Member postings for julian atkins

I think the answer is in the question ie 'worn'

They would almost certainly be 10BA at 62 though. Also it is not at all uncommon for BA screws to be rather under the specified OD.

Cheers,

Julian

Edited By julian atkins on 23/09/2016 10:32:51

Good try John, but there is no way the Southampton Club would encourage anyone like Ben (or anyone else) to build a Tich, as Duncan also commented upon.

You must be the only person to be happy with the performance of a Tich.

I am quite sure Ben has the necessary skills to build a 5"g loco. I started my first when 16, with, unlike Ben, no engineering background whatsoever.

Cheers,

Julian

Yes, well done Ron!

(I should perhaps add that Ron hasnt received and fitted the batch of commercial inline check valves I sorted out last weekend for him due to a delay in the post).

Cheers,

Julian

Hi Ben,

If you were asking about 5"g, Doug Hewson used to sell complete kits for wagons but they werent cheap.

Not aware of any kits for 3.5"g.

Learning how to use a petrol strimmer and offering to help out at the club might be thought more worthwhile and beneficial to your club than making 3.5"g rolling stock by most members.

Hope you enjoyed running the 3.5"g Brit. Cant see why you shouldnt run it pulling 8 or so punters on public running days.

I will send you a PM on the 'other' forum.

Cheers,

Julian

Edited By julian atkins on 21/09/2016 23:55:12

Use ME threads 3/16" x 40 tpi as long as the copper is thick enough.

I have a spare set if you want to borow them.

Cheers,

Julian

Incidentally, Ron was apparently quoted £200 by one guy to sort out these check valves. I do these sort of jobs free to help out fellow miniature loco builders, and do the same for problem injectors.

It annoys me when guys like Ron buy stuff in good faith from reputable model engineering suppliers and the stuff turns out to be faulty.

Cheers,

Julian

I dont think it would be fair to disclose too many gripes, but of the 4 commercial check valves Ron sent me all 4 leaked.

I've made countless check valves over the years. I dont think there is any magic in making them seal perfectly, just good engineering and machining practice.

Ron's commercial inline valves were 3 of 1/4 ball, and 1 of 3/16" ball he sent me.

The seats of the 1/4 ball type were badly made with the hole not reamed plus a chamfer on the seat. I took a whisker off each seat in the lathe, then reamed the holes. I used a hardened steel ball bearing to biff the seats with a proper drift then the stainless balls were replaced with precision ceramic balls. I also altered the other end which was a straight slot to 2 slots at 90 degrees and altered the lift which was rather constipated. All burrs were removed which wasnt the case originally. 2 or 3 of the originals had machining swarf that would easily have caused the balls not to seat, and another had thread sealent that was generously applied gumming up the works.

All 4 tested on my compressor and sealed perfectly.

I've seen some horrors over the years of commercial fittings particularly injectors. These were not badly made, just badly finished.

They are back in the post to Ron tomorrow hopefully.

Cheers,

Julian

K N Harris never made any miniature loco boilers, or a miniature loco, something LBSC frequently jibbed at him with arguably good reason given the jibbing back!

Mike Palmer 1 must be in error in his research.

K N Harris got (in retrospect) somewhat surprising medals for his small stationary engines in ME exhibitions circa after WW2. You will have to look at the details why I say surprising.

However he had a time served engineering background with a decent steam engineering company of stationary and I think marine business. He never had any experience workwise of loco work.

He was a most clubbable personality of great wit and skill, and at people management. He was a loud personality in presence and appearance, with a 'loud' checked suit usually and equally loud tie.

He got the best of Jim Ewins in a famous club meeting of the SMLS in the early 1970s which is still recounted.

However, this is all completely 'off topic' for which I apologise.

Cheers,

Jlian

Hi Duncan,

A most interesting discussion.

The pure drawbar pull is not a factor of just the weight pulled (number of passengers plus weight of passenger trolleys, and the dynamometer car - which is really quite heavy and I reckon equal to carrying 1 or 2 extra passengers). The number of passengers, as has been commented previously, is really a red herring.

A canny driver will request the numbers of passenger trolleys and the number of passengers on each, and whether adults, children, and perhaps no 'large' adults.

The driver is not allowed to touch the brake unless in an emergency for obvious reasons. If he is going too fast, the Observer watching the dynometer readings will warn the driver. If the driver ignores, then disqualification can result.

I have mentioned previously that the best way to get a decent near constant drawbar pull is to pull on the uphill gradients slowly, and then keep pulling down the downhill sections. This also optimises the steaming rate as a constant, and is line with Sam Ell's work at Swindon, and also the best bit of advice re IMLEC that came from Laurie Lawrence.

So many factors affect drawbar pull - as others have mentioned. Drag on curves, quality of the passenger trolleys, behaviour of the passengers etc. A heavily loaded passenger trolley may cause the bogies not to swivel easily on curves creating a great deal of extra friction.

One has to take a view on grate size. A larger grate requires more coal used to get it into a fit state ready for the run. More coal left on the large grate at the end of the run therefore cancels this out. The 30 minute run should be sufficiently long for the coal consumption figures to be reasonably accurate. There is a proviso to this - most drivers will run the fire down very low on the last two laps. This requires a great deal of confidence and skill to avoid a disaster on the last laps.

There are lots of examples of the same design of loco producing wildly differing results in the hands of different drivers.

