Member postings for Ajohnw

I'd probably use a 5amp one due to the wire size. Daren't say that on here.

I suspect the actual physical sizes come from how many cable ends an electrician can stuff down each hole not the actual current rating.

John

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He appears to be using a mains lead not a ring main so a 16amp one would be fine. Even at that size the bare wire ends may need doubling over to get a nice fit.

The only problem with using them really is making sure that the wire is under the screw.

If it came to a race between a 5amp one and a ring main fuse I'd back the barrier strip and wire used against the ring main fuse.

John

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Edited By Ajohnw on 01/01/2017 15:37:58

Some links for you.

**LINK**

**LINK**

And probably the right size for you and a far more sensible price.

**LINK**

Some call it connector strip. Others chocolate blocks but that tends to be electronics people.

John

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You should fit an NVR switch. The main idea is to prevent some one switching on being unaware that the machine will start. That might include you.

My answer to that in the past when there could have been prying fingers about was to put a main switch well out of reach but I could always have forgot to switch things off. Actually if some one has that problem, kids really I'm not convinced that the usual position for a combined NVR and stop button is ideal. What that does is prevents an operator from having a surprise when a switch some where else is used 'cause they forgot to turn the machine off.

The NVR also takes care of when the mains fails - it does at times.

I don't see your problem really. Just go get some barrier strip. As some one mentioned don't have a switch on the earth leads.

John

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You just need a piece of barrier strip with a rating that is suitable for the motor. Use one way to link the earths.

The small size is aimed at lighting - 5amp. The larger one power which I think is 25amp. There may also be a middle sized one. You'll probably find them in DIY stores. Screwifix and Toolstation are bound to stock them also electricians suppliers. RS, Ebay etc.

They are shrouded so can just dangle about. If you want to fix in place break off 2 and fix with a screw.

Interesting problem. If that box had anything to do with general electrical wiring in houses, factories or what ever it's illegal to not provide an earth terminal.

John

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The video suggests what I did in training. Very slightly below centre for the flat but that was for a flat bottom for cap head screws. No need for relief when the end is being ground just do it very very slightly out of square. The other aspect would be more tricky now. Add a bit of rock when the the flat on the d is filed. There is no way I can file that flat now so I just mill them flat. I'd add too much rock naturally.

One I remember was to provide 1/64 clearance pocket for something like 3/4 dia headed cap screws. The flat was about 0.002" under centre. Once it was shown to work on mild steel it went straight into the instructors pocket. I'm sure he wanted it for his own use. One day he said we had better do D bits and picked me. Probably because I am 6ft plus and the vices were too low for easy flat filing. I can't remove metal that quickly with a file now either. It only took a couple of mins. Takes longer to mill one.

I've made a couple at home and they have usually worked ok. Only problem has been not letting red heat work it's way right through before quenching or too high a cutting speed or feed. They need to be fed slowly and also be kept cutting for things like cap head screw pockets. Hole size wise they aren't that much worse than a reamer if everything is square on etc. Not used them for that. My recollection is reamer + 5/10ths max D bit plus 1 1/2 thou max.

John

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Wont be getting a so called fresh turkey from the same source again. They should cook in about 2/3 the time of the others. It came in a posh box with award stickers on it - probably given for a new way of selling at higher prices. Too much "juice" came out of it too. The eating aspect was ok though.

The compressor has a bit of a problem. No gauge on the output just tank pressure. Cheap to fix with a gauge and an unequal ended T piece. No drier. Down to the design I suspect as if fitted easily it would foul on the reservoir. Best answer seems to be some tube and compression fitting mounting the drier on a hole in part of the plastic mounting. Or maybe dangling on the pipe. I have some 10mm table w kicking about. If the rating doesn't measure up I will probably graft a V compressor pump onto it. The price didn't look to bad for a reservoir, control gear, frame and wheels etc. I think a 2hp one would do it easily.

Another mistake on the welder. The tube fitting on it is for 8mm I think. I bought 6mm assuming I could change the fitting using 1/4 bsp parts. It's 1/8 and also used to hold the gas valve in place. I hadn't measured the size of the what looks like aquarium pipe that comes with it either. I think that would take the pressure needed but thought if I have to buy tube may as well replace it. 8mm wouldn't have increased the cost of the bits significantly.

The holiday period is holding up getting bits and pieces anyway.

Standard size 17 tig torch parts wont fit the one that came with it. I did wonder but now have some. The fittings used appear to only be available from China.

The plasma torch does take standard fittings - It comes with a plastic shroud for the nipple nut that fits onto the welder. I assume this is due to the voltage. One problem. It's loose in the plasma torch bag and not fitted. To save taking the torch and lead apart I suspect I'll avoid touching it. When it's on anyway.

John

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I've no idea what you are making but suspect I would be thinking of a redesign that didn't need so many pieces.

John

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Gut for what ?

Comparing it with a Student. Similar but less HP. Build wise both probably have had the gear head designed to cope with the torque at their lowest speed.

