Here is a list of all the postings IanT has made in our forums. Click on a thread name to jump to the thread.
|Thread: How best to fix a partly failed Silver Solder joint?|
Sorry Dave - Mea Culpa!
I was focused on the "How best to fix a partly failed Silver Solder joint?" - and lost sight of the fact that these parts have been finish-machined. Reheating (to the levels required for silver soldering) might well cause distortion problems - as Neil has pointed out.
I used to use just firebricks for my soldering hearth - but they suck a lot of heat and things seem to take much longer to get up to heat.
I've been using variations on this set-up using ceramic blanket for a while now and it works much better. It does 'glow' almost white hot at times and seems to get a bit brittle but I think I only paid about £6 for it (3-4 years ago) - so it's not expensive to renew. The rear 'wrapper' is a piece of stainless steel left over from a domestic cooker extractor - and it never gets hot - the original paint is still intact.
The steel (laser cut) assembly is being SIF-bronzed (which takes a good deal more heat than silver solder) and the ceramic really helped to get it up to yellow-red heat quickly (I couldn't hold the torch and take the photo at the same time though!).
I'll go with Kwil on this - provided the " gap " is not too wide then I'd re-solder it.
I'm kind of assuming here that the brass bit is sat squarely on the steel bit and that there was a good 'mechanical' fit in the first place. Otherwise, you will not manage to fill the gap using capillary action - it won't work. I guess another concern is that the work was not 'bound' correctly (applying heat can move things around a little) and that the existing solder has set at an angle (e.g. one end of the joint is higher than the other). If you are happy that it's just a poor solder joint however - then the following should work.
BTW - The existing solder joint should have a slightly higher melting point than any newly applied solder (because of alloying. I certainly would not try to take it apart (or use soft solder...)
Clean around the area as best you can first - I'd give it a really good soak in pickling solution (I use citric acid) - at least 24hrs with something gentle like citric and then slightly abrade & prick around the area that needs actual treatment to get any old flux/muck off. An old toothbrush is sometimes sufficient. You need it really clean.
Another thing that I do is mix my flux with methylated spirits (instead of water). I use a type of 'Sif' silver flux and I don't get a "creamy" flux (as is often referred to in the texts) but more of a 'gritty' mix. However, this can be packed around the joint (with a pointed lolly stick) and seems to really keep the area clean well provided you don't really overheat it.
Talking of which - try to get the assembly up to heat quickly - but evenly - without playing the torch on the area you are going to work on too directly. I use ceramic blanket to keep the heat focused - it's not expensive and works really well for small assemblies.
The flux will 'flare' as the meths burns off (but not bubble) and as the assembly goes red the flux will turn clear. Heat your silver solder rod and dip it in (powered) flux and then dab it on the area you need to seal. If it's hot enough, it will melt - other wise the work is not up to heat - so don't try melting the solder onto the work. Re-dip the solder and wait a second or two and then try again. You need the work to melt the solder to get capillary action (in order to fill the gap). Once you get 'melt' run the solder along the gap but you shouldn't need to do too much - the solder should get pulled along and into the joint almost instantly. As soon as this happens - remove the heat and leave to cool naturally (no dunking in water etc).
There may be other methods/theories that will work but I've done this myself - so I know it works. Soldering (and brazing) is one of those things. Just when you think you've "cracked it" - you do something fairly routine and it don't work as well as you expected. I hope practice does help make perfect eventually however.
Hope this helps Dave - good luck
|Thread: More Info|
I think they were Gordon - I seem to remember seeing both pumps and casting kits in their shop window when they were still based in Henley-on-Thames.
|Thread: What did you do today (2015)|
Used to get the occasional 'sippers' on board the Minesweepers based at HMS Tamar (Hong Kong - I used to repair their landlines). So where rum is concerned, I developed a taste for Pussers fairly early in life...wonderful stuff in moderation - lethal otherwise.
Fortunately - my (ex-matelot) mate still keeps a bottle handy - so I usually get given a sip (and very occasionally even a 'gulp' when I go down to visit him !
