Member postings for Andrew Tinsley

Frankly I would not consider a Proxxon mill to be other than a toy. I have seen several of the Proxxon offerings that you mention, they simply are not good enough for working in metal. My own experience of Proxxon tools is they are expensive for what they are and quality isn't very good either.

Jason's mention of Sherline is a much better prospect or the smaller Sieg mills from Arc Eurotrade.

You say you are limited on weight to 20 Kgs. Mills depend on rigidity and that means weight! Your 20 Kg limit means you simply won't get a decent mill for the tasks you wish to use it.

Andrew.

I purchased a Sanou 3 jaw 4" chuck recently ( I think it was from Arc, had their logo but a Sanou number) I cannot fault it at all. Brilliant quality, irrespective of the low price.

I believe that Sanou have upped their quality standards over the last year or two. I would not bother looking elsewhere for a new chuck.

Andrew.

I have always had super fast service from Tracy Tools.

Andrew.

All plating needs super clean surfaces. Nickel plating (and nicasil dipping) is straightforward. Chrome plating isn't and requires toxic chemicals. I did a little, 40 years ago when the toxic items were to be had Would not recommend it now, even if you could get the chemicals. Horrendous problems in disposing of the solutions afterwards, as well. Leave it to the professionals!

Andrew.

Never had any real problems machining RSJ material. If you have the space, keep it, you will find a use for it.

Andrew.

Hello Martin,

The factory was at Leicester, but near Syston, not Wigston. As a shadow factory, it was run by BTH. After the war it became the BTH lampworks and then it became Thorn Lighting , taken over by GE of the US and closed by them and is now a Sainsbury supermarket and car park.

I shall certainly post some shots of the completed drill. but that is now some weeks off as I have managed to muck up the motor, converting from star to delta. Not too surprised at that, but I doubt if the motor would take a VFD with its linen insulation! So looks like a professional rewind job. There is a massive mounting arm integral with one of the motor end plates, so a new motor would look all wrong!

Andrew.

Edited By Andrew Tinsley on 23/03/2021 14:45:00

Edited By Andrew Tinsley on 23/03/2021 14:53:16

Hello Hopper,

It is certainly a piece of history, but I doubt that many people would bother with it! The bearings are ball bearings top and bottom of the main shaft. Each with a thrust race running on the bottom of the bearing housing. I at first thought they actually ran on the bottom cage lip of the ball bearing, until I cleared the accumulated gunge of old grease. Surprisingly the bearings were in good condition.

The top speed is 10,000 rpm. I now know that there were two three step pulleys for the 3 phase motor. The high speed one is missing and I will need to turn up a replacement. It is too big a diameter for my ML10, so it will have to wait until I finish a lathe refurb, or lock down finishes, so I can use a friends bigger lathe.

I doubt it will get much use, but it has been under my bench for 30 years and I thought it about time I did something with it. Once reassembled I will need my engine hoist to shift it, I guess it weighs at least 100 kilos and maybe quite a bit more!

Andrew.

John, I would be amazed if Brook Crompton could supply a spare box for such an old motor. They have difficulty in supplying data about them, let alone spares. But go ahead and prove me wrong.

Andrew.

Hello,

Thanks everyone, that gives me a fair choice, although none of them is easy to find and they seem a touch expensive if you can find them!

Martin, the drill came from the old BTH shadow factory in Leicester (It even has the air ministry plaque to prove it) The factory later became Thorn Lighting. It was painted in Air Ministry blue to make sure that people knew who it belonged to!

Andrew.

I am starting to reassemble the Herbert high speed drill which was used in a shadow factory producing Merlin magnetos and starter motors.

All is looking good and I note that one of the many plates on this drill, it says "Use Prices RM Belmoline grease on the high speed spindle bearings" It even says the machine was supplied with a tin of said grease. Now some 80 years later, the tin is missing!

So what is a good replacement for this "High speed grease" other than my usual Castrol Lithium grease? Maximum spindle speed is 10,000 rpm and the bearings are a combination of ball and thrust races. I might as well get the right grease after cleaning out all the old stuff.

Regards,

Andrew.

It is a very early ML7 lathe probably 1947 to 1951 vintage.

Andrew.

Just sorting out some taps and came across an LAL 1/2" x 22 TPI tap. As far as I know, this isn't a standard Whitworth size, although Tracy Tools do list them.

Is it some kind of Whitworth special and if so what for?

Andrew.

Edited By Andrew Tinsley on 18/03/2021 15:23:38

Might be worthwhile to check the spindle thread. 920 lathes have either a metric spindle thread or an imperial one. Don't ask how I know.

Andrew.

Thanks gentlemen,.

My memory is playing false and it looks as though one needs 900 degrees C for SIF bronze. That being so, I shall either have to fork out for new bottles or drag out my trusty Oxford arc !welder! I shall give the Oxford first go, as it is the cheaper of the two options.

Thanks again for everyone's input.

Andrew.

I need to SIF bronze a crack in a cast iron "fire pIt" It is about 6 mm thick. I would normally V out the crack with an angle grinder and use oxy acetylene with appropriate flux and rod, job done.

However I have given up my BOC bottles because of the horrendous rental cost and have yet to source a cheaper supplier. So I am stuck with using propane with either my Bullfinch or Sievert kit (both having a wide range of burner nozzles.

As the SIF bronze process takes place at around 700 centigrade, if I remember correctly, I should be able to use propane kit. But never having done so, I am a touch wary of the type of nozzle to use, a local flame or one that is more diffuse? Any recommendation as to the nozzle to use? I don't want to spend a lot of time experimenting, as it is too cold outside to mess about.

Andrew.

Well a little different to the title. I am dismantling and refurbishing an old Herbert High speed drill. There is a brass cover over the top of the top quill bearing. It is mounted on a brass flange, which has 4 neat squares cut out and which are distributed at 90 degrees to each other. Hence my very poor description of it as a castellated nut!

Now I am assuming these squares are to take a form of spanner rather like a C spanner, but with square rather than round pins. I am curious as to what such a spanner would be called, or do C spanners come with square as well as round pins?

I am assuming that this dome needs to unscrew to get at the bearing hence my query. There is no problem with fabricating a "spanner" to fit, Not sure if I should make a C spanner type tool or to make a socket to match and use a Tommy bar.

Andrew.

Seems to me that most people miss the point. If the motor is high current, low voltage, then the brushes need to be designed for a high current. If it is a high voltage, low current motor, then the requirements for the brush are low current. So what are people arguing about?

I don't know the ins and outs of brush technology, but I am certain that the brush composition varies with the current taken.

Andrew.

Hi Grindstone Cowboy! Whatever makes you think I had you in my sights? I find your replies to be interesting and very practical. Compared to the guy I am thinking about, you are an absolute angel! I bet no one has called you an angel for a very long time. I don't think anyone has called me that either!

Regards,

Andrew.

Can a moderator please delete.

Andrew.

Yes, there are a minority of people here who are grumpy, pedantic and self opinionated plus the fellow who always gives most unhelpful answers and is usually wrong.

Apart from this odd half dozen members, the rest of the folk here are always most helpful and well mannered, until some one turns up and starts slagging off the membership. Then unsurprisingly the majority of people feel very aggrieved.

Andrew.