Say the chinese had designed it for 3hp. Chances are that given the same work to do the student would last longer as it would be very likely to be more heavily built. I'd say that is probably true of all of the machines warco sell in that range.

Martin mentioned the plus of the warco. 1 thou taper over 9". Also that he can get a decent finish with at 2 thou cut. I suspect it would take a lot of good luck to find a Student that will do that and as affordable to the same degree.

What your asking really depends on diameter and how fast you want to work. That is likely to depend on the power of the motor and the gearing. I think you need to talk to some one who machines it regularly. My limited experience with the stuff I had problems with is that sharp tools are essential and don't allow any rubbing. That was using the usual HSS drill on the particular material I had. I've no idea what carbide would do but would expect it to consume more power when turning even when used at HSS speeds.

John

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If the seller is who I suspect it is more data is very probably on their web site.

John

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The link to Oz leaves me wondering what % silver people use ?

John

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It's an odd thing about chinese lathes. They may have the oddities such as the 2 that Martin mentions. Others can be a bit lacking in the minimum lowest speed area as well.

The lathe you have asked about isn't that far off a student really. All that may offer is a 3hp motor rather than 2. That too according to lathes co uk has a rather high lowest speed. Not sure that is correct on the MK2 model but I used one a long time ago and did a lot more on other machines. The M500 is a much bigger and more powerful machine and also has the low speed most might want. Not all people could cope with a 12hp motor. Even something like a Triumph 2000 which was very popular uses a 7.5hp motor.

On Martin's comment on 17.5" dia wheels the cutting speed would be 300 ft/min. Which is pretty high and could cause a number of machines problems. For comparison this page gives some numbers for HSS. For carbide many would just double them.

**LINK**

If you don't receive any sensible answers on turning 316 I would suggest that you join practicalmachinist. Stainless steel topics often crops up there so even a search might help. If you give people an idea of the size of the work and the power of the machine etc I am pretty sure that there are people who would give you some idea of what to expect in terms of feeds, speeds and depth of cut.

Hope that doesn't upset Neil. If it upsets JS great.

John

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I started thinking spiral when I was looking for BSP taps Alan. I thought that way I will only need one for each size. On small sizes where I'd guess the OP's problems are not so sure though so wouldn't even try it. I reckon by the time the size gets to M6 a casual approach is ok. M4 too usually but worthy of some effort to get it right except maybe on aluminium.

Just thought. Something I haven't seen mentioned on here. When holes are tapped really the fully tapped depth shouldn't be above 2 diameters of the tap size. Same as nuts really. Going past 1 1/2 diameter engagement doesn't make things stronger. The hole may need to be deeper to leave some where for bits to go but it doesn't really need tapping any deeper.

John

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Edited By Ajohnw on 30/12/2016 21:01:14

The usual reason for breaking taps is the wrong sized hole or tap going in at an angle - the last one being pretty famous at the smaller end of the BA range. If you look around you may come across the ME sensitive drill and tapping attachment - aimed at making sure that the tap goes in at the same angle as the hole. It's not unusual for drilling machines to have tables that are well out of square with the spindle or for people not to bother checking.

Another common reason for broken taps is not reversing every 1/3 turn to break the chip.

There has been posts discussing thread engagement figures - in other words increasing the size of the hole above the theoretical.

It is possible to buy good quality carbon steel taps. I was missing a size and noticed some used for sale on ebay. They wont be used much so no problem using carbon steel taps.

The stuff in cheap sets is usually useless. I bought one once at the dearer end of cheap as I needed some UNF. They were crap and wouldn't even start cutting a thread without a lot of pressure.

One set of metric I bought came from screwfix. Their precision set that may have changed. They are ok but the stocks are cheap and nasty. The adjustment on the dies is novel as well and doesn't work for me.

Tracy Tools have been selling taps and dies for a long time and will also get things in to order. I doubt if anything they sell is junk.

I believe some people are using ArcEuro serial taps.

The London Tap and Die Co are relliable. There are loads. Drill Services and others.

I thought I wanted some BSP taps recently. Would only be used on brass and not that often so carbon steel would be fine. I did find a tool store that sold both these and ground HSS. I then found fittings at a more sensible price. On the other hand a real tool supplier is unlikely to sell rubbish as it's not good for repeat business.

If you want to tap stainless good quality serial taps would probably be a good idea. Cast iron is hard on taps too. Mild steel, brass and aluminium tap pretty easily if done correctly.

John

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Edited By Ajohnw on 30/12/2016 20:05:11

People can make a hob without a lead angle with just the rack form and do what Jason has shown. Hardened etc silver steel. It wont work too well on low tooth counts. That needs both parts to mover relative to each other.

The button method can be used to get a pretty accurate tooth form and also used to make multi tooth cutters.

I vaguely recollection that it was Tubal Cain who mentioned another way of keeping costs down. Don't buy the entire set of cutters. As the forms get modified and aren't perfect just close using a lower count cutter above it's range should be ok IMHO as that is how I would go about it. Where things start getting daft is at the lower tooth counts so if cutters are being bought do it on the basis of the lowest tooth count you need to make. I think TC mentioned it on the basis of buying a 1/2 set.

