Member postings for martin ranson 2

To Bob Worsley please, I am always fascinated by the question of the old world versus the new ... I am definitely back in the stone age for my small models ... and happy to stay there ... how model engineering is perceived by a newcomer to the hobby I am not sure ... at the moment M E magazine seems to be firmly locked onto a lot of huge heavy models and quite a lot of full-size equipment as well ... obviously the editor can only publish articles that he receives ... however, from the viewpoint of a total beginner I wonder how we all appear ... my opinion is that he or she will think that a huge well equipped workshop is essential before doing anything .. lathe, miller, shaper, planer, oxyacetylene, bending rolls, large stock of metal etc, etc ... the bigger the list, the more the cost, ... there is also the size of workshop necessary to house it all ... somehow I think a lot of people could be dissuaded from starting to try making anything because they do not possess the experience, the skill, the space, the contacts etc.

I would love to know how other modellers view my opinions ... surely a total beginner needs a simple, low cost model to start with ... something to complete with a limited amount of hardware.

martin

Hello Mark ... not sure where you are in East Yorks ? ? there is a model boat society in Bridlington ... there are 3 model engineering societies possibly near you ... Hull, York and Pickering ... they probably all have web sites ... the one at Pickering does crop up on the club news page in Model Engineer magazine ... there are also several small groups of people with garden railways, such as the 16 mm society ... someone in these groups might be able to help with problems.

martin

To all who replied to my question .... thank you ... my original reply to everyone arrived as "edit post" and now seems to have vanished from the forum ... never mind.

martin

Wow ... what a lot of information from so many people ... thank you everybody ... that should keep me busy for quite a while.

TO NIGEL GRAHAM 2 please ... how did you know I was trying to write a book ? one section I am stuck with unfortunately ... in the "jam butty mines" at Knotty Ash there was an 18 inch tramway system ... the entrance is secret and guarded by the "Diddy Men" ... I cant find any of them to arrange access ... without important facts like these the book would fail ... maybe I should stay in the garden and talk to the tame frog who lives on my railway track ... he keeps playing "chicken" as my locos are approaching him.

To Mick please ... as a PPS to the above ... if you do end up cutting it all apart you should be able to carefully re-use all the bushes so they are not scrap ... if you gently cut through the leaking tube and examine it under a magnifier you should be able to see where the silver solder has penetrated to ... is it only on the outside of the main tube ? does it penetrate right through to the inside ? is there a decent fillet on both sides of the joint ? could I ask how you made the holes for the cross tubes ? are they reamed ? drilled ? there are always a lot of ideas how to make the best joints ... my way has been in use for many years and came about following my early failures ...I drill the holes slightly undersize and gently file them out until the tube is a tight slide into place ... using a small triangle needle file make 3 tiny notches round the circumference ... by tiny I mean only a few thou. ... if it is properly fluxed you ought to get a double fillet of solder ... at least if you have to scrap the boiler it will be useful knowledge for the next one.

martin

This may sound odd, but it is for a new M. E. project ... can anyone think of any more well-known frogs to ad to this list ??

Kermit from the muppets

The frog king from shrek

Toad from wind in the willows

These things are important in the modern world ... we must be aware of literary giants like these ... I hope someone can add a few names please ?

To Mick please ... I hope you can fix the leak with some of the methods above ... I have had the same problem with SF 55 ... I do not think it flows as well as the old EF 2 ... I know this does not solve your problem, but when I produce a boiler with cross-tubes I use SF 24 as a first fix .... clean it all up and then go round everything again with SF 55 ... use LOTS and LOTS of FLUX for the SF 55 ... I now get through much more flux than with EF 2 ... yes the soldering looks heavy and messy but nobody sees it inside the boiler ... I agree with one of the replies above, I would scrap it and put it down to experience ... I have had to do this with one of my boilers ... nearly in tears, but I did not think it would seal itself ... do not forget that the cross tubes up at the boiler top may be partially out of water if the level gets a bit low ... this could ruin any sealant you use.

As a P.S ... when you silver solder the main tube into the boiler, try to stop the heat travelling down the tube ... I have several very scruffy "heat stoppers" made from copper sheet ... 1 mm or 1/16 thick ... imagine a 1 penny coin with a handle like a bent spoon ... different diameters for different tubes ... bend it over the side of the main tube end ... the more mucky and grubby the better ... less chance of gluing it in place with silver solder.

martin

To Neil please ... I will try to send another thank you for the information you sent ...my reply appeared on the screen as edit post ... it has now disappeared ... I was just checking to see if anyone else had answered ... I have just been to our local B and Q to buy some ... they do not list it any more ... thank you again for the information ... I will keep hunting.

