Member postings for Ajohnw

Neat Jack. For people who might want to use nitric acid first which is probably partly intended to clean it any idea of the concentration? It's usually low as in anodising.

John

-

You will find that to get increased cutting torque you will still need a belt change and that running 3 phase motors at low speed via an inverter for long periods even under the miserable power levels they may provide when used like that can burn the motor out. There aren't any free lunches in this area.

What most people do who convert ordinary lathes is something like doubling the power of the motor. That means that if they run it at half speed they will have the same torque available as they did with the original motor. When run like that in situations where that level of power is actually needed for long periods the motor is very likely to burn out. In some ways it's better to speed them up but the motor manufacturers aren't very happy about that, balance issues and the armature might burst.

There was some one on another forum that became very annoyed when he finally realised what variable speed means. It's pretty simple really HP or Watts in terms of motors is a product of torque and rpm. Torque is set by the current the motor can take so tends to be constant. Reduce the RPM by 1/2 and loosely speaking the power is reduced by the same amount as the torque is the same. Do it with a belt etc and loosely speaking again torque is doubled.

John

-

Edited By John W1 on 11/09/2015 00:17:53

Edited By John W1 on 11/09/2015 00:19:03

Apart from Kv, very high voltages, there isn't really any need to worry too much about volts unless you intend to grab hold of it. Kv is more of a problem as it can creep up probes etc even via grease or dust. Once it breaks down the resistance drops and higher currents can flow - hence being very careful about things like CRT TV's. Mains voltage doesn't have that problem unless people are rather silly.

DC is reckoned to be worse because it's continuous where as AC isn't. Shocks from one arm to another are more lethal as they will pass through the heart. Most of the info in this area is obtained by electrocuting pigs.

John

-

I reckon it's a bit over priced at the moment but after it's been there for n months .................... ??

Not that I will be tempted.

John

-

Sounds a little more like nitrate to me Neil. Something that wont be so easy to buy. When it's sold as fertiliser something else comes with it. That is a cracking oxidiser on it's own. There is some really bad press about some of these as they miss the fact that they need something to oxidise to explode etc - Special branch etc might get attracted to this thread.

The action sodium hydroxide on skin is probably similar to KOH which is much worse. Skin gets a sort of soapy feel to it - skin cells. Best wash thoroughly asap. I know from personal experience that KOH is still ok if you fail to notice for a short period. Hot stuff - well most people are fully aware that even water can burn and heat will make any effects caused by what's in it worse.

Being realistic though - would some one boil this concoction on the stove? Suppose some might with care turning it down as soon as it simmers but I would expect the mix to have a pretty high boiling point and personally I would use a lab type hot plate or similar. Would people take some precautions - gloves etc. I would hope so. Would any one in their right mind melt the solids first and then add water - I'd hope not. Sounds like the nut cases may go to the right place. .

My comment about heating effects comes from one of the MSDS sheets concerning cleaning up large spills of the solids.

The web is a dangerous place in some respects in areas concerning chemicals. Some years ago I came across a method of oxidising diatoms. This does need powerful oxidisers even mixes of them. No signs of it on the web. It came from a book intended for older school children under supervision. I mentioned it on the web and soon it was all over the place. No mention of what was going on and possible problems and worse still some one thought that one of the chemical would be best diluted as it must be safer. Trouble is that it doesn't work at all then so people might play around with quantities - that really could cause problems. A paper was even produced stating that it should be diluted. The other problem is that it's for small scale use. Again no mention and if silly things are done it could result in a strong acid being sprayed all over the place or even minor explosions. The fact that it was diluted wouldn't help at all. It's really best to try and find original sources of information in these sort of areas from reliable sources. That can be difficult.

John

-

I don't mind people mentioning that substances are toxic but perhaps it would be a good idea to state LD50's to give people some idea just how toxic it is. Sodium Nitrate for instance is 3236 mg / kg. It's classed as an irritant and an oxidiser. Oxidisers can be problematic when mixed with some substances as combustion can result. Bit like gun powder and potassium nitrite which also serves as an oxidiser - they need to be the right other ingredients, another oxidiser may be a very bad idea. The cancer aspects are thought to relate to substances formed when it's used to cure meat.

