Bridgeport R2E3, Anyone still have one? Looking at buying one

a guy local to me has one that has been "modernized" or re-worked using Mach 3. I know little about this machine but it would give me CNC cability with not a lot of money. I'm buying a manual bridgeport this weekend and I rather not buy a 6+k retro kit for it because it still has it's limitation. There's a Taiwanese milling machine that is superior in being converted to CNC that I could pick up.

Info below

"Bridgeport R2E3 CNC mill, Mach 3 controls, Gecko Stepper Drives, Bob Campbell Breakout board Rare earth magnet stepper motors. 208-230 Volt 3 phase could be modified for single phase operation."

Are you a hobbiest? If so, Mach controls would be OK. If not, stay away. Stepper motors are not true CNC stuff. That would be a servo motor. There are others here that have the same opinion.

http://www.practicalmachinist.com/v...worth-buying-bridgeport-series-1-type-324675/
Post #9

If you need a CNC, buy a CNC and not a converted kneemill.
JR

JRIowa said:

Are you a hobbiest? If so, Mach controls would be OK. If not, stay away. Stepper motors are not true CNC stuff. That would be a servo motor. There are others here that have the same opinion.

http://www.practicalmachinist.com/v...worth-buying-bridgeport-series-1-type-324675/
Post #9

If you need a CNC, buy a CNC and not a converted kneemill.
JR

Click to expand...

Hobbyist I am. This and BOSS seems (to me at least) better option than converting a bridgeport that started life out as a manual milling machine. I do know a few guys that run MACH 3 that started out and transition to job shop, who still use it. I guess they know something I may not? I'm just starting out. I kinda gave up looking for a lathe and found manaul bridgeport and the one above. Though about picking both up that would 1) get me started 2) generate income (side jobs) to for the machines to pay for their selves quicker.

This was my first CNC, 22 years ago. We bought it at auction. It came from a now defunct vocational high school that was dropping it's machining class. GO FIGURE!
Anyway, only seniors got to use and train on it with the teacher.

In 1994, the R2E3 we bought was in excellent shape. Machine held very tight tolerances.

Here is my warning to you about this machine:
The dovetail Y axis way is this machine's Achilles Heel.
Over time, the machine will experience bad gib/way wear.
Because of the machines rapid traverse (250 in/min.) and the weight of the X axis, vises Etc. above,
the dovetail way on the Y axis will wear rapidly. Especially in the middle. Aka SADDLE WEAR.

We ran light production on the machine. Job shop work. The machine was toasty by 2001.
You could barely run it for +/- .005 work at best. It needed a complete saddle resurface.

Ask yourself this question:
Ever see newer CNC Mills using dovetail ways?
There is a reason. Not just cost. The linear way is a better all around way. That is not as prone to this problem. Even on our Hardinge CHNC lathes, Dovetail way, we send the carriage all the way back at indexing to promote even wear along the dovetail. But, this machine does not have the weight on top of the way, as compared to R2E3 and, is covered in flood oil all the time. Makes a big difference.
Bottom line: A DOVETAIL WAY IS A BAD DESIGN FOR A CNC MILL. IT IS AN OLD DESIGIN MADE FOR MANUAL MACHINES.

I would suggest you move your setups all around the table. And to write a program that does a big circle and/or moves all around the table. Also, increase the way lube volume.

Good luck with your astromech droid R2D2!