Edited By IanT on 19/03/2015 10:31:23
|Thread: marking out pcd's|
Being more of an Old 'Codger' (than an Old 'Bodger' John - frankly I doubt you would have hired me in the first place. (with Smilely!)
After all by the time you had finished this - I'd still be faffing around looking for (the correct threaded) bolt (or bolts) to cut into three suitable lengths, then I'd be digging out a collet chuck to hold them (being too short to grip securely in the 3J without damaging the threads) - setting over my top-slide (which I spent 10 minutes last week making sure it was really true) to turn the screw ends into 'points' before I could actually start on your method (which I agree is a simple one). In my workshop by this time of course, I would have mounted my angle plate, trued it using the faceplate, lined up the chuck and be drilling my first or second hole.
Later (using your approach) when I came to drill the holes in my drill press - Sods Law would decree that the back-plate is a casting that has a tapered nose on the back end and (being a complete novice) I'd probably faff around some more worrying about how to hold the back plate true in my vice without any 'rock' - my vice of course not opening wide enough to hold the backplate's outside diameter. Being a complete twit - more faffing about would undoubtedly follow.
So, No - I don't think I would have got the job in the first place..
Fortunately (unlike your good self) I don't have to make a living at this game - I just have to enjoy it in my own spare time - which I most certainly do.
(and that's another smilely!)
There are lot's of ways (variations on a theme) of doing this but the one I use is as follows..
As Neil says - turn your register - and initially try to get a very good fit on the chuck - no movement
Then mount a faceplate true on the cross-slide and bolt your chuck (facing outwards) to it with a bolt (or threaded rod) through the chuck centre. Install your drill chuck in the lathe mandrel, together with a bit that is a close fit into one of the chucks mounting holes. Juggle the chuck around on the angle plate till the drill will just enter one of the chuck's mounting holes. Once the drill enters the hole smoothly (use the saddle movement to test it) tighten up the chuck's through bolt.
Change the 'aligning' drill bit for a centre drill and place the back plate onto the back of the chuck and clamp it (I use a large G clamp). Start the hole with the centre drill and then change it for a 'clearance' bit (e.g. a drill size that is a clearance size for the tapped bolt hole you just lined up with). Carefully drill into the back plate till you are almost through it. Unclamp the back plate and finish drilling through it in the drill press. I will admit that I didn't last time around - I did it all in the lathe but was very careful not to drill into the tapped hole
Then it's easy. Rotate the back plate - use the new hole to bolt the back plate to the chuck and centre/clearance drill the second hole - BEING VERY CAREFUL NOT TO DISTURB THE CHUCK. Unbolt the first hole, rotate the back plate again, bolt 1 & 2 holes up - and drill the third hole.
Now you can just leave it like this and it should be good.
However, I like to mount the back plate onto the lathe and take just a 'smidgen' off the register - enough to allow a slight adjustment. I then bolt the chuck on (but lightly) and test it with some 12mm silver steel gripped in the jaws - just tapping it true against a DTI. Then I tighten the back plate bolts fully and test again. Obviously a 3J may not be true on other material sizes but I know that it should be fairly good in at least that one spot.
Hope this all makes sense. It's easier to do than explain.
You will need a fairly large angle plate to do it like this but they are very useful items to have on the lathe anyway...
|Thread: ROYAL SHAPER|
Well I guess you would know that the table feed was always truly vertical Thai.
You could then have the top-slide set over to some other known angle (and leave it there) and still cut vertically using the table feed (probably have to move the tool/clapper though) - so it might be useful on some production runs. You can do this manually too of course.
But I agree a top-slide power feed would generally be more useful although I'd have to stand and watch it (which I don't always do on normal traversing cuts) - so I may as well also 'twitch' the down feed whilst I'm doing so... I think I'd prefer a tilting table on balance - but again it's not something that I can't live without.
I like my Acorn too Ady!
Happy Shaping everyone!
|Thread: How to use a die?|
It's been a long held belief on the "craft" side of our world Andrew (e.g. by many 'craftsmen' that a properly tempered and honed carbon tool can take a keener edge and therefore give a finer cut than HSS. The downside being that the carbon tools don't like excessive heat, which is why carbon tooling was generally abandoned when HSS came along.
