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: Aircraft General Discussion|
Model Engineering content. The Duxford comment above kindled this thought.
Stearman Biplane at Duxford. Was owned by one George Lovett last of Lyn, Ontario, Canada. He was in the RAF, flew spitfires at the end of the war, then lots of jets, including 11 atlantic crossing deliveries of the Sabre?? back when. Left mid-50s, to Canada, where he crop-dusted.
And, was a good model engineer; traveling to lots of shows in the north east of North America.
The story from George about the Stearman at Duxford - they were playing cards one rainy morning down east in Canada when some royal navy person came in, and asked "are those your aircraft?" George said "yeah, Want to buy one?" And, they did. Helicoptered it over to a Royal Navy ship, and the rest is history. He still had a couple more in rural hangers, so loosing one for $$ was likely not an issue.
My first thought was "yeah, right". The Duxford one says on its web page "Evergreen Aviation Services" then one day I found his business address in the Canadian Government directory, which matched his home address. Here's one page describing spraying in New Brunswick:
I really liked George. Quiet man, had to listen carefully. Crashed 3 aircraft, lived to tell the tale. He used to drive his camper van around to meets; one meet I left a book in his camper on "Canada's WWII War Ace", with a note saying that I thought he'd enjoy the read. Got a note back (still have it) giving his thoughts as a contemporary, not having been beside the war ace, but in proximity. Did not know at the time George had been assigned to the Med flying spitfires, probably would not have known if I had not dropped off the book.
George lived to a ripe old age.
|Thread: What lathes have you had?|
The worst lathe I had: An old pre-1890s "Sebastian Lathe Co." 9" diam swing lathe that used to be treadle powered. Chatter-city, tough to change speeds, no dials.
Best lathe I have: An Emco Compact-8. In fact, for a while I had two of these, one to CNC. Sold one, the one left has the CNC VFD on it, which is great. (did not complete CNC config)
Lathe I wished I had not sold: An Emco Unimat-SL. Sold it and got the Sebastian. What can I say. Sigh.
Lathe I don't know why I still have it: Kerry 1124. Not even plugged in for a couple of years; thought of building bigger projects, but hindsight is 20/20. The Emco is like a sports car, the Kerry like one of those articulated lorries. Give me the sports car any day. My projects appear to be downsizing, thus:
Newest lathe: Sherline, metric, with steppers and LinuxCNC control from my aborted Emco conversion above. Was thinking about their CNC Chucker lathe, but will see. The Sherline works very well; need spindle encoder for cutting threads. Also got handwheels, so can remove the step motors, and put the handwheels on. Wish, though, that the fasteners were also metric. At least they are not BA or Whitworth!
One area of manufacture that I have not purchased a lathe from: Asia. No issues, just never had the opportunity.
|Thread: What to do,what to do.|
4 jaw sc chucks hold hex stock just fine.
I have one, but the ER25 is used most often, followed by a 3-jaw SC, then 4-jaw SC, finally, way down the list, a 4-jaw independent. I rarely machine from castings, thus the SC and ER chucks are most used.
Here's a pic (posted before) of a 4-jaw SC holding hex:
|Thread: Which Qctp for mini lathe?|
I've got an original A2Z alloy tool post on my Emco Compact-8. It replaced a *really* badly made steel one.
When I put the A2Z one on, it was noticeably weaker; more chatter on my "normal" depth of cut.
However, it works well, and I do lots of smaller parts, so it has stayed on the lathe since.
I'd rather try the steel "000" size, but can't be bothered to source one - the A2Z one is ok for me, but might not be for others.
|Thread: Sherline owners|
To emphasize Martin's posting above, the one American posting was by a fellow on modelenginemaker.com, "Crueby" from Rochester NY who built a 1:16th scale Shay on his Sherline equipment, and took photos of the process.
Sure, things were tight at times (machine wise) but he did not need an 11x25 lathe and 10 ton milling machine to produce works of art.
I got his picture of his Lombard Log Hauler into the club chat section of ME a year or so ago; maybe you'll remember it.
Anyway, if anyone wants to see what Sherline equipment can be made to do, look at the above web site and look for the builds by "crueby". It certainly opened my eyes.
1) I have a Sherline lathe that is fairly new to me. Seems very good from what I have turned so far.
2) I have had a Sherline CNC rotary table hooked up to my KX1 and it has been spectacular.
3) The machine screws are the UNC style, which is a shame, as I'd rather they were metric. (metric feed screws though on the one I have)
4) As mentioned, the documentation and plans and parts breadth is incredible. And, I, too have been really impressed with the work produced by others.
|Thread: Advice on Choosing A Mini Lathe|
I've wanted a mini-lathe for years, and finally got one, after looking at lots of the far-eastern ones.
