Search found 645 matches

by Julian Roberts
Wed Apr 24, 2019 7:03 am
Forum: Track and Turnouts
Topic: rail/wheel profile - prototype has problems too
Replies: 22
Views: 1056

Re: rail/wheel profile - prototype has problems too

As the train negotiated the curve, the first two right-hand wheels of the leading bogie of the class 37 locomotive climbed the outside rail of the curve and derailed to the outside of the curve. The third wheelset on the leading bogie stayed on the rails until the bogie reached the crossing of a se...
by Julian Roberts
Wed Apr 24, 2019 6:21 am
Forum: Guest Book
Topic: REF: Rail wheel profile and "to do" list update
Replies: 4
Views: 351

Re: REF: Rail wheel profile and "to do" list update

Thank you very much Andy.  Regarding your video that Will put on the related thread - how much did the vehicles weigh, do you know?  I did dip into your long discussion with Will and others regarding the competing merits of compensation and springing but couldn't find what I seem to recall reading s...
by Julian Roberts
Tue Apr 23, 2019 6:55 am
Forum: Track and Turnouts
Topic: rail/wheel profile - prototype has problems too
Replies: 22
Views: 1056

Re: rail/wheel profile - prototype has problems too

Bill pointed out that the weight of an empty 16 ton wagon was 7 to 8 tons. So just 16g for us. Experience of coal wagons at exhibitions where the 50g weight is mostly in the detachable coal load is that the empty wagons run considerably more unreliably. Keith corrected me. Our profile is not of the ...
by Julian Roberts
Mon Apr 22, 2019 5:21 pm
Forum: Guest Book
Topic: REF: Rail wheel profile and "to do" list update
Replies: 4
Views: 351

Re: REF: Rail wheel profile and "to do" list update

Andy regarding the discussion on weight in the related thread, do you have any views?

Have you already described elsewhere how you make the crossings of the street track in your photo?
by Julian Roberts
Sun Apr 21, 2019 5:26 pm
Forum: Track and Turnouts
Topic: rail/wheel profile - prototype has problems too
Replies: 22
Views: 1056

Re: rail/wheel profile - prototype has problems too

A few years ago, the American Passenger Transport Association were evaluating a proposal to adopt a different wheel profile for LRT trains, one with a greater flange-contact angle. The idea was to allow higher speeds on sharp curves. Makes me think that a less-prototypical profile might help our ov...
by Julian Roberts
Sun Apr 21, 2019 7:35 am
Forum: Track and Turnouts
Topic: rail/wheel profile - prototype has problems too
Replies: 22
Views: 1056

Re: rail/wheel profile - prototype has problems too

Network Rail standard NR/L2/TRK/2102 specifies a nominal track gauge of 1438 mm on curves with a radius of between 200 and 178 m. That's from the Ordsall Lane report which is much more thorough. So just 3mm widening is the first step below 200m radius, while at Doncaster it was 20mm wide. Guy, the ...
by Julian Roberts
Sat Apr 20, 2019 7:06 am
Forum: Track and Turnouts
Topic: rail/wheel profile - prototype has problems too
Replies: 22
Views: 1056

Re: rail/wheel profile - prototype has problems too

The bogies of the class 37 locomotive each have three wheelsets, which increases the overall wheelbase compared to a two-axle bogie, and this is likely to have adversely affected the ability of the bogie to corner. Yes....but.....they've been running since the 1950s! The question that occurred to m...
by Julian Roberts
Wed Apr 17, 2019 6:33 am
Forum: Layouts and Operations
Topic: Bristol Barrow Road
Replies: 56
Views: 6902

Re: Bristol Barrow Road

Thanks Robin and Phil. The Hornby mechanism is impressive! I've looked quickly right through the thread - fabulous :thumb ; I can't see anywhere what kind of controller you have, and whether it is something that gives enhanced slow speed control, or DCC for example. You mention you had 4-6-0 problem...
by Julian Roberts
Tue Apr 16, 2019 5:57 am
Forum: Layouts and Operations
Topic: Bristol Barrow Road
Replies: 56
Views: 6902

Re: Bristol Barrow Road

Robin - that is wonderful running at slow speed! Could I ask what motor and gear ratio you have there?
by Julian Roberts
Wed Apr 10, 2019 6:34 pm
Forum: Starting in P4
Topic: P4 wagon Compensation(springing)
Replies: 31
Views: 1585

Re: P4 wagon Compensation(springing)

There was quite a bit about the various bearings designs in an article by Russ in Snooze 186
by Julian Roberts
Tue Apr 09, 2019 3:59 pm
Forum: Exhibitions
Topic: 2019 S4 North
Replies: 33
Views: 4098

Re: 2019 S4 North

I must say I agree with Paul and Gavin, though I was lucky enough to see the hill in operation several times. As well as the reliability and believability of the operating (and I think all the layouts were commendable in these respects but this is all the more challenging where shunting of wagons is...
by Julian Roberts
Sun Apr 07, 2019 8:48 am
Forum: Layouts and Operations
Topic: Dorset 1937
Replies: 17
Views: 2806