Not being a metallurgist I can't explain why this might be but I do use 'carbon' steel cutting tools - mostly when I need a shape (or size) of tool that I cannot get in HSS or that I don't want to grind to shape or size!. In these cases I can shape (file or machine and then harden/temper) a tool in some kind of carbon steel (e.g. old files, silver steel etc.)
For my particular needs these tools can cut very well, so are very good for occasional/specialist use but they do need care to avoid overheating - not so much when turning but when working very small section tooling on the grinder or with any milling tools. I don't generally hone most of my HSS cutting tools but do so on some carbon ones - especially the smaller 'custom' tools where I want to get a very clean finish.
There has been some debate over the years about the need to hone a cutting tool (at all) but (and again this is a laymans view) if you are cutting very small work (with a small tool) then it seems to stand to reason that a 'smoother' cutting edge will give you a better finish. A carbon tool can take a very keen edge and it seems to take it easier than HSS - which you can also hone of course - but this is a very subjective view. I am sure there will be clockmakers and other people better qualified than me to explain the 'physics' of all this.
Of course, I don't 'hone' my dies and given the choice I'd always buy HSS dies/taps but I do have some larger carbon dies/taps purchased from new, which were about half the price of their HSS equivalents at the time - but which I only expected to use a few times, so the lower price was the clincher.
I guess that I've never worried too much about "why" things work, being much more concerned about whether they actually do (or do not). I think it's also worth remembering that our needs (as hobbyists) are often very different to those of Industry.
(Could use a pre-view function - would avoid re-editing)
Edited By IanT on 17/03/2015 10:48:00
|Thread: Looking for three issues of MEW|
I'll have them Neil - let me know what you want.
You should have my email details.
|Thread: What metal for a profile tool|
Well the "classic" way Eric was to anneal an old file, grind or file the teeth off, drill a hole of the right diameter in it, cut off the unwanted half and then harden & temper the remaining bit.
A slight improvement on the idea is to bore the hole with a slight taper, which will provide more clearance for the cutting edge.
|Thread: How to use a die?|
Probably just a personal thing Tom but my ME and (best) BA taps and dies are only used on brass/bronze - I don't use them on steel - let alone stainless.
When I say "best" BA taps and dies - I generally reserve my newest ones just for brass but once (if) used on steel they are marked, kept separately and then only used for steel thereafter unless I have no other alternative. I simply don't use my ME (32/40tpi) set on anything but brass/bronze. Not sure this is absolutely necessary in practice (and I may be wandering perilously close to superstition in this area) but It's what I do. Fortunately, I have enough BA taps/dies in the sizes I use regularly to be able to afford this luxury and it only takes a little discipline to observe the rule...
I don't worry nearly so much (well not at all in fact) with my BSW/BSF/Metric/other screwing kit but then they are used mostly on mild steel anyway. But if I was going to be regularly cutting small/fine metric threads in brass or bronze - I might keep some to one side for that specific use too.
Anyone else have this practice or is it just me?
|Thread: EN STEELS and their uses|
This whole subject can get very technical and complicated Clogs - but for the layman (e.g. me & you) I find this simple chart covers all of my needs in this area.
|Thread: How to use a die?|
All of my imperial dies are split but most of my metric ones are not. However, the "unsplit' ones should also be accurately set to final size.
One solution for you would be to turn a slow taper on the end of your work piece (suggest equal in length to the depth of the die and use a die holder to get the die as straight as possible (a fairly simple turning operation and something always useful to have in the future). You should then be able to get the die started in the lathe. Once started I sometimes take the work out of the chuck and hold it in a vice (better than over-tightening the chuck jaws to stop the work turning).
Once you have the thread you want - then turn/face off the tapered part of the work piece.
Alternatively - if you have a screw-cutting lathe - "part" thread the work and finish it with the die. Doing this as a two part operation will help get the thread straight, greatly reduce the work the die has to do and you don't need to worry quite so much about final sizing of the thread using just the lathe (wire gauges etc.)
|Thread: Did you choose a career or did it choose you?|
My mate decided he wanted to become a motorcycle despatch rider in the Royal Signals. Getting paid to ride a motorcycle across country sounded pretty good to him but I was not so sure about the Army bit. I went along to the recruitment office with him anyway and was persuaded to do the joining exam ("You may as well have a go son - rather than just sit there and wait" - says Recruitment Sgt "Leafy" Lane).
