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Member postings for norm norton

Here is a list of all the postings norm norton has made in our forums. Click on a thread name to jump to the thread.

Thread: renew driving licence
05/02/2020 10:38:27

Thank you Pete for finding that. Hmm, looks like you have to pretend you are a lorry driver, and I guess go through the same hoops every three years after 70?

05/02/2020 09:33:36
Posted by Michael Gilligan on 04/02/2020 20:45:42:
It’s worth checking here, Norm : **LINK**


Thanks Michael, I thought you were querying or adding some information.

That link is the DVLA description of licence categories. I am referring to categories C1 and C1E that are on my licence, and many others, these having been referred to as the 'big lorry' up to 7.5 tonne MAW category that people may decide is not needed past age 70.

My reason for posting is to warn those who regularly tow something that it is very easy to exceed 3.5 tonne GTW.

What I have not seen published is the fact (?) that these categories are routinely removed at licence renewal at age 70; it must be written somewhere. And how to retain them. I was reporting what others have said to me and would like to see the official text.


04/02/2020 20:13:42

I see that no one has mentioned towing something and the combined maximum weights being over 3.5 tonne GTW.

Us old boys have rights in our pre-70 licences to pull a big caravan or trailer with boat, etc. behind a large 4X4 or small truck or even a van like a VW Transporter. It is easy to exceed 3.5 tonnes GTW (Gross Train Weight).

As I understand it that permission is lost at age 70 renewal, unless you apply in writing for the new licence with a letter from a doctor stating you are fit to retain that over 3.5tonne licence category.

Thread: Question about Harrison lathe
31/01/2020 20:07:08


I fitted a 2 pole three phase motor and inverter to my 140. I spend most of my time working it at 25Hz (half speed) but the motor will wind up to full speed, to double the lathe single speed, which the 140 was designed to take. You can even get a 140 two speed plate to put on the front.


Thread: Leaf springs
26/01/2020 11:18:15

1/32" seems rather thin for such wide 3/4" spring leaves. Is this for a model, a steam engine? Smaller 3/8" wide springs would use about this thickness.

M-Machine sell 3/4 x 16swg ( 1/16" ) spring steel strip for £3.30 per foot, and 3/8" in the thinner gauges. I would make 3/4" springs from this.

Edited By norm norton on 26/01/2020 11:18:54

Thread: Making leaf springs
15/01/2020 14:22:16

Hewson discussed the springs for a Britannia in ME210/4453p526.

There is something about weights and adhesion theory in ME211/4470p808

The issues are using the right steel in its tempered state, then hardening and tempering for springs. Then deciding from the model weight what the correct loading is per axle, and how much compliance (spring rate) is best, and measuring the deflection obtained (ideally in a test jig). Because 100% tempered steel springs are often too firm for an application, there are options of substituting some leaves in Tufnol, using bronze instead, or machining slots in the (soft) steel leaves.

I don't think I have seen an article attempt to address all of this. But if you search the Model Engineer Clearing House Forum (best to do this through google 'leaf spring' ) the subject has been well discussed in recent years.


edits - killing smilies !!

Edited By norm norton on 15/01/2020 14:28:53

Edited By norm norton on 15/01/2020 14:29:21

Edited By norm norton on 15/01/2020 14:30:21

Thread: VFD Question
08/01/2020 15:52:14

Ahh.. Thank you Martin and Andrew - got that.

So I (and perhaps two others in the world) have been misunderstanding the output from the workshop VFDs that we use. It is 240v phase-to-phase, and if there was a neutral it would be about 133v on each phase to neutral.

I guess the rules of physics say that one cannot phase shift 240v AC by 120 degrees and again by another 120 degrees, otherwise we would get 415v quite easily.


08/01/2020 14:20:39

I thought I had a limited understanding of this, but now I am confused.

