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Member postings for John Alexander Stewart

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

Thread: 7 equi-spaced holes on a pcd - why?
05/02/2018 13:03:33

Tony, looking at Jasons' pic, 8 holes/studs may fit in really well, and simpler to divide (for those not into CNC).

That's before coffee has kicked in, so draw it out yourself, and see if 8 would do better in your workshop.


Thread: Hand shaper
18/01/2018 13:50:08

I love shapers, but:

Had an older Drummond hand shaper; it ended up being sold to a fellow club member, who in turn sold it to someone in another area of Ontario.

Beautiful machine. But, in the time I had it, it scribed exactly 3 lines, for something resembling a graduated dial.

It took up a lot of workspace. A piece of artwork, but, I don't own a machine-tool art gallery.

Years ago I had an AAMCO 7" powered shaper, which again was great, but it was slow, chips went all over the workshop, and one could not do what a vertical milling machine could do. Sold it when I moved to NZ for a bit.

Would I purchase another shaper? You bet! Have my eyes on one if I can clear out the workshop some more; would I use it though? Hmmm...

Thread: 3 1/2 inch small boilered TICH
17/01/2018 21:21:17

Hi Ryan;

Just to add support to two recent posts:

1) My Tich - I did do the "screw-in" thing, but my regulator was a coarse thread 1/4", screw-down regulator (much like the blower valve, but larger) and it works fine. It's a large boilered Tich, so the regulator is like LBSC's Disc in a tube regulator, but with the screwed spindle.

2) I'm re-starting my 3-1/2" Martin Evans designed "Ivatt" and will most certainly use Doubletop's message - the boiler is done and tested, but PTFE ring not made yet.

On the Tich, sealing the regulator with all of those threads is a bit of an issue, and LBSC did not have PTFE or other newer materials available to him.

Oh, and you are GOING TO BUSH ALL holes where things thread into the boiler? Screwing directly into copper sheet is now recognized as a bad thing to do.


Thread: JYE Tech DSO Shell
14/01/2018 17:16:34


Thanks for this post - it does indeed look interesting. I've got a project on the back burner that requires a scope for any chance of completion - and this one has the bandwidth that will allow me to see what's going on.

Having a scope, no matter how basic, is a big boon for any electronic work - even a very basic scope adaptor I made for my BBC micro got me out of a few holes!

Aaaand.. when I was a kid, an 1802 microprocessor (CMOS) could be clocked at 0.0hz, so with a debounced flip-flop, and the most inexpensive analog volt meter (with obligatory missing front cover on the meter) one could trace wiring as it was running essentially DC.

I made lots of 1802 computer stuff....

Thread: "It" comes to life again
12/01/2018 13:31:29

Dean, as others have said, well done.

Colours. I'm finishing up my 3-1/2" gauge Shay, and have a 3-1/2" gauge Brit "2MT" that in reality were black or green, lined or unlined. But, there is one in preservation that is in lined maroon, and looks quite interesting.

Whatever you do with your CAD model building, don't graffiti it!


Thread: Required diameter for cutting male metric threads
10/01/2018 16:11:52
Posted by JasonB on 10/01/2018 13:22:31:

I did about 30 studs the other day M1.6 M2, M2.5 and M3 all cut straight onto nominal 1/16" 2, 2.5 and 3mm dia stock if I had skimmed them all both ends the job would have taken ages. All cut with a tailstock die holder under power. No wonder it take you a lot longer than me to finish an enginesmile p

(to Jason and Gareth)

Jason: Bijezuz - where do you find metric stock? All I can find here is inch-based, even though I'm in a metric country (Canada). Ok, plywood is metric thickness, inch dimensions (in feet, of course) but we are not talking about Plywood. I can see why Muzzer moved back to the U.K.

ALL of my threading requires turning inch stock to metric dimensions, maybe that's why it takes me so long to finish an engine? frown

BTW - I'm jealous; those of you in truly metric countries are lucky; those of you in truly metric countries who choose to use BA I don't understand! wink

Gareth - as Jason points out, use a tailstock die holder, nominal diameter (or slightly less if turning the stock first) and just go for it, as the kids say. I use hand power to thread (turn chuck by hand, power off of course), and I do have some odd-ball size dies, in which case I use them in a hand-held die stock, but rest the die stock against a drill chuck in the tailstock, which really helps with the alignment, and "forcing" the starting cut by keeping pressure on the die stock. One arm of the die stock rides on the lathe compound rest, so left hand turning chuck, right hand advancing the tailstock ram - works wonderfully.




