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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: 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.

Norm

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?

Thread: Displacement lubricator - with or without valve ?
06/02/2019 09:41:53

Yes we all agree that the steam condenses in the lubricator vessel and it is this that displaces the oil. My apologies if I misled by not saying that I agreed with this basic principle at the start.

Our discussion is whether this Simple Displacement Lubricator might be a continuous system or a cyclic one. This lubricator uses the same entrance and exit to the steam line, or steam chest as fitted by Stuart. I suggest that the flow direction must cycle. An experiment would be simple to do - just connect a steam line to it and leave it under pressure, and see if it gradually fills with water and all the oil transfers to the steam line.

There is another configuration sometimes called the Hydrostatic or Ramsbottom style that has a steam inlet, typically from the regulator supply, to the displacement vessel and a separate oil outlet to the cylinders. These do not need to cycle and are effectively continuous. They were developed for use on full size steam locomotives and even included sight glasses to observe the dripping oil flow. If configured to take some steam directly from the boiler they would then operate continuously. They are still used on some model locomotives, especially GWR variants.

05/02/2019 19:38:41
Posted by duncan webster on 05/02/2019 15:57:30:
Posted by norm norton on 05/02/2019 14:37:35:

The steam enters the oil chamber and condenses only when there has been a change in pressure,

That's not how it works, steam enters all the time whilst there is steam in the feedpipe. It condenses and sinks to the bottom displacing oil back into the steampipe. I think you need to make sure there is no trapped air.

Every respect Duncan, but your version makes less sense. You suggest that steam keeps flowing through the pipe, and any small jet or valve, at the same time as oil flows the other way? Which end of the pipe has the higher pressure? A cyclic system however will follow the inevitable pressure changes in the steam supply. A small bubble of air is necessary to allow that cycle to execute and balance the pressure in the reservoir to that in the steam line.

Thread: print-offable and laminatable chart
05/02/2019 14:46:46

I love the last line in the chart showing what you need for 569 TPI (!!!) Can't think of an immediate use for that..

Out of interest, what is the finest thread used on a practical object that is known of?

Norm

Thread: Displacement lubricator - with or without valve ?
05/02/2019 14:37:35

The steam enters the oil chamber and condenses only when there has been a change in pressure, i.e. you start the engine. Then when the pressure drops some oil will be expelled into the steam line. If running at constant speed there will be no additional oil introduced. The volume of oil displaced each cycle also depends on the amount of (compressible) air in the reservoir at the start.

It just needs a reasonable one inch or more of small bore tube to tee off the steam line and possibly a jet of 0.010" or 0.020" in the line if it does empty the oil too quickly.

Thread: Drilling Small holes in Gunmetal
03/02/2019 16:55:26
Posted by Russell Eberhardt on 03/02/2019 11:39:32:

I broke a number of 12 BA taps until I discovered Rocol RTD compound. I've not broken one since.

Russell

Well said Russell. I completely forgot that. I use the same all the time - essential on the taps.

03/02/2019 10:29:14

For small drills of this size I have never found that adding anything wet helps. Lubricant starts to work when things are getting hot.

As Jason has said, once the hole is drilled then use the chuck to help line up the tap. For 10 BA and smaller grip the tap with a small Pin Vice, not a Tee Holder, and just use finger and thumb to rotate and sense the resistance. Don't grip the Pin Vice in the chuck, just use a pointed rod to visually align things. One finger on top of the Pin Vice to get it to bite and descend. Take it out every turn and brush off the swarf.

For bigger jobs a spring centering tool can be held in the chuck, but I don't find one helpful with tiny taps, and the tops don't have locating holes anyway. If you have not got a Pin Vice then look for some genuine used Eclipse ones on eBay. Don't buy cheapie £10 new sets as they won't grip and will be off-centre.

01/02/2019 09:35:19

It is essential to have sharp drills for bronze with no lip wear whatsoever, or they will drill undersize and then bind.

Best to buy new ones for the job and get a decent quality brand. Cheap ones will jamb. This link is a good ME supplier and is happy to post just a few drills. **LINK**

Have you got a nice small chuck to fit the mill? Best not to use silly high speeds, just 600-800 RPM keeps it controllable. Feed down slowly, just fast enough to produce a slow output of swarf. Apply a spindle brake slightly to stop it descending under its own weight. Lift the drill out every 1-2mm to clear the swarf.

