Opal Mining Newsletter August-31, 2006 on Mining Underground for Opals in Coober Pedy

August 31, 2006.

Opal Mining Update - No 64

Back to work, but still got Problems working.

At last my friend Boro is back, so now I can get something done at last, if I had known more about this gearbox I may have started on it 2 weeks ago, but I have a simple policy with things if you do not know or understand what you are about to get into DON'T, it could make things worse and I used to be a Fitter & Turner, but nice to have plans of what is on the inside then you know how things work and what to expect without them you could cost yourself more money and time, anyway we are on it at last.

I had started to pull the gearbox apart, but I only got the broken half apart about an inch and half and it got stuck there, so as I did not know how it was put together and I had no plans on it, I thought it would be better to wait for Boro to come back and give me a hand as he knows this gearbox very well and I did not want to make things worse by trying to force this part off, but as you can see below it is off and only took Boro about 10 seconds to get it apart, the way it works is not how I thought it would be on the inside and now it is apart it is very simple in the way it works and is assembled.

As I said it is very simple the way it works, it operates by what is called a Friction Drive, all that means is that one shaft drives off another shaft, by pressure being placed on the surface area at the ends of each shafts and the brake (which is what broke) pulls one shaft away from the other shaft by pressing clutch plats on 6 double springs, thus releasing the driving pressure created by these two shafts being forced together by the springs, one of the brake arms inside had broken and locked the clutch plates in and disabling the drive on that track, hence the breakdown and here we are.

Where the 2 arrows are above is the showing the 2 ends of the hardened shafts that come together and cause the machine to have traction, as I said this is called a friction drive and is a very simple but effective method.

Here is a close up of the inside of the broken half of this gearbox, at the front is the shaft that as the brake handle on it and this is where the problem is, at the rear is the clutch plates, there are 6 metal plates and 5 clutch plates, the metal plates have 9 tabs on them to stop them spinning so the clutch pads can do there job, then there is this unit that is located on the spline end of the shaft.

The part that has the moving arms on it pushing the clutch's in revolves around as the machine is moving, as you can see it is very dirty in here, has not been cleaned in a lot of years, very little oil came out of this box and at some stage it has had some water in there as well, so will have to give it a good clean as well.

This is part of the arm that has broken, you will see a bit more of this later on when I am repairing it, right now I have to keep stripping the unit down and then clean it completely.

I am removing the brake arm shaft right now so I can get the broken arm parts off it and repair them, this shaft had a couple of broken spring pins in it which hold part of the arms in place, which I have to knock out before I could get the shaft out, this also was part of the excess play that was in the brake lever and was causing me to have problems in applying the brake when I had to, this gearbox was in a bad state of repair for sure and was in need of quite a few repairs to bring it back to normal.

As the right side was in bad state, I thought it best if I also took the left side off to clean it as well, and just as well, it was in a worse state then the side that had broken down, a little bit of water came out of this side when I took it off, as you can see on the bottom there is some rust, not to bad, but not good, there was also a pin ready to come out at any time, looks like who ever repaired this the last time did not put a split pin in as I have never seen where one of these brake, plus there was no broke parts of it in the bottom anyway.

And this side had also been broken in the past and the repair was very bad, the 2 arms had been welded on the shaft and 2 of the spring pins had also been welded in place, where the pivot pin is hanging out this hole turned out to be worn out of round and needed to be fixed and a couple of those arms that have the so called pins welded have also to be repaired as there was tow much play in them, so I have a bit of work to do fixing up, thankfully not a expensive breakdown.

Here Boro who has plenty of experience on this gearbox is attempting to grind off this weld so I can remove the pins from the arms and then I can remove the shaft, if I had been at Ross's workshop I would have done this, but as I am at Boro's house he is doing this for me, but after this I will take over, Ross right now is down in Adelaide and will be back in a couple of days, everything about this breakdown has been wrong for me, with the people I need to help me or with Ross's workshop being closed has cost me time, which I am happy to say I have plenty of off and does not cost me anything, just frustrating waiting.