Edited By John Alexander Stewart on 10/01/2018 16:12:36

Thread: Q.C.T.P's
10/01/2018 13:11:29


One item that makes me love them is that, when making batches of parts, they all come out the same, as when you mount a new tool, it goes exactly where you want it to be.

One mistake I made at first was to have a handle on the toolpost that allowed me to swivel it around. It should be locked in place so that tools go back on in the correct orientation; for instance, a parting tool simply drops on, and no faffling about ensuring that it is aligned properly. One set of vees parallel to the centre line, one set at right angles - lock it down and forget about moving it after that.

I've got two QCTPs; on my smaller lathe, I have a small piston type made of aluminium, and it's not very good for taking heavy cuts, but the usefulness outweighs the flimsy-ness. It'll get replaced by a 0XA one maybe this year. (or, 000 as some suppliers, like Arc Eurotrade call the size) My larger lathe has a BXA toolpost, which is as rigid as Gibraltar.


Thread: valve events
09/01/2018 23:50:24

Julian; not been on for a while, but, if it matters, I have a locomotive with CI cylinders, and piston valves with teflon rings, "O" rings as backers.

Works well, except that there is a timing issue on one side so can't notch up - *that* was scheduled to be fixed in 2017... (best laid plans) It has been running on teflon/"O" rings for 20 or more years now.

Anyway, not that it matters much, as the choice is yours, but another check mark for "like" the idea.

Not sure if what I have matches what Roger did, but it must be fairly similar.


Thread: Black 5
09/01/2018 15:35:29

Hi Dev;

Have a peek at the National 2-1/2" gauge association - **LINK**

They have a Black 5 in their designs page.

I was a member of this association - and was impressed by their organization and determination, but (sadly) the closest track with 2-1/2" to ME here in Canada was 6 hours drive each way, and the local club would not put in a 2-1/2" gauge rail, so sold my little locomotive on.

There's lots of good that comes in small packages; I really like the smaller locomotives.


Thread: Elidir - 3 inch scale Hunslet
08/01/2018 14:57:13

Very impressive!

Question: What else is happening in the smokebox, with the cast valve, and the superheaters?


Thread: Sun Dogs in Mississauga
08/01/2018 02:29:49
Posted by Neil Wyatt on 07/01/2018 17:46:42:

You worry about insects when it's -30C....


Gotta be tough to live in Canada.

wink 2

Thread: What did you do Today 2018
06/01/2018 20:17:53

Today, I did not pontificate about computers. wink

Instead, I'm working on a batch of injectors, DAG Brown design, but "metricated" and the 13 overflow caps are now slotted, using a specially made jig and file, rather than a 4.5mm end mill.

Also figuring out how to connect the steam to cylinder line on my new Shay locomotive - it did fit, before painting! Hmmm...


Thread: New member
02/01/2018 19:45:07

Hello Anthony - don't worry about Neil - when I read "Georgia" my first thought was "that warm place way south of me" then remembered that there were a couple of other Georgias around. Actually, I'd have expected him to think of South Georgia, still owned by the British, I believe.

The 20 foot lengths are a bit of an issue, as sometimes even the cutting charges that I have to pay up here in Canada cost more than the material.

You may also find that lots of items are actually turned all over, so making something out of a bit of larger material may actually happen more than you expect, so you may not require as many sizes as you think.

The Brits are in luck - they can purchase material in small quantities...


Thread: What Did You Do Today (2017)
01/01/2018 04:05:33

Well, engineering related. No New Years steamup, high of -23 forecast, and with the "wind chill" it'll be minus 37. We decided just to stay inside and drink champagne, or something.

Somewhere on Youtube, **LINK** I have a -18 new years day video up, with a Conway steaming on a portable track, and the steam leaks are quite visible. Fortunately, we have warm water from the nearby kitchen, to keep the pipes to the axle pump from freezing.

One year (Winter Olympics at Salt Lake City, yours truly was on "steam train duty" one of the non-lifting injectors froze, which called for a nice heating with the oxy-acet set, with rosebud tip on the end. (not by me, fortunately).

Oh well - a few months from now we'll be complaining about the heat and the mosquitoes....


Thread: 'Free-Wheeling' a Steam Loco?
29/12/2017 17:46:50

Canadian practice was something like:

Inside Stephensons - remove the straps, so that they get lost for preservation; (as per the E10-A in Morrisburg, ON)

Remove the connecting rods, keep the coupling rods on - but that means removing the return crank.

