Take a look at Industrial Hobbies Mill. There are a number of people that have converted them. You could also find a larger benchtop CNC mill like a Dyna 2800 and convert it. I think some of them even had a tool changer.

I think if you are patient, ask around, watch the local classifieds, something may turn up.
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Re: Thinking of a Bridgeport CNC Conversion

Post by Bruce_Mowbray »

I also suggest keeping your manual machine-manual. CNC is nice but it's not for everything. I have both in my shop and while I can do everything on my CNC mill that I can do on my manual Bridgport, and more, there are times when the manual machine wins. The flexability of my manual machine is much greater than the CNC mill. The "feel" on the manual machine is better. The ease of quick setups on my manual machine tends to outweigh the CNC.

As mentioned, there are plenty of old series X Bridgeports out there that sell for less $$ than a manual machine of similar wear level. Even if you get one with a Boss control, these are easy to repair. I used a series II BP with a Boss 3 control and an Ericson quick change tool holder system for years and enjoyed every minute of it. They make great hobby machines.
Bruce Mowbray
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Re: Thinking of a Bridgeport CNC Conversion

Post by V8 BUG »

I don't really want to buy anything more. I like the size of the BP Mill. This would do most of what I need. I will not convert the machine if I cannot keep it manual as well. The 2 companies listed above keep the machines manual as well as cnc. I guess you could call it an option if you want to use it that way. My BP has a Mill-Rite 2 axis DRO with glass scales that would stay on the machine. Im not sure if i could tie that in for feedback on the x and y at least.
I may be crazy but I am thinking I can add the CNC option on this mill for about 2-2500 doing all the work myself. Keling has a kit for the electronics for about 1000 with steppers and servos for 1300. I am getting a quote from Motion in London Ontario for the Rockford Ball screws. Brackets I can make. Belts and timing pulley's are not that expensive. I already have a spare PC to run it all.

I have to get hard numbers before I cut any steel or order anything. If I do anything it will take time to pay for all of this.

Thanks for the comments and keep em coming.

Kevin
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Bill Shields
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Re: Thinking of a Bridgeport CNC Conversion

Post by Bill Shields »

Jim:

If you don't mind, I would prefer my ball screws be precision ground....unless I am missing something and you are just working the end of the screw

V8 -

yes, we have a lot of customers (and an large office) in Windsor. I am sure you can still purchase ready-to-go ball screws from several sources.

I have a BP Series II that originally had an NC control on it 3 x 2 table.

Picked it up for $750 and put a Fagor control (with ball screws) and a z-feed on the quill

OK...cost me $8,000 before it was over with, but runs good and does all I need.
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Re: Thinking of a Bridgeport CNC Conversion

Post by JimGlass »

Bill: PM sent
Tool & Die Maker/Electrician, Retired 2007

So much to learn and so little time.

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