Brian,

Have you looked for carriage equivalents elsewhere. I just saw this range at Igus and it looks similar https://www.igus.co.uk/product/930 . The Igus material may be more suitable than nylon which can be annoying to machine.

Manny, A common implementation would use pin 16 as the spindle reverse but due to the limited IO it seems to have been used for the tool changer. It might be the person that converted it wondered how useful spindle reverse is and left it out in favour of the tool changer. I use reverse spindle direc...

There's some details of a Fenner card here http://www.denfordata.com/bb/viewtopic. ... 645&p=5510 showing where to connect a 5k pot, do the details match your card. Searching for 522A3700 turned up questions but no answers.

The question about whether a pot could be used to test the 0-10V input and speed control functionality came up recently but IIRC for a Sprint board, the technical data indicated it could be done that way and the board provided the 0V and 10V references to do so. Do you have the technical data for th...

From what you describe you're using a 0-10V signal to drive an optoisolator which isn't going to work. IIRC Mach3 and typical BOBs use pin 14 to provide a PWM signal through an optoisolator to circuitry that converts the PWM to a 0-10V signal which is what you need so it's isolated from ground as II...

I'd be interested in any electrical and mechanical changes with regards the Orac ATC. I'm not going to apply any mechanical changes to mine any time soon as I've already stripped and rebuilt it with new bearings, they seemed OK but as it was apart they were cheap enough so changed them. The pawl was...

On the Triac pins 41 and 42 of the 50 way connector on the motherboard are connected to +5V, the board looks like yours so with the 50 way IDC cable removed as is the case with yours the 5V won't get to the connection block.

Manny, I didn't mention 69, connection 79 is connected to ground when the SGR is powered and not when unpowered. 61 is connected to +24V. Good you've got the extra IO so I expect you can run everything. Which BOB is that? OK I checked the wiring diagram PDF and it does show that 69 is connected to +...

Near Bath in Wiltshire.

IIRC I ran across information about the toolchanger and Mach3 here on the Denforddata BB so it shouldn't be too hard to find with the search facility. It may have been related to a Triac toolchanger as I have a Triac but a manual tool change one but I saw it when reading previous threads to see if a...

Manny,

No it was the relay you linked to on Amazon in your first post. Is the tool changer side of things working or is it done with a manual tool change? I might be possible to get it working with Mach3 as others have written scripts but would need another parallel port to control it I expect.

General Purpose Power Relay AC 24V Coil and Product Name : Electromagnetic Relay;Coil Voltage : AC 24V;Contact Capacity :10A 240VAC/28VDC

I forgot to mention before that the relay you linked to in the original post was an 24V AC relay coil, you would need a 24V DC coil relay.

From looking at starmill-pc-electrical-diagrams.pdf 61 is +24V and 79 is connected to OUT0 of the original control card likely connected to one of the ULN2803 drivers on the original board so if the wiring is the same you could do that, just check the new switching device is good for the extra curre...

Manny, From https://en.wikipedia.org/wiki/Parallel_port#Pinouts and your image both those unused pins appear to be grounds. You should be able to check the pin assignments in Mach3 and see how they match the pin usage on your 25 way D to find out if there are any output pins left available, I think ...

Can you post some better pictures of the custom card and its companion. From the little shown the custom card looks to be Vero board with transistors interfacing to the 25 way D but it's not very clear, the companion card looks off the shelf with some relays and may have a frequency to 0-10V isolate...

The first driver gear doesn't seem to be taken into account, the one on the end of the lathe spindle and the 28 tooth? forward/reverse feed? intermediates directly after it before the stud gear, they will effect the overall ratio. The lathes.co.uk information does call the gear on the end of the spi...

For cutting metric threads on the lathe with 100% accuracy you need a 100 and 127 tooth gear but there are some other combinations which are close enough that for most practical purposes they're fine. There are a number of online pages that can do the calculations to work out suitable combinations g...

Mine is a later Triac PC but it still uses SD2 and SD3 cards but as they don't have the heatsinks so I presume they have newer switching devices that produce much less heat. I've seen SD2 and SD3 advertised with the heatsinks on them so presume they're the earlier design but I haven't seen anything ...

Pin 8 on the 16 way is given as /energise and likely connects to the SD cards /energise input (pin 30 row C) which when pulled low activates the output drivers. You could also step the drives manually to check for power by just pulling the step line to ground.