Member postings for JA

In the past this has been discussed at length on this forum with references to a number of scholarly papers. In other words this has been extensively researched by museums, the timber industry and others.

In essence all timber is corrosive to some metals including mild steel. The corrosion is due to acetic acid.

A very late at night post which I generally avoid,

JA

Edited By JA on 03/04/2023 23:10:00

At least it was before the Second Law of Thermodynamics was formulated. The First (conservation of energy) might just allow pertetual motion (there has to be no energy loss, ie no work done, no friction etc).

I now expect a comment such as "What has the Second Law got to do with this"?

JA

What is this? An advert?

I am not looking further or trying to find out.

JA

Sorry Chris. I will not be in the firing squad.

I will happily use a junior hacksaw for cutting through the small final diameter sometimes left from parting off. This is done with two blocks of wood over the lathe bed and with the lathe switched off. I do not consider this bad practice.

There are far worse things you can do on a lathe. At work, about 50 years ago, we used a rather big lathe for measuring the break-out torque of a large pipe coupling. This was only matched be using a tensile testing machine as a very large vice.

JA

Edited By JA on 25/03/2023 19:04:02

The reason I asked is in the past there has been some debate about the practice.

My present largish lathe is the first I have owned with a power cross feed. After I got it I happily used the powered feed for parting off until this was discussed in a forum. The opinion was that the practice was an absolute no-no. So I went back to using a hand feed.

Recently talking to others who know what they are doing I got the universal reply "Why give up using the power feed if you have never had problems".

The more I think about it using a hand feed is a sign of a lack of confidence and a power feed ensures the tool is continuously cutting.

Many thanks, and I am going back to using the power feed. There is always the big red button.

JA

Instead of hijacking the running thread on rear tool posts I have a simple question:

How many people part off on a lathe with the cross feed powered instead of hand operating the feed?

JA

Some of the photos posted seem to show the parting off tool mounted in the rear post with the cutting face upwards. In other words to part off the lathe would have to run backwards. I strongly believe a lathe, for any cutting, only rotates one way. I hope my observation is wrong.

I use a rear tool post on the Myford but have yet to do so on the little lathe. Watching the parting off bronze on the little lathe the build up of chips, trapped between the tool and the work, is alarmingly rapid. This leads me to believe a rear tool post works because it prevents this build up chips, just let gavity work.

JA

My conversion calculator is now a slide ruler, very quick and, generally, quite accurate enough.

Somethimes the old ways are still good.

JA

Edited By JA on 17/03/2023 21:36:28

I did not go due to the prior bad press and that it is over 200 miles from me.

I have seen photographs of some very good models but I would be interested in knowing which traders attended.

JA

Keith & Martin

Thanks for the details on super and subscripts.

Martin, I have just taken a look at your link. How am I going to remember that at my age? Perhaps I could if I removed Imperial Units from my brain.

JA

I am trying to understand the above. Please, no one, DO NOT explain unless you are going to tell me how to put superscript and subscript in to a posting.

JA

My one annoyance with the SI system is the use of names like Newton and Pascal. I think parameters should be expressed in their fundimental units. For example the units of force would be kg.m/s^2 (it would be nice to have a superscript font).

One has to suspect some form of nationalism here. Perhaps it will end when a parameter is named after Santos, the great Andorran physicist.

JA

Edited By JA on 10/03/2023 12:10:02

The above is nice and may be a justification for making mistakes.

Many do not learn from their mistakes. You do not have to make mistakes to learn something.

Yes, we all make mistakes. Sometimes you can be proud of them. Occasionally they can be really useful.

JA

I believe all drivers had to have been firemen first.

At the start of my apprenticeship I was in digs. One of the landlady’s sons had been a fireman on the Midland Region expresses. He had a jumper while passing through Burton on Trent station at speed. It completely wrecked him.

I never wanted to be an engine driver.

JA

Too many but I have never damaged myself.

In my experience it is always the operator's fault.

The blame culture does not work in your own workshop. When I get the chance I need to start a lessons learnt log (just like work). It will be a spread sheet with all entries in large upper case Ariel bold. Perhaps I may use it as a screen saver.

JA

No. That is a new topic and I have been resisting starting it for a few days. At present I have got my hands full with the minor disasters of life (not weather or health related).

JA

After five days we have returned to the question and probably the same answers.

Model engineering will truely go metric when there is the demand. The majority of us are boring old farts (excuse me) who can handle Imperial and SI units and even worse argue about their merits. The younger generation have, in general, little knowledge of Imperial units and don't want to know. The change will come during their time and it will be slow since the hobby is, at present, moribund (and not just because it is snowing). How the change takes place and managed is outside our influence, fortunately.

JA

Dave

Pay a visit to the Withshire County Archives at Chippenham. They should be able to tell you all about the building.

It seems to me that we are suffering from cabin fever having been driven out of our workshops by the cold. It should be warmer at the weekend.

JA

And the someone comes along with a spring balance. I believe they are very very common.

Really this thread is going nowhere. Perhaps I should blame Isaac.

JA

I made one and I use the little hide/copper headed Thor mallet in preference.

JA