Here is a list of all the postings John Baguley has made in our forums. Click on a thread name to jump to the thread.
|Thread: Website Articles - Simplex|
The Simplex articles are available for download (subscribers only) on page 5 of the 'Latest Articles' Click on the link at the bottom of the home page.
|Thread: Docstrader valvegear simulation|
can't give you a definitive answer but I had this myself some time ago. I can't remember if it was with the Dockstader software or one of Bill Hall's versions. It's actually a windows error message, not the valve gear software. I did a search on the net for 'Invalid floating point operation' which came up with loads of results and suggested cures. I eventually found something that did cure the problem but I can't remember what it was
Hopefully someone with a bit more computer knowledge might be able to point you in the right direction.
|Thread: Live Steam Royal Scot in 'O' Gauge|
I was going to build a RC version of one of these a few years back but then moved up to bigger gauges so it didn't get started.
I got the full size drawings from GLR but IIRC at the time they could not supply any of the castings. I finished up buying the wheel castings from Alan Harris. Superb quality but not cheap (about £150 for the complete set).
It shouldn't be too much of a problem to fabricate cylinders etc or machine them from the solid. There is very little on any loco that you really need castings for.
The original loco was built by Severn Lamb for a French client but it was designed by Martin Evans.
|Thread: Adverts over the top of postings|
Just noticed this but only on the 'Elbow Engine' posting. This time it's the adverts on the right hand side that overlap the text. The other posts seem ok. The first post on the elbow engine does contain a link to Youtube which may be the offending item?
|Thread: Fluorosint , mica filled ptfe|
I initially got the Peek bearing grade from RS but later got some from Davis Industrial Plastics which worked out a bit cheaper. If you go on the RS website and search for PEEK, it will come up with all the various grades available along with the data sheets. It's not cheap but not in the Fluorosint league fortunately!
I did look at the glass filled PEEK but I got the impression it's not suitable for bearing surfaces as the glass makes it quite abrasive (could be wrong though).
I presume you've got the plain stuff without additives?
no, I didn't try the PEEK just for the heads. I was making the complete valve from it. I eventually abandoned it when the loco seized solid storming up the steep gradient at Chesterfield's track! Part of the problem though is the steam temperature as the loco has a very high degree of superheat and I think the cylinders run at something like 200°C when working hard.
I used ordinary plain PTFE for the new heads I made which seems ok. Like you, I found the price of Fluorosint slightly offputting! The beauty of Fluorosint though is that apparently it has a similar rate of expansion to bronze.
The PEEK may actually work for separate heads as the expansion does not seem to be so much of a problem so long as a bit of clearance is left between the bore of the head and the bobbin to allow it to 'squeeze' inwards when it expands. The PEEK does have a lower rate of expansion than plain PTFE, but still high compared to bronze etc. Incidently, the PEEK I used was PEEK bearing grade loaded with PTFE, graphite, and carbon fibre.
One good point that came out of the experiment is that I found the PEEK to be excellent for coupling rod bushes etc.!
Edited By John Baguley on 22/02/2010 12:22:10
Mike, if you are thinking of making the complete bobbin from PEEK, I would not advise it. The expansion is too much. For a running fit at operating temperatures the valve will have to be a very sloppy fit when cold. I experimented with the material for my Helen Long cylinders and eventually abandoned it. I now run bronze bobbins with PTFE heads. Works a treat.
|Thread: Blown X1 Mill speed control|
last year I repaired a couple of driver boards for the Machine Mart mini lathe (C3 etc) for a friend at the club. He was on his third board and getting fed up with the cost of the replacement from MM. I replaced the output mosfets on both with a higher spec version from RS and so far so good. The originals were the standard IRFP460 but I replaced them with IRFP22N50A which have a higher rating. The probem with the original IRFP460 is that they can't stand the current drawn if the motor stalls under load. By the time the fuse blows, it's too late!
|Thread: Brass nuts on boiler stays?|
At least the threaded stays won't fall out or move at the worst possible time
Brass will be fine for the nuts. It's been used since LBSC days for stay nuts. I still use them for the boilers I build with caulked stays (shock, horror )
You don't really need the nuts at all if both ends of the stays are going to be silver soldered. You only need them if they are to be caulked with soft solder (Comsol etc.). Nowadays, most people just use plain copper rivets for stays with the heads inside the firebox if they are all silver soldered.