If you want to do a Neil I would suspect that a nice hefty acme or these days trapezoidal tap is a better option but with the blank gashed first and the edges thinned down. Not sure by how much but would suspect about 1/3 of the diameter of the tap. Maybe 1/2 tops. The ones that are on my Dore Westbury and dividing head were made like this but sadly the person who sold me the miller wouldn't part with the thing used to do it.

When buying propa cutters metric may well work out cheaper. As Rod has noticed. Plus some metric ones happen to have a circular pitch that works our rather nicely in imperial.

John

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Edited By Ajohnw on 30/12/2016 19:32:09

I'm not convinced that any one is Michael. It's probably not a good idea to start looking at the standards side of things.

It is interesting to compare here with there though. Oz for instance - rather interesting as it gives an indication of what they have done there - 2 official certs for download.

**LINK**

It's what's needed really but I would hope that the rules do allow variations providing the strength requirements are met. Eg my embryonic boiler would probably have an excess of tubes passing through it which could mean that there was no need for stays. Maybe not thicker end plates as well.

Not much elsewhere. Panics about state boiler regs in the USA.

Looking at Oz they have turned it into a bit of a money go round. Nice round prices for booklets but not TOTT. On the other hand I am not sure what the exchange rate is now. What they have done though is attempted to preserve the hobby. They have also taken on a certain amount of liability.

John

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I sometimes have the wish for dro but manage fine without. I get the impression that magnetic scales are getting more popular and also have an interest in one that can be found by googling Yuiry's Toys.

The neatest one I have seen for relatively easy tidy installation is one by Newall. The price though - ouch. I got the impression that Renishaw might do something similar at some point but no signs of it last time I looked.

John

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There is another area that very probably comes into this. It took around 10 secs to find this just searching pressure vessels. There may well be others.

**LINK**

I've no idea if what ever there is about needs to apply.

These may include design aspect as that is probably the most important aspect of the lot. I know of some in other areas that even include the sums needed to ensure that everybody uses the same ones.

Taking Andy's example 1.99L 100,000 psi - nothing wrong with that if it is designed correctly to work like that.

It all comes down to design in the end. Design needs facts not opinions. If those facts aren't available they have to be determined. It seems that the facts in this case are sort of available but some what I usually refer to as a committee decides that aspect isn't relevant to what they have decided off the cuff to do.

John

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I used to know some one who imported items from an ebay seller in the US and then sold them on ebay. The seller gave him a bit of discount. He reckoned that postage was included. This was over 10 years ago.

Also some one who sold fishing tackle small scale. Same problem. Tax made it more difficult to compete with the big boys. In this case the collection fee was significant as well.

Personally I think it should be opened right up as it's the big boys that lobby for changes. They don't want people selling things cheaper than they do. If we are to become a nation of people who sell hamburgers to each other and hair dressers etc in a situation where rather a lot of the things we buy are imports I feel opening it up to give smaller outfits a chance would benefit all of us eventually. Say a nice round number like £1000 and tax for every one over that. I also suspect HMRC would get more if they arranged to collect tax electronically without a collection fee as well. The other thing about tax on £1000 plus is that it is worth collecting - collecting tax on £16 worth is pretty pointless and costly really.

Then Curries would go just in time and only ever order £999.99 worth at any one time. I'm sure that could be handled but with some complications. Maybe £1000 is too much but at the other end of the scale £15 is stupid. The £18 limit I suspect had been around for a very long time and was never ever increased.

That leaves items delivered that are marked as being worthless. Our postman says they get a lot of them. I suspect most if not all are pretty low value items. Personally if items are on the pricey side I always pay tax. I may ask for a reduced price on the paper work to cover the collection fee. Some things I don't buy as the collection fee would make it too expensive. In that case there is usually some one some where who sells at an acceptable price. Some charge a lot more.

John

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Edited By Ajohnw on 30/12/2016 13:48:51

I don't think it's a laughing matter Fizzy but on the other hand I don't think this thread will sort it out.

Nick has thrown some interesting light on CE marks. I am sure I have seen comments that in some cases these small boilers must be CE marked. These comments may or may not be correct.

That really sums it up. Also such comments as competent persons, sound engineering practice and other garbage like that. It needs all setting down more clearly. A problem though. In the end the quality of the item will depend on the maker. Go too far and few people will be able to make them because most wont have the qualifications that they would need. Things like materials, good practice and sums for the design side of things plus some no no's that might crop up could be tied down.

A lot of work. Probably why it hasn't been done and as some one mentioned earlier going through the legislated aspects is hard work and they may change periodically. When I look at them I always wonder why there isn't a decision tree to help point to the right parts. Legalised requirements are usually always a pain to go through. Legal speak always tends to finish up like that what ever field it covers.

There is nothing to stop some one from building a boiler for their own use. Some additional information might make that aspect a bit safer. It's the sort of thing I might do at some point which is why I have looked around at the subject. I reckon I can cope via over design anyway based around things that I can easily get rather than a kit.

John

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