Well, my mate had perforated eardrums and failed his medical, so never got to ride cross country for a living. There was nothing wrong with my hearing, so I didn't fail the medical and became a boy-soldier at 17 for 10 shillings (50p) a week.
Never got to ride that bike cross-country either but did learn to drive a 3-ton Bedford and finally passed my motorbike license in Hong Kong - but on my own bike !
Met the missus and decided to leave HM employment 10 years later, otherwise I would probably have done the full 22. Got made redundant three times in Civvy Street but each time this took me off in different directions that I wouldn't have taken otherwise. All in all, it worked out pretty well but no great career plan - just lot's small things that seemed to 'nudge' me this way or that..
Been retired now a while and that seems to suit too, in fact I'm not sure how I ever managed to squeeze work in.
Oopps - it's coffee time - got to go !
|Thread: 3 1/2" Gauge Discussion Group|
No one has mentioned any of the N/G 3.5" engine designs that are available. Larger/Heavier engines - and some fairly straight forward. I sold my 'Russell' some time ago but still have the 'Conway' (fairly simple) and 'Lew' (not so simple) chassis down the Shed. However - I made the move down-gauge (by an inch) some years ago.
"The smaller gauges are seeing a revival; the locos are more manageable and the castings and materials cost less"...... This of course also applies to 2.5" gauge too - perhaps more so !
And just for JAS - modern image is starting to appear in G3 circles too - how about this one (it's not the engine you mentioned as being at MEX I'm afraid).
Edited By IanT on 11/03/2015 12:34:04
|Thread: Loco boiler pressure|
In Gauge '3' (2.5" at 1:22.6) I would say that most live steam engines are run at around 80psi even though they are being used in a "scenic" setting (e.g. not passenger hauling). You could most certainly run a steam engine at a lower pressure and there might be reasons to do so in G3, one of which would be the 3 bar/litre boundary.
Essentially the boiler test certificate requirements (required at G3 GTGs and at any MES Rally) are less onerous if the boiler is <3BL. The bar/litre is a combination of the total water capacity of the boiler x the normal operating pressure, so reducing the operating pressure can bring some engines below this 3B/L boundary (at least in G3).
However, assuming you will be running on your own track - formal boiler testing may not be an immediate concern for you, although I would still recommend you familiarise yourself with the general requirements and make your own safety checks. You can find more info at the Southern Fed website.
Overall though, I think Neil probably has the best advice for you.
Get the boiler built as originally specified for the engine design (again assuming they have been built to an existing design - LBSC/Evans etc.) and run it at the recommended pressure. If you have a boiler built for you make sure you get the maker to provide you with a hydraulic shell test certificate too. You are going to either spend quite a lot of time building these boilers/engines yourself - or paying someone else (a lot) to do it for you. So it makes sense to end up with an engine/boiler combination that is saleable for a fair price should the need arise.
Edited By IanT on 11/03/2015 11:26:22
|Thread: TurboCAD Explode/Create Fragmentation?|
Not a feature in the DL version as far as I know Neil - it maybe available in the (more expensive) Pro version.
I'll also do as JS suggests and go and ask the TC Forum (yet another Forum to join!) and see if they have any useful advice on the subject.
Thank you for the feedback. I will experiment a little and see if I can find a way to "under" explode my drawings - or perhaps delay any grouping action and thereby minimise the risks of this occurring....
Part of the problem may have been that (in this case) I had built up quite a few small groups as I went along (modifying & changing various assemblies as I went) - and it does seem quite hard to then 'ungroup' in an orderly fashion without this fragmentation effect.
Possibly a potential weakness in TC, combined with poor process on my part, resulting in a problem
In case anyone is interested - here is the prototype engine shown at the G3 AGM in February. Still work to do but coming along..
Edited By IanT on 10/03/2015 10:40:41
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