Hurco KMB-IS CNC update

Leith,

Ok I have been thinking about what you stated with needing special tools for disassembly. I can't think of anything other than the brushes that would be a issue for taking apart or re-assembly... and you would pull the brushes before taking apart. Not sure what would be needed for these. I can understand a different type of motor where you would need to stick a awl into the end and "pull" the brushes off the commutator to get it apart... similar to how a 1980's style GM alternator has the holes in the back where you put a awl in and hold the brushes off for re-assembly, then pull the awl the brushes pop down onto the commutator. Just not sure what is needed for special tools. I can see if it had a built in encoder and needed something special to get it apart, but for these old type brush motors just not sure what would be the issue other than the brushes which once again would be taken out

The encoder is on the outside of the motor and it is not a absolute encoder, so it is not critical to get the encoder back into a exact position. If it was an absolute, then the encoder would have to be timed to the keyed motor shaft so that when you put the motor back into the machine it would be exactly where it was taken out at. Incremental encoders are not the same and it is not a issue, so I have a feeling the videos you watched are probably talking about the encoder being the big issue, but this is all my speculation.

I can't say how the tach would be built, but once again those brushes would be removed also. That is the only thing that may need something special, but just can't think of what would be needed other than maybe a awl to get into a spot and push something out of the way. Definitely curious, as this is going to be a problem for me one day also.

Need someone to chime in that has done Electro-Craft motors. Maybe Tom can shed some light if he has come across one. I will try to do some research later and see what I can find.


Robert

OK. Took a closer look at the brushes. One in particular was pretty whacky.

There's sort of a plastic/metal carrier that aligns the brush to the armature. This carrier was actually rotated about 90 degrees from where it should be. Pretty bad sign. Not sure why I didn't notice this the first time through.

I managed to re-align the carrier close to where it should be. I also found a hole saw about same diameter as the armature and used that with some sandpaper to try and put the right shape on the brush.

Put it back together, but no difference. I thought it might at least see a little improvement.

This all begs the question about how the brush got turned 90 degrees in the first place? This 90 degree twist had to be the result of some previous trauma to the armature/brush.

Leith,

Yeah that sucks... something definitely not right at all. Not sure how this one will be as I have not tore one apart yet, the last motor that I tore apart had the slide in type with really small screw holding it in place. Did the brush on this particular one have the same arc as all the others? or was it all wonky looking? The reason I say, is it may have finished coming loose when you took out the brush. In other words, the brush with the arc on it held to the position and the screw was in but just enough to keep in place with the brush in place, but once take out it was loose enough to spin at that point. Just depends on how it was built.... a bad thought would be the piece dropped down into the commutator and is why there is copper on the one brush so bad. That is not a good thought

I will do some searching tonight, but I would get prepped to take it apart. I will see if I can find anything as it has been awhile since I have searched about the motors. I did some hard core searching years ago, but people do put things on the internet so you never know there could be something out there about them. I did do a little looking on Ebay for a used one and they were all over the place. The correct one was too pricy and I would make a offer of $100 before paying what they want. To me they are only worth about $100 max as you have to factor in the usage and how wore out they are.

I saw the next model number down (E702) on Ebay for $75 plus shipping and it was brand new, it's too bad its a 702 and not a 703. Each number separating them is what makes the length of the motor itself... not counting the tach section, but only the motor you get 5" for 701, 6" for 702, and 7" for 703, which we both have the 703's. Plus Electro-Craft had freaking up teen dozen models of the same type, so trying to find something on one is pretty hard. Plus I am sure it's proprietary with Hurco, and they didn't want the info out there at all as people like you and me would just fix it ourselves and that is repair Hurco lost.

I have something I am working on (EtherCAT terminal), but will see what I can find later this evening. I am surprised this has popped up on you, but I have a feeling this was the last major issue and someone miss diagnosed some things for all the other that was taken off...

Will be back later,
Robert

Here's where the mystery connector and black box connect to the terminal block on the bottom of the relay board.

Pin 1 - Black
Pin 16 - Green
Pin 21 - White
Pin 23 - Red

My guess is if you know the function of pins on the terminal block, you can make a good guess what this thing is for.

Leith,

Ok I looked real quick and instead of an Indexer, it may have been external coolant. The TB3-21 is what I thought would have been 22 for the index trigger. 21 is where flood coolant, and spindle fan hook at. I believe 21 only becomes live when the spindle is "on".

This is what I have for the numbers.

TB3-1 (+24V Positive 24 volts at all times - comes from TB4 power supply)
TB3-16 (Negative - also connected together with TB3-15 and 17... they all tie to the ground stud in the controller)
TB3-21 (+24V Positive only when spindle is on = I will check this on my machine to see if it does only fire when on)
TB3-23 (I don't have this one listed in my notes, but will find out. From the previous indexer schematic it shows as positive)


I think it will be for flood coolant. If the machine did not come with it, then I could see Lockheed adding it as they would use coolant. Just odd that it is 4 wires, as I would think they would only need 2 as a trigger. It all matches up for the indexer, except for 22 is the indexer not 21. But 21 does have the flood coolant tied to it. Will do some more research tomorrow. I have to get in bed, already past midnight... time flies, LOL.


Will be back tomorrow,
Robert

Leith,

Got back on as I realized I had a brain fart... yeah there will be 4 wires to the black box as it will need power with 2 wires and the other 2 should be the trigger. Didn't think about power to the Opto22 board, Duh....


Robert

Negative evidence of flood coolant.

My guess is they were using it for some sort of monitoring.

Leith,

Ok you may not see any sign of the coolant equipment as it was external. In other words the machine has no coolant lines or anything showing that it came OEM with flood coolant option. So then they would use the Opto22 for a trigger to an external flood coolant setup to come on with the spindle. There would have been its own little unit like a hydraulic power pack with tank, pump, return line from table and out line to the spindle.... all of which would have been removed when they took the machine off the floor.

But we will never know... they could have done some other I/O function that we are not aware of... Plus I am assuming Lockheed did this, and may have been CSU. I will still check the TB-21 connector later and see if it does come on/off with the spindle. I have to get back to work, but will be back later today... Hopefully can get you some more info.


Robert

Attempting to figure out the RS-232 ports.

On the quill cover on the front of the machine, there is an engraved plastic label that says "KMB-1m". Machine has what I call a J head which matches pictures I see on the web labeled "KMB-1M'. I think the -1S machines have the rectangular heads.

Documentation that came with the machine is for the -1S.

But... I can't find any RS-232 connections. There is a single round amphenol connector on the back of the control cabinet. Its clearly a hacked in feature. There is no J5 on the MPU board.

I found some documentation for the KMB-1M on the web. It clearly says there should be two round amphenol connectors. Doesn't say RS-232 is an option.

Kinda weird. Maybe my machine is some sort of in-between bastard?

Ok, just able to fire my computer back up... were getting some crazy bad lightning. Were use to it, as we get thunderstorms everyday, but today has been some bad stuff.

Ok give me a bit to respond. If the lightning get's bad again, I will have to shut down and come back later.


Robert