If a residential road is fed with three separate phases of 240v, then each house takes a feed from one of those phases and has single phase 240v. If an industrial premise takes all three phases then (I assumed) it has an available feed of 415v (or 380v or whatever) 3 phase. Correct or wrong?

Or are there transformers on the old poles to drop 415v lines down to 240v domestic?

Now if you take one of the 250v phases, and put it through a VFD box, is the output actually three separate 250v sine waves each shifted by one-third of a cycle. If so, why is this phase adjusted supply not producing 415/380v 3 phase?

I need to see the actual AC diagrams perhaps of the two 3 phase scenarios I have described. I think Gerard was asking the same question.


Thread: Drilling hardened steel
08/01/2020 10:08:23

Hi Andrew

I think I can visualise what you are saying, as I guess you have the centrifugal bob weight set up for a classic British twin. The first thing I would suggest is that the bike is going to run a lot better if you fitted an electronic ignition like a Pazon or Boyer. However, if you want to keep things as they are and not spend too much then I understand you are looking for a simple fix.

I am going to be more simplistic than the previous contributor's good engineering suggestions. The bob weights are always very sloppy on the pins, and tend to go from full retard to full advance in a sudden jump anyway. Precise engineering is not essential. Why don't you fix a solid bush made from bronze or even cast iron into the bob weight hole with loctite. You could custom shape the insert by hand filing to match any worn hole shape. The loctite will fill gaps if you make the shaped insert a press fit in. Then drill a hole, in the right place, that just fits over the existing worn pin. You could dress the pin by hand if it is very mis-shapen or tapered. Use a long, thin strip of emery to work it round and smooth. Hopefully it will still be big enough to do its job of holding onto the bob weight.

Maybe nearer to bodge-engineering than precision but it is always possible to over-engineer a repair job.


Edited By norm norton on 08/01/2020 10:12:04

Thread: Myford super 7B Chuck threads
03/01/2020 15:52:05

Thank you for the fractions idea. But I am on a Mac and not a PC. If it helps others, I have discovered [ctrl][cmd][space] brings up a character map for the Mac and search 'fraction' (singular) gives a few.

Question is, do my two dimensions read correctly on other people's computers? 1⅛", 7½".


Edited By norm norton on 03/01/2020 15:53:51

Thread: valve gear simulators
19/11/2019 09:46:47

On a Mac you load a program called Crossover, and that will run all manner of DOS written code within a specific window. Crossover costs a few pounds (i.e. not much) and although there are free alternatives they require a bit more thought to run. You can get all this information by searching the web. Ask for things like 'run windows programs on Mac' but you do not need a full windows emulator.

Then there are a few valve simulators to download. Although most are Walschaerts I know that the Dockstader has Stephensons. Search for 'walschaerts stephensons valve simulators'.

Edited By norm norton on 19/11/2019 09:47:20

Thread: Fusible plugs for model loco boilers
16/11/2019 23:21:21

I understand that they are not recommended for 5" gauge in the UK. Speak to an informed club boiler inspector and refer to the boiler code documentation. Sorry I cannot be specific on where to find this.

Thread: 3HP Compressor quality and noise
14/11/2019 10:35:01

I am looking for a bigger compressor and I know that I would like a 3HP, belt drive 14cfm with a 100 litre tank. This is the biggest I could run on single phase 13-15 amp and I only want occasional spraying and air tool use.

There are a number of known suppliers (e.g. R-Tec, Thorite, NuAIr) who stock branded compressors to this specification in the £480 - £560 (incl.vat) price band. However there is an equivalent compressor called a Burisch BT390 that is available for £276.

Now that is a lot less money for my intermittent use, but why is it so much cheaper? Is it going to be horribly noisy or will it fail after 12 months? If I ask the suppliers I know what they will tell me, but I would be interested to hear any independent view.

Thread: Operating manual for a Harrison 140 metric lathe
13/11/2019 10:12:20

These imperial tables for a 140 were all on the Harrison Yahoo forum site, I am sure I put some there, but it is all shut down now by the recent Yahoo policy. There is a new Harrison site and I will have to see if the files of reference data have been transferred across.