Have fun!

Thread: Myford 33t and 34t gears for metric threads
29/01/2019 10:02:26
Posted by Mike Poole on 29/01/2019 09:31:36:

Fit an electronic lead screw and sell the gearbox and change wheels. I may have just talked myself into a job.

Hmm.. the electronic lead screw will have to be exactly synchronised with the main spindle rotation.

27/01/2019 09:57:38

Mike

A google search for Myford 33T, Myford 34T comes up with lots of links.

Read this past thread for more information as well

https://www.model-engineer.co.uk/forums/postings.asp?th=125630

Norm

Edited to add that the John Stevenson mentioned in that thread is now no longer with us. But the gears are now made by others.

Edited By norm norton on 27/01/2019 09:58:32

Edited By norm norton on 27/01/2019 10:00:52

Thread: Piston rings
14/01/2019 14:03:32

Peter

The o-ring will wear a flat face very quickly. It will work for several hours until it does.

Ideally you want to fit cast iron split rings and I appreciate these can be tricky to make. I have just made a set and If you want help then message me. If your bores are accurate to diameter then you can buy rings from someone like Reeves, but they are about £13 each.

An alternative is split PTFE rings riding on top of o-rings. But this is as tricky to make as cast iron rings IMHO.

If you pack with a PTFE/graphite square material it will work fine for a few years, but be prepared to replace it one day. Not the end of the world and the quickest solution.

Norm

Thread: what solvent cleaner to use?
07/01/2019 21:07:42

Inhibisol TF90 contains the following, according to the manufacturer's MSDS sheet:

Hydrocarbons, C7, n-alkanes,isoalkanes, cyclic propan-2-ol; isopropyl alcohol ;isopropanol

I would regard that as a reasonable set of solvents to use.

07/01/2019 20:53:12

Its good to warn people if something is a problem, but the Brake Cleaner + TIG link does not sound right.

The Brake Cleaner we can get from motor factors in 5l containers is a mix of methyl acetate, hydrocarbons like petroleum spirit and around 50% acetone. It is formulated to be moderately 'safe' in use and contains no chlorinated solvents.

To make phosgene COCl2 you need a chlorinated solvent and heat. That link to the USA page shows an aerosol can of tetrachloroethylene, which is as bad for the environment as all other chlorinated solvents. I guess it is labelled as "for cleaning your brakes"?

I use conventional Brake Cleaner a lot.

 

Edited By norm norton on 07/01/2019 20:58:25

Thread: Selecting a VFD for a Harrison lathe.
10/11/2018 11:19:56

Daniel

The 140 is a lovely lathe - well done getting it. I hope you have got the tailstock as well and the big 4-jaw chuck that the school might have had. The 140 was Harrison's later, metric version of the LS5.

I fitted a metric shaft 1.5kw 240c 3 phase motor to mine. I just cannot remember if I had to modify the pulley bore. I have feeling it went straight on the new motor. The motor fitted the existing lathe frame with just some 2" sleeves and longer bolts to raise the motor. This all suggests that Harrison had fitted a modern spec motor. Measure your existing motor's shaft diameter.

I went to Newton Tesla and bought the motor, Mitsubishi VFD and a dongle controller together. It will cost you bit more than shopping around on eBay but you will have a nice system with start/stop, forward/reverse, jog/run and speed all on the controller in front of you. If budget is an issue then go it alone but you need to be confident in your abilities in programming and handling hefty voltage wiring. You MUST NOT start/stop the motor by breaking the supply into or out of the VFD. Wire the VFD directly to the motor and do not use any of the Harrison control switches.

I actually fitted a 2-pole motor (rather that the usual 4-pole) as it gives me the possibility of double the usual lathe speed. The 140s were built for it and you can get front plates that show the doubled gearbox RPM. To be honest I rarely use the higher speed, but I do run the lathe a half motor speed most all of the time and it is much quieter. The motor is perfectly happy for the usual light and moderate load jobs.

You can get some extra change wheels and will be able to cut all the imperial threads directly from that metric gearbox.

Edited By norm norton on 10/11/2018 11:22:31

Thread: Running coal fired 5 steam engine on gas
29/05/2018 10:56:20

Kevin

As has been said above, without seriously big burners, and a large bottle of propane, you will struggle to get enough heat into the boiler to produce useful steam.

