where to begin to convert a Delta Tau CNC controller application to Linux CNC

Just typed out a long response, looks like it was lost...sorry about that!

Here is a new one: www.sterlingint.com/lathes/optoform-80

Here is a used one, sold: caeonline.com/buy/machine-tools/precitech-optoform-50/9133282

Optoform 50. Two air bearing linear slides, and one air bearing spindle. Machine uses something like 10CFM of compressed air.

I have never actually seen one, so I don't exactly know. Drive is Delta Tau controller. Delta Tau no longer--it is now Omron. machine made in 1990's, and has been used for grinding interocular lenses. Interocular lenses are the lenses used to implant in people's eyes following cataract removal surgery.

We wish to make contact lenses with these things.

I did ask about the drive: 0-12 volts is what I was told, however I would be surprised, and probably 0-10 volts driving custom-made Kollmorgen motors. "Everything" about the lathes are outdated, and why I asked about where to start with the conversion of the program to Linux CNC.

Linux is a DIY system, and since they take weeks to respond to our requests, I would rather be on my own than depend on them.

With the slides being air bearings, pretty sure encoder feedback with some sort of velocity feedback because cutting torques are really small. ALso t he machine has a vibration isolation base using some sort of air bearings. Best surfaces in the business...

Definitely not stepper motors.

Regarding macros. I have decades of experience designing and making contact and optical lenses--even before the advent of computers. We just did not have enough money for the custom programs. All of the programs date back to Sir Isaac Newton--about 400 years with updates due to computing power.

Pretty sure the program itself is relatively straightforward with the needed changes in the control language from Delta Tau to Linux CNC.

All you really do to make contacts is generate curves. These are relatively small curves, usually in the 6.00mm-15.00mm range. There are some complex curves, however, I believe these are handled by the host computer, and either downloaded or the host computer generates the code for the lathe itself. I just do not know.

Due to taking months to get any service, we are slow with information. Pretty sure the lathe runs on DOS.

Hello:

For our other old CNC for making contacts, the whole program fits onto a 1.44mb floppy disk. It has not worked in years.

Regarding the contact lens prescription:

The doctor takes keratometer readings, and spectacle Rx. Some doctors design their own lenses. We prefer to design them for doctors because we have more experience in designs. We have a custom-program to do this.

We make gas permeable contacts. The majority of lenses are soft lenses, and probably represent 98% of the contact lens business. Our part has been slowly dying for decades. When I started, there were approximately 450 contact lens labs, now there are less than thirty in the US.

The lens prescription is sent to the lab--either designed for us, or we design. Most are called in, but we do get them by email and fax. Remember, we do have HIPAA compliance to deal with!

From there, we essentially use a canned accounting package, and create a work authorization order. This includes the base curve (the back-side curve of the contact lens) that goes on your eye. Then is the distance (front or near, or bifocal) prescription. Note that there are many designs for contact lenses where the back and front interact to do different things optically. Then the diameter. From that point, we design the edge of the lens using peripheral curves. This is the design of the lens for optimal comfort. This edge design includes the peripheral curve (back-side of the lens) this is the area from the base curve to the edge of the contact lens; the actual edge shape, and the curve transitioning the edge to the front of the lens for the distance prescription.

Think of your cornea as another refractive (or "lens) surface.

It is all relatively simple, and is on the job training. I am the last employee, and trying to survive a few more years.

The diameter can vary quite a bit from about 8.0mm-20mm depending on the lens design. Most gas perm contacts are 8.8-9.5mm. Specialty lenses called sclerals are popular right now. Also expensive.

I could spend hours on this subject; please ask. Just know that having a telephone conversation is probably easier than articulating my thoughts in emails.

The complicated part of making optics is you are making something relatively accurately, and add the fact you need to see through it. This also gets complicated because many people have complicated vision problems. As we get older, these get more complex, but understandable. Add things like trauma, and various health problems that will effect your vision like Keratoconus, or diabetes, or glaucoma, or cataracts, for examples.

When everything is ground, we then final check-out the power, diameter, and check it in a microscope before sending to the doctor, then doctor to patient.

I don't know enough details--I would say the machine runs on ASCII commands.

I would explore some kind of gcode generator. Take your curves and parameters and output the necessary gcode using python.

So, it sounds like you could use Linuxcnc in lathe mode, you'll obviously need to get control of the servos and the encoders/linear scales for feedback. Servo tuning will be paramount to the accuracy you need.

Do you run multiple cutting tools ?

The other side of this is you need gcode generation, to take your curves and turn them into something linuxnc can handle ie gcode.

Probably need a custom hal component to run the air bearings. I imagine they need to have positive flow prior to motion, this should be easy to do with hal gui using machine on and mwchine ready hal pins.

Nothing sounds extremely difficult, just labor intensive

Thank you very much for your responses, and thank you for your continuing suggestions!

I did ask the motion controller company today...It is a delta tau, and uses G-codes!

Also, did call Omron's technical assistance, there is a tool using the serial port that is quite complete to take the program off of the machine, and it is more complete, according to Omron, than using hyperterminal, and more detailed from hyperterminal or putty. It has been removed from the listing on their website, but using the search feature, it can be found, if this makes sense.

Will be downloading soon, and will install on a couple of computers. Will also be purchasing a DB-9 to USP cord. Let's hope all works as suggested.

Thank you, again,


david