Hi Everyone,
I am a newbie to this wonderful forum and am hoping someone might be able to help me with a little information. I recently aquired a Bridgeport BOSS 3. I have dealt with many Newer CNC's but none with this kind circutry boards.

I need to know how I can hook up a PC using a current loop converter. There is plenty of information on where to buy one online. But I have not found any information on the wiring schematics for a BOSS 3 control. Ebay has a lot of stuff but it is all for BOSS 4 and up controls none for the BOSS 3.

If anyone has a pin out diagram of the "Local" plug on the machine and what wires need to go where on that plug it would be great. Or possibly a step by step setup to wiring an RS232 into the machine? I have a lot of experience with RS232 communication but not with the Bridgeport Series of control boards.

Any information would be greatly appreciated. If someone has some ideas you can email me at thesaxnut@netscape.net

Thanks,
Zach

The problem is that the BOSS 3 is so old that it has no circuitry for RS232. The 20ma current loop was the communication standard for a type 33 teletype. The type 43 had 20ma and rs232 capability. Both allowed editing as well as tape punching and reading. Be aware that the 20ma had a bad habit of blowing a transistor in the circuit. I replaced a lot of those many years ago. In other words, it was not that reliable. Now that the ancient history lesson is over, I need a email address to send you some data.

George

George is right!

I bought several boss mills when they were new 30 years ago and even back then the series boss 3 was constantly down couldn't have enough transistors!

Its a miracle it still fires up at all! Your best bet is to junk the old control and install new drivers, break out board etc. The old BP iron is worth the upgrade assuming ways and ball screws are good and the same goes for the steppers!

There are several post on this forum of DIY.

Hope that helps.

JimPAC

Thanks George and JimPac for the information. I have heard a lot about the BOSS 3 blowing transistors. The guy I bought it from kept it in very good condition. he had three other BOSS machines in addition to the BOSS 3 that I bought. The ways on this machine are in excellent condition and the scraping marks are very visible throught all the ways. I am amazed that most of the control still works on this machine all except the MDI function which is why I would like to hook a PC up to it.

George my email is thesaxnut@netcape.net if you have any information that would be greatly appreciated.

Zach :D

----- Transcript of session follows -----
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Final-Recipient: RFC822; thesaxnut@netcape.net
Action: failed

Tried to send you some stuff.

Yes, the final drive transistors would blow very often (2N6547) but the trnsistor on the 20 ma current loop circuit on the ERS board also had a bad habit of blowing.

George

George,
I did not seem to get the email you tried sending me. Maybe it is my spam filter? can you try sending the information to zkissinger@summitsteelinc.com

Thanks,
Zach

Fellow forum users. I finally got all the connections made for the RS232 hookup. A big thanks to George for sending me all that info and to others who helped me get the wiring connections correct.

Now I have a different problem. To start all connections to my PC are good. I can send and receive with no problem to the machine. My problem is when I send a simple program to the machine I can not get the machine to run the program. I think I have exhausted all my resources. Is there something i am missing? I put the machine in setup and press edit and then send the program to the machine. From the manual I have it says the machine should output BOSS 3.0 INPUT which it does and it seems to me it has taken the program. But when I put the control in AUTO and depress the Start/Continue button I get nothing. No movement at all on any axis. Do any of you guys have any idea what this could be? I have a copy of the program below and it is really simple:

NT1/1.0
G0G90X-2.0Y1.5T1M6
G0X.116Y-.116Z.1
=N50/70
/G0G90X1.25Y-.39Z.1
N2G0G90X.116Y-.116Z.1
N4G83X.116Z-.44Z-.24Z-.18F60
N6X.366
N8X2.181
N10X2.431
N12Y-1.604
N14X2.181
N16X.366
N18X.116
/N20G81X1.25Y-.39Z-.32F60
/N22X1.75
/N24Y-1.32
/N26X1.25
N28G0G90X.116Y1.5Z.1
/N28G0G90X1.25Y1.5Z.1
N50M00
N60G0G90X-2.Y1.5M2
E

When I download the program from the CNC to the PC it then reads back like this with question marks all over the program:

NT1/1.0 ?
?
G0G90X-2.0Y1.5T1M6?
?
G0X.116Y-.116Z.1?
?
=N50/70?
?
/G0G90X1.25Y-.39Z.1?
?
N2G0G90X.116Y-.116Z.1?
?
N4G83X.116Z-.44Z-.24Z-.18F60?
?
N6X.366?
?
N8X2.181?
?
N10X2.431?
?

Does anyone have any idea of what the question marks might be? is the machine not reading the code correctly that it won't initilize the program? I am at my whits end with the machine. I thought something could have happened in transport when the riggers moved the machine like a wire broke or a short in a circut? The guy who I bought it from ran programs like this daily on the machine and I saw it run programs before I bought it.

If anybody can tell me what I am doing wrong or has any information that would be great. Thanks again for all the help.

Zach K.

Why not try some MDI rapid moves to prove the control works?
A feedrate moves requires the spindle to be on.

George

I have a boss 4 cnc. I have replaced the transistors in the power supply and all axis will
move in rapid, but when i program a feed rate the machine does not move. I know the
feed is inhibited unless the spindle is turned on-but what tells the cnc the spindle is on?
I have very little information on this control-can somebody help?

There are micro switches on the sides of the large spindle forward and reverse contactors that tell the control when a contactor is engaged with means the spindle is turning (in theory-you could be in neutral).

George

Does anybody out there have a an electrical schematic for the wiring and circuit boards for a Boss 4.
Thanks

Zach- If you are loading a program from the pc, make sure you initiate XON after you get it into Input mode. Mine gives me the same type of gobledegook if I don't. Another thing to look at: When I try to save a program to the pc that's already loaded in the BPT, The file ends up corrupted. I think its my old PC-TALK terminal emulator at fault. Anyhow, all I do is go into the file using notepad or a word processor and eliminate the extra characters that end up after the M2 at the end. The characters that end up in the file are unrecognizable by the CNC, and don't appear when I list it in the terminal emulator...only when I use notepad or similar.

The problem might be unique to me, but I thought I'd bring it up.

Have you tried to type in a simple pgm when in Input mode? The BOSS system will give you the type of response you're getting with just one unrecognizable character.

Rob