Sodium hydroxide also referred to a Lye is caustic. Although the wiki disagrees I reckon it's often sold as sugar soap. Best thing for people who want to make use of substances like this is to look at it's material safety data sheet and react accordingly. It's pretty obvious that people shouldn't wash in it or drink it. One thing it mentions is violent reactions when water is added. What this means in practice is that heat is likely to be generated when it's added to water so that needs to be done slowly. Very similar to never diluting strong acids with water, the acid should be added to the water while stirring.

To me though like all metal colouring treatments other than some that very definitely can be dangerous it sounds a bit iffy and people may well finish up with something that isn't the black they want.

One thing concerning both substances is that fairly large volumes of both can be bought mail order. There are pretty extreme rules about what joe public can easily buy and what can be shipped by ordinary carriers. People are still expected to use some common sense.

John

-

Maybe there is a web site that goes through fault finding on this style of machine but I can't see any signs of one that does it thoroughly.

John

-

I did wonder about something along these lines once but based round a short portacabin

**LINK**

Maybe they removed the milling machine.

Doh - the edit was to add several ? marks at the end of the title.

John

-

Edited By John W1 on 10/09/2015 16:29:15

It might be worth posting a photo if the wiring including the motor circuit and it's connections. I did have a small mill at one point that used a brushed motor but never had any need to go near it. Bearing that in mind it might use either a permanent magnet motor or one with a field winding. I suspect that the motor speed would vary if there is something up with the field winding or the connections to it. The fact that a fuse blows suggests that one winding, field or armature is ok.

John

-

I would have thought play sand would do a decent job. If too soft sharp sand. The rock people use a range of abrasives easily found on ebay but shot blasting grits work out a lot cheaper.

Ideally for easy separation something which floats in water would be ideal - hence nut shells I suspect. You could buy a load of pistachio nuts and enjoy eating them. I think Liddl do them loose - not sure I only buy the cashews.

John

-

Have you checked that the cross and compound slides haven't slackened off Brian? The manual on the lathe suggests checking these rather regularly. I'll also add that while you might want an oil free life it's needed on lathe slides. You can probably buy slideway oil off ebay. Just a smear is needed. When adjusting slides it's best to remove the lead screws and adjust for a little friction when they are pushed by hand WITH the oil on them. It can be done via the handles but it's easy to over tighten and wear out the lead screw nuts more quickly than they should. One problem with slides is that often there are no oiling points so the best way to apply it is to remove the slide.

Tools may be blunt now. You could sharpen them again with an oil stone buy running the tool on it's cutting edge side along it. Notice the word oil again - it will improve the cutting action. A light oil is best. Grade 400 wet and dry paper should do a decent job too - oil or soapy water on it, Just make sure it's on something flat.

Tools generally don't cut very well if above centre. Best way to check is to face something off on the lathe - just in case the bed is bent. If you look carefully when it cuts to the centre you will see if it's above or below centre. A few thou under is best.

I hesitate to mention the last thing that can cause problems - loose head stock bearings. You really shouldn't be having that problem yet and the manual gives no clues as to how to check and adjust them. It's very easy for people to mess this up and wreck the bearings very quickly.

John

-

That's exactly what biodegradable plastics are supposed to do Neil. Some shops around here have used them for years as they don't cause problems when disposed of.

Doesn't have much to do with recycled plastics which as far as I am aware are a mix of harder plastics and probably some sort of filler. Lots of plastics are not keen on UV from sunlight but ordinary window glass doesn't transmit it very well. Rhino is a pretty well known brand

**LINK**

John

-

I just have to ask how you know !

I suddenly thought that there used to be a recycled plastic compost bin in the garden so can't help wondering.

John

-

If you want to go as big as possible you might be able to get a feel for size via a fly cutter. Your question can't be answered really as size, depth of cut, speed and feed rate all determine the HP needed. More cutting points helps a bit with feed rates.

Personally if I had your machine I would probably be more interested in horizontal milling if I had the full horizontal attachment that supports a bar for cutters at both ends. Flat surfaces rather than dished due to head alignment errors.

You might find some demo's that use the machine on youtube.

John

-

Edited By John W1 on 09/09/2015 13:32:42

Lucas used to do their 1/4" blade connector items in drums around 15" dia or so and about twice as long at something like 60 rpm, probably a bit slower with nothing other than the parts in them. Circa 2/3 full and inclined at some angle that also caused them to tumble. I'm guessing the sizes but wont be far out. They wouldn't have any interest at all in separating them from some sort of compound. They made them in enormous numbers on modified CVA high speed presses that had been speeded up. 240 / min if I remember correctly.