martin

In the latest issue of Model Engineer, issue 4612, Martin Gearing is running a series concerning the ME vertical boiler ... he mentions the use of a thread sealant for use with propane gas ... please could Martin (or anyone else ) tell us the name of a suitable product ?? ... hopefully I can buy it at the local plumbers/builders merchants.

martin

HI PETE ... just a thought about your transmitter ... if it does not work very well with the Roundhouse valve, then are there any "rate switches" on the transmitter to adjust ? ... it might be called something else on your transmitter ... moving one of the 4 main sticks from one end to the other of its travel will move a servo by a certain amount ... instead of the old method of adjusting linkages, the amount of servo travel can be set electronically on various transmitters ... is there a switch, a potentiometer or a bit of electronic button pushing to set up, to match the required servo travel for each channel ? For the same amount of stick movement the servo will move less or more.

Looking at the superheater ... wow, that is a lot of surface area in the coil ... that will certainly warm up the steam flowing through it ... maybe more than you need ? Have you tried the assembly by using a spare piece of copper tube away from the boiler ? ( do not burn your fingers ) It may be worth double-checking that there is no tendency for the flame to head out backwards into the cab instead of up the smokebox and chimney ... the coil could be causing quit a lot of obstruction to the gas flow ... I would consider experimenting with smaller amounts of 1/8 tube inside the fire tube before I built everything into the cab ... however, if it does work it would certainly be more economical than my loco.

martin

HI PETE ... I am still not sure how you intend to drive the valve spindle ?? obviously a sail winch can do multiple turns, so are you intending to couple this directly to the valve spindle ?? It might not fit in the cab though ??

If you use a small size standard servo under the floor, surely it would be rather dodgy to try to make a simple linkage to swing the valve operating arm by 90 degrees each way of centre ?? However clever the transmitter is, it must end up shoving a servo arm in one direction or the other ??

I am surprised the Roundhouse valve is not suitable, there are thousands of these in use with radio control locos ... I assume you do not want to make your own valve ?

still confused ... martin

HI PETE ... the R/C valve you ask about ... it was covered in parts 1 and 2 ... page 355 explains the modifications ... photos 6 and 10 show the valve ... figure 12 is the drawing ... the valve I used was an old one with a coarse thread ... some types achieve full opening in a small amount of turning by having a very blunt cone on the valve spindle ... this is the opposite idea of a long slender needle valve.

If your servo turns by 180 degrees whose make is it please ? ... all mine turn by about 40 or 45 degrees either side of centre ... this gives a total movement of a bit less than 90 degrees ( a right angle ).

Some people use a long radius arm on the servo to drive a short radius arm on the valve. This needs care with assembly or else the valve arm can flip over centre !!

Some people cut their own coarse threads by using the lathe to produce the coarse pitch ... if you use commercial taps and dies then the most coarse one I know is 1/4 Whitworth, this is 1/4 x 20 thread ... if there is another type then perhaps someone will let me know ?? Something about 3/16 or 5mm would be useful ??

I have seen some people use 2 gears mounted on the valve body ... so 90 degrees movement on the servo drives the valve spindle by twice as much which is 180 degrees.

hope this helps.

martin

TO NEIL WYATT please ... your request about "shorts" ... is it intended for MEW or does it apply to the ME magazine as well please ?

martin

HI PETE ... as regards the superheater ... you obviously like experimenting ... go for it ... no guarantees though ... I assume you are putting a loop in the 1/8 pipe to take it back out more or less where it came in ... let me know how you get on ... I have occasionally thought about it, but never got round to it.

I do know some of the commercial makers feed a length of pipe all the way down the fire tube so it arrives in the smokebox and then down to the cylinders.

For any superheater just make sure there is no soft solder anywhere too close.

Please tell me how you get on.

martin

HI PETE ... looks like the loco is progressing O.K. ... if it needs about 1.5 bar, or 22 PSI, to spin over with the wheels clear of the floor, then possibly there may be a few tight spots to "ease" with a reamer or a file ... possibly the valves are not QUITE in the right place ... equal travel each end and correct timing can make a dramatic difference to performance ... how did you manage to get SWMBO to build a tender for you ?? when I mentioned this to my SWMBO she said something like "bleep bleep deleted" and marched off to her sewing room.

For the string could I suggest you find the nearest large shop with a haberdashery department ... the string I always use comes from there ... lots of colours and sizes ... the reel I have at the moment is WENDY SUPREME LUXURY COTTON DK, coloured white ... I assume DK means double knitting ... I smear the length of tubing with lots of 1 hour epoxy resin, and then I tie one end of the string into place with a single knot and start winding as neatly as possible ... tie off the other end with a single knot and wipe all the surplus resin off the exterior of the string ... leave to dry overnight ... give the exterior a light sanding to get rid of all the prickly bits.

Nearly forgot, use a pair of disposable gloves `cos it`s a bit messy on the fingers.

