Search found 735 matches

by Julian Roberts
Mon May 20, 2019 9:52 am
Forum: Track and Turnouts
Topic: Joggled Stockrails
Replies: 65
Views: 6454

Re: Joggled Stockrails

Hi Martin and Philip Yes the reliability aspect appeals to me too. I can't recall where he wrote it on this Forum but Russ Elliott talks somewhere of "the wisdom of the joggle". But my reason for starting this thread was to understand exactly what the stockrails do as I was unclear on seve...
by Julian Roberts
Sun May 19, 2019 3:47 pm
Forum: Track and Turnouts
Topic: Joggled Stockrails
Replies: 65
Views: 6454

Re: Joggled Stockrails

Hi Phil and Martin Thanks, that's good to know I've understood correctly. I don't like to imagine these types of issues being disagreed about at 12" to the foot. It is actually very tricky to get right in a model, especially the very slight bend needed at C. Yes it seems to me that any advantag...
by Julian Roberts
Sun May 19, 2019 10:05 am
Forum: Track and Turnouts
Topic: Joggled Stockrails
Replies: 65
Views: 6454

Joggled Stockrails

I am trying to properly understand something that is, I think, taken as something perfectly simple by most of us. What exactly happens with joggled stock rails? This follows discussions on two other threads https://www.scalefour.org/forum/viewtopic.php?f=5&t=6257 https://www.scalefour.org/forum/...
by Julian Roberts
Sat May 18, 2019 3:43 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 290
Views: 41661

Re: Crab Comet conversion

This is to (somewhat belatedly) acknowledge the mention in the Snooze from Will. My main reason for doing this thread was because I became known for the thread on gauge widening, where it was justifiably said "Why don't you do some modelling". This was to correct the impression that I neve...
by Julian Roberts
Tue May 14, 2019 6:30 am
Forum: Steam Locomotives
Topic: Ivatt Class 2 2-6-2 tank
Replies: 18
Views: 2115

Re: Ivatt Class 2 2-6-2 tank

Thanks Dave. I've looked up the Brassmasters Ivatt truck instructions - they give this link which I think illustrates your description above

http://www.clag.org.uk/comet-pony.html

If required I suppose the spring force can be adjusted by varying the wire thickness and/or number of coils?
by Julian Roberts
Mon May 13, 2019 7:03 pm
Forum: Steam Locomotives
Topic: Ivatt Class 2 2-6-2 tank
Replies: 18
Views: 2115

Re: Ivatt Class 2 2-6-2 tank

Fantastic, Dave. Thank you for putting all this here. One aspect I'd be interested to understand better. The trucks are sprung using hair-pin wire springs and the top plate bears against the pintles mounted under the frames (mentioned above). I think I can see these springs. But on the Crab thread y...
by Julian Roberts
Mon May 13, 2019 5:33 pm
Forum: Chassis and Suspensions
Topic: Chassis Speed Building - Records and Methods
Replies: 17
Views: 1462

Re: Chassis Speed Building - Records and Methods

Sounds like you are taking the fun out of it if I'm honest Jim Knuckles - Jim said that on the related thread in answer to Andy's similar ideas of speedy but accurate chassis build kits, and 5 minute crossing assembly. At first I agreed but then thought how my ideas of what I might achieve in my li...
by Julian Roberts
Fri May 10, 2019 10:14 am
Forum: Track and Turnouts
Topic: Turnout construction - Question here please.
Replies: 123
Views: 19986

Re: Turnout construction - Question here please. Temporarily diverted into joggled turnout switches.

Hi Martin and Howard Just a brief clarification. I hate the look of overscale joggled points and haven't made any before. I've made undercut "proper" (as I would affirm) turnouts successfully. Yes using fine sandpaper though not I confess with a swiped butterknife. (My chaotic household of...
by Julian Roberts
Tue May 07, 2019 7:15 am
Forum: Track and Turnouts
Topic: Turnout construction - Question here please.
Replies: 123
Views: 19986

Re: Turnout construction - Question here please.

For REA switches the joggle depth is 3/8" (0.375 inches) and the joggle return length is 6 inches. For older pattern straight loose-heel switches these dimensions vary, but are usually similar. For GWR old-pattern switches the joggle depth is 3/8" (0.375 inches) and the joggle return leng...
by Julian Roberts
Mon May 06, 2019 9:41 pm
Forum: Track and Turnouts
Topic: Turnout construction - Question here please.
Replies: 123
Views: 19986

Re: Turnout construction - Question here please.

Thanks Martin for your rapid reply. I have managed to lose my response. Just briefly, you have a description of how to make undercut semi curved switches at https://www.scalefour.org/forum/viewtopic.php?f=5&t=4408&start=25Inbox (In broad terms it's similar to Tony's description on the relate...
by Julian Roberts
Mon May 06, 2019 6:48 am
Forum: Track and Turnouts
Topic: Turnout construction - Question here please.
Replies: 123
Views: 19986

Re: Turnout construction - Question here please.

I have copied this useful additional infornation from https://www.scalefour.org/forum/posting.php?mode=quote&f=5&p=66129 to try to keep questions on this thread. If it helps to understand what's happening in a joggle, I have added a red line to the diagram: http://85a.co.uk/forum/gallery/2/2...
by Julian Roberts
Sun May 05, 2019 8:02 pm
Forum: Steam Locomotives
Topic: Ivatt Class 2 2-6-2 tank
Replies: 18
Views: 2115

Re: Ivatt Class 2 2-6-2 tank

OCD or not, and aren't we all in that boat in varying degrees? - it is very useful that you've commissioned those injector details Dave. The problem seems to me, if I am making kit x, how can I know that somewhere there may already be obtainable(through the good offices of someone like yourself) jus...
by Julian Roberts
Fri May 03, 2019 11:46 am
Forum: Exhibitions
Topic: 2019 S4 North
Replies: 37
Views: 6326

Re: 2019 S4 North

Many thanks for your help, Jim and James. :thumb
by Julian Roberts
Tue Apr 30, 2019 10:19 am
Forum: Exhibitions
Topic: 2019 S4 North
Replies: 37
Views: 6326

Re: 2019 S4 North

The organizers of the show did a terrific job. I'm sorry to bore them, I'm wondering who to contact to see if I could have left a pair of glasses in a black case left anywhere at the show on the Sunday. Unlikely to be around after all this time, obviously.
by Julian Roberts
Sun Apr 28, 2019 8:20 pm
Forum: Steam Locomotives
Topic: Crab Comet conversion
Replies: 290
Views: 41661

Re: Crab Comet conversion

Hi Allan thank you for getting back to me. I'm really sorry to hear of the damage to Grayrigg. Especially when you're wanting to concentrate on your new layout. Anyway the Crab performed its first goods test services very satisfactorily on Kettlewell and was passed for running there. I was pleased t...
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: 2328

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: 25
Views: 2413

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: 2328

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: 25
Views: 2413

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: 2328

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: 2328

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: 2328

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: 109
Views: 12428

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: 109
Views: 12428

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: 2973

Re: P4 wagon Compensation(springing)

There was quite a bit about the various bearings designs in an article by Russ in Snooze 186

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