Cheers,

Julian

Hi John,

Like Bob Youldon I have a considerable amount of old asbestos impregnated graphite yarn. The square braided stuff of asbestos type crops up on ebay from time to time though is banned from supply these days by the UK ME suppliers.

I have tried the new stuff supplied. Quickly consigned to the bin as useless.

Rather than twirl up PTFE tape (which can easily get eaten up and cause all manner of problems) turn up PTFE bushes or split bushes.

You can soak hemp in tallow but tallow doesnt like gunmetal or brass. Far better to try and buy the proper stuff or accept Bob's very generous and kind offer. There is a bit of a trick to fitting it in miniature of which perhaps more anon.

Cheers,

Julian

Hi Derek,

You are doing a fine job.

If you intend to fit a proper boiler and run the loco with a driver and a passenger (or two) behind, then you will be on a raised track so no problems with the wheelsets.

If on the other hand you intend to run it on a scenic railway with turnouts/points, then the wheelset dimensions will be very critical.

If however your proposed scenic railway has no turnouts/points then dont worry.

Cheers,

Julian

Hi Howard,

You ought to make a very good miniature example from the Reeves drawings. I am more familair with the 5"g design, but have seen some excellent LBSC 3.5"g examples running and pulling a decent load.

When you come to the boiler if you are making it yourself give me a shout as a few potential problems as per LBSC's Britannia boiler in 3.5"g. If you are thinking of a commercial job for the boiler then no need to worry.

Cheers,

Julian

Hi Duncan,

I wouldnt anaylse these things too much based on one year's results.

There have been all sorts of surprising results since 1969. Very quickly the water consumption figure was dropped from the equation. Some years have been blighted by bad coal, and some years by greasy wet rails. Some years certain passenger trolleys were defective and kept derailing.

Large tender locos do very well overall. It does not take much on the driver's part to rest his arm on the tender inadvertantly and perhaps push the tender forwards so causing a complete misreading on the drawbar in the loco's favour. The late Phil Hains got disqualified from IMLEC for this in 1970 or 1971 with his 5"g LBSCR E1 tank loco where his edging on the drawbar was more noticeable than on a tender loco.

Certain individuals have regularly won. Percy Woods with bog standard LBSC locos, Bill Perrett with his much improved Speedy, and Lionel Flippance, Alan Crossfield and John Heslop to name but a few. Others whom I knew and might have been expected to do well with excellent locos came well down the list regularly.

I remember quite a bit of correspondence years ago that the dynomometer cars (in those days the Bristol and Birmingham cars) produced way off results for certain heavy loads, but I stand to be corrected on this.

The formula used for IMLEC is not exactly fool proof. The maths is beyond my abilities, but there are certain problems in the formula. This has (to the best of my knowledge) been acknowledged for many years. The canny drivers take advantage of this. The rest of us who have taken part are so scared stiff and stressed that just completing the 30 minutes is enough!

Cheers,

Julian

I can categorically confirm that the shank size is often smaller than the twist bit OD. Not by more than a thou or two.

I regularly use drill shanks for certain precision purposes, and they often mike up smaller than the other end.

PS most of my stuff is Dormer.

Cheers,

Julian

Thank you John and Bazyle.

You have both confirmed my memory, even if my short term memory cant remember a drill from a mill!

Cheers,

Julian

Hi Tim,

Unless I am mistaken, 'Alpine' was the branding of the products sold by Graham Engineering at the time Mike bought his mill.

Cheers,

Julian

Hi David,

Before you make the rebate in the pistons for the packing, see what you can obtain first and how it compresses. The depth and width of the groove means nothing unless you know the packing. Old fashioned asbestos graphite square braided packing still crops up on ebay.

There is a trick to compressing this packing and sizing the groove which seems to be a lost art these days. If you get it wrong the packing is either ineffective or far too tight.

The specific sizes mentioned on the drawing would have been for a particular standard supply from ME suppliers many years ago. None of that is allowed to be marketed these days and will be of quite different (and IMHO) inferior type. But ebay is your answer.

Cheers,

Julian

Hi Mike,

When you get to the cylinders and valve gear give me a shout as I have some improvements.

It is a lovely loco. The valves between the cylinders is a bit of a challenge, but one of Martin Evans' rather good designs from his early period. The boiler is an excellent design.

Cheers,

Julian

Hi Mike,

Graham Engineering of Aston Road Birmingham...just off Spaghetti junction...

I am pretty sure they went out of business many years ago.

My first engineering stuff bought was from them in 1983. The 3 files have long ceased to cut, but the engineers square and hacksaw frame, and bench vice are still in daily use.

Hope you get the mill sorted.

Cheers,

Julian

Hi Greg,

Your queries are very specific to the Australian Boiler Code.

I suggest you show the Jubilee drawings to your club boiler inspector and follow whatever advice he provides.

If it were me, I would use 2.5mm for the outer wrapper and inner wrapper to the firebox. I would use a much closer stay pitch than the Aussie code, which will of course necessitate quite a few more stays.

I really need to dig out the drawings for the boiler then PM you. I would probably re-arrange the tube layout, and set the smokebox tubeplate further back, and would definitely fit silver solvered phos bronze bushes for all fittings and attachments

It is quite an early Martin Evans design.

I am surprised you havent posted same on the modeleng.proboards.com forum.

Cheers,

Julian

Edited By julian atkins on 06/09/2016 22:36:17