Member postings for Andrew Tinsley

hello Dave,

yes I should have said 100hz flicker for magnetic ballasts. This frequency is way above what the average human eye can see. I don't have information to hand about the subliminal effects, so can't comment.

I have examined HF ballasts which operate from as low as 4kHz to near 50 kHz. The basic problem is that the circuits are mainly multivibrator. This leads to a sharp edge on the cut off which produce harmonic oscillations into the mHz region, thus producing copious interference in the RF spectrum. Few HF ballasts have sufficient RF suppression. As Muzzer said, they are cheap Chinesium crap, as opposed to the expensive Chinese stuff manufactured for reputable European majors

Interesting that you sited the GE blurb. I had a hand in writing it!

Andrew.

HF ballasts operate in the kilohertz regions. They are usually a multivibrator circuit. This means that the resulting hash can go up into the medium and even VHF wavebands. This is why I don't like them. I can't listen to my radio because of the interference.

Andrew

In an amateurs workshop, strobing is unlikely to fool anyone into thinking that the machine isn't in action. Large workshops with multiple people are another thing altogether.

Yes I calibrate my tachometer with a fluorescent tube. You can still get the effect with a tungsten filament lamp (although much less of a variation). The eye can't respond to 50 or 100 Hz unless you are a very odd man out, so this isn't the flicker you see with an old fluorescent tube.

I reiterate that LEDs are not always flicker free. It depends on the electronic drivers. Some of the cheaper drive circuits produce the same sort of 50Hz flicker as a fluorescent. You get what you pay for in driver circuits.

Andrew

I don't want to stir controversy. However the resounding vote for LED tubes may be a mite misleading. People usually swop from fluorescent to LED tubes because they are dissatisfied with the lighting levels. They are then amazed how bright the LED tubes are. However they are usually comparing old worn out fluorescent tubes with new LED tubes. Need I say more?

With regard to the colour temperature of tubes. There is a much wider choice of colour temperature in fluorescent tubes than for LED tubes. People never ask for a colour temperature when they buy tubes and therefore usually get around 3000K tubes, as they are the most common.

LED tubes are not necessarily free of flicker, it depends on the circuitry of the drivers. Having said all that, LED tubes are more efficient. At the current time they are also quite a bit more expensive, which tends to reduce their efficiency advantage over life. One other thing to note is that the claimed lifetime of LEDs is usually very optimistic. The life is critically dependent on temperature. The higher the running temperature, the shorter the life! It only takes a small temperature rise to significantly reduce the lifetime to failure.

Obviously LEDs are the future, but right now, the advantages are not as large as people think. When the chokes fail on my fluorescent tube installation, I will probably change to LED tubes, until then, I shall keep my 6000K fluorescent tubes. By that time, the LED tubes will be significantly cheaper than they are now.

Andrew.

I have always used ordinary fluorescent tubes plus chokes and I have never had any stroboscopic effects! Even if you did, the racket that any machine tool makes would tell anyone that the system was working and not stationary!

HF driven tubes are a bit of a pigs ear. They should be a touch more efficient, but they radiate all sorts of high frequency hash. This can cause the effect you are experiencing. I would never use HF gear in a workshop, mucks up my radio!

Andrew.

I have an ML7 on a Myford stand and never thought about height. I have just finished refurbishing a 9x20 lathe for a disabled friend, It is approx. one foot higher than the Myford and it is a joy to use, no bending or straining. It is much higher than most lathes and I am 5 foot ten inches high. Made me think!

Andrew.

P.S. I now have to reduce its height considerably for use by my friend.

Not sure if we are talking jig (scroll) saws or bandsaws here. I have the previous incarnation of the Aldi bandsaw. It was end of line and I paid £40 for it. It is excellent on wood and providing you get a fine tooth blade it will cut non ferrous sheet material like a hot knife through butter. This, despite it being having far too high a cutting speed, according to theory.

Andrew.