Looks like he did a good job and I have knocked out the pines, well there was only 2 in there the small ones and one of them was not even a spring pin but a bolt with the head cut off and welded in place, this is a very bad repair job, I could not do a job like this no matter what it cost, if you want a machine to work for you and make some money then you have to look after them and do repairs properly so they last and also so they can be taken apart again easily should something brake again, looks to me that this was fixed so the machine could be sold and they did not have to worry about fixing it ever again.

A bit more grinding was necessary with a flat wheel so he could get close to the edge of the arms, you can see the middle part of the gearbox on the left and the brown that is some rust that is on it, this will also have to be cleaned up before it can be re-assembled again, I will also have to make sure that the bearing in there is in good condition or it will have to be replaced.

These are the parts that need to be fixed, the 2 shafts have wear on them that needs to be filled in somehow, the 2 small arms have the small hole out of round with wear, these will have to be bronzed up and re-drilled, the unit on the right is the one that has been repaired before and I will have to undo the weld and re-repair it and the left hand unit is the one that broke on me and will have to be repaired also, this I will do with bronze.

At the top is 3 of the 4 pins that have wear in them, the one on the right is very bad, but have decided that I will make all new ones which is 4, I am using a standard 3/8 high tensile bolt to do this job as the pins are 3/8th in Dia, so this is the easiest way of making them, you can see that I have measured and drilled the holes, just one more bolt to do, then I will put them in the lathe and turn the heads down to size, then I will cut them off to length, chamfer the ends (take the sharp edges off) and job is done.

Here are the finished pins, also the arms and a plate that is attached to one of these arms with one of the pins, this plate is off the unit that had been repaired before I have taken apart again, the hole was again flogged out of round so needed repairing, as you can see I have bronzed them up, I have already drilled one hole so you can see what I have done and that the hole is now back like it should be, now to re-drill the other 2 holes and I can carry on repairing the rest.

Here are the 2 units finished and assembled, you can see that what I call levers have been bronzed in place, I have also put some bronze on the other ends to give then a bit more strength as these corners seem to be a weak spot, but this repair has been done right and should last for many years now, but if not will be a lot easier to fix again if not, as the lever that was welded incorrectly was shortened and bent so did not work as it should, these levers now should work properly and what they do apart from holding the 2 plates straight that the arms are pined to, it that when the brake level is pulled up, these levers also push against the plate they are resting on in the photo.

This plate is the one that pushes against the clutches and pushes the springs in and releases the friction drive and the when the brake handle is pulled up all the way these levels lock the brake on, in other words they keep the clutch pads locked down so there is no drive to that track, this is what happed when it broke, it must have locked the clutches in and I had no drive on the R/H track, but I have never been able to lock the brakes on while I have had this machine and I must admit it been had for me to apply the brakes, now I know why as all these arms and levers had two much play in them through wear and tear, pins hanging out etc and could not work properly, now they can, I hope.

Here are the 2 shafts nearly repaired, I have made up some liquid metal and applied it to the worn areas of the shaft after they were cleaned in the worn areas, then I wrapped some tape round the metal to stop it from running and left it for 3 hours then I removed the tape and put them in the gas oven for an hour to help cure it, then I took then down to Ross's and put then in the lathe and cleaned then up and they came out very good, not like new but no more wear, so will do the job nicely, would have made 2 new shafts but we don't carry this size metal bar up here and Ross's lathes are a bit to worn for me to turn down bigger bars with any accuracy over this length, so this repair will do.

Here are the units assembled and finished, now to clean the middle part of the gearbox, which is the part with the gears in it, after that I will put it all back together and will be ready for going back on the field with it and as soon as I can get a hand off my mate Peter, will be able to put it back in the machine, pulling it out by yourself is one thing, but to put it back requires 2 people to lift it up and push it in and under the frame work and then to lift up one end while I align the bracket that holds it in place and put the bolts back in, then we can do the other side, after that I can do it all myself.

