Member postings for not done it yet

If it is fixed in position, it is important. If it ‘floats’ there is not much you can do about it. I can’t remember which it is (on my 2B).

As I, too, said on the 4th “Do carry out a hydraulic pressure test on the receiver. They are unlikely to fail, but they only fail once.”.

Simple enough - fill the receiver with water and carefully increase the pressure from a pressure washer or (as I do it) with a grease gun. The grease gun method needs more grease than maybe expected as the receiver will expand as the pressure inceases.

Synchronous/asynchronous. Point taken. I meant the type of motor on the typical scavenge pump on a dishwasher/ washing machine. Can’t remember what they are called. Fixed direction, cheap and also found on cooker oven fans.

It looks, to me, likely to be a synchronous induction motor of about 90 Watts? Just working on current, assumed power factor of Cos Theta = 0.8 and likely heat losses.

A pic of the motor might help. A usual 1/4 horse power induction motor would consume rather more than 1/2 an Amp and not be of fixed rotation.

As to the HP - maybe it was supplied by Hewlett Packard? (Joke)

Let’s be sensible, here. I know nowt about the rules for acetylene, but….

Location may make a difference to the rules/laws. You have not provided that information.

As above, there may be a difference between a discrete workshop building and one which is part of your habited house. Again, you have not provided details.

Most certainly, butane bottles within the house, in the UK is permitted. Propane is not (because of the higher pressures involved). All calor-fuelled cookers, etc must have the bottles sited outside.

Non-flam gases are permissible - lots of oxygen cylinders are used for people with breathing difficulties. Soda-stream bottles have been in existence for decades, some fire extinguishers contain CO2, some even run bars in their homes!

However, in any case, your house and contents insurance may be negated (if you think you are insured) unless the company is aware and the policy adjusted to include the risk.

Just remove those parts that prevent it fitting within the access. No point in totally dismantling if actually unnecessary.

A much longer piece than necessary, roll it to radius and machine to size (likely sawing and then finish-machining to size).

Nearly 2m, in diameter - and only about 50mm long- is not a great deal of change from straight, flat or with a bit of a filed ends?

Depending on the surface finish required, maybe even surface grind the section required, before bending - and protect that surface during the bending operation.

OOPS. The sector is going to be about a metre long? Just use a linisher for the very slight curved end?

Edited By not done it yet on 05/09/2023 09:12:03

Dunno what it cost, but presume the outlay, thus far, is minimal. That said, if the pump works to design (pressure and output) it will be worth modifying. That pump may well be rather superior to the current crop of cheap pumps on the market wrt to longevity. Likely claimed as less efficient than a modern pump, therefore old-fashioned, by those selling the modern ‘buzz-boxes’. My compressor is, by appearance, much older than that unit - and I have no intention of changing my old cast iron pump!

I see lots of dead compressors, or cheap unpopular machines. So I would obtain one of those, with the applicable parts, to convert the machine to the more usual operational specifications.

As stated earlier, if the compressor will only be needed to restart just a few times per hour, the motor would likely be OK. If one has space another possibility is to increase the reservoir capacity (another receiver in the system and just switch it off when fully charged.

Do carry out a hydraulic pressure test on the receiver. They are unlikely to fail, but they only fail once.

Agreed, John,

Alkali aggregate reaction was my take, on the original use of that term. Recognised from about the early’70’s as I recall - particularly with cement manufactured by the ‘dry’ process (as opposed to the ‘wet’ process where the raw materials were fed to the kilns as a slurry). The dry process involves heat transfer within cyclones as the kiln exhaust gases exit the system and the powder feed descends the cyclone tower before entering the kin at near to (or even above) calcining temperature - depending on whether extra fuel is injected at the flue gas exit to the kiln. Alkali metal salts (mainly as chlorides and sulphates), sulphates were a result sulphur content in the coal and gypsum in the raw materials These mostly evaporate in the kiln burning zone and recirculate by condensation within the cyclone tower. This led to build-up, and possible blockage, in the final cyclone feed pipe - from the hottest cyclone to the kiln.

The alkali metals either eventually passed through to the cement clinker or, in some cases some exhaust gases were bled away, via a bypass system, where the high alkali metal salts were collected (along with a fraction of what was the kiln feed) and dumped back to the quarry. In the much less energy efficient wet process, the alkalis were generally lower, even though far more coal was consumed in the process (approx twice the amount!). They were collected in the dust collectors and dumped in the quarry.

As a addition to the discussion of RAAC, it may be noted that the ‘norm’ for removing frost protection from curing concrete/mortar was around the ‘5N’ level - 10N levels were typical for one-day strengths under standard condition, so less in cold weather - so any RAAC which might absorb water could suffer from frost damage. Not a good idea for flat roof structures - so just yet another risk with older buildings - and particularly roofs over (heated) swimming pools!

