The Sajo mill is here

[Bernd]

Trion,

Freddy Flintstone would be proud of you. 

Bernd

[Trion]

Well, I gave up on the hard round bar and found myself a new one in the scrap box. This is mild steel which I got when we did pull tests at school. Machined away the neck region where it had torn of, and it was good to go


Found a die and tapped the end to M10


And turned it along the length to give a nice surface. I also made a section at the end with reduced diameter, to be able to fit a plastic knob


And assembled! I might add that I'm just a tad proud of that


If one should wonder why I chose the plastic ball on the end, this is where I got it from..


While beeing at it, I figured I'd do something about the locking handle aswell. It had worn threads, so I freshed them up with a die, before I wanted to fit a plastic knob to that end too.


But I found a problem, the inside diameter of the ball was about 11mm, while the threads were only 10. So I thougt about it for some time, before I came to think about this guy who posted his way of making springs on madmodder
Some steel wire was coiled around the threads, until it measured about 14mm OD. Then the plastic knob was drilled to 13mm.


I had ofcourse managed to wind the wire as a left hand thread, so had to do it again


Pressed the coil into the knob


And then there was just a matter of turning the knob on the handle. It was almost like winding it into some threds, and I was able to tighten it as hard as I could with my bare hands without it slipping


Sorry for the badly lit picure, but here you see the improved head. You can also see where I got the inspiration from, for my tapered handle mount
If I had a proper burner, I would try to heat up the quill handle and dip it in oil to give it a hard brown surface like the locking handle. But, I guess I have to leave something for me to do in the future too

[Bernd]

And proud you should be. Nice job. 

Bernd

[Trion]

Thanks

Off to the workshop to start on something new now. I have a feeling that a tool gloat is coming this weekend..

[Trion]

Have you noticed how badly the switch panel is hanging off the machine? I certainly have!
Also, when the mill is running and I press the emergency stop switch, the whole shop goes dark as the ground-fuse (if that's what it's calles, anyways means that there is electricity going through the grounding wire..) goes out - have to find the cause of that too..
So yesterday, I removed the cover in front of the knee, to see what electrics were inside it.


Then I removed the panel mount from the knee, where a whole bunch of "sugar bits", as they are called here, were revealed..


The casting of the mount has been broken off and badly welded on again, not exactly plane to the rest of the surface, causing oil and dirt to enter and make a right mess of the electrics inside


So I removed the mount, cleaned it up a bit and took a new shot just to show how bad it was


Out came the angle grinder, and the big machinery fled to hide under some bed sheets.


First, I have to say that I have not worked with cast steel before!
Now that you are warned, I tried making a relieving cut in the old weld and then mount it in the vise and straighten it with a hammer. Only thing that happened, was that I chipped of the edge around the mounting hole in the corner
Next up, was trying to bend it. Again mounted it in the vise, and this time I took a good pipe wrench and applied ofrce. It broke off...
So I was left with the two parts, and now had to align them. First I ground away some of the old welds, then I mounted the parts on the vise's hammering plate with some vise grips


I welded a bit on the outside, found a smaller hammer and pounded the welds, as I've heard you should to that when welding cast. Althoug I have also heard that you should use special flux covered electrodes, not a regular mig welder with CO2
Then I began welding from the inside, to strengthen the piece up, and avoid any major deflection.
I also welded on a bit where I had broken of the edge, that would have been difficult with flux electrodes!


Then I drilled up new mounting holes, trial fitted it, and filed the holes a bit


New trial fit, with switch panel. Seemed ok when i pressed the surfaces against each other.
I also opened the switch panel to have a look inside, to see if there could be any visible cause of the electricity going to ground when using the emergency stop. Nothing to see there..


I thought about painting the parts, but then I would have liked to reomve the switches too, to do the job properly. However the switches seemed to be mounted to the switch panel in such a way that I would definetely destroy some old plastic clips when trying to remove them. So that was out of the question. I am going to have to redo the machines entire wiring when I convert to 400V anyways..
Without the urge to put on paint, I simply bolted everything back together and applied a bit of sealant on the mating surfaces.


How's that for straightness?



I also considered moving the entire switch panel to somewhere next to the quill handle. But after several trial fits and considerations, I decided it would be too much work, and there would be times where the panel would be har to reach. The thought of having to reach over the table, quite close to the cutter, to access the emergency stop was also making a few alarm bells ring..

[Bernd]

Nice save on that electrical box.

That short sounds  like a wiring problem. Although I would assume that the "E"-stop would drop out a relay in the control box. Do you have a wiring diagram that came with the machine? Maybe we can figure it out.

Bernd

[CrewCab]

Nice work Trion   

Very enjoyable thread    I get the impression your having fun as well 

CC

[Rob.Wilson]

Lookin Good Trion   

Great thread


Cheers Rob

[Trion]

Thanks fellas

Yes, there is a wiring diagram in the first pages of this thread, although not so reader friendly. And I am pretty sure Bernd is right that there is a wiring problem, because the fuses only blow when pushing the e-stop while the machine is running. So it's taking current somewhere it shouldn't be, while when the machine isn't running there is no electricity to go that route..


