Search found 195 matches

by andrew jukes
Sun Dec 14, 2014 8:21 pm
Forum: Tools and Techniques
Topic: Which Araldite?
Replies: 15
Views: 7039

Re: Which Araldite?

Thanks Martin. That's helpful. If I'm forced to buy the 2011 version, I hope the shelf-life is long as 200ml is going to last an age (and I hope it really is the same stuff as I'm used to using). Best I take my time and read the data sheets properly. I wonder how recently the retail product got chan...
by andrew jukes
Sun Dec 14, 2014 1:52 pm
Forum: Tools and Techniques
Topic: Which Araldite?
Replies: 15
Views: 7039

Re: Which Araldite?

Not sure where that gets me, Keith. Examples of the two types I'm concerned about are at: http://www.ebay.co.uk/itm/like/151293225435?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff...
by andrew jukes
Sun Dec 14, 2014 10:34 am
Forum: Tools and Techniques
Topic: Which Araldite?
Replies: 15
Views: 7039

Which Araldite?

Over the years, I have used Araldite - the proper stuff, not the rapid rubbish - for lots of modelling purposes, valuing its strength, slow setting (adjustable with temperature) and insulating properties. Recently, I ran out and have been trying to get the same product for future use. There seem now...
by andrew jukes
Thu Nov 27, 2014 10:24 pm
Forum: Vehicle dynamics and trackholding
Topic: Tractive Effort
Replies: 14
Views: 4548

Re: Tractive Effort

Something else that's a surprise. If you google coefficient of friction(µ) for steel on steel, you find results like this: Steel (mild) on Steel (mild) 0.74(static) 0.57(kinetic) This of course is for clean dry specimens in lab. conditions. But it is still astonishingly different from the 0.25 or 0....
by andrew jukes
Wed Nov 26, 2014 8:04 pm
Forum: Vehicle dynamics and trackholding
Topic: Tractive Effort
Replies: 14
Views: 4548

Re: Tractive Effort

It's a Pacific, with pitch totally controlled by the bogie and Cartazzi truck and with very soft springs on the driven axles, pre-loaded appropriately so over the required (small) deflection range the load on each axle remains effectively constant. No problem!

Andrew
by andrew jukes
Wed Nov 26, 2014 7:03 pm
Forum: Vehicle dynamics and trackholding
Topic: Tractive Effort
Replies: 14
Views: 4548

Re: Tractive Effort

OK. So Bill's quote from the LMS diagram book simply tells us that the Pacifics need a higher coefficient of friction (µ) than the others if they are to make full use of their potential tractive effort - at least 0.25 rather than between 0.20 and 0.25. That may be interesting but doesn't help in fig...
by andrew jukes
Wed Nov 26, 2014 10:19 am
Forum: Vehicle dynamics and trackholding
Topic: Tractive Effort
Replies: 14
Views: 4548

Re: Tractive Effort

Bill wrote:
My LMS loco diagram book gives an adhesive factor of between 4 and 5 for most of the locos. Only the pacifics are less than 4.

That's rather confusing.
Does it mean 'between 20 and 25% for most and only more than 25% for the Pacifics'?
Or have I completely misunderstood.

Andrew
by andrew jukes
Thu Nov 13, 2014 12:09 am
Forum: Vehicle dynamics and trackholding
Topic: Tractive Effort
Replies: 14
Views: 4548

Tractive Effort

Apologies if this has come up before, but I am curious as to what was achieved by locos in the Deputy Chairman's Cup and how it compares with the 30% factor of adhesion often used in assessing the tractive effort of full size locos. Finding the data was wonderfully easy. 'Search' on here pointed me ...
by andrew jukes
Fri Oct 31, 2014 12:37 pm
Forum: Layouts and Operations
Topic: Tor Giffard (TG) former LSWR routes of North Devon 1951-1971
Replies: 121
Views: 31876

Re: Tor Giffard (TG) former LSWR routes of North Devon 1951-

Dave wrote This afternoons conservatory session has involved joining together pairs of C&L thick plastic turnout timbers to suit the length requirements of the Templot diagram. A spot of superglue to the end of one sleeper whilst holding the two against a metal straight edge, on a glass surface ...
by andrew jukes
Wed Aug 20, 2014 12:11 am
Forum: Starting in P4
Topic: Trackwork options for newbie
Replies: 75
Views: 22905

Re: Trackwork options for newbie

Mark said: This is not to everyone's taste and just proves that there is more than one way of skinning the cat! The theory that people offer for not liking it is that there is a stress at the point of contact between the brass strip to the switchrail because it can not flex. This is why I use the br...
by andrew jukes
Tue Aug 12, 2014 11:13 am
Forum: Starting in P4
Topic: Trackwork options for newbie
Replies: 75
Views: 22905

Re: Trackwork options for newbie

Although I agree with all those who recommend building the first Ecactoscale kit 'as is' (and certainly endorse Allan's comments on making sure the switch area is if anything overgauge - I use a +0.2mm gauge there to be sure), curving these turnouts in a limited way is not difficult. The important t...
by andrew jukes
Thu Jun 26, 2014 10:05 am
Forum: Trains: Model and Prototype
Topic: Exacto wheels and Back to Back
Replies: 13
Views: 5228

Re: Exacto wheels and Back to Back

Having (as Exactoscale) sold these wheels at exhibitions without ever