Member postings for ChrisH

In a previous life I was a boiler and pressure vessels surveyor and as such was deemed to be a 'competent person'. In those more practical days a 'competent person' was considered to be 'someone with the knowledge and experience to understand, know and anticipate the likely faults and defects and where to find them'. With the number of surveyors required them, when we had a large manufacturing industry, had the surveyors been required to be of 'incorporated engineer level' the industry would have been woefully short of surveyors. Progress is not necessarily a good thing!

Chris

Exactly Neil, what has been the record on safety? Is there a pressing need for new legislation based on documented accidents, or is this, as has been suggested, yet another  step down the road of the nanny/big brother state?

Chris

Edited By ChrisH on 22/11/2012 22:09:52

Gordon W has a good point. So,if one has the capability to design and do the calcs for a boiler but if you don' t belong to a club with an 'in-store' tame boiler inspector, for whatever reason, then what? Who do you get to check over the calcs and design?

Plus, if you do manage to devise a traceable paper trail for the materials then what? Who do you get to do the in build inspections, hydraulic test and steaming test?

Serious queries - I am not a member of of any club at present but do want to build a boiler!

Chris

The problem with testing on air is that if there is a leak the air just hisses out gently but pressure is maintained, so in a noisy environment a leak could be easily missed. But with a hydraulic test when you have a leak, even a drip, the pressure drops off dramatically. Plus, the drip leaks a wet patch shows the location of the leak, whereas the air leak leaves no trace.

So a pressure test should always be done with 100% water.

ChrisH

G'Day Don,

On all the big ship main engines I worked on, the cylinder liners were cast iron and the piston rings were also cast iron. Cast iron works well against cast iron, I would go for C.I.

Regards, Chris

Hi John, (Bogstandard2),

My mill/drill is the Warco 'Economy', just about the same as the Axminster ZX25, the Chester Eagle 25, and a few others I guess besides. My view was that it could only be trammed by shimming between base and column and that should last for ages, but, I am indebted to you for attaching the link to your dual gauge tramming tool. What a well written thread! As it happens, I have a couple of gauges going spare, looks like another project to put on the "must do" list!

Cheers,

Chris

I have read that a milling machine should be trammed before each project and even before starting work each day.

What I do not understand is why this becomes necessary. Assuming only the one person ever uses a milling machine, and that it is not abused, why once the mill has been trammed to an acceptable degree of trueness should it go out of true?

If a mill is of robust and solid construction what moves to send it out? I am thinking heavy vertical round column mill here, with solid base securely fastened down with four strong bolts.

Would be grateful for illumination on this please.

ChrisH

Terry at 17:16:41

Good reply - well said

Chris

Blooming 'eck, I thought my shop was bad, but I'm not in the same league as you guys, makes me feel quiet good..................

ChrisH

Humm, maybe a change in company policy is called for then Clive. When I did my 'apprenticeship' with a shipping company as a marine engineer back in the 1960's, a couple of months before my aprenticeship finished I had to sign a contract to stay and work for the company for two years, otherwise my apprenticeship was not signed off as completed. Ok, they had you by the short and curlies, but in their position I would have done exactly the same and got a return on the company's investment.

Chris.

Edited By ChrisH on 22/09/2012 21:45:48

Warco now supply cutting oil without you having to buy a machine as well! I got some a few months ago - they said their carrier had now agreed to transport it. I think they do 2 and 4 litres containers from memory.

Chris

Edited By ChrisH on 09/09/2012 23:00:11

Edited By ChrisH on 09/09/2012 23:00:38

It used to be -and probably still is, I don't know if the regulations have changed over the years - for air receivers in industrial, factories or working premises, to have a statutory through examination every two years plus a working examination.

Hi,

Many thanks to all who have replied so far.

Re the backplate, for me I was tossing up between the black steel and the cast iron, both quite similar on price. Still undecided!  Max chuck speed is supposed to be about 1600rpm, but I've not measured it.

Don't do much hex work so the 4 jaw would be OK as I would still have the 3 jaw for that. Both the 3 and the 4 jaw from Arc can come with soft jaws, which was an attraction. I have read Harold Halls method of making soft jaws which I was considering for my old 3 jaw - sounded like an interesting exercise to say the least!  I'm leaning towards a 4 jaw, just need to convince myself.

A quick look on the web established that Thame Engineering are still in business, and I will also check out second hand chucks.

Chris

Edited By ChrisH on 31/07/2012 18:57:08

Edited By ChrisH on 31/07/2012 18:44:19

Another "What does the team think" query, or rather queries, as there are two!

I have an old but very good IMO lathe, but the 140mm dia chuck is a 3 jaw self-centering that has seen better days. It is OK and servicable, but the wear means it is not very accurate and stuff rarely runs anything like true. So I was thinking of maybe getting a new chuck. But which chuck?

I have a faceplate come 4 jaw independant chuck of about 200mm dia, so was looking at maybe another 3 jaw chuck. Then I read a couple of articles where the use of a 4 jaw self-centering was considered a better bet than the 3 jaw. Mr ArcEuroTrade's 160mm dia Indian made 4 jaw looked attractive, plus one can get soft jaws for it. But the weight is 9.6kg, which seems a lot. The 3 jaw is 7.7kg by comparison. The lathe is a Weiller 280Z, a German machine from the late 1960's early 70's BTW.

So, Query 1, is a 4 jaw self-centering a better bet than a 3 jaw self-centering, even though it is heavier?

The new chuck would also need a backplate, which would have to be made from a piece of material at least 160mm diameter by 60mm thick. I have looked at available material and I could get a lump of cast iron, or steel in either bright or black.

So, Query 2, which would be the best material, cast iron, bright steel, or black steel?

Regards,

ChrisH

Edited By ChrisH on 31/07/2012 15:17:16

Thanks David - it's fine for me now too!

Regards, Chris