Centroid Community CNC Support Forum

Is it possible to use the encoder inputs for Axis3 and Axis4 as handwheel inputs if no drive is connected? I'm doing a lathe retrofit and I need one of the extra encoder inputs for the spindle.

The drive inputs on the Oak cannot accept a stand-alone encoder signal (there is no 5v available). The Oak does have two DB9 stand-alone encoder inputs, but you would be using one for the spindle encoder. An Encoder Expansion Board ($395) adds another 6 encoder inputs.

Sure. You just need to make sure that you provide power to the encoder as those axes connectors of the OAK board are meant to connect to a 3rd party drive, which is usually powered by +24VDC so the only power on those connectors is +24VDC. The majority of encoders are powered by +5VDC. You should be able to use the same +5VDC that is used to power the OAK board. You will also need to make sure that you correctly set the MPG/Handwheel encoder parameters correctly. Parameters 348 and 351 are used to tell the control which encoder input you are using which for the 3rd and 4th axes connectors, the values would be 3 and 4 respectively. Parameter 348 is used for the X axis handwheel while parameter 351 is used for the Z axis handwheel. Then you will also need to set parameters 349, 350, 352, and 353 correctly for the encoder that you are using. Please read chapter 14 of the operator's manual as it goes into greater detail on those parameters. Another option would be to go the route that ajaxliviu suggested with the encoder expansion board.

Ajax_Tech,

Thanks for the info - that saves me $400!!
The OAK install manual only goes up to chap 6, so I'm assuming you are referring to the T-Series Operator's manual chapter on Configuration. That's my current bedtime reading

The PLCADD connectors are a perfect place to pick up +5V for the AXIS3/4 handwheel encoders. Do you have mating connector and pin part numbers for the PLCADD board connectors?

That is correct. I was referring to the operator's manual not the installation manual. The operator's manual goes into more detail on all of the various parameters and more. If you ordered a PLCADD1616 board, you should have received a component bag with it that includes all of the mating connectors as well as various resistor SIPs. The SIPs that are installed on the PLCADD1616 board when it leaves Centroid are 2.2kohm SIPs for use with 24VDC power but if you are planning on using 12VDC for your input power, you would replace the existing SIPs with the 1kohm SIPs and if you were planning on using 5VDC for your input power, you would replace the existing SIPs with the 470ohm SIPs.

I think what tblough had in mind was to use one of the PLC expansion headers as a place to tap into 5VDC from the Oak logic supply, rather than as a place to connect a PLCADD1616 board.

While that would be feasible, I think it would be easier and less obscure to just run wires from the RQ-65D supply.

Regarding the original task, though: you could connect one handwheel encoder to the remaining DE9 encoder plug (P2 or P1, encoder input #5 or #6), and the other to the MPG header on the lower left edge of the board (H19, encoder input #15). You still have to terminate a high-density JST plug, but at least all your encoder conductors go to the same place, and Centroid included that plug housing and its contacts with your kit.

The attached picture is from a Chevalier lathe on which I did that. Spindle encoder goes to P1; Z handwheel encoder goes to P2; and X handwheel encoder goes to H19.

CNCSNW,

I was thinking of using the PLCADD connectors for picking up +5V, not for using them for the intended purpose of adding an expansion board I'll just figure out the mating connector when my OAK board arrives. I did not realize I could use the MPG encoder inputs. Would you mind sharing your OAK PLC program that handles the MPG/Handwheel input?

I just wanted to confirm and document that using the Oak AXIS3/4 as encoder inputs pulling 5V power from the PLCADD connectors works without issue.
The PLCADD connector housings are JST #PADP-12V-1-S and the crimp terminals are JST #SPH-001T-P0.5L, and the AXIS connector housings are JST #PUDP-30V-S and the crinp terminals are JST #SPUD-001T-P0.5