Before anyone writes in about a source of Phillister head (or Fillister!). The modern ones are quite unlike the old American screws. The modern ones are more or less slotted cheesheads without the slightly domed heads and indeed curved sides.

Andrew.

Jason,

You are quite correct about the Phillister head bolts they are common on old US spark ignition engines. I wished I could source some, but no luck even in the USA! Some of my old O&R engines could do with new phillister head screws!

Andrew.

Certainly an HB carb, but the rest of the engine is a mystery. Looks like a good home build.

Andrew.

Well the real fat controller was based on the late Rev Teddy Boston. A real gentleman and steam enthusiast with a railway around the rectory grounds!

I believe that the owner of the Lathes UK site has the spares you need.

Andrew.

I remember a chap who was a Chindit in Burma. He said that Orde Wingate wore a topee and had a Flit gun which he used regularly. Must have worked for him, but goodness knows what else he killed.

Andrew.

Ah! not exactly liberation day. Just price increases. Look at the pound going down.

Andrew.

I have an Axminster version (small type). As long as you don't expect to bend, cut and roll thick material then it is fine. It isn't a professional tool, so don't expect professional results.

For thin gauge material it produces a perfectly acceptable job. At the price I paid for mine it was a bargain. A little practice will pay dividends before you use it in anger.

Andrew.

Difficult one! Most people will have one or the other and will probably favour the lathe they have.

I have an ML10 in good order and with sufficient bits and pieces to keep me happy. I suspect one of the real difficulties will be in the cost of accessories for an ML10. Just look at the asking prices for fixed and travelling steadies. Sit down before you do! having said that, such things are relatively straightforward to make. but do you want to make bits for your ML10 or make projects like locos?

Mini- lathes are getting to be very good in quality and spares are good and plentiful, not to mention inexpensive. ML10s command better prices second hand, in good nick. All a bit of a minefield to choose between the two.

I will stick to my ML10, although I suspect the overwhelming majority would say keep the mini lathe.

Andrew.

I have the same type of drill. I bought mine for £15 because the DIY Chain had gone bust. There were 4 left and I nipped home to get an engineer's square. Checked them all out and got one which was as near as could be, with vertical column at right angles to the base and a tight quill .

It has been a minor miracle. It will drill mild steel with a half inch drill, without any hassle. It only has the so called 300 watt motor (and I bet the O/P is a good bit less).

OK I got very lucky with this buy, almost in the "precision" class for a load of potential Chinese junk. The only thing that is wrong big time, is that the table deflects when doing heavy drilling. I use a scissor jack to stop this, but I wish I could find a real cure for the deflection. I don't know if it comes from the swivel table or the collar. One day I will come up with a good idea. But by then I shall probably have burnt out the motor.

I wish I had purchased the other three now. A cheap way of getting motors, NVR switches and reasonable pulleys!

Andrew.

I have done anodising for years and it is pretty fool proof. If you want to give it a try, buy one of the kits that several companies sell. A friend used Ebay for his kit and he got excellent results first time.

Please note the Safety warnings that come with the kit and also in the above replies.

Dyes can be problematical, I have used Dylon initially but not all colours work. The Reds do and the Kingfisher Blue as well. Some of the greens don't work and it is said (not by me!) that the pores left by the anodising process are very small (true) and some of the large molecule dyes won't go into the pores (which I doubt).

You are probably better off buying the correct dyes for the anodising process. If you are going to use the anodised product on say a finned jacket for an IC engine. I believe there are dyes which don't degrade at higher temperatures. The Dylon reds last a long time but eventually go a sort of pink shade in IC application.

Andrew.

Yes I just grind them down to a plug configuration, like Jason. Maybe take it a bit easy in case you soften the first few threads.

The points and dimples are used as centres when making the tap. They are also used if you ever sharpen them, but that probably isn't going to happen!

Andrew.

Hello Murray,

Zoro is Cromwell's version of themselves for us poor model engineers. Prices are supposed to be cheaper, but still make me wince.

Andrew.