I picked up a Sherline lathe.
It is incredible. Well put together, feels like a dream.
A fellow from Rochester, NY built a Kozo "New" Shay on one of these, and his Sherline mill. In less calendar time than it took me to do mine on larger machines, AND he cut the bevel gears himself.
There's also a Cowells, and the Peatol/Taig.
The *only* complaint about the Sherline is that all the fasteners are UNC/UNF, and I'd appreciate metric, but that's a small quibble. I did get metric feed screws.
Are these not mini-lathes as well?
|Thread: emco pc turn 55 conversion to mach3|
David beat me to it - threading.
LinuxCNC works well, and blows Mach3 out of the water, from what I hear.
The reason seems to be that LinuxCNC uses two spindle sensors - one to mark 0.00 degrees, and the other divides the spindle rotation by "lots". Mach3 only has the 0.00 degrees and interpolates the spindle rotation from that.
I use "Mesa" boards, which seem to be inexpensive compared to Mach hardware. The whole stuff just works.
Note: John Stevenson (miss that guy) and I used to "argue" - he liked Mach3, I like LinuxCNC, so my comments above regarding Mach3 are from discussions with Mr. Stevenson, not my personal experience.
|Thread: Completed models - just out of interest|
I echo these thoughts.
I agree with Duncan, which is why maybe we have a disagreement on the Tich locomotive - for me, getting it to go around in circles, pulling me and possibly another body, is a challenge. My larger 3-1/2" gauge 2-8-2 is much less fun, and weighs in at close to 10x what Tich does. And, with Tich, it gets plugged up after 10 minutes of running, so time to take a break and socialize.
I've finished my 3-1/2" gauge Shay locomotive, currently sitting in a glass case in our living room, and I doubt it'll get much use, if any. Nice to look at, though.
Like Thor - I just gave away a ST steam pump to a friend to get him kickstarted in stationary models, after he sold his large 7-1/4" one. He'll use it, I certainly won't.
I don't think I was always this way, so I accept that there are many ways to enjoy this hobby, so however one gets satisfaction from model engineering is fine by me.
Edited By John Alexander Stewart on 24/03/2019 14:32:33
|Thread: KX1 CNC Mill Clearance Offer|
"you go into a jobbing shop today"
Most certainly, any jobbing shop is repetitive slogging. (at least from what I've come to understand)
Where I worked (NOT as a machinist; but the machinists did stuff for MY work) the guys there made one-offs on CNC mills. No manual mills. They were artisans in what they did. It was called the "model shop".
They used CNC as a tool to enable better precision and less scrapping of complex parts, and allowing redesign without issue. They were making scientific and military prototypes, so nothing (especially from us!) was cast in stone. Some of the Virtual Reality stuff I did (now in our Canadian Science and Tech museum) was CNC'd to make it look less "agricultural". In this case, they made duplicates, as one set was for a traveling road show (Europe, half way across the pacific, etc).
They could not believe that I did not have CNC at home in my shop; I, too, originally thought CNC was for blasting through material making thousands of parts, until these guys educated me.
So, I use CNC now, and I'm not going back!
|Thread: Dial indicator probe threads|
Just a note - the link mentions M1.7, which is, IIRC, only a JIS metric standard. It's *really* close to a BA size, and my theory is that it was simply metricated way back when so that British equipment in Japan could be repaired. Yes, the thread form is different, but for many applications, it's close enough.
I also think that there's also other BA sizes mapped into odd JIS metric.
Anyway, someone may find this useful, or someone may actually come up with an equivalent chart, or...
|Thread: Making nameplates|
I made some for a friend by engraving from artwork. Did write this up for Diane, but article was probably too long and the software was free, so has not appeared in print.
In essence, I drew it up, saved it as a jpeg file, and sent it into LinuxCNC, which understands image formats and will engrave from that.
All I needed to get was some engraving cutters, From my album, the first results:
|Thread: KX1 CNC Mill Clearance Offer|
With regards to having 2 machinists (one a CNC robot);
I've found that I can't concentrate on doing complex stuff when my CNC is running. Cleaning the shop, doing the washing up in the kitchen; that kind of stuff I can do.
I've always got an ear open listening to the CNC for "strange sounds" like material coming loose, cutter dulling, etc.
I don't know why; the little KX1 (running LinuxCNC) runs for hours and hours without issues. I'd presume that Mach3 would have the same reliability, but no experience with that SW so can't comment.
Maybe it's just me being paranoid. I'd (honestly) like to hear on how others do with leaving the CNC mill running, while going and doing something else complex.