Re: Dorset 1937

Neil I've just caught up with this amazing thread. Are those figures brush painted? This link is the only one I can find on a Google search that refers to Mike Walshaw's 00 layout "Westport". It is based on Swanage and he now lives there. He has written extensively about it in various maga...
by Julian Roberts
Sat Apr 06, 2019 8:29 am
Forum: Starting in P4
Topic: P4 wagon Compensation(springing)
Replies: 31
Views: 1585

Re: P4 wagon Compensation(springing)

Hi Beakie One of the issues I've had is buffer height. I made models before I had the pukka height gauge. They are slightly low. 20190406_060529.jpg But they are the same as some rewheeled RTR vehicles. 20190406_060340.jpg In fact there's the same inconsistency between these two RTR vehicles. 201904...
by Julian Roberts
Fri Apr 05, 2019 5:57 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

20190405_171825-1.jpg I'm pleased to say the screw-on return cranks that incorporate a bush for all the rods have proved their worth (in terms of the time and effort to make them) and, with nail varnish applied as a glue for the last two or three turns, are staying screwed down and in position thro...
by Julian Roberts
Thu Apr 04, 2019 12:31 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Having disassembled the chassis I ascertained the middle wheel crankpins were not going to be removed without ruining them. So I got on with making my own equivalent of the Ultrascale recessed crankpin as previously described. Otherwise the chassis is ready to paint. The gears are now 1:120 and I ha...
by Julian Roberts
Thu Apr 04, 2019 9:00 am
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

.... does anyone else find that the loose fit of the crankpin bush on a AGW (or even Sharman Wheels if you still have any) can cause a problem. Loco "chassis" that will can be propelled or run smoothly when the crankpin nuts are loose sometimes develop a tight spot when the nuts are tight...
by Julian Roberts
Mon Apr 01, 2019 8:58 am
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Hi Allan! The Crab chassis is being painted but I hope to be able to arrange a test on Grayrigg before long with you. What I mean about modelling weight is the way a train stops and starts. It's got to be able to go slowly to before there is even a possibility it can start and stop realistically. DC...
by Julian Roberts
Wed Mar 27, 2019 9:36 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Jim thanks. I'll report on any progress. Dave thanks for your suggestion but I hope you wont mind if I hopefully politely disagree as I did with Allan last page. I've made plenty of locos now that prove noise is no issue. They are all either 80:1 or 108:1. The layouts they are for have a maximum rea...
by Julian Roberts
Tue Mar 26, 2019 4:24 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

( I edited and extended my previous post) Disassembled, the chassis gives me cylinders more easily worked on to do the drain cocks. Thanks again to Dave for the idea of the Brassmasters detailing kit, I read the online instructions which say Scottish engines had shrouds around the valves, and that m...
by Julian Roberts
Sun Mar 24, 2019 8:20 am
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Dave B thank you!...I've only myself to blame for many of the issues I'm writing up here (as a blog of one step up two steps down which is the case with all the locos I've made). I've "freelanced" so much it is a long time since I looked at the instructions! Certainly there's nothing about...
by Julian Roberts
Sat Mar 23, 2019 9:17 am
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Aha Dave, at last the answer to my opening post question 18 months ago, thanks to you! I'm glad it's not only this musician who can't read a GA drawing (and that even professionals can make mistakes). Any more than the average person who likes listening to music will be much enlightened looking at a...
by Julian Roberts
Fri Mar 22, 2019 3:27 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

No problem DaveB! On with the job, with a couple of hours to get on. The LHS gear was shown working about a year ago but I've had trouble on reassembly. Now I seem to have found the return crank can be secure if it is wound on two full turns so the long bush has been shortened so that the crank tigh...
by Julian Roberts
Thu Mar 21, 2019 8:12 am
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

Thanks DaveB - but are Exactoscale tapped 1M? No information available on their current website. By the way I didn't answer - the Bachmann fallplate does its job getting in the way in a devilish manner if I couple the tender and loco not quite correctly. But done correctly it is fine. And regarding ...
by Julian Roberts
Wed Mar 20, 2019 6:59 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 253
Views: 27933

Re: Crab Comet conversion

. A threaded, concentric, bush which fits on the pin accurately would seem to be the answer. . (ReGibson bushes) If the long bush was available threaded it would give a better return crank fixing too. My thoughts have idled over the practicality (or otherwise....?!) of finding suitable brass tube, ...
by Julian Roberts
Wed Mar 20, 2019 4:54 pm
Forum: Steam Locomotives
Topic: Some North Eastern & LNER Locomotive Builds
Replies: 151
Views: 13765

Re: Some North Eastern & LNER Locomotive Builds

Phil O wrote:Very evocative photos, with the sunlight streaming in.

Phil.


And writing, too!!

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