Normal load-bearing concrete has a compressive strength of around 40 Newtons per square mm. This stuff never had any substantial compressive strength - 4Newtons per mm^2 - so should really only have been used as supported panelling.

It would appear that its light weight was too much of a tempting idea to use it - such that the supporting structure could also be down-specced. IMO, it should never have been used as a ‘roofing material’.

Your typical garage base would be made with ‘20N’ concrete - and need to be 150mm thick, probably with some form of reinforcement in the base - either a layer of weld mesh, or stainless steel needles (or even plastic fibres) in the mix) if expected to be loaded heavily. That concrete would be laid over a well compacted sub-base, too.

RAAC concrete - if one could call it concrete - was not only lightweight (more like a mortar sponge) but was also much cheaper to produce (the virtual final strength was achieved in less than a day compared to a month for normal concrete). Normal concrete would be made based on the 28 day strength, but would continue to slowly gain strength - possibly over several years.

One thing that is not suspect is the cement. Cement, made to BS12 was perfectly adequate for the purposes for which it was specified, in structural concrete. Your average sectional concrete garage panels are stronger than this stuff. I never came across this stuff and cement was proper cement until the industry started to blend in things, such as fly ash, in the 1970s (to compete with cheap imports from Europe).

This problem is down to architects along with cheap building design and construction. What do they say? Buy cheap, buy twice. It is coming home, now….

When I wanted a bit more ease of operation, I went directly to Arc Euro Trade. Unfortunately (afaIk) they only do digis up to 100mm.

Speed reduction, from the motor to driven shaft, will be a torque multiplier. Power is power at whatever speed is chosen/available. Torque is basically “shaft speed x power”. Expect up to 10% losses in each stage of speed reduction (nothing is 100% efficient).

‘I don't think it has a centrifugal switch as it doesn't seem to click in and out when it fires up? I could be wrong in assuming this however?”

‘Nothing to be lost by trying more capacitance, fingers crossed. Otherwise it will be necessary to confirm the motor hasn't got a centrifugal switch by looking inside, and making sure the contacts and mechanism are both OK.”

Check for the switch making on slow-down, not breaking on start-up! Without power, it should be slowing quite gently with no added sound from a heavily loaded motor.

But as per Dave, visual is the definitive check (to avoid having the start winding overheating the motor)

Edited By not done it yet on 27/08/2023 14:54:00

A 90 tooth gear is one complete turn on the more common rotary tables? I have mis-counted or something before now; I am now much more careful to try to avoid that mistake, whatever it was.

I have mostly made aluminium gears which is more easily cut in a single pass.

Jason, you will have a PM shortly.

I don’t know about use other than for bells - where it has an extremely good scrap re-cycle value!

I did manage to mess up the last 90T gear I cut which will now have to have the teeth turned off and the blank used for a smaller gear when the need arises.

You could machine off all the teeth and a bit more, then replace that outer ring and teeth with a a machined ring either with teeth or machining the teeth after fitting the ring (likely the better option🙂 ).

I’ve not done that, but have replaced the central drive hub on an already-cut gear.

Preparation(sanding)

Not done any brass since buying my surface grinder, but surface ground steel items most certainly resist tarnishing - far better than when machined on the mill. Any surface imperfections will be points where tarnishing will be initiated, but surface coatings should avoid that factor (and adhesion of those coatings may be superior on a ‘rougher. surface, compared to ultra-smooth metal finishes).

Exactly spot on, correct and already slowly being realised by the authorities.

One clear example was the Trading Standards seizing of approximately a thousand cheap chinese diesel air heaters. late last year. These heaters, while being cheap and likely without the best of instructions, were (IMO0) ‘satisfactory’ for the purpose for which they were designed - if used responsibly. They were offered as vehicle parking heaters, not for installing inside habitable buildings, which has become a popular use - according to the number of youtube videos on their use.

But lets agree, here, that lots of things are used for purposes they were not designed for. One example is the alarming number of knife-crime threats, injuries and deaths - using tools, designed for kitchen (or other legal applications) as weapons.

It’s OK, Cyril, you won’t find one that large on your myford lathe!🙂

Likely a plastic gear would do (yes, I suppose 3-D printers can seem to be noisy - particularly if running overnight)?

A small lump of 15mm thick Aluminium sheet could be a good starting point - not too noisy to do indoors with hand tools, I would think?

I’ll stick with my mill and gear cutters, mind. Far easier and faster. My hand tool skills are a bit lacking for jobs like that.