Here is a list of all the postings Phil H1 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Digital back issues|
Sorry for hijacking your thread John.
How far do the model engineers go back? I am interested to know whether they go back to about 1975ish? If they do, I will stop being so miserable and subscribe.
|Thread: Loco wheel profile chatter|
I machine wheels using a face plate method not dissimilar to the method described by Duncan. I have machined a few directly onto the face plate to get the hole straight and in the middle.
I have read both the M Evans and LBSC descriptions and I don't like the bit about boring the hole from the back but they always seem to describe a faceplate (usually and old unused locomotive wheel) for machining the tread. I have seen a mandrel mentioned but I didn't like the look of it because it seems flimsy.
I have never suffered with any chatter using the faceplate method. I haven't machined a huge number of wheels - about 25 to date.
|Thread: Rob Roy Build/ Rally|
I tried that (emery round the smokebox tube) - obviously not quite carefully enough because the axis of the smokebox curve is a bit off. Not by a mile but it is just noticeable. It is correctable because there is still at least 1/16" of meat left before the saddle would have a height problem.
But its a nice suggestion that can be measured before hand (across the sanding drum). Perhaps a round wooden former similar to your idea Rick but put it between lathe centres to keep it true. Then clamp the saddle 'true' to an angle plate and feed it into the sanding drum VERY CAREFULLY. I wouldn't need to take much out to correct the axis.
I was sceptical at first but it does actually look like it will go on the face plate - as per the book. Again, the snag with that option is sliding it around to get the correct position/ radius.
So I might go the flycutter/ cross slide route as you suggest. That option allows me to cut the chimney base to suit too and maybe even the dome base at a slightly tweeked radius.
I think you might be right. After all, I do want to finish this thing one day.
I've done some more measurements and there is good and bad news. The bad news is that the saddle is actually slightly short of 2 3/16" long but the saddle fixing screws will be ok.
I think one of the trickiest steps from here is to machine the smokebox radius or I should say setting it up to machine the radius will be the tricky bit.
Unfortunately, my saddle casting (bought many years ago) is short. It is supposed to be 2 3/8" long but is about 2 1/4". So I have two options;
1. Machine the existing saddle casting and make it look like a shorter cast saddle as used on many other real engines. Or add some metal somehow - maybe an additional plate at the back.
2. Bin the saddle casting and form the combined smokebox and saddle from a continuous brass strip 2 3/8" wide as the real engines of this class.
I would like to take option 2 but I suspect it will be rather tricky. Is this something that should only really be done with bending rollers or will the 16g brass sheet form quite well round a wooden former (with lots of clamps of course) i.e., has anybody done this successfully - any experience/ advice out there?
|Thread: Are we being listened to on the phone|
Have you had the covid vaccine yet? It could have been the tracker that they inject.
|Thread: Was Draw Filing ever a chargeable offence in the RAF?|
'There are plenty of jobs where appearance is the only parameter required so if draw filing provides this then why not use it? Appreciating its limitations is important but it certainly has its place.
Mike, sorry to disagree but once you have learnt how to file properly, you never ever use draw filing ever again.
My guess is that the RAF were stopping its use to sort of force their apprentices to use the right methods.
I can understand it. Draw filing was frowned upon when I was an apprentice but I wasn't with the RAF and it had absolutely nothing to do with surface finish because you can achieve a brilliant surface finish by using the file properly.
I even saw the explanation/ diagrams in a craft type text book that explained why draw filing was very bad practice if you wish to achieve a straight edge or flat surface.
Holding and using the file properly, lengthwise across the surface means that the length of the file 'helps' to keep the file flat on the surface and with care, it helps to remove the high spots. If you do it properly, you can easily achieve surfaces within 0.001" and you don't really need emery cloth to polish it either.
With draw filing, the width of the file, being much narrower, actually helps it to ride over the crests and hollows of a work piece and can actually exaggerate the lack of flatness. Yes it will be shiny but it is much harder to achieve a flat surface.
I wish I still had the text book. It was one of those old fashioned, good quality apprentice style books.
Anyway, we spent the first 12 months covered in engineers blue, using a file every day and it works. The text book and the apprentice instructors were definitely right.
|Thread: JB Weld|
Yes, tongue firmly in cheek. And yes Jason, you are right. I prefer to see fabricated or machined from solid rather than the use of castings.
Nigel, painful? My association with Rob Roy that I started in 1977 and is still at the chassis stage does kind of feel a bit long and torturous but I still seem to keep going for some weird reason.
Thanks for the clarification chaps regarding the pack type.
It obviously works and looks good. I am very impressed with the marine engine cylinder 'casting' in one of the other threads by Tug and I have noticed Jason using the stuff more than once on his stationary engines.
It just feels a bit like cheating. This JB stuff - like laser cut parts and accurate digital read outs on milling machines is making life too easy. I have always thought that model engineering was supposed to be a long painful experience.
This is really interesting and I will be searching for uses. Please can you clarify which of the two packs you used for these tests and or would you expect the same or similar results from either of the packs?
|Thread: Two or three axis DRO|
I have a Chester 16V and I was not really convinced about DROs. Anyway, in a moment of madness, I bought a M-DRO magnetic kit for X, Y & Z axes and it is impressive - I've seen the light, I'm converted.
I also have a cheap DRO available (not sure where I bought it) and I will be fitting it to the quill.
|Thread: Don Young's 'Doncaster'|
I really nice engine. I am struggling in the lower division with the small 0-6-0 Rob Roy build so it is nice to see something substantial. I'd be very interested to know all sorts of information e.g., how long, all traditionally built or have you used laser parts. Who built that very neat boiler etc.
|Thread: Making Minnie water gauge|
I have recently had similar problems. I suspect half the problem was that I was treating the bronze like brass. Whether I tried old or new drills - no difference it was still really nasty.
What seemed to help in my case was to slow the machine right down and I used plenty of oil inside the hole and take it really easy in stages as Jason has said.
|Thread: Bolton triple expansion engine running at last|
Really nice Tony. I looks like a lot of work went into building that.
The arc conversion looks nice but it says that it won't work on a Super 7 lathe. Does anybody know of a Super 7 equivalent modification?
|Thread: Myford spindle rectification or replacement|
If you can clearly see and feel the bruise on the thread, a diamond needle file might help. I bought a set of different shapes and they are excellent.
I didn't look through all your clips but I did see a few that clocked the spindle. I thought it was running really well and not worth disturbing if the thread clean up works ok.
|Thread: Model boiler safety calculations|
I think you have demonstrated my point regarding small model boiler calculations. The author talks about a safety factor of 6 or maybe 10. Then you say that the a letter suggested 5000 rather than 7000 be used in the equation - so why bother at all?
I think that small copper boilers are quite well established regarding plate and tube sizes and that is all based on many years of successful use. There is absolutely nothing wrong with successful historical information being used because it works.
I think we should avoid trying to suggest some kind of design engineering in taking place by throwing some equations about when there s clearly no sound basis.
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