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Member postings for Another JohnS

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

Thread: Hacksaw Reamers for Injectors
02/12/2021 19:36:50

Hi all;

A few years ago I started building about a dozen Derek Brown 12oz injectors, then but life took over, and the D-bit style reamers were only half made. The cones are the last thing to do before testing them, so I have to finish (or make a new design of) reamers.

Nigel; Bob Bramson wrote of an interesting way of holding the D-bit style reamers for milling the flat - in essence, one supports the reamer with soft solder in a half-circular groove, which after machining is then melted out, so I don't think the solder bath idea (although a great idea) would work. But, what do I really know!

I did make a Worden grinder, so I could grind HSS round blanks, I guess, but the idea of taking a cheap hacksaw blade and make a reamer out of it sounds like a nice little thing to do as an experiment. Also fits in with my Scots heritage.

Always learning; John.

02/12/2021 14:15:49

May I ask what may be an obvious question to some?

In the "Injector Wars" in Model Engineer (19 November 2021), mention is made of using custom-ground cheap and cheerful hacksaw blades as reamers for injectors.

How are the reamers used? By hand? Powered and held, or done on the workbench? Blade in a tool-post?

I'm just wondering how one would use one accurately.

Thanks; John.

Thread: Vee belt question, for Centec 2B
21/11/2021 15:25:26

Hi all - thanks for the responses - all great ideas. John.

20/11/2021 19:46:46


Time for Vee belt change on my Centec 2B with vertical head.

Two questions though; can someone shed some light here?

1) Motor to gearbox has 2 belts, in parallel, and they say "Gates Truflex 2680 Made in Canada X 3" Any idea what the "X 3" means?

I presume that if I purchase 2 at the same time that they should be the same length, or at least close enough for what I'm doing with my mill.

2) From my measurements, the gearbox to vertical head is 29 inches long standard vee belt, section "2" or "4L" (I assume the same, just different nomenclature). No writing on the belt.

As things are mail-order, or order-in-with-restocking-charge, I'd like to try and get this right first time.




Edited By John Alexander Stewart on 20/11/2021 19:50:39

Thread: QCAD/CAM
17/11/2021 17:23:38

Michael - maybe off topic, maybe not?? You decide.

I'm a CamBam Linux user, and a QCAD linux user. Paid the "subscription" for both of them.

I actually do 99% of my CAD on my Linux machine, my Windows partition containing Alibre Atom 3D and Meshcam gets turned on maybe every 6 months or so. I just like Linux, and do share my monitor with an Apple Mac Mini, and poor old Windows comes last. I did download CAMBAM on Windows, so I do know it starts up, but have not actually used it. (nor Meshcam!)

I build to plans; I enjoy making parts; the 3D designing part of my brain gets used for other things other than Model Engineering, so likely my thoughts are different than the norm. I do watch what Jason does; fantastic work.

My current project is finishing up two Southworth 3" pumps; I just QCAD up the parts, CAMBAM them, and transfer the gcode files to my CNC machines in my workshop. I'm building 2 of them, and parts are interchangeable, as one would expect. After that, back on my Martin-Evans "Ivatt", when that's complete, we'll see.

Saying the above, my thoughts are to use Windows 10 more often, but it seems to be always updating when I turn it on, so there goes my evening. My CNC machines all run Linux, we have a couple of Macs and Macbooks and iPads/iPhones, so Windows is definitely the odd thing in our abode.

I did write a few articles in Model Engineer showing what I did with QCAD and CAMBAM when building my Kozo Shay locomotive, if that is of any interest to you.


Thread: GPS as a low-speed Speedometer
07/11/2021 15:40:03


A couple of things to think about.

1) Over here (Canada) "WAAS" helps with GPS accuracy, so long as you have line of sight to a satellite in geostationary orbit. Down to about 1.2metres, if I remember correctly, which helps with positional accuracy. Otherwise it's about 8 metres accuracy.

2) I do have a UBLOX GPS receiver with Kaman filtering and (of course) accelerometers; it's used to "smooth out" GPS readings. Unfortunately, you have to do some maneuvers to set it all up; 20km/hr, left and right turns, that kind of stuff. Hard to do that in a sailboat with a displacement hull speed of 6.5 knots, so I do have an accelerometer and have recorded tracks (GPS, with corresponding accelerometer values) to try and roll my own filter; some sailboat owners have found GPS lacking in northern fjords.

3) Heber Valley Railway #618 has/had a GPS speedometer; now way back at 2002 when I was helping, I was informed that the GPS speedo was not accurate below about 5mph. That was before WAAS, etc.

4) You may be near enough to an airport with a GPS augmentation system, but I'm not sure off-hand how normal GPS receivers would find and track this.

All fun stuff - John.

Thread: Back to Imperial
18/09/2021 13:15:36

Over here in Canada, I'd love to be able to purchase more material in metric. Unfortunately, the local metal suppliers have told me that supplies come from the USA, so if I wanted some (eg) true-metric round brass rod, it would have to be ordered from Europe. We, although a metricated country, are surrounded by lovers of the inch.

