Hardinge DSM-59 Start/Stop Switch

Can someone explain how their start/e-stop switch used on the later style speed control panels as shown in the photo functions? Is it a momentary push/pull or maintained? The part number of the switch, PTY4211, is shown as a 3-position switch. Not sure what of the third position. I’ll explain why I’m asking. An earlier post of mine, I asked about relettering the speed panel. My newly acquired lathe looks as if someone sprayed a cleaner on it. Painted is streaked and every tag (High/low, Fwd/Rev, etc) is bare aluminum. The black has been washed off including the speeds on the speed indicator panel. While I went back an forth with Hardinge via email on price and availability of the panel and tags, I looked into making new ones. Well, it turns out, the tags and panel are still available. Not cheap, $90 for the panel, but easier then spending hours making a new one. One catch, only the later style is available. Mine is the earlier style with separate “Faster” and “Slower” button with no stop. So that’s what brings me to me e-stop questions. I will appreciate it if someone can answer my question.

Here are pictures from a 1989 DSM59 catalog. I see that they show both versions of the spindle speed control box. The new style control has a maintained contact pull to start and push to stop button at the top. This type switch is available with illumination, but the light does not have to be connected. The lower switch is a momentary contact single pole double throw center off flipper. It looks like Hardinge changed the printing and switch type, but kept the same two switch holes, which are probably 30.9 mm for common Allen Bradley and other switches.

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I have a NIB Allen Bradley 800T-FXQ24RA1 push-pull switch that has a 24 V bulb in it. I think you can get 120 V bulbs to fit if you want. This switch is rather new, as evidenced by the Made in China by Allen Bradley/Rockwell Automation on it. I have an older version of the same switch installed on my Hardinge HSL lathe and it has the 120 V wired to alert that power is on and the spindle will turn if the switch is pulled.

I may have an A-B 800T flipper for the speed control, but I have not looked.



Larry

Thanks. I found a PDF A/B catalog earlier today and have been reading to understand the nomenclature. I order a 3-position A/B switch today on eBay for the Faster and Slower operation. I just don’t understand what a 3-position stop switch would be. I’ve wired emergency stop switch before but it was either on or off. Never seen a 3-position stop switch.

Think of the middle position as neutral. Momentary actuation when you push in from, or pull out from, the neutral position.

Thank you. That’s the answer I’m looking for.

sfriedberg said:

Think of the middle position as neutral. Momentary actuation when you push in from, or pull out from, the neutral position.

Click to expand...

These A-B push-pull switches have no middle position. There is a spring toggle action that holds the button either all the way in (open-off) or all the way out (closed -on). The light circuit is internally connected to an NC switch so that it is lit when the machine is off, but power is on, and not lit when the machine is on.

Larry

Thanks, Larry. If I had wandered out to the shop to play with my machine, I would have noticed that (no middle position).

Okay, so more accurate description (entirely redundant with what Larry just said). Think of this as a toggle switch, except that it goes in and out, instead of left and right.

Back to confused again. As an example, the e-stop on my lathe is “out” so lathe can run. If I push it in, power is interrupted. For me to release, I must twist and it springs out on its own.
So the e-stop used on the Hardinge is maintained either “in” which is “off” or “out” which is “on”? What I’m confused about is why the switch part number when looked-up, the description is 3-position.

One possibility is that someone made a mistake. Here is a picture of the HC chucker control box. You can see the coolant control switch has three positions. The same switch is used on the DSM, but it is located on the end of the cabinet.

Larry