[boysandjeep]

I'm ready to replace my Dynapath 10 system with an Ajax CNC. I've been reading a lot on the forums and it seems the best choice for me. I haven’t found a post that address the same situation so I thought I’d start a new one.

Background;
Clausing Kondia knee mill, 3 axis Dynapath 10 factory install, with ServoDynamics 1525 amplifiers, Baldor 500 in-oz, Big MHO, brush servo's tach and encoder feedback. Current state; 1 encoder lost the once per rev signal, ailing power supply, and a corrupted EPROM. Need to upgrade with a math coprocessor to be able to drip feed G code. So it seems it would cost as much to fix it as to upgrade. I'm reasonably knowledgeable about hooking things up and can read a schematic.
My plan;
Remove the Dynapath system.
Replace with a Allin1DC from Ajax.
Replace the encoders with ones from Ajax.
Replace the operator panel with the handheld one from Ajax
Use my own PC and Flat screen
Get the console arm from Ajax or Get an Ergotron arm from Ebay.
My Questions;
Since my Dynapath power supply is dying what should I use for a power supply for estop circuits, limit switches etc. What voltage?
Can I use the power supply/rectifier from the SD1525 for the motor power?
It has a 220 to 80 Volt transformer, can I get a rectifier for that so I can keep the SD1525 complete?
Anything else I should consider?
Anyone else done something similar?
Any thoughts, advice, etc. would be appreciated.

[cncsnw]

I just helped a customer complete this type of conversion.

We used his original transformer (80VAC secondary) to feed the Centroid rectifier (CAPBRDLO assembly).

We used the 12VDC from the All-in-one unit for input power (limit switches and E-stop switch).

We changed the original "home" switches to normally-closed contacts, so they could serve as limit switches as well as home switches. Centroid/Ajax requires separate switches for plus and minus directions; can home off of limit switches; and requires that these switches be normally-closed.

We used his original contactors for emergency stop, spindle forward/reverse, and flood coolant.

We used his original motors and 1000-line encoders. Precision would have been slightly better with 2000-line encoders, but the original ones were good enough for his purposes.

[boysandjeep]

cncsnw, thanks for the response.
Nice picture, I hope I dress my cables out as well. That cabinet looks just like mine, transformer, fuse locations, etc. You answered all of my questions and reminded me of the one I forgot to ask. (And some more)

Do you remember what part number you used for limit switchs?

Did you keep the operator panel?

Did you have a hand wheel, if so does it work witht he controller?

I haven't had a chance to research that yet.
I was debating about getting a VFD for the spindle motor but I could copy what you did and upgrade later.

Any second thoughts or issues with Ajax? It seems pretty straight forward.

[cncsnw]

We used the original limit switches.

We did not keep the Dynapath operator panel. I don't recall if it had a handwheel on it.

We left the space in the center right of the panel open for possible later addition of a VFD. It will be a little tight, but a 3HP V1000 should fit.

[cnckeith]

cncsnw, thanks for the retrofit info and the photo of the cabinet. Looks like a nice clean install and it must have been an economical retrofit being able to reuse so much of the existing control system. are there any photos of the completed machine?

[cncsnw]

No overall pictures. With all respect to the customer, his shop does not exactly resemble a machine dealer's showroom :-).

Yes, it was quite economical, even with three days of my time to do the installation for him.

[Aftershock]

I retrofitted a Dynapath 10 on a Lagun mill with an Ajax control quite a wile back. I am guessing at least 8 years. It is using the DC3IO. I still have 3 Dynapath 10 controllers stacked on top of each other in the shop. None of them have a good IO board.

I did everything you listed in My Plan except add an arm. My 19" flat panel is just mounted next to the head of the mill and the pendant either in my hand or stuck with the magnets to the side. I also added a power supply purchased from Ajax for the limit switches, etc. It is powered by 110 on a separate circuit along with the DC3IO and PC. I used the cap and bridge combo included in the kit to get my 110 DC off the 83 volts AC coming from the reused transformer.

Contactors for main power are turned on by a relay powered by the 5VDC power of a hard drive power cable inside the PC. The PCs power switch is wired in parallel with the original push to power switch on the front of the mill. So hit one button, powers the PC which in turn powers everything else. Do a software shut down of the PC and it powers everything else down.

One thing I wish I had done at the time of the conversion because I never went back to do it is add an additional contactor for reversing the spindle. Since my original controller did not have this feature, it did not dawn on me how easy it was to add with the new one.

[boysandjeep]

Mill Lessons Learned
So I finally got around to writing this up. I pulled out the old Dynapath 10 System and went with the Ajax All-In-One DC system. I purchased it through CNC Services North West (cncsnw), and I would highly recommend them. I have no regrets and am very pleased with the product.
The encoders were easy to install, my encoders had a .250 inch shaft that went into a helical coupling. The encoders I got through CNCSNW had a .250 dia bore. I just used a .250 dowel pin to connect them and drilled and tapped the motor housing of the Baldor Big Mho DC motors. It worked great.
Things I would do differently if I did it again.
Get a crimp tool and pin removal tool for the D-sub connectors, cheap and available on ebay.
Use the same color coded wire as shown in the wiring diagram provided, it simplifies trouble shooting.
Buy a VFD right away and don’t try and mess with a phase converter and hooking up contactors.
Use quality terminal strips on DIN rail, available from Graingers etc.
Try to work on it continuously, don’t take several week breaks, I forgot where I was several times.
Use the pc power supply for the E-Stop circuit, no need to buy a separate power supply.
I bought new limit switches before I realized the ones I had were both normally open and closed it just depended on how they are hooked up. The mill originally was wired normally open, the Centroid wants normally closed.
Things I’d like to see improved:
The wiring diagram is a little jumbled, it would be nice to show the connections and not just refer to the location. It could be split into 2 or more sheets to make it easier to read. It is all there just not as easy to use as it could be.
The instructions could use some editing to make it flow better, for no-electrical guys it would be nice to include examples of the various ways it could be connected with more diagrams to explain.
Things I’m glad I did:
Bought the system through CNCSNW, Marc was great and still answers all my dumb questions.
Used some cheap monitor arms for the monitor and the operator panel. I got them at a place called Weird Stuff Warehouse for $25 each and a keyboard tray for $5. Super simple and they work great.
Bought the VFD from Automation Direct, took me a little time to figure it out but once I did it works great.
All in all I’m very happy with the system, but I am a mechanical engineer by profession this is merely a hobby for me. I’m not trying to make any money with it I just enjoy it.
Hope someone can benefit from my experience. I dont' check the forum alot but if someone has questons or wants pictures PM me.