Member postings for Andrew Tinsley

I have used ground steel stock and have had no problems thus far.

Andrew.

Hello Bazyle,

I was simply thinking of connecting the variac to the input of the VFD. That way you have the VFD rectifiers in circuit before the caps.

Andrew.

So what is the way to reform a set of VFD caps? Simply hook up to a variac and slowly up the volts to mains plus over an hour or so?

I must admit I am a bit askance at having to reform the caps after a year. My electrolytic caps are fine, even after a few years in storage, are VFD caps some special sort of aluminium oxide caps, as they appear to be somewhat delicate?

Andrew.

Well I don't reckon kids are any more stupid today than they have ever been. Looking at the majority of oldsters in my age group, makes me realise that they are as thick as two short planks.

Andrew.

I did try Mapp gas a good few years back and it was significantly better than either butane or propane. However I have oxy acetylene so it didn't get a lot of use.

I believe that the current Mapp gas is a different formulation to what it used to be, but others may know more.

Andrew.

Thanks for that supplier, new one to me but presume you recommend them.

Andrew.

I have managed to lose the names and contact details of a couple of band saw blade suppliers that I have used in the past. Can anyone recommend a good supplier?

Thanks in advance,

Andrew.

Looks like a pre war Slag engine from the USA. It looks very familiar, I will try and put a name to it.

Andrew.

Not sure if I have misunderstood your comment on machining V pulleys. If you look at an early Duplex article on the subject I think they shows how to do that job using a form tool on an ML7.

Andrew.

By the time you think that your fluorescent tubes need replacing, they are long past their best! If you replaced them with new fluorescents you would be saying how bright they are!

LED lights are more efficient power wise and will probably last longer. But don't bank on it! I have been an all LED household for a few years now. I have worked in lamp manufacture so I keep records. The claimed lifetime of LED lamps has not been born out by my observation. It is shaping up that you get a little over half the claimed lifetime.

Not arguing that LED lamps are the way to go, but the reliability stakes are not as good as claimed. LED lifetimes are very sensitive to ambient temperature.Claimed lifetimes are usually made from tests on a single LED. As soon as they are placed together, the temperature goes up and the lifetime comes down! A fellow worker developed some machine ring vision luminaires using 20,000 hour guaranteed LEDs. The effective lifetime of the luminaires in service was 3000 hours before failed LEDs became a problem.

I will not be replacing my workshop fluorescents with LED versions anytime soon. I shall be waiting for a price drop and an improvement in lifetime before I change. I would guess a couple of years to wait before this happens.

Andrew.

Edited By Andrew Tinsley on 03/03/2018 14:21:54

Edited By JasonB on 03/03/2018 16:48:29

Full size practice on the few engines that were so fitted, were Hoffman roller bearings. So needle bearings would be an equivalent?

Andrew.

I don't have a smartphone and don't watch TV. I could not live without my radio though!

Andrew.

Hello everyone that have contacted me re MEW 219. I am now fixed up with a copy. But thanks for all the offers of help for which I am most grateful!

I didn't realise that it took some time before an advert appeared in the "Wanted section". I assumed that it was instantaneous rather like an answer to a post. Apologies for my ignorance!

Thanks again everyone,

Andrew.

I don't seem to be able to post in the "wanted section"! I would like to buy MEW 219 or maybe someone could scan an article from it?

Mr Moderator, feel free to delete this post if I am contravening regulations! I just cannot post in the wanted section for some reason!

Andrew.

Sounds pretty dangerous to me. I know of 2 deaths caused by explosions with people trying to braze petrol tanks. It just isn't worth the risk.

Andrew.

I would not bother with mixing synthetic and castor oil for such an old design of engine. Just use castor and methanol and don't worry about compression ratios as methanol fuel will run at very low CR without any trouble.

Modern ABC and AAC engines are said to run best on synthetic oil and I don't argue with that. If being used for RC, the engine can always be shut down if it goes lean. I still fly control line and you don't have the luxury of shutting down if this happens. So I always add 5% castor to the fuel just in case!

Andrew.

Castor will break down under high temperature. However the products are still able to lubricate This breakdown continues with higher temperatures, but the residuals are still able to lubricate. This is why castor has always been used in model IC engines when there was a possibility that the mixture might lean out.

Once you have had a runaway and all is cooled back down, then you have some very viscous remnants of the castor oil left. Best to do a good strip down and clean at this stage. so maybe not ideal for lubricating superheated steam!?

Andrew.

I have heard that acetyl polymer is good for leadscrew nuts. It has even been suggested as a material for model IC conrods!

I can't believe the latter and would have grave doubts about the former. Can someone explain why it should be good for leadscrew nuts? I have certainly seen it used in the US for this purpose. however I am a doubting Thomas!

Andrew.

I seem to remember someone , somewhere, writing that bronze would wear a steel leadscrew, Where as brass nut would wear rather than the leadscrew. Ergo, it is preferable to use brass.

I have no idea if the above is true, hence my query. Obviously it is cheaper to make a new nut than a leadscrew.

Andrew.

The above says it all, the nut being for a steel leadscrew,

Regards,

Andrew.