Plasma table

[Hood]

I know, only kidding... Sure it'll soon loose the bright colour as and when it fills up with aluminium dross

It is weird, some people get really hung up on colours. I remember the guy in the fishermans association shop used to take great delight in picking a green or blue lighter out of the box, colour dependent on the fisherman and always the wrong colour just to wind them up

 

[MCKDAVID]

aye, never got into fiootball at all, rugby aye, but football I was hopeless at it, so never took to it, even watching it bores me to tears.....

 

[MattH]

Do you have any vents in the shipping container?

With the issue of aluminum dross in the water bed creating hydrogen it might be good to have a couple of full time vents.

 

[Brad93]

Do you have any vents in the shipping container?

With the issue of aluminum dross in the water bed creating hydrogen it might be good to have a couple of full time vents.

You’d have to cut so much aluminium to get a hydrogen build up.

 

[James1979]

You’d have to cut so much aluminium to get a hydrogen build up.

Whats it like being in there health wise if you are cutting? I've not cut Ali on mine yet so not looked into it.

 

[MCKDAVID]

most shipping containers have vents in each corner anyway. Either way looks like Hood always cuts with the door open anyway, so should be plenty ventilation, we're talking about a coastal location in scotland after all.... never much shortage of "ventilation" up there.... ahhahaha

 

[Brad93]

Whats it like being in there health wise if you are cutting? I've not cut Ali on mine yet so not looked into it.

The aluminium oxide disassociates under the arc releases Ozone (O3) which isn’t good for you.
The water is what disassociates into hydrogen and O2.
You gotta watch your plasma fluid because if that’s got chemicals in it that can form toxic compounds you’ve got problems.

All fumes will likely contain nasties. Water bed does catch a lot of fumes.
Water bed with a fume extraction arm (LEV) would be the best.

 

[James1979]

Yup that's one thing we aren't short on.

Did the desiccant mod today but not fired it up yet. I will let you know.....

 

[Hood]

Do you have any vents in the shipping container?

With the issue of aluminum dross in the water bed creating hydrogen it might be good to have a couple of full time vents.

There are vents in it, think three down each side.

 

[MattH]

most shipping containers have vents in each corner anyway. Either way looks like Hood always cuts with the door open anyway, so should be plenty ventilation, we're talking about a coastal location in scotland after all.... never much shortage of "ventilation" up there.... ahhahaha

Trouble is that the process can go on for 12 hours or so.

It usually causes people issues when the cut a load of ali, then load a full sheet at the end of the day. The gas builds up under the sheet over night and gets ignited the following day when cutting starts again.

 

[Hood]

Trouble is that the process can go on for 12 hours or so.

It usually causes people issues when the cut a load of ali, then load a full sheet at the end of the day. The gas builds up under the sheet over night and gets ignited the following day when cutting starts again.

I think the majority of the issues happen if, as you say, a sheet is left on the table and the hydrogen gets a chance to build up overnight. Even then I think it is usually more of a problem when doing submerged cutting or with the water level touching the underside. I never leave sheets on the table, never have and normally don't have much left anyway after I have been cutting.

 

[Hood]

I got a bit more done today.
First off was when I opened the container I was greeted by a thin surface of ice

I made up some fittings and welded them to the tank and screwed a central heating pump on and moved the tank into the container and got it piped.

I then opened the valve and let it drain into the tank. It took 15 minutes as it has to feed through the pump. I think I will make another drain valve that goes direct into the tank.

Some pics of the ice in the drained table.

Very pretty

I then filled the tank up again with the pump to see how long it would take, it was fairly good, just over 3 minutes to get to this.

I also welded the extensions onto the 6 slats and got them fitted.

Here is a vid of the table filling with the central heating pump.

 

[Hood]

Today I made up a sump from some 4" box and a bit of 10mm plate, tapped 1 1/4" BSP.

Drained the table and cut a square hole and welded the sump in.

Fitted an old valve I had but it leaks slightly so waiting on a new one arriving.

I then milled out two 30.6mm dia holes in a 50mm x 50mm x 70mm chunk of aluminium, tapped one of them 1" BSP, milled a 32mm hole in the tank lid and then welded the alu to it.

Fitted an old hosetail I had then refitted to the tank.

Draining should now be a lot quicker than the previous 15 minutes, hopefully the rubber hose will turn up tomorrow or Thursday.