John

-

It looks like John found what I intended to post after logging in. At least it's below 60% concentration otherwise a special section of the ADR regulations apply. It will have to be a specialist company that handles it. The problems are outlined on a pdf linked to on this page

**LINK**

It would be best to be very clear about the concentration when talking to them. It might be feasible to take it too them.

It may turn out that it's "fairly" easy to transport. There would be a need to look further to find out. Chemical supply companies ship many things that need double packaging and also must be below certain amounts that can vary according to what it is.

John

-

They came with the house - around 26 years ago Neil. My wife washes them periodically but the colours don't fade. No idea how old they are. I'd guess 70's or so. The colours in the shot are pretty accurate.

Sweden it seems stick to around 2700K max for led lighting. I assume this is to avoid exposing peoples eyes to the level of far blue that higher colour temperatures need. Those do tend to have higher wattage figures but as far as our eyes are concerned this wont be that apparent, Actually having played around with 6k and higher high power leds I reckon that the Swedes are bang on and that they are best avoided.

These are the lights and the bulb

**LINK**

I've also tried the type some others use on here, low voltage and a single led but the above give a larger pool of decent levels of even illumination. A Swedish lighting engineer told me they also blend in well with the strip light I have - they do too.

John

-

Edited By John W1 on 09/09/2015 00:03:12

LOL I've had the usual blue ones crack over time without any UV exposure at all. No windows in the room they are in anyway so shouldn't be a problem. I've also sized a shelf so that they just fit so I can't pile things up in them.

John

-

I think you will find that modern electronic ballasts for fluorescent light work at a much higher frequency than 60Hz. There can be a problem with the old ones in the Europe with 50Hz as they can make 3000rpm look stationary but in practice having seen this it's more a case of the rotation rate looking a little odd even if the rpm is carefully tuned.

I use a modern lower diameter 5ft 60w tube light with an electronic ballast plus local machine lighting. That gives a decent level of room light but my ceiling is pretty high. As you can see from the photo that has been posted ceiling lighting doesn't produce very even lighting. The local lights I use are sold by Ikea. They are on flexible stems that can either be fitted with a shelf clamp or a base for wall fixing.

I also have shelves directly behind the lathe -excuse mess, I am having a very slow tidy up, the milling gear will be some where else soon and more holes needed in the angle for mostly tail stock bits an pieces. This shows the light I mentioned - cabling to be tidied up when I am sure about where it will be fitted.

The light takes some very semi spot led lights which they also sell. The light will probably finish up on the next shelf up. Ikea don't sell cool white led lighting at all which I personally think is a good thing. The blue output on those has to be very high and the wattage ratings are misleading as out eyes are not very sensitive to the blue they emit. The fluorescent is a broad spectrum daylight type as I am also interested in photography and the PC I use for that is in the same room.

The room has concrete floors covered with decent quality cushion flooring - a sort of soft lino. Swarf sweeps up easily. Carpets are bad news if there is swarf around. Cold feet are best fixed with some home made duckboard. Wood laths will do for that.

If it's a plain raw concrete floor I would at least coat it with a sealant suitable for foot traffic. There is wide variety available.

The shelves were cut into 8' strips from 8'x4' sheets of 16mm mdf at the DIY store that supplied it and mounted on shelf brackets that plug into strips that are fixed to the wall with raw plugs and wood screws. B&Q in the UK but the shelving brackets etc are much cheaper at Screwfix - same company same things. These are the brackets

**LINK**

Plus the wall trips to match. With circa 2ft spacing they will take a very high load. I also have some racking but I feel something more flexible is needed by the machines.

John

-

The ceilings in the house are something around 11ft.

I've bought a similar one before but went for a 6 shelf unit that was a bit taller than these but found that I was wasting a lot of the height as the shelves were too far apart so this time I bought two 5 shelf units that are 1.8m tall. The uprights come in 2 pieces with a "clip" for joining them. The lower 5 shelves will be where most of the weight is and the top one of those is only just over the height of one of the upright halves.

The other mistake I made last time was going for ones that were deeper so this time I went for 300mm. More likely to tip but the weight will be far lower down than it was on the other ones which were 2m? tall. I don't intend to put anything with significant weight on the top 2 shelves which are held up using 4 of the 1/2 uprights from the other set. The shelves below that run up to the normal height of the units - for boxed reamer and tap / die sets etc. The big gap is for a small lathe.

John

-