I will post my simple .jpg of information here in the hope that it is readable. If not message me with your email and I will copy it to you.

harrison 140 tpi plate copy.jpg

Thread: CH Motorised Valve Radio Interference
01/09/2019 12:03:22

I have had a good try at searching the web for a few answers on this, but surprisingly few thoughts about what ought to be a common problem. Most seem to put up with it, or complain that British Gas can't fix it, so I will ask for some thoughts here.

When my gas boiler system motorised valve operates any DAB radio drops out for the 12-15 seconds and now the super fibre internet router also trips off and then does its usual power back on. Funnily enough, the TV seems unaffected. The DAB radio drop out has been going on for a few years.

The various web answers point to thermostats, boiler gas valves and motorised valves as being the guilty objects. But no thoughts on suppression given. It cannot be the roomstat (happens in the Summer), I have a newish Worcester Greenstar boiler, but the interference does coincide with the actuation and duration of the motorised valve when the hot water tank thermostat seems to be ending its call for heat.

Apparently there are resistor/capacitor sets in some motorised valves. Do you think I can try putting a capacitor (or pair) across the motor feed cable supply? What size and type and do I affix a L-E and a N-E pair?

Or have I got to dismantle the motor drive and replace any capacitor that might be lurking in there?

It might be the tankstat if that can take 12-15 seconds to trip off, but unlikely perhaps.


Edited By norm norton on 01/09/2019 12:05:45

Thread: Dam Solution?
08/08/2019 10:06:54

quote above : "The Victorian construction of the dam appears to be perfectly sound. It's well over a century old and even with the failure of the spillway it's remained functioning despite taking some very serious damage."

The above is something I agree with, although I am not a dam or construction expert and I have only seen the broadcast pictures. Local residents are saying things like "we were saved from an imminent collapse". Who ever thought it was about to give way? There were no reports of water penetration, which normally precedes a collapse.

Certainly any consulted engineer would have to report that its condition was weaker than before the overspill, and that it might give way if more water came over the top and removed a substantial amount of the soil wall. I suspect that liability and risk management then took over and the various agencies all stated that it was in danger of imminent collapse with the need for evacuation.

It will be interesting if any reports appear from any construction expert regarding how much soil wall had been removed and how much weaker it then was, with the full head of water behind it.

Thread: Timesaver - which grades?
11/07/2019 09:59:09

There is/was a small 'sample or trial' kit of eight little tubs (2" dia. x 2" high) that I bought a few years ago.


Thread: Sealing Threads
09/07/2019 10:09:36

Hi Alan

Search for Rocol Steam Seal which is designed for this very job. Suppliers on eBay, and Heritage Steam are a good company.


Thread: Piston Packing
28/02/2019 10:09:00

Hello Peter

The packing needs to just standing a 'bit' proud, but it will be all over the place with high spots and hollows. Once it is in the bore it should even itself out. Yes you want to be able to 'just' pull and push the piston gripping the piston rod. It will be tight so oil it.

Make a conical adapter (5-10 deg internal taper) that you feed the piston and packing into, then line that up with the cylinder bore to easily slide in. The inside bore of the adapter exit should be the same as the cylinder bore. The taper helps squeeze it all into shape.


Thread: print-offable and laminatable chart
06/02/2019 09:56:06
Posted by John Purdy on 05/02/2019 17:50:11:

The last half dozen or so lines on the inch chart are intended as fine feeds.

Very rude of us John to find humour in your fine feed numbers and I apologise for starting it. What you have listed is a perfectly logical way of showing the fineness of feed.

But I like that idea that at 569 TPI my Myford Series Seven might do better than the 'world's finest known thread' of 508 TPI. I might have a try, should I sharpen the 60 degree Whitworth tool first?

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