I am now back home, ready to go on the field tomorrow, I have organized Peter to come and help me and this time I have borrowed a trolley so it will be easier to get the gearbox back to the machine, instead of lifting it, nearly broke my back when we brought it out, its a heavy little thing and I am not getting any younger or stronger, anything to make life easier for me from now on.

This is my mate Peters partner he is also called Peter, we have reached the start of the drive where the tunnel machine is, you can just see it in the background, as you can see it was a lot easier to get the gearbox here on the trolley and quick, now we will go and put it in, not much to take photo of doing this as it looks just the same as when I took it out.

It is in and Peter and his offsider has gone, now all I have to do is to take the slack out of the tracks and put some weld on the pins that I ground the head off to try and get them out, this will stop them from coming out in the future as I operate the machine.

I had some trouble getting the right hand track tight, so I brought the machine back out of the drive so I could see up the front of the tracks, but again I got it wrong about this grease ram worked, I thought the ram pushed forward against a wheel tightening the track, but in fact the ram where the grease nipple is pushes backwards and the reason that I could not get the slack out was that the big bolts that hold the gearbox in had to slackened off so the ram could do its job.

Then I would have to retighten the bolts again, these bolts were loose when I went to undo them to take the box out and so I got caught again, but as I said I am still learning my machine and how it is put together, so all I lost was a bit of time, now it is back up the drive, the brakes are working better than they ever have and do actually lock in place should I need to lock them, this will be only needed when I am turning the machine to start another drive, not when I am in a drive tunneling.

Back at the face and working again at last, there is some potch in the face on the left hand side, I have had material nearly all of the way in this drive and I still have some way to go before I reach the shaft in front of me, so hopefully I may find some opal.

Now I have some Alinite coming in from the roof, I hope this will come down and meet the level than I may have a chance of finding a pocket of opal, I like Alinite on or near the level for opal.

No such luck with the Alinite, it did not last long at all and has now gone, I still have material in the face and along the left hand side wall on the level, but not thick and no color as yet, but the level has been slowly rising up and I have been also going up, it is also dropping to the sharply to the left as you can see, this is a good sigh that there may be some opal somewhere to the left of the machine, but there is a lot of area in that direction and I will work in this area from the shaft in front of me when I get there and have worked out the area from the shaft the pipes are down right now, so will be a few weeks yet before I can move the blower to the shaft in front of me.

Here where the arrows are is the potch (material) some of it is about 1/4 inch in thickness, but is of no use to me no matter how thick if no color is present, I still have about 20 feet or so to the shaft, but the ground is very wet and I am getting blocked up after only 4 feet of drive, was thinking again about quitting this claim and looking for a claim where I could mine the level above, but its hard to leave this claim when I am on material most of the time and the claim has proved itself with producing opal and some good opal at that, mostly crystal, so I may have to keep at it for a while yet.

Today I am helping my mate Peter, he is going to move his rig and unlike mine he requires 3 people to pull the buckets, him and his offsider to stack the buckets as they are brought up and me to operate the electric switch for the motor to bring them up, for people who are new to this newsletter, this machine is called a Elevator Rig, it is the cheapest way of opal mining here as it only has to run one generator to run all of the small electric motors that are required to run the many 11 foot conveyor tables below.

I use 10 foot pipes and Peter use 11 foot conveyor tables, there are not to many of these here in Coober Pedy, but the machine is not easy to move like a blower, nor do you set this machine up if you are not going to work the area for some time again not as easy or as quick to move as a blower, but cheaper to run per foot.

Here the buckets are all now up and stacked in place and the rig is now ready to be moved, Peter did have a problem in pulling up the buckets, one got caught at the top and broke the chain which had to be fixed before he could continue and that took about 1/2 an hour to do, so even with 3 people it was not an easy job.

And this is how I had to leave the bottom of the buckets, just hanging at the top of the shaft so that when he moves the rig and sets up on the next shaft he will be able to see when the buckets are in the middle of the shaft, like they are now.

This gives you a better idea of how big the rig is, this machine runs on about a drum of diesel a week, where I would use about 1.5 to 2 drums a week to do the same footage, this runs only one diesel generator which runs all of the electric motors on the conveyor tables below and the tunnel machine and I run a diesel engine for running the blower to create the vacuum and another diesel engine to run the generator to operate the tunnel machine, but Peter cannot move his truck on his own, he has a problem with the flywheel on the truck and cannot start the engine, so he is now waiting for a friend to come with a big front end loader and pull him to the shaft he wants to move onto and I will not be there for that photo.

I have bought a 12 volt electric diesel fuel pump and I am about to assemble it right now, was pumping the diesel out with air for my compressor, but was taking to long, this will speed things up for me as it pumps about 48 liters a minute, so will take about 3 minutes or so to put 150 liters up in the fuel tank, with the other one it took me about 15 minutes or so.

Here it is finished, have not tested it as yet, but the motor works, so should be alright, but have noticed that this pump is not really made to be taken out of the drum every time I want to fill it up, to much involved in undoing grub screws and nuts, so will have to modify another drum for it.

And here is the drum, I cut a bung out of an old drum top I had on the field, and then cut a hole in this drum and went down to Ross's workshop and got him to solder it on for me, so now I can have the pump permanent in the drum and will not have to remove it when filling the drum which will be done in the other bung hole.

And back to mining, I have not done a lot this month again, especially since I have got the machine repaired and back in action, the ground is very wet and I am not getting much footage done before I have to quit for the day, this below is after I had done 5 foot - 2 inches and I pushed it as long as I could before I had to stop as it would not pull the dirt anymore, as you can see the elbow is very blocked.

And this is the telescope to match it, not a nice job unblocking this lot and I have the same underground, with the bottom 90% elbow and the telescope, then I also have the telescope that is behind the machine, it is not as bad as this but needs to be taken off and cleaned out and I have to do this every day before I start work.

So have decide that I have to quit this type of ground, its no good working in wet ground, better miners than me have quit in wet ground, far to much trouble and work for one man even two, so I will quit this drive and bring the machine back again, I have only done 14.5 feet in the last 2 weeks.

I thought I had found a partner to come and work with me, he said that he would start work with me this last Monday so I stayed at home and waited for him, but he came to see me on Sunday and told me he had changed his mind and would look for a paying job, so I have had 5 days off for nothing, but would not have changed the situation I am in right now if he had turned up, would still have quit the drive.

So what I am going to do now is, I am going to pull the machine back tomorrow Saturday, but first I have to start the blower and get all of the dirt out of the pipes below as it did not clear them when I stopped the blower and as they have dirt in then I cannot pull them up, so after that has been done, about 5 minutes work I will pull the pipes and bring the machine back out of the drive.

I will then start another drive to the left of this drive but at a right angle, the ground should not be as wet here, I want to do a drive under an old working next door and see if there is any opal or material there, this drive will have to go at least 70 feet in length, and the ground is still damp, but should be able to do a mornings work before the elbows need cleaning and if I get that far with little trouble and hit material or opal, I will do more dives in the direction.

If I don't find anything or hit wet ground again, I will quit and abandon the claim, before I can pull the equipment out of the claim, I have to find another claim to move everything to and this may take me a few days or longer to come up with, but I will not work in wet ground again, I have spent over 2 and a half years working in this and getting no where quick, so is time to get out of it, not easy finding another spot that is producing material and some opal, but the time has come to move on, so about another 2 weeks or so in this claim and I could be finished, pity because I know there is more opal around in this wet ground but is not worth the effort any more.

Again I Hope you have enjoyed this issue and look forward to the next one, hopefully I will have some more good photos to show you in the next issue and maybe some of Good Looking Opal and lots of it, I am still hoping that this will be a good year for us, but only time will tell, so stay with us over the next few months and find out what goes on in our part of the world as far as Opal Mining goes.

Stay Tuned for the next Issue, who knows what I will have to report.

Until the next issue.........

and wish me lots of LUCK.

Cya Later, Stuart Bird.

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