Note that I did have ONE problem with the KX1. Actually, my software and hardware; I had set up the software (hand-tuned by me - yeah right! bad idea!) so that pulses to the stepper controllers were right at the limits according to the spec sheets, and one of the stepper controllers missed a pulse (about 1 in a million) when stepping one direction. Backing off the minimal numbers solved the problem. Lesson - never trust the minimum numbers on spec sheets!
For quite a while I worked at a research site that had a machine shop about the size of a football pitch.
2 friends worked there. One of them left years ago, then a year or two ago I left.
Anyway, friend #1 - "what do you have a manual mill for? All ours are CNC. You want to make one-offs - come over here and I'll show you conversational programming" (my eyes went wide open!)
Friend #2, has a shop @home, 2 CNC mills, zero manual mills. "why would anyone have a manual mill??"
These guys are machinists by profession (doing precision research projects, not metal bashing), and I'm not. So when these well trained guys ask a question and show me how a pro does it... I'm all ears.
the olde saying "you can lead a horse to water but you can't make it drink" applies here.
I think Neil'll work it out in the end.
Neil - if I may:
I've got 2 CNC mills; a KX1 and another larger one.
Both have MPG controls.
I use the larger one (right now) mainly as a pillar drill; the mpg I use just magnetically sits on the table, and I can control height of the head, speed, table movement, with the mpg.
This mill has a quill for drilling holes with "finger feel"
The MPG has different scaling options, so I can easily place the table accurately or quickly.
It has a built in DRO - which in LinuxCNC I can make full screen, to quickly and pretty accurately place holes.
That seems like a very kind and good offer; especially the display/damaged ones given away.
I have a KX1 that I got here in Canada, came without stepper controller. John Stevenson and I argued about it, but in the end, he came to the conclusion (by querying the factory) that it was a KX1 made for internal consumption, but somehow leaked out of China.
It has been a fantastic bit of kit. Now, I did power it myself with LinuxCNC and a Gecko G540. Can not comment on Mach3, but that seems to be ok. As mine stands, it runs for hours and hours without complaint.
The KX3 looks like another good machine.
I hope all of your stock goes to good homes, and that they get well used.
|Thread: emco pc turn 55 conversion to mach3|
1) There's a fellow who posts here sometimes (can't remember his name at the moment) who had figured out how to drive a parallel-port equipped Emco CNC lathe from LinuxCNC. He and his father got a batch of them.
2) A local club member took his Emco Compact-5 CNC lathe and LinuxCNC'd it, including tool changer. Works very well, when he gets the chance to use it. (young family syndrome)
3) If you have a Tormach 1100, you'll know that the PathPilot upgrade (*) is LinuxCNC with a Tormach UI and conversational programming layer.
(I put a star on "upgrade" as I know we all have our own preferences, and some people have difficulty with anything other than Windows on a computer). Tormach dropped Mach in favour of LinuxCNC for a reason.
4) I CNC-converted a Unimat SL lathe, which I gave to a club member, and have recently picked up a Sherline lathe, CNC controller is my old LinuxCNC one from my Unimat-SL. Sherline's CNC controller is LinuxCNC, so that's another company who chose LinuxCNC for their products.
I'm a LinuxCNC advocate, as, not only is the price right, it just works 100% of the time for me, on 3 machines. I have converted to the "GMOCAPY" UI, which I like more than the standard UI.
Again, there's lots of choice out there; every solution has good points and bad points.
|Thread: Silver soldering problems.|
Q: Do you tightly clamp the 2 pieces?
Q: Do you heat from the "other" side as the silver solder is at?
Q: Do you leave a small gap for the solder to go into?
Thought 1: You might want to centre punch some marks on one of the pieces to give that hairline gap for the solder to flow through. I centre punch *everything* that I'm silver soldering now.
Thought 2: As Jeff says, more heat and more flux. I sometimes use a "poker" rod to add more flux. Inside, I use a plumbers propane torch, which is really not good for much more than silver soldering really small stuff. You do want the pieces to come up to temperature, especially the inside of the joint....
Keep going, practice does help.
|Thread: Hemingway Radius Grinding Attachment Ref: HK 1312|
I've made it, but not used it much.
I think that you'll find that the accuracy is in the setup; all it really does is hold a toolbit and allow you to move it in a circle of about 180 degrees. Fine feed is by the screw on the back of the tool holder.
I should use it more; work and family stuff has got between me and my workshop recently - so the lack of use is not a black mark on the tool design.
I made my semi-circular table on my smaller CNC mill, out of brass, 1/8" thick. Also made the tool holder slider (that slides on the semi-circular table) out of brass on my CNC mill, also.
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