I'm sure it'll work the same way for Britain - you are surrounded by metric; importing inch-based things from the USA will be more expensive than metric from more local suppliers.

(yes, there are mail-order suppliers of metric metals, but expensive including shipping and import duties. Fortunately, metric fasteners are becoming more popular and available locally)

Thread: origin of CAD
10/09/2021 22:33:12
Posted by duncan webster on 10/09/2021 22:04:21:

Probably got the processing power of a wrist watch today

I do remember going to the then supercomputing centre (RUS) in Stuttgart, when people there were research buddies, and, in one bar area, there was a liquid-cooled CRAY (CRAY-2??) computer, wiring visible through the plexiglass covers, and it was used as a table for standing around drinking beer, the power supply bench surrounding the cray CPU was, well, a bench for sitting on.

The chief buddy of mine said something like "it's only a couple of years old, but cost too much to run, so it was re-purposed".

I'll tell you - it was *very* weird using it to hold pitchers and glasses of beer while we stood around socializing...

I did have a nice little SGI Onyx-2 computer (a purple cube about desk height) that I got from a department that did not like the $10,000 (CAD) yearly maintenance fee, so I used it for a year or two off-contract. Eventually, my early Linux computers worked faster, but were not nearly as neat, and it was sent to "crown assets" for recycling or selling on.

Changed times... for the better in my opinion

10/09/2021 12:39:14

I'm with SOD - vector math has been around for millennia. Quaternions for at least 150 years. Bresingham's line to pixel algorithm came out when I was still in diapers.

Maybe I'm biased, though. We see history through our own experience and yours might be *very* different than mine. I spent quite a bit of time on writing code for 3D graphics rendering when working, and I see CAD UIs as just one way of generating 3D data for rendering. (the graphics code I wrote/managed is/was open source; for a bit was distributed by Apple in the days before the App Store, downloaded millions of times; some funding came from the US DOD, and likely still is the most used and longest running open source project managed by the Canadian Federal Government)

Thread: Steam operated drain cocks
14/06/2021 02:27:49

I made some from the US model engine maker from a long time ago. I made my copies about 10-15 years ago now.

Work great! Piston valve engine, so wanted something that would act as a relief valve if required.

The one Hans shows above would be better than the ones I made; rather than annealing brass disks, the o-ring makes it simpler.

Great little addition to a locomotive.

Thread: Recycling of Wind Turbine Blades
17/05/2021 15:26:47

I don't know. It takes energy to get the materials to make them, then energy to make the blades, energy to move them, to place them, to remove them, to ship them back, and, finally, to take them apart.

Might it not be easier to just use less energy?

I know that it's not a popular view these days; the current trend seems to be using more energy to solve "the climate crisis".

Gosh - that reads like it's a "Baah Humbug" moment!

Thread: Masso CNC G3 - Worth the price?
14/05/2021 12:43:53

Ed - thanks for the write-up.

I've got 3 CNC machines here (although one is a little Sherline lathe, was going to CNC an Emco Compact-8 but never got around to it so sold it on)

All 3 machines have small dedicated PCs running LinuxCNC with Mesa cards. Only a trackball-mouse as input, no keyboard. Right now, no network. I take stuff via USB from my office to my workshop. Machines boot on power, so I turn on power to the machine, it boots. All 3 computers have identical hardware.

Two have been running for years, no issues, although work/life has taken me from the workshop quite a bit over the last year or two. The Sherline lathe is the one that has not had much time; currently no spindle encoder. (was thinking of just taking a MASSO one from Sherline and using that) so not a lot of experience with a dedicated lathe, unfortunately.

LinuxCNC did go through a bad spell - real-time modules changed, and the new one is not (from what I understand) that great with the old parallel port one-byte-at-a-time protocol.

I think that, our small club here in Ottawa, of those with working CNC metal working machines in their workshop, 100% are LinuxCNC.

Each to their own, of course, there's no 100% correct solution to anything.

Thread: Sherline
22/04/2021 14:47:39

Dave - if you (or anyone else) wants to see what can be done on Sherline equipment, have a look at:

Chris and his Kozo Shay build

over at This fellow hails from NY state in the USA, and makes more in a day than many of us make in a year.

I made an "old Shay" from Kozo Hiraoka's plans; mainly on an Eco Compact-8, so when I followed along on how he made the "new Shay" on Sherline equipment (including cutting gears from brass) needless to say, I was both humbles and impressed.

22/04/2021 13:00:36


I, too, have a Sherline CNC lathe and mill. They were purchased for a potential house downsizing (moving to a smaller place), but that's been put on hold because of COVID, so not used as much (yet) as I had originally planned.

I've got bigger CNC mills, and use the same software. I've actually got 2 sets of software; I use Linux for work from home and one of my desktops, I also use Apple computers for software development. So, saying that:

On Linux, CamBam, and QCad, CamBam can do some lathe CAM, which has worked well with the Sherline lathe.

