Member postings for not done it yet

As ME's, we do get hyped up about accuracy,

Some might, I don't unless a particular accuracy/precision is required.

Like most times to drill through a cylinder centrally it is close enough to 'graze' the cylinder with a milling cutter (or even a drill bit) and dot punch in the centre of the flat/mark. Simple, quick and accurate enough for larger diameter items. My aged surface plate is good enough for me and mostly gets used for flatting surfaces by laying on a strip of abrasive paper. A plate glass sheet would be more than good enough, but perhaps likely to get broken.

No point in having a real super-dupa surface plate unless you already have a good surface grinder, I reckon. But a good job we are not all exactly alike.

Transformers are designed to run hot.

Have to disagree a tad here. Heat is a wasteful byproduct and so reduces the efficiency of the device. Transformers are built to withstand heat, but are designed for minimum heat production, shirley? If they could, they would run cold and not need high temperature winding insulation. A simple trade off between high efficiency and cheap production cost.

Does anyone have issues with variable speed lathes and the motors burning out ?

There are always exceptions. My lathe motor runs at constant speed, but the lathe spindle speed is infinitely variable between max and min limits. No problem of overheating the motor and no need for electronic speed controllers. Cheapness is not always bestness!

John is quite right about modern day transformers, particularly from china. I believe all new units are required to have a rating shown. This ranges from one to five, or six, in roman numerals, the best being the higher numbers which waste far less power than the poor ones.

Basically the magnetic flux is lost from the unit, instead of being concentrated and used where it is effective or the windings are substandard in the poor units.

Think about things a little and you will realise the turns ratio, to reduce the voltage from 240 to 12V is 20:1. This can theoretically be achieved with 20 turns on the primary and just 1 on the secondary. Or it might be achieved wit 200 and 10,

2000 and 100 or any other combination of that ratio. The lower numbers will not work as well as higher numbers.

Also, the transformer core needs to be designed so as not to retain its magnetism (it needs to change at the mains frequency) and the induced currents (eddy currents) in the core material need to be minimised (that is why cores are laminated and electrically isolated between laminations).

Further design parameters, like isolating the primary (at mains voltage) from the safe secondary voltage, to avoid mains voltage being fed to the output in the case of failed windings, can be arranged with windings separated to each end of the core or one winding enclosing the other. Both work, but the efficiency is not the same!

Good transformer design is not a simple matter as all the above aspects are inter-related!

One of the problems with some motorway stretches is the inability, or reluctance, of many drivers to use all the available lanes.

I once went from Northampton to Luton, unhindered at a fairly high speed, using only the inside lane of the M1 whilst traffic was often clogged, in the outer lanes, with slower moving traffic. Often an empty lane between myself and slower moving traffic. I don't class 'staying in lane' as undertaking.

Traffic density is measured by some of the many cameras along the route and if everyone used all the lanes sensibly, the vehicle spacings would be much safer in the variable speed limit sections.. I find the M25 is often slowed by inconsiderate lane hoggers. Likely the 'drivers' who don't know how to change lanes!

Agree with Tim. A location would be good. Responders should not have to search for or guess.

Same problem with a previous thread. He was in Stafford, then.

I would be checking output voltage and current to find the wattage of the load as a first step. I might then be looking at input power v. output power to check for efficiency, if not overloaded. It cannot be good if the case temperature is near 50C (in the shade) as the internal wiring temp may be considerably higher.

A decent one should only be losing about 3-4W as heat. Do check your IR thermometer as some are notoriously inaccurate, but the power supply should not get to untouchable temperatures from internal heat generation, that is for certain!

I would not think that an impellor pump (non postive displacement) would be affected by blockage in pipework, only if the impellor is rubbing. Is it direct drive or magnetically coupled? If the latter, is it driving continuously or is the motor decoupling continually?

No expert, but I would think that if only one side has been ground flat, the other will not be (fairly obvious, that?).

In that case, a straight edge would sort out the two?

Does the instructions really matter if the bed length is 6'', 10" or 12"? There are more important features than simply bed length?

Does the instructions really matter if the bed length is 6'', 10" or 12"? There are more important features than simply bed length?

What does the gear stick do? If it is a PSA gearbox, it could be the selector mechanism. Had two that failed in the same mode. Cheaper to change the box than repair, in my case (high mileage and box needed to come apart for new expensive bits in an older vehicle), as a second hand box was easily sourced. Unfortunately the replacemment went the same way.

That fan pulley on the compreessor will not have such a high speed rating, I would think. Beware.

have already made the valves.....methinks this may make the job harder?

Practise on a piece of scrap 2.38mm bar first?

Make a delrin nut thread from your screw and fit into the old nut after turning out the old thread?

Leave the A1at the A47 intersection at Wansford and drive towards Peterborough. Sacrewell is on the left only about a quarter mile from the A1/A47 flyover. Clearly signed, I think.

A good day out for a family, let alone the extras on site.

I think you approach the target size by small increments, otherwise they become unmanageable and one risks breakages or gouges in the holes.

Three core and earth of about the same rating, per core, as the incoming 230V single phase supply. No need for a screened cable if it is short lead, I believe. Details will be in the manual.... somewhere!

If you don't know, it would perhaps be better to get the job done by an electrician.

As XD 351.

Many buzzbox alloy compressors are driven at near 3000rpm. Better to buy an old cast iron two stage pump that will do the job at about 500rpm. Many of these inefficient pumps need 2 or 3 kW, so a small briggs may be ''hissing into the wind' to drive it properly. Even better would be to gef a decent Honda engine!

Briggs engines were rated as a flash horse power, not continuous. That is why the Honda engines of the same nominal power (but DIN rated) were deemed such better engines.

I once had a generator, rated at 1.5kW, driven by a briggs. It would stall out while trying to start a freezer, unless it was given extra revs to overcome the motor starting load. Freezer was rated at 160W, so would have needed about a kW at start up.

Slitting saw?

Pressure is force multiplied by area. You have both area and force indicated so you should be able to calculate the pressure. It must have an internal pressure relief valve. Whether that is adjustable or not is not clear. It is unlikely to be adjustable by a factor of three, mind. Depends on motor power and flow as well as pressure.

You could change your ram for one of three times the area and recalibrate the scale!