Well, I said there might be a tool gloat this weekend..
I found out that a friend of mine had no less than three monstrous machining vises he had got from a shop upgrading to newer tools. When I got there, I really understood the meaning of monstrous. The biggest one was over 50cm long and a struggle to lift with two men! Besides, all of them were hydraulic! So we talked a bit, and he explained that he only needed one, to use as "regular" bench vise. So I could pick the one I wanted and have it for free 
I took the smallest one, because the bigger ones would have made Y-direction travel absent on my, in perspective, quite tiny mill!!


Pictures, pictures.. I know




There are no names on it, only thing are these numbers stamped in the casting: 2262 994


This vise already protrudes a bit into Y-direction travel because of it sticking over the table..


Width of the jaws are 160mm, not extreme but ok. One jaw is missing, so I'll need to come up with something there..


The vise can be opened up to 30cm, by moving the fixation bolt seen to the right



So what's the right thing to do, when you have got new stuff? That's right, pull it apart and try to understand how it works!







Yesterday I had all evening, and nothing else to play with, so I decided it would be a good idea to clean it up a bit


One thing led to another, all of a suddden the vise had been treated with an angle grinder and a wire wheel, then with a flapdisc, washed with ethanol, then some tougher stuff and finally masked for paint






The question was if I was going to paint it in durable gray epoxy primer or the cheaper sajo-green one component paint.. That led me to check out the test piece which had been standing in old coolant and oil for a few weeks now. A quick scratch test with a knife revealed that the paint was a bit softer where it had been left in coolant. But since it is a vise, and probably is going to get quite a few scratches, I decided to go for the cheap paint anyways.


Some minutes later it looked like this




Today it's getting another layer of paint. Then I'm going to let it dry for a couple of days. After all, there are only a few degrees celsius inside the workshop. Cant wait to get it assembled though

[DMIOM]

.....I took the smallest one, because the bigger ones would have made Y-direction travel absent on my, in perspective, quite tiny mill!!  ........ This vise already protrudes a bit into Y-direction travel because of it sticking over the table......

Just a little bit of - literally - orthogonal thinking. Although its usual / traditional to mount the vice in lne with the Y axis, you could mount it in line with the X axis and the operating handle off to, say, the left hand of the table?

Dave

[Trion]

Yes, I guess I could, but then there wouldn't be any room for a rotary table and maybe a smaller vise
Actually, the biggest vise had the possibility to use the handle both horizontally and vertically, that would be even better suited when mounting paralell to X-axis. But like I said, I want to keep a bit of space around..

[Bernd]

Trion,

I'm trying to see if I can diagonse what your electrical problem could be.

Lets try to take this one step at a time.

Is the "emergency" button supposed to turn off the spindle motor or the whole machine?

I took your pictures of the prints and tried to make them larger in my photo program. Then I discovered I can't read Norwegin very well. Although I can make out some of the words. If you could take a higher resolution picture of the prints and e-mail them to me. My e-mail addy is in the members file. Maybe I can figure out were to start looking.

Bernd

[Trion]

Wow, you don't have to go to so much trouble just for getting the emergency stop working! But thanks!
Actually, I had already planned to bother a friend of mine who's an electrician, and reads norwegian

But since you ask, I would assume the emergency stop to kill everyting on the machine. The machine only has 2 buttons that can start it or parts of it. Either the start button or the fast feed button. When the emergency stop button is pressed and the machine isn't running, nothing on the machine works, but no fuses go. When the machine is running and you press the regular stop button you can hear a relay clicking and the machine stops. The start and stop button control both spindles, feed motor and coolant pump, depending on the settings on the cabinet door. And as you know, if the machine is running and you press the emergency stop, the ground fuse blows and the whole shop goes dark.

My very limited electrical knowledge tells me that there is something wrong with the wire going from the emergency stop to the relay. As this wire only leads current when the machine is running and the emergency stop is pressed.


On another note, I assembled the vise today


But as you can see the color is a bit off. And when you get up close, the finish isn't that great. There are a few running marks and scratches. But it does the job

[Darren]

Even so, that's a very nice looking vice 

[CrewCab]

Looks good from here 

CC

[John Hill]

Looks good from here 

CC

Yes!   It looks really good from the other end of the world!

[Bernd]

Trion,

I'm just courious as what could be causing that. I also never heard of a ground fuse. But then the electrical codes are different over there. Well when your friend finds out let me know what it was. All I can think of is that the wiring is somehow messed up from a previous owner.

BTW, nice looking vice. Now all you need to do is paint the machine to match.   Just kidding.  