A "Steam Test" for official purposes requires a full coal fire, with full blower, to check that the safety valves can release all the steam produced.

If you want to test your boiler for minor leaks and is the pipework ok, etc. then make up a water hand pump, valves and gauge and then hydraulically test at the boiler's normal working pressure.

If you want to test the cylinders and running motion then get a compressor that can shift at least 4 cufm.

Norm

Thread: X3 mill spindle tightness
11/05/2018 09:42:10

Richard

There is a small pin that locates in the R8 tool groove. Just check it is not possible to push that pin through the spindle and into something and cause drag. I cannot recall exactly the geometry, but I had a problem with mine and stripped the spindle to fit a new pin that I made.

Some tooling has grooves that are too shallow and I have had to hand (diamond rotary) grind these to be a few thou deeper.

Norm

Thread: Nickel Plating
30/04/2018 09:38:10

I have done quite a lot of nickel plating successfully on motorcycle parts. It can work very well, and I put nickel straight onto steel, which is what all the domestic home platers do. Yes, for chromium 'best' plating it should be copper, then nickel, then chromium onto the steel job. I suspect that copper makes an 'easier' bond onto steel when you have less than perfect surfaces, and you have a thick polishing surface to improve the final finish - you cannot so easily polish the nickel layer.

I have stripped old chromium from 50 year old parts and found just nickel underneath. We CANNOT home plate chromium because of the cyanide baths required, never mind more recent hexavalent chromium toxicology concern.

Ramon, you can't really do it on the cheap - it's like all jobs. The BIG issue is getting clean objects. New steel is perfect to plate but anything old takes a big effort to clean and get an activated surface. It means that you need various alkali and acid cleaners to follow the mechanical preparation. You need heated, stirred baths and a means of voltage control and current readout. You also need to practice on a few jobs. Like welding and spray painting it is 70% skill and 30% tools.

There is also a nickel+zinc process that produces nice finishes on fasteners, but it is no easier or cheaper to use. Gateros are a good, small company to deal with.

Norm

Thread: Bridgeport Mill - Convert to 240v Single Phase
27/04/2018 10:14:07

I have a Bridgeport and have converted it to to a VFD driven 220v 3 phase motor - BUT... it is not a simple job.

You have what is called a 'pancake' motor and these CANNOT be converted to 220v. Your quickest way of getting it working from a domestic supply is to use a rotary converter (Transwave) but these are not cheap. I did use a static converter for a couple of years and it worked, but it was fussy about the higher speed if selected.

To fit a conventional flange 220v motor in place of the 'pancake' you need a simple, thick steel adapter plate. There is no head rebuilding, just an 8mm plate that slides in place of the 'pancake' flange and holds the motor in the middle.

The problem then is that no readily available motors have long enough shafts to hold the pulley in the right place. I was fortunate in getting help from John Stevenson and he modified a new motor. I have heard of others who fitted extension stubs, but then suffered vibration. Personally, I think an extension stub, locked onto the shaft, and then turned true by spinning the motor clamped to a lathe bed, would give an acceptable result.

Once you have lengthened a motor shaft, and made an adapter plate, you then need to do quite a bit of re-wiring in the cabinet. It is best to set that all to single phase so that the front switch box still operates the contactors and nicely switches on the VFD. If you have a Bridgeport table axis drive then that will still happily operate on its 110V single phase once you have re-tapped the transformer.

Norm

Thread: ME Vertical Boiler & Hand Pump
16/03/2018 10:49:21
Posted by JasonB on 15/03/2018 12:12:22:

I have sent Martin a link to this thread so hopefully he will see your query too.

Quite a few people use a conical seat even done it myself, the angle gives a sharper knife edge and the ball seats more easily as I understand it. Though as you say a 7/32" slot drill is a quick way to do it and avoid making the tool. Reamed or bored would be ideal.

What would be more of an issue is the smaller hole being drilled may not be perfectly round so knife edge or not you may not get such a good seal.

Edited By JasonB on 15/03/2018 12:13:11

Jason, nice clear picture, thank you.

When you make a screw in seat like this how do you ensure a seal of the thread. Loctite them in?

Norm.

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