For the paint just use ordinary household emulsion ... mine is Dulux matt white ... put some in a small container like an eggcup and fill it about 3/4 ... add a bit of water to dilute slightly ... stir it in ... apply 2 or 3 coats ... again use some fine sandpaper to smooth off any remaining prickly bits ... I have used this method for over 30 years and it is very durable ... if it gets mucky simply repaint it.

martin

HI PETE ... nice to hear from you ... I am not too sure which 10 BA bit was too long ... I assume you mean the bell crank shown in figure 48 ... but you seem to have sorted it ... when you put the chassis on compressed air how much air pressure did it take to run slowly ? ... mine will run totally free on about 4 PSI and needs about 8 PSI on my home-made rolling road.

As regards the burner, all I can suggest is to check all the dimensions and check how much gas pressure is arriving at the jet ... figure 20 shows the gas restrictor ... it should be possible to slow the gas down with this restrictor ... too much pressure is a common cause of the flames lifting off the burner surface. A few months back we were talking about the I.D. of the fire tube in the boiler ... you used thick wall tubing if I remember correctly ?

If you are closing down the workshop for winter, that is a real shame ... is there no way of adding some insulation on the inside of the "shed" walls ? maybe polystyrene blocks faced with ply ? you must be very patient ... I could not wait 4 or 5 months to get back in there.

martin

TO JASON B please ... thanks for the hint, message received ... however I do prefer to only answer questions on the public forum ... for example Petes` question above, about lighting the gas flame ... I assume that may be of use to other people ... if I start using 2 places to answer questions then I get less time in the shed "metal-bashing" ... even if I get into trouble with SWMBO because I should be mowing the grass.

martin

HI PETE ... I am not sure about how to find private e-mails either ... I am not the worlds best at driving computers ... I much prefer to be in the "shed" cutting metal ... nothing has arrived to print out ... so do not worry about the test spec ... not yet anyway ... if it becomes the preferred method we will hear about it soon enough ... thank you for the offer though.

For the method of lighting the gas ... open the gas valve SLIGHTLY ... count up to 2 or 3 and apply a light at the chimney top ... there should be no need to open the smokebox door ... if people open the gas valve too much then everything fills up with gas and there is usually a very loud pop ... this is one of the reasons I always fit a pressure gauge on the gas supply to the jet ... it gives a clear indication of how much pressure is arriving at the jet for start - up ... once lit I usually keep the pressure down a bit because the tank is full to the eyebrows and occasionally it can spit liquid gas into the jet ... after a few minutes the flame can be set to your desired level ...usually this is a fairly high flame to warm everything up ASAP ... then turn it down again as needed for actual running ... keep an eye on the boiler pressure gauge ... I try to stop the safety valve from lifting because it wastes a lot of water.

martin

HI PETE ... just a thought about gas tanks ... in your message above dated 30th. Sept ... if someone wants to ban heat shunts, then what constitutes a heat shunt ?? surely the back end of the boiler gets hot and passes heat to the cab and also to the cab floor ?? if the cab floor passes heat into the gas tank, then is the floor considered as a heat shunt ?? this whole idea about heat shunts surprises me.

martin

HI PETE ... thanks for the information on gas tank testing ... if we must use ever higher pressures for testing then it is very easy to switch to "plan B" and simply put a central stay through the length of any future tanks.

The main cab is 1. 2 mm brass sheet ... I used ply for the roof to make it lighter and it was also easier to bend ... if you can bend the brass neatly to the correct curve then by all means use that ... this is all coming up in part 9 arriving very soon.

For the oil trap we have already mentioned this earlier... yes there is a drawing error ! ... 0. 25 would be better ... either move the hole or re-bend the 1/8 pipe ... keep annealing it so it bends easier.

The bit about NOT USING A HEAT SHUNT surprises me ... my main problem is always to keep the tank from going COLD ...I position tanks away from the boilers and use the shunt to supply a limited amount of heat into the tank .. this can only happen if the burner is lit ... it makes a very stable running system ... to remove any heat shunt might create a daft situation on start-up ... the boiler will be cold, the tank and everything else will GO COLDER ... so initial fire-up on a cold day could be very frustrating and take a LOT longer ??? Using boiling water for the boiler is not always practical.

HAVE I MIS-UNDERSTOOD WHAT THE RULES MEAN ?? please let me know ... if what you have been told and passed onto me is correct then any steam-up on a cold day could be a real pain.

Do you think you could get any information from the G1 group please ?? if they gave you this information then surely some of them could already be struggling ??

Maybe Roundhouse have found a magic way round this potential problem ??

For the clamping of the actual oil trap ... yes, it is held very nicely by the bits and pieces round it ... mine has survived a lot of running over several seasons.

martin