Bernd

[Darren]

You have a point Bernd, I would have considered it quite a dangerous situation to have a fused ground.... if this blows and the machine becomes live 

Trion, I think you may have your wires crossed 

[DMIOM]

Trion,

I'm just courious as what could be causing that. I also never heard of a ground fuse. But then the electrical codes are different over there. Well when your friend finds out let me know what it was. All I can think of is that the wiring is somehow messed up from a previous owner.
....

The reference to ground "fuse" may be what we poor non-Nynorsk/Bokmål speakers would refer to as a "Ground Fault Interrupter" or "Earth Leakage Trip" / "Earth Leakage Circuit Breaker".

.... BTW, nice looking vice. Now all you need to do is paint the machine to match.  Just kidding.  ....

No no no - what you have to do is get the vice working for a living so it acquires the same hard working (hard living?) patina as the rest of the machine!     - actually, maybe that's why subconciously you chose the less durable paint 

Dave

[tinkerer]

When you say ground fuse, is it like a ground fault that when it senses an electrical current, it kills everything by kicking the circuit breaker in the plug in, disabling the entire circuit? It sounds like you describe the entire shop going dark, which would mean a fuse or breaker at the main is getting an overload.

[andyf]

  I wonder if the main relay which fires up everything on the machine is supposed to be wired up like a no-volt switch, holding itself on until current to its coil is interrupted by pressing the push-to break emergency stop which should be in series with the coil, but someone has managed to wire it up so that the emergency stop is acting as a push-to-make, in parallel with the coil. Then, virtually all the current which was going through the coil would be short-circuited direct from live (hot) to neutral (cold), which would not only de-energise the coil and open up the relay contacts, but also blow the supply fuse.

With the machine disconnected from the supply, a continuity tester could be used to establish whether the switch was in push-to-make or push-to-break mode, and whether pushing the switch was establishing a connection to neutral (or to earth).

Andy

[John Hill]

I agree with Dave that the 'ground fuse' may be an earth leakage detector.

Now we do not know if that location has earthed neutral or not (we have earthed neutral in NZ) and it may be that some component is connected to phase and ground instead of phase and neutral but it is difficult to imagine why the fault only occurs at switch off.

It is a long guess but if the emergency stop switch is double pole it may be that someone thought it a good idea to ground the motor leads, or even the relay coil, during an emergency stop in which case the inductance of the motor or the relay coil may have enough back emf to trip an earth leakage breaker.

[Bluechip]

The machine appears to be supplied from a 3Ph + Earth, two of the phases are picked off to supply T101 on photo 2 to give a 220v source.

This goes through the various switches to energise the contactor coils.

One side of the 220v secondary is connected to frame earth it seems.

On pic. 2 there is a 'PB 1' connected to the 220v tapping, in series with the overloads on the various contactors, which then enables 220v to go to the control switchgear and  then to the various machine functions.

I cannot see, from this diag. where any ELCB, Trip, whatever, is connected. But then, I am not too good on Swedish or the somewhat non-standard symbols.

It would seem likely that PB1 is the EStop. Not certain though.

What is a 'BOMMOTOR' ?

'MATTNINGSMOTOR' ?

Tried to translate, got 'BAR MOTOR' ... handy for the legless ...  

Which fuse(s) blow?

The input fuses appear to be 50A. If they're letting go, I shall maintain a discreet distance.  

Dave BC

[John Hill]

The machine appears to be supplied from a 3Ph + Earth, two of the phases are picked off to supply T101 on photo 2 to give a 220v source.


This goes through the various switches to energise the contactor coils.

One side of the 220v secondary is connected to frame earth it seems.

Yes, I see that too but that is a transformer isolated DC circuit so its hard to imagine how that can cause an earth current.

On pic. 2 there is a 'PB 1' connected to the 220v tapping, in series with the overloads on the various contactors, which then enables 220v to go to the control switchgear and  then to the various machine functions.

I cannot see, from this diag. where any ELCB, Trip, whatever, is connected. But then, I am not too good on Swedish or the somewhat non-standard symbols.

As the whole shop goes dark I assume the ELCB is in the main shop fuse box?

John

[Trion]

I must say, I'm amazed!

To clear up some misunderstandings, what I call a ground fuse is in the electrical box of the building, supposed to prevent people from dying when touching a live wire and something that can lead to ground. The ground fuse is activated by only a few milli ampere. DIMON is absolutely correct

The reference to ground "fuse" may be what we poor non-Nynorsk/Bokmål speakers would refer to as a "Ground Fault Interrupter" or "Earth Leakage Trip" / "Earth Leakage Circuit Breaker".

The zero phase of the three phase is not ground on 400v systems, but I'm not sure how the 220v is. Ofcourse, this system is 220v..

BOMMOTOR - boom motor, the motor mounted in the boom driving the vertical head
MATNINGSMOTOR - feed motor

You seem to have looked more into this, than what I have done myself. I'm sitting at school now, and the teacher is talking about convergent solutions of cfd analysis. I think I ought to pay a bit of attention, will chime in on the electrical issue later today.