Both CPR and CNR stored locomotives for a bit in case of requirements. Here's a picture of a CPR locomotive stored:


(courtesy of Ray Kennedy's web pages)

Note the lack of coupling rods, the return crank still there, but the crank rod is not attached. I think, if you look at the front of the cab, the "thickness" of the running boards is due to the connecting rod being placed there.

You don't want the motion work, or the pistons moving about for a number of reasons; pumping of air, lack of lubrication (even if mechanical lubricator, the oil should go in with steam to keep it very liquid, and going to the right places)

Thread: Magazine wrapper
20/12/2017 20:02:23
Posted by Neil Wyatt on 20/12/2017 18:39:36:

Sorry, no - they get stolen too often in transparent bags!

Mine come in transparent plastic bags, with a piece of paper with name/address on it; no mailing label stuck to the bag. (Canada delivery). Last one arrived yesterday, the one where "Wally" gets his teeth.

Somehow they also arrive out of order; I have no idea how Neil arranges *that*.


Thread: Pressed hornblocks
17/12/2017 14:14:25

Hi Tom;

I know what product you are referring to - I used these when building my Tich. No, I don't have any more!

I did read somewhere where they were made of soft material that wore quickly. Maybe not the best choice?

The normal cast hornblocks (which I've used in my soon-to-be-completed 3-1/2" gauge 2-6-0) seem fine and took just a little bit more machining (for the "bolting face", I just used the pressed ones as-is, as I remember it).

Good luck with your Tich; JohnS.

Thread: Live Steam Loco Questions
15/12/2017 19:06:08

Stew - as to my little Tich pulling people; a number of years ago I took it (on the plane, as cabin baggage, of course!) to Winnipeg, Manitoba, Canada.

I did borrow a heavy riding car. I brought along some coal.

Anyway, the Manitoba track is long but quite flat; a fellow model engineer, who was about 18 stone or heavier, said something to me as I stopped for water - "that little thing can sure pull!"

So, without thinking, I told him to "hop on!"

Fortunately he did, and the little 20 lb Tich took us around their track; attached is a picture of me coming back into the station area. Tich is really hard to see, but YES, these locomotives can sure pull.

(note, not that I think that a Tich is the best all round locomotive, but it certainly helps you sharpen your firing and driving skills, and is easy to cart about)

It will make it around the Waushakum Live Steamers elevated track, Google it if you wish. A long track with over and under style bridges. I'd make one run, then really clean the fire, as the long grades required a good fire.



15/12/2017 18:53:25


It's random thought day from me today.

1) My little Tich (about 20 lbs) has pulled somewhere about 450 lbs. These little locomotives can pull more than one would expect, but it does take time to learn how to fire if using coal. A larger locomotive would make the driving easier.

2) Castings. I live in Canada, where castings imported from Britain are expensive to ship. However, fabricating everything is easy; maybe spoked wheel castings could be purchased, but the rest can be fabricated.

3) My latest locomotive is a Shay geared locomotive, as built in the USA. It is designed by a fellow named Kozo Hiraoka, who has a series of books that not only have geared locomotive designs, but he also shows how to fabricate everything - no castings required.

4) A fellow from the state of New York built Kozo's "New" Shay design using small Sherline equipment; he built it in something like a year, and, the job he did is impressive and the output beautiful. His writeup was on a site called "".

I think your attitude is great - I'd expect that any club would be lucky to have you as a member.


Thread: Netta v BR class 2
15/12/2017 18:36:24


I'm close to finishing a 3-1/2" gauge class 2, designed by Martin Evans, and had the Netta plans drawn by LBSC. I think the 5" one is by Don Young?

Random thoughts - take what you wish from them:

1) LBSC drew about 4 gauges in 1, so chances are that there are issues; (2-1/2, 3-1/2, 5, and maybe O gauge?) so maybe less frustration with the newer design;

2) Boilers - I'd expect the newer 5" 2MT to be better in the design front, but no matter what, you might want to ask your club boiler inspectors;

3) Anything between the frames is a problem to get to for repair, so the less between the frames, the better, in my opinion.


Point 3 came from my large 2-8-2 in 3-1/2" gauge; getting at the axle pump is a problem, and it needs looking at again. Something is dripping water under there, and as long as it puts enough water into the boiler, the drips can continue. The locomotive (not including tender) is 120 lbs, so is not a "lift up with one hand and peek underneath" simple inspection.

The 3-1/2" 2MT is designed for 2 injectors, and my 3-1/2" Shay is being completed without anything connected to the trucks (the design has a water pump)


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