New and overwhelmed.

Hello everyone, hopefully this is the right place to post this, and I'm sorry in advance for the long post.

To start my name is Adam and I have a custom cabinet/furniture shop that I run alone.  It is just me, from the Janitor to the CEO.  Well, I'm wanting to increase my production and the best way for me, would be a full size cnc.  Unfortunately I lack the funds required for such a purchase, so I'm thinking of retrofitting an older machine I came across.  For some background, I do own an xcarve, (small 30"x30" cnc, which uses a dewalt router) and laser cutter, have done designs and generated some g-code in fusion 360, but my primary cnc experience is with Easel, which is Xcarve's own web based processor for the cnc, and illustrator and lightburn for the laser.  Basically they are both extremely user friendly.

So that's the background, here is where I'm currently at...

I will say that diving into the world of building/retrofitting a cnc is like drinking from the fire hose.  I've read and watched so many youtube videos my head is spinning...  So that's why I'm here.  I believe I have settled on using Linuxcnc for the cnc control, but that's as far as I've gotten.

What I'm wanting to do:
Years ago my dad purchased a machine from a government surplus sale.  It came from Clemson University and is called a Data Technologies DT9066.  It was built in 2000.  Good luck finding information about them.  Anyway it, for all intents and purposes, is a cnc machine, but doesn't have a z axis or spindle.  It is a machine that was used for prototyping cardboard packaging.  It has a drag knife, creaser, engraver, etc.  It's working area is 90"x66", and has a vacuum hold down table.  I am thinking I can modify the gantry to move it and get a full 96" of working area out of it.  I'm going to have to modify it anyway to have a z-axis, as the gantry only sits about 2" from the bed.  Currently I do not have photos of it, because it's covered in junk as it's become a catch all in my shop, since it was essentially useless to me.

When we assembled the machine in my shop years ago, we connected it just like it was at Clemson when we got it, and it worked as far as moving around, so the motors and amplifiers are working.  The problem is the computer that controls it is incredibly old, and from what I understand the "motion controller" for it, is built into another computer tower, and the internals make absolutely no sense to me.  There's a tag that says "Gaudax" on one of the boards inside of it, but I couldn't find any info on that.

What I do know is it currently has 3 Servo's and amplifiers.  They are Magmotor servos with encoders on them.  They are driven through Copley Controls model 303, and 306 amplifiers, which is the start of my predicament.  

I know I will need to add another either servo or stepper for my z axis, that's obvious, but I was looking at various control boards, or break out boards, or motion controllers, and have seen some that will work with either analog, or digital step/dir but not both, so I think I'm going to have to either stick with an analog servo for the z axis, or replace all of the electronics with steppers and drivers.  On one hand, it may be easier to stick with all servos, because I've read good things about them, on the other hand it may be easier to start from scratch with new steppers and drivers, I mean the stuff on there is already 24 years old, and on the other other hand, maybe there's digital drivers for those old servos now, who knows?

I just don't know what to do next, so I am looking for advice.  If there is a mesa board that will function with the old analog amplifiers, will it also be upgradable if they go out and I have to replace them with newer digital drivers?  Would it be better to replace everything? (I said mesa because that is what usually comes up when I'm researching linuxcnc)  

Oh, and when considering board options, ideally, in a perfect world, and not neccessarily all at once, I'd like to have an ATC spindle, and eventually a rotary, since I'll be processing sheets 48" wide, but my work area is 66" wide, I figured I could put an atc rack down one side with a rotary in front of it, if that makes sense.  That way the machine will be able to do anything I could ever want it to.


Sorry for such a long post, but I figured it'd be best to get all the information I could out at once, so please let me hear your comments, suggestions, advice, etc.  I am in the very early "planning" stage of this build, so I am open to anything.  I just want to keep costs down as much as possible, but am willing to spend a little more if it will make for a better end product.

Thank you,
Adam

So I guess it's one of these:
www.govdeals.com/asset/16511/685

Looks quite sturdy but it's kind of hard to say without the details.
One thing you might want to check is the kind of mechanics they use to move the axes (acme screws, ball screws, rack and pinion, etc) also if it actually has motors for both sides of the gantry and what size the motors are.
A router will likely need a fair bit more lateral cutting force than a drag knife.

That is actually the exact machine he bought.  That's exact one is sitting in my shop.

As far as the servos, I'll attach a photo, forgive all the dust and junk, it's been sitting dormant in a dusty shop.

And they are rack and pinion drive.  There Are two servos on either side for the Y, and one for the x.  Size wise I don't recall, but the pattern from what I could remeber matched a nema 23 or 34... I don't remeber for sure.   It looked like a stepper would bolt right in if the servo was removed.

Tommylight thanks for the reply.  I'm going to research those tonight.  

It's funny, I'll think I've got a good handle on things, then I'll read something or watch something and then be completely lost again.  

It wouldn't let me upload the photo of the rack and pinion and the servo, so here is the servo. They are all 3 alike if I remeber correctly.  They x axis one is covered in junk right now, I can't get to it.
 

So I read about the 7i96s and 7i84 last night and some this morning, and I have another question.

It appears to me that the 7i96s has only one set of analog output, which would go to a spindle, and the x,y,z axis pins output step/dir. Are you saying the x,y,z pins can be changed to output +-10v instead? or is that what I need the 7i84 for?
If so, which 7i84 should I get, sourcing or sinking? I have no idea what either of them mean.

The 7I96/7I96S are step/dir controllers. The 7I96S has a one channel 0 to 10V
output for spindle control. I think tommylight suggested the 7I96S as it gives
you some step/dir outputs for added drives.

For an analog  servo system you need multi channel analog outputs and
multiple encoder inputs. You can add these to the 7I96S either by adding a 7I77
or a 7I85 and 7I83.

A 7I84 just adds more digital I/O say if you have a tool changer.

Sourcing means for example an output device that supplies +24V to a load with a negative common

Sinking means for example an output device that grounds its outputs to drive loads with a +24V common

PCW wrote:

The 7I96/7I96S are step/dir controllers. The 7I96S has a one channel 0 to 10V
output for spindle control. I think tommylight suggested the 7I96S as it gives
you some step/dir outputs for added drives.

For an analog  servo system you need multi channel analog outputs and
multiple encoder inputs. You can add these to the 7I96S either by adding a 7I77
or a 7I85 and 7I83.

A 7I84 just adds more digital I/O say if you have a tool changer.

Sourcing means for example an output device that supplies +24V to a load with a negative common
 

Sinking means for example an output device that grounds its outputs to drive loads with a +24V common

so now I'm a little more confused.  I just read about the 7i77, which seems like doing the 7i96s plus 7i77 would get me where I want to be, but then I looked at the much cheaper 7i83, which appears to do the same thing?  

and you said pair the 7i96 with a 7i77 or 7i85 and 7i83, so why would I need the 85 and 83 together?  So is a 7i77 essentially like a 7i85 and 7i83 put together on one board?

I'm sorry for my complete ignorance, but so many of these cards seem to do the same thing, especially to someone like me who has no clue about things...

While you might be able to turn that drag-knife machine into a router, I think you will get better results for less money (time is money) by simply starting out with a used machine that is already a cnc router. Used machines can be surprisingly affordable. And you may not even need to do a retrofit, but if you do starting out with all the important pieces of the puzzle in place is a bit help.