[mhackney]

The switch that came with the G0704 is a Kedu KJD17B (note there is a typo in the manual, they list it as a KJD178). The switch has a feature called "Remote Trip" that is the A1 terminal on the back. I have searched to try to understand what that is and how to use it. The G0704 schematic (see below) shows it connected to the spindle direction selection switch. I suspect that what it did was shut off the spindle motor if you try to reverse direction with the switch and the spindle running but it has been years since I had this on my mill I don't recall. Does anyone know what the Remote Trip feature is and how it is used? If it is what I think - some signal on A1 forces the KJD17B to trip - I'd like to cause the switch to trip when the eStop button is pressed.


Attachment 253218

[mhackney]

Here's a link to the KEDU catalog for this switch: http://www.kedu.cn/Catalogue/Electro...ue.html?page=9

The grizzly switch is case GF and F2 function.

[joshuaz2]

A1 is voltage to the magnet. L1 is fed thru the motor direction switch and out pin 10 to A1 then thru the magnet and out pin 14 to L2 any switching of the motor direction switch will interrupt the magnet voltage causing the motor to turn off. So if you put your kill switch in the wire from the direction switch pin 10 to starter pin A1 that would work to stop the motor. hope that's clear as mud.


Roy

[mhackney]

Thanks Roy. I've actually removed the spindle direction switch and want to repurpose the KEDU switch in my new panel.

Terminals 13 and 23 connect to 120v AC. I think what I need to do is put my kill switch between A1 and terminal 24 on the KEDU switch. The kill would be a NC. Does that make sense?

[joshuaz2]

completely.


Roy

[joshuaz2]

was right the first time.

[mhackney]

I found this in the G0765 lathe manual:

Attachment 253282

Here the terminals 13 and 23 go to mains.

[Fastest1]

Michael, Thanks for that schematic. I have just taken my electronics box off the side of the spindle head. I am using a KBMM 125 and eliminating the directional switch. In doing so, can I still reuse the tach? The tach seems to get L1 and L2 from the same point on the drive but I wouldnt think it was necessary, just sharing. I would think L1 & L2 from the source would be just as good.

Do you understand what wires 5,11,12 & 14 are for?

My limited understanding says that 5 & 14 are the power for the tach.

If you put your Estop between 24 and A1, are you using a relay or bringing a leg of 120v thru the switch?

[mhackney]

Ah, look in my G0704 build thread and search for "tach". I actually modified the grizzly tach to use a 9V supply directly and cut the board down to a reasonable size. It was very easy to do and works great.

The grizzly KSP circuit board has an AC- 9V DC convertor that wires 14 and L2 supply. I simply removed that device, cut the KSP board down to remove all the uneeded stuff and used 9V directly.

[mhackney]

Here's a link to my tach modification: http://www.cnczone.com/forums/bencht...ml#post1214286

[mhackney]

Forgot to answer your last question... I assume that 120V goes through the switch but I have not hooked it up yet. Hope to do that tonight.

[Fastest1]

That was exactly what I wanted to know in regards to the tach. Is there a way to port that spindle index back to the BOB? Just curious on that 1, might be hoping too much.

About the EStop, doesnt industry standard usually use low voltage for the panel controls triggering the higher voltage relays? (I understand we are hobbyists but we do try to implement the safety procedures as we learn them)

[mhackney]

I think so, that's what I plan to do next actually. I think it might be as simple as splitting the leads and running those to the BOB. I seem to recall doing that on my mini mill.

I think that low voltage for estop circuit is common practice but not standard. I'm still on the fence about it myself. I simply wanted to reuse this magnetic latch starter switch and when I discovered the interrupt I thought it would be good to use. But, I need to figure out how to make sure both my control panel (up by the mill with the on/off, estop, pokeys keys, C6 and motor controller) and remote box (with the bob, drivers and power supply) are estopped properly and in unison. I am leaning towards a 24V estop circuit with relays to enable a contactor. Just need to sort the wiring between the panels to keep it simple.

[Fastest1]

The more I think about it. I like the idea of the Estop killing the spindle (of course it could be done with a relay too or also).

Since I took the electrical box off the side. I installed that KEDU switch and an additional Estop where the Z dro (caliper) was. I might just install the tach there and take the KEDU back out and place it elsewhere since it could be tripped thru the estop. Still close enough to hit start of course.

[Fastest1]

A1 to 24 does indeed energize the magnet. Great to know.

I guess originally that was for the chip shield we all bypassed. Now my EStop kills the spindle and Mach all without a relay. Works great.

[mhackney]

Actually, I think it was to prevent switching the forward-reverse switch with the motor running. Follow the circuit diagram and that's what I get out of it.

My only hesitation with this is that it will require 2 steps to reset the machine on startup or after an estop.

[Fastest1]

You are probably right or maybe both switches ran thru it?

In regards to the 2 step restart. I dont see a problem. Before I was doing the 2 steps to stop. I didnt ever like that.

[mhackney]

I am thinking about that, but will likely use a really to activate a contractor in my main electronics panel. The "challenge" is figuring out how to do this simply. I bought an estop with 2 NC switches. I planned to run the mag switch (A1-24) through one side and a 24V circuit to activate the contractor through the other. I think that will be reasonably compact on the remote panel since I'll only need 2 wires for the 24V circuit.

The new estop comes in this week. Meanwhile, here is my panel starting to shape up. The estop will go in the empty hole in the upper left. The power on switch we've been discussing here is mounted on the left side of this box (this is just the sloped front panel).

Attachment 254602

And here's the back side. Starting to wire up the PoKeys. the RPM display from the original G0704 is in the upper right on this photo. The small circuit board positioned vertically is the modified tach from the original controller. The device with the red and green LED lit is the PoKeys.

[Al_The_Man]

The switch is a compact example of just about every switch fitted to Chinese import machines, commonly known as a DOL (Direct On Line) starter it is a method by magnetic coil of defeating automatic restart when a power outage occurs.
There is a tried and true E-Stop circuit that has been used for many decades using a small multi-contact relay to moitor the whole E-stop string, there are many examples here.
http://static.schneider-electric.us/...0140CT9201.pdf
Al.

[mhackney]

Thanks Al, I downloaded and read that PDF many times after I saw you post it elsewhere. A really great resource. Originally I thought there was something to be gained by resuming the switch with the mag coil. I am building a small slope panel box that is mounted on my enclosure that will provide a front panel. I'll have the estop there and thought the power on switch for the spindle control board made sense. I don't have a lot of room in the box and it already has a 9 and 12 v wall wart along with KBMM225 control board, the pokeys and a few other things. I'm thinking now that I should just run a 24V estop string from my main electrical box (under the mill) up to the estop. I'll have the 24V wall wart, a 24V 4PDT relay and a contractor in the main electrical box with the wall wart powered on when I turn on the on/off switch in this remote box. I'll need to add a momentary contact button on the main panel to energize the starter coil like figure 2 on page 6 in the document you linked. I was thinking that I could use the KEDU switch for this but maybe it is more trouble than it is worth.

Cheers,
Michael