On Windows (which probably has not been booted in 6 months) Alibre Atom3D, and, if I remember the name correctly, Meshcam.

I just never turn on the windows computer, the Linux one is booted 24/7, so I use the 2D CAD/CAM system 100% of the time. I have tried (successfully) to run Windows in a virtual machine under Linux; it worked, but is slow and not as responsive as I'd have liked. The 2D CAD setup does things well enough for the parts I'm making.

Hope some of the above helps! John

Thread: "TINKER" tool & cutter grinder
09/04/2021 14:03:31

Wandering a little bit here.

I had a Tinker once - made by a Frank McLean, who wrote in Live Steam and has a book of his articles available from Village Press. He was the first tool designer and machinist for Lee Valley, some here might recognize the company.

I actually never used it - shortly after I purchased it, I had to move around the world (to NZ) for work; lent it and some other tools to a fellow club member who was very short of retirement funds, who subsequently passed away and the contents of his workshop auctioned off to other club members. When I returned, I found the workshop equipment I had lent in other peoples' workshops, and they had paid $$ for it so were not returning it.

Long story short - I built a Worden, 100x better, and I'd think Harold Hall's jigs are equal or better than the Tinker, if you want to use a standard bench grinder as a base.

Thread: CNC - What's the Problem?
01/04/2021 13:22:49

I use CNC extensively in my workshop. (when I get in there, that is!)

I figure that it is like the change from making parts to fit, to making parts that fit. No longer any need to stamp mating parts for assembly, the parts just fit.

Look at the Sherline CNC products, although they have gone now to an expensive CNC controller. I do have a CNC-ready Sherline lathe and 5400 mill, but have only used them for manual machining at this point. (have 2 cnc mills, a KX1 and a larger one, both LinuxCNC driven, that work well)

I am a real fan of LinuxCNC; each mill has a small computer with monitor and one of those track-ball mice things (no keyboard) so they are self-contained. When I turn power on to the electrical socket for the mill, the computer boots in a few seconds, and bobs' your uncle - ready to go.

Thread: Are we being listened to on the phone
27/03/2021 13:42:37

Just for the fun of it - circa 2014-2015, when the organization I worked for was in upheaval, I was asked (an Internet protol and app guy) to work with RF frequency guys to put forth ideas for increasing throughput on cell phones.

Anyway, I created this picture - Wired magazine with Andrew Snowden on the "cover", and a utility to show where tracking connections went - I figured that about 80% of the data transported was "fluff", 20% real-user-wished-for data.

Needless to say, the report was thrown out - these RF guys wanted RF ideas, not caring about the amount of data.

I'm sure the tracking, etc is much worse now. The red names are the sites that the tool reported as being "fluff"


Thread: Gravity and Weightlessnes
19/03/2021 13:20:40

"You are decending by vertical lift into a very deep coal mine and the only light is from a safety (Davey/Stephenson) lamp. The rope fails and the cage free falls to the bottom of the shaft. What happens to the light from safety lamp before you die? Comment: This has everything to do with gravity and weightlessness"

In the absence of "gravity induced" air flow, the lamp would go out. Now, how you'd have oxygen and no air flow in a vertical lift in free-fall, *that* is an interesting question!

Another interesting question - if you have liquid fuel, are in free-fall (say, in geostationary orbit) and are "weightless", how do you fire up a rocket engine? I mean, the fuel will just be floating about, not waiting at the bottom of the tank to flow into the engines...

Thread: Updating KX1 to USB or Ethernet Controller
25/01/2021 15:12:14

My KX1 has been running with LinuxCNC, a Mesa 5i25 and a Gecko G540 (parallel version) for about a decade so far.

Both of these products now come with Ethernet connectivity, if you want to go down that route. The Mesa 7i76 card has (if I remember correctly) 5 step control outputs, so you can have x,y,z,a and spindle if indeed that is what you require.

Do you really require a pulse stream for the spindle? Mine has a board inside that drives the spindle from a 0-10v isolated input - here is a link to the control board: little machine shop board. I know it's the same board because LittleMachineShop used to distribute MY old blog info with this board without attribution. sad

(The KX1 I have came without control electronics, (had steppers, limit switches, spindle speed control board) the late John Stevenson and I discussed this via email, and it seems mine was an "internal to China" model, so I just added it all. Spindle control was via the typical 0-10v input as stated above)


Thread: How to Search for Text Inside Multiple PDF Files at Once
21/01/2021 15:24:33

I keep finding Windows amazing. I'll admit to not using it much, because I seem more comfortable with Linux and MacOS on my desktop machines.

On both Mac and Linux, if you have searchable PDFs (i.e. ones with text, not just a giant image) all one needs to do is to open the file finder, and in the search box, type the text you are looking for. Voila.

It's so simple, so useful, just to search all files for the text.

Or, did I miss something? Likely, knowing me.

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