Bridgeport Series 1 conversion and other stuff

Hi List,

Since this is my first posting to this list I thought I would start with an
introduction: I heard about this list from the ModelEng list where I have
been a member for several years. My application is Home Shop centered
around 7.5" gauge Live Steam railroading but my interests range far and
wide. I have an Electrical Engineering degree but my field is software
development. I have only read this list for about a week. I have been very
interested in the intelligent/passive (better than smart/dumb ;-) ) driver
discussion and I understand the issues but I'm afraid I'll be able to
contribute little since my "hands on" EE theory knowledge is 1970's vintage.

Among other things I have an Enco 9x42 Bridgeport clone that I have added
"Home" CNC to (X and Y only so far, Acme screws) and an Emco Maier Super 11
lathe that I have also adapted to CNC (again, no ball screws). I use an
AHHA 4 axis driver and their Artisan software.

I have found 5 Bridgeport Series 1's (Boss 5 & 6, one 7) in the area with
prices down to $1,000 and I've been thinking of getting one, throwing away
the tape-based controller and substituting the AHHA driver/software.

Questions:

1) Can you tell me the drive current requirements of the steppers on a
Series 1? (I have 6 amp drivers)

2) Are there things I should look for on these machines prior to
purchasing? I'm currently looking at overall condition, backlash (how much
is too much? can they be adjusted?), etc. If at all possible I'll try to
check the machine under power. If they don't have power can I get to the
axis's to pull them over by hand to check backlash?

3) I just read a list message about pneumatic tool changers. Never
thought of that, I've got lots of cylinders around here. Guess I'll look at
those Bridgports with an eye to the easiest tool mounting to adapt to "auto
change". I think at least one of them had an "RS 30" type (I'm not very
familiar with mill quick change tooling any pointers would be appreciated).

4) Any other pointers before I jump into this conversion?


As I mentioned, I use software from AHHA which is DOS based. It has it's
good points but I would like to find driver software that is Windows-based
or that will run in a "DOS Box" window. I'm aware that there has been
discussion on this list of the relative merits of Windows, DOS, etc. as an
OS. My desire for Windows is due to: 1) The ability to network with the
other systems in my home where I do design, etc. 2) The ability to switch
back-and-fourth to other programs like CAD to modify a part geometry and
then back to the indexer software without having to re-boot, etc. 3)
Software (if well written) has a consistent "look and feel". I'm aware that
a multi-tasking OS like Windows does not lend itself to real-time but this
is my goal.

Keep in mind that I'm probably a "beginner" compared to a lot of members of
this list but ... my thoughts on the intelligent/passive box "line of
demarcation" is that it would be best to put as little "hardware" in place
as possible (enhances flexibility) but that it should include enough
hardware help (interrupt and position buffering, etc. within reason) to
allow a non-real-time OS to achieve smooth contouring, etc. (keep in mind
I've only read a weeks worth of messages here so this may have already been
hashed out ...). In my situation I value flexibility over speed but I
realize that situations/preferences vary.

I understand that G-codes are not all "standard" but I think it would be
desirable for the indexer to be able to load a file based on G-code subset
so some minimal "file sharing" can take place with existing resources. The
file might require some "tweaking" to resolve the G-code incompatibilities.

As a software developer I've thought that an interesting approach in the
indexer software would be to support an embedded language like Visual Basic,
etc. to make the environment "extensible" (I can program VB faster than
G-codes!). Of course if it was VB that limits the OS environments.

Has consideration been given to features in the "Black Box" to support
feed-hold without loosing position in a stepper only (i.e.: no DRO feedback)
environment? This would support Hold/Resume and enable coordinate
measurement applications, etc.

I guess I'll stop there except for a couple more questions:

1) Can anyone recommend windows based indexer software that supports
lathe and mill modes that I can use with my AHHA driver box (accepts S&D,
etc.)?

2) I'm looking for a program to aid in creating G-code from DXF files.
Recommendations? I have BobCAD but I'm VERY frustrated with it. For the
development sequence I currently use TurboCAD, BobCAD and AHHA Artisan.

3) I have a demo copy of SolidWorks but haven't played with it much
yet. Are there SolidWorks users on the list that can help me if I get
stuck?

4) Can someone give me a source for inexpensive (but well made) ball
screws and nuts?

5) What approaches have people used to add CNC to the longitudinal feed
of a lathe? I currently drive the right end of the screw cutting lead screw
and engage the 1/2 nuts to use CNC but this is probably not a good long-term
solution (lots of backlash I always have to account for). My lathe has a
separate shaft to drive "power feed" but I didn't think that the pinion &
rack could be counted on to be linear.

Sorry for the ramble. I don't usually post such long messages. Hope I
haven't worn out my welcome already ...

Regards to all,

Chuck Hackett
Omaha, Nebraska, USA


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