Edited By John Baguley on 05/02/2010 15:01:05
|Thread: Martin Evans Columbia Castings|
Blackgates Engineering list them in their catalogue.
|Thread: Matin Evans, Holmside|
It was serialised in 14 parts starting with Volume 143 issue 3558 and finishing in Volume 144 Issue 3590. Relevant issues are 3558, 3561, 3563, 3565, 3567, 3569, 3571, 3573, 3575, 3578, 3581, 3584, 3587, 3590.
Edited By John Baguley on 20/01/2010 11:27:28
|Thread: Captive steam fittings (on loco's))|
the easiest way to adapt the original fittings is firstly to make a new valve stem with the outer part that the handle fits to a smaller diameter than the threaded part. Then make a new gland nut with the hole to fit the reduced stem of the valve. The gland nut then stops the stem from being unscrewed completely.
|Thread: lifford hall|
The backhead clack is for the tender handpump feed. The boiler does have two topfeeds but they were meant to be fitted without bushes, hence the lack of them. The idea is to drill two 1/4" holes in the boiler barrel either side of the safety valve bush. The top feeds are fitted into these holes and secured to the barrel with bronze screws and run over with soft solder to seal. I doubt if this would be acceptable now but I don't think it would be too difficult to retrofit a couple of bushes as the only joint you are liable to disturb is the safety valve bush. Would be a doddle if you know someone with oxy-acetylene gear. That's assuming the stays haven't been soft soldered. Would still be possible with oxy-acetylene to keep the heat local and a bit of care.
Ivy Hall was never intended to be a replica of a real Hall but instead LBSC's idea of what a 'modernised' Hall might look like. Lickham Hall was the closer to scale design that he did for Reeves, much to the annoyance of the head of Model Engineer at the time!
Have replied on MECH re the top feeds.
|Thread: Stephenson valve gear for Derby 2P|
I will probably be able to do it for you if nobody else volunteers. I have the original LLAS articles with the drawings etc. Designing valve gears is pretty straightforward nowadays with the help of the work of Don Ashton etc.
|Thread: Yet another boiler making question|
is it just a rivet you've used to hold the firebox wrapper to the tubeplate and end plate whilst soldering these joints? I presume you haven't installed the firebox into the boiler shell yet?
If so, I wouldn't worry about it at this point in time. Wait until you've got the whole boiler assembled and you come to do the stays which you obviously intend to silver solder. You are going to have to get the whole firebox and outer wrapper damned hot to do the stays anyway so try and put a dob of Easyflo on the offending rivet then (inside the firebox). There's a good chance it probably sealed anyway with the solder that has been drawn into the initial joint.
Incidentally, you'll probably need to get a Cyclone burner to do the stays inside the firebox. If you have already soldered on the firebox backplate it's very difficult to keep an ordinary burner alight in such a small space.
Edited By John Baguley on 18/12/2009 21:53:43
Mabel is an inside cylinder LNWR 2-4-0 so they definitely won't be the same cylinders. The stock codes on the Reeves website are different.
|Thread: Flux for HMP soft solder?|
The 'traditional' flux is Bakers Fluid but you have to keep slopping it on all the time as it quickly evaporates. Carrs Black Label works quite well but with the same evaporation problem. The difficulty is finding a suitable brush to apply it with that will stand the temperature without going all black and horrible! Maybe something like an eye dropper would be a better way of applying it?
|Thread: LBSC Petrolea|
It's mentioned indirectly on page 326 of Volume 92, No. 2291 under hydraulically testing the boiler and should be 80psi. Unfortunately I can't scan the page myself as I've just replaced the old PC that went bang at the weekend and my scanner won't work with the new one!
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.