I am still having occasional faulting of the motor and I am starting to think that the trucks may just be binding, they are kind of knackered so I may just end up getting some round rail as it seems reasonable on the X and should be plenty good for a plasma.

 

[henry Kadzielski]

Good evening @Hood. I also had some motor tripping some time back, for what seemed to be no apparent reason. The linear bearing blocks had run out of grease and the balls were binding up. Not possible I thought as the machine had 'done little work' well so I thought. Bit of lube on the linear rail and all was good. I have fitted the grease nipples to the linear bearing blocks and now periodically grease them. No problems any more.

 

[Hood]

Aye, I tried greasing these but it didn't help much. It is weird, can run continuously for hours, full axis travel back and forth with an M47 in the code to repeat and then it will fault. It will then usually keep faulting but leave a while so I don't set about it with a sledge hammer and it will again run for a while. Almost as if it is heating up but I have checked the temp by hand and no noticeable increase.

The trucks are knackered though, they were ones I got second hand and they were shot then, had about 12 I think and managed to get about 5 out of the lot by using bits and pieces from the others, they have lasted 5 years so I can't complain really.

 

[awemawson]

Could it be the motor driver at fault Hood?

 

[Hood]

It is possible I suppose. I monitored the current feedback of the drive on the laptop the last day using the drives software scope and it was peaking out about 5 amps which is nothing as the drives are, if I recall 10 amp continuous and 20 peak. Then again the fault is supposedly a regenerative issue so don't know.

Might rob one out of the Beaver Mill and see but I am fairly confident it is the rails. I might check through the other 4 trucks and see if some of them are better.

 

[Hood]

Today the new valve turned up, well two actually as I thought I might as well get a spare seeing as they were so cheap, so cheap in fact I reckon they must have made a mistake. Of all the sizes the 1 1/4" ones were the cheapest.

£3.19 for a 304 stainless valve, fair enough it is a reduced bore valve but even still.

Well they turned up and yes they were indeed 1 1/4" and non magnetic so I am very happy, could have got 4 valves for the price of the brass hosetail

Got that fitted and then moved on to the return lead. I have decided to have it bolted to the frame and also have a clamp for connecting to the material being cut, we will see how that turns out.

That weld on the front of the table is annoying me, sound enough but looks bloody awful I will probably end up hauling the welder out again and redo it

I removed one of the trucks from the left side and it was shot but I checked the spares I had and found one that seemed good so I put that on, two or three hours of running back and forth without a fault but I will just have to wait and see as it has done that previously then faulted again.
I was going to order some round rail today to replace the profile rail but when I got the price I decided not to bother, the rail itself wasn't too bad but I was quoted £150 incl VAT for delivery. The guy gave me dimensions and weights to see if I could get it cheaper and I could but it was still going to cost me £88 incl VAT so I will just wait and see if my faulting issues have been solved by the better truck.

Just waiting on the rubber hose now but I am more or less ready to start using the plasma, have a few sheets of 5mm Alumininium coming on the 9th so that will be the first real test I suppose.

 

[Hood]

I forgot to update on yesterdays progress. I got the fault again after running for about 30 minutes so decided to haul a drive out of the Beaver mill. Saved the config from the plasmas drive, swapped over the drives then updated the Beavers drive with the plasmas config. Still the bleeding same, so it is not a drive issue.
I then decided to have another look at the trucks, I noticed that when I was removing the front truck I could slide it out even with the rear one still bolted down, can't do it the opposite way so it looks like the front truck is fractionally lower than the rear one. I wondered if that could be causing the issue so instead of cranking down the bolts on the front truck I just nipped them up. I ran the back and forth code and it ran for 6hrs and never faulted so hopefully this time I have got to the bottom of the issue.

 

[Hood]

Oh and still waiting on the 1 1/4" hose. Ordered off eBay, supposed to be delivered yesterday, I get a message at 5:25 yesterday saying it has been despatched and here is your tracking. So not happy about that especially as when you go on the tracking it says they are expecting it, in other words they just booked it at 5:25 on Hogmanay so it won't be picked up until tomorrow at the earliest and most likely Monday and then F knows how long Hermes will take to deliver it.
That is the last time I will be dealing with them, they stated, when I bought on Monday, that it was 24hr courier, so really it should have been here Wednesday, well I suppose it might be but which bleeding Wednesday I don't know.
Rant over