I think I killed the Junkford

Normally I machine these parts in the big old girl, Mori Seiki mv-80 but the lcd replacement for the crt won't be here till tomorrow. So I got 3 of them finished and it worked better than I expected in the Johnford. Then the Johnford issues started to arise. I was drip feeding the program to it, These were the first parts I've ever had to do that to on this machine. All was good until the finish pass on the 4th part. It stopped the spindle and there was nothing on the remote screen. It did throw an error light but no apparent error code. So I rehomed the machine and started it again. It did the same thing, in a different spot, approximately the same x spot but different y. This time it put the emergency stop on, still no codes. I thought it might of had a broken wire for the x stop or something hitting the over travel switch. So I took the cover off and cleaned around the limit switch, everything looked good. I reposted the program to start at the front of the part and tried again to the same result. Then I thought it could be an issue with the dnc/baud rate since I had changed the baud rate to 19200 instead of 2400 or 4800 whatever the old mori is set to. Started the program again with the same result. Then the last time I tried it, the Machine wouldn't move at all. Spindle stopped on the part, machine won't move. Check for error codes and when I tried to restart the nc I got 3 error codes for the toolchanger. Wtf? The program didn't even have a toolchange in it, just one tool. When I tried to start the nc again the tool unclamped for some reason but still wouldn't move the table. Hit the nc button again and the tool clamped again. Then I started to smell something burning. Sure enough a little bit of somke coming from the electrical cabinet. So I quickly shut down the power and opened up the cabinet. The small fuse below the red light was still smoldering. This can't be good.

It will make good re-inforcing steel to put in the foundation for the
new machine foundation.....

digger doug said:

It will make good re-inforcing steel to put in the foundation for the
new machine foundation.....

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Nah, too many voids. At least strip the sheetmetal off first.

Looks like an MTB designed breakout board for the I/O. There must be something shorted. Start checking the various switches and see if you can find one that is shorted to ground.

Milland said:

Nah, too many vhttp://www.practicalmachinist.com/vb/images/smilies/skep.gifoids. At least strip the sheetmetal off first.

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Wouldn't have anything left....Johnsfords are only sheetmetal......

Instead of the problem being linked to a spot in the program do you think it repeated a few times at about the same position in X?

I bet you have a switch wire shorted.

ewlsey said:

Looks like an MTB designed breakout board for the I/O. There must be something shorted. Start checking the various switches and see if you can find one that is shorted to ground.

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Thanks ewlsey that’s what I was thinking. Just needed a few to think about it some more away from the thing. Btw I’m gonna owe you a case of your favorite beverage for all the help you’ve pointed me in the right direction on

digger doug said:

Wouldn't have anything left....Johnsfords are only sheetmetal......

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Hey now digger...there’s a little chunk of iron in the middle of it. I might be headed your way with the snowmobile if you guys keep getting that enjoyable white stuff

Garwood said:

Instead of the problem being linked to a spot in the program do you think it repeated a few times at about the same position in X?

I bet you have a switch wire shorted.

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The more I think about it, the more I think that is probably the case. I’ll start pulling covers in the morning. If I can’t figure it out by the time ups shows up, my attention will shift to the new lcd screen. So if I find the problem and fix it, what are my chances of just re soildering to fuse back to the board and being good?

CNC Farming said:

Hey now digger...there’s a little chunk of iron in the middle of it. I might be headed your way with the snowmobile if you guys keep getting that enjoyable white stuff

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Enjoyabe you say ?

My snowmobile friends aren't out in it, they claim it's too cold....

Most of the snow is in downtown Erie, the snomo clubs are in the county (the normal
snow belt areas), and we have maybe 18" at most, the trails are open however.

Most J Ford boards have a black block that will open from the top to allow glass fuse replacement.
J Ford also has an habit of using junk wire and over straining DC busses, standard trouble shooting practice does not apply!

ifixcnc said:

Most J Ford boards have a black block that will open from the top to allow glass fuse replacement.
J Ford also has an habit of using junk wire and over straining DC busses, standard trouble shooting practice does not apply!

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I kinda figured they were junk, when I saw the "flex conduit" was a paper thin
shiny vinyl hose that looked like it was taken from a Hoover.

Forget hot chips, even sparks from an angle grinder would have
punctured it.

Based on this observation, and the main power switch was not "LOTO Capable" as purchased, led me to believe the wiring & controls were junk.

Looks like I wasn't wrong.

ifixcnc said:

Most J Ford boards have a black block that will open from the top to allow glass fuse replacement.
J Ford also has an habit of using junk wire and over straining DC busses, standard trouble shooting practice does not apply!

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I got most of the covers off it this morning, still have a few more to go. She needs a good cleaning and some wiper seals and way cover seals replaced while its down. The 2 wires in the picture are for the limit switches and the way covers has obviously been rubbing them. The worst one is for the x axis, but it doesn't appear to be through all the way to wire but maybe it is. Other picture is the board again. I turned the power on again quick after I had discovered the wires. The board instantly got red and started smoldering around the fuse. So I'm assuming the board is now junk?

The board instantly got red and started smoldering around the fuse = Bad sign. The low cost components are under rated for any extra load. A good board repair guy could probably fix it. Probably an over rated fuse in your holder. A short should take out the fuse, not the board. Steve O's parts guys prices are not that bad, but their delivery time often Sucks.
Find and fix the short with an Ohm meter, before powering up again, so you don't burn up anything else.

The fuse should just pull out of the board. I'd get it out of there before you burn something up.

The board can likely be fixed, but it depends what a replacement would cost.

ifixcnc said:

so you don't burn up anything else.

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I see it a bit differently....

I'm thinking the OP should pile kindling all over and around said junkford,
and pray that it "Lights off".....

digger doug said:

I see it a bit differently....

I'm thinking the OP should pile kindling all over and around said junkford,
and pray that it "Lights off".....

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If only it was in a separate building...

I took the fuse out of it, unfortunately the fuse holder came with it. Is this repairable? I'll be getting a price on a new board. I took another look at the limit switch wires and the one for x axis does look like it probably is cut into a wire. What's the best way to check this? just strip the wires back around where it has rubbed or can I check resistance somewhere?

Go through the board and check every wire that says "DC24V" to ground.

You will see they are in pairs. One says "DC24V" and then next to it will be an input. The current is supposed to go out to the switch, then come back to the board if the switch is closed.

If one of the 24V wires shorts to the frame of the machine, it pulls too many amps through the circuit and should blow the fuse (it "shorts out"). For whatever reason, yours cooked the board instead.

It could also be possible that one of the inputs is shorted to the frame and when the switch closes it shorts out.

Ok I'll go through and check them again and then I'll try to put something touching the limit switch wire to the machine and see if I get anything different

Ok I checked resistance from ground to all the lmt wires. reading of .050 across all of them. Then I held the x axis limit switch and got a reading of about .042 on one of the x axis wires and nothing on the rest of the wires. Then I tried to simulate the way cover coming in contact of the x and y wires and got a .062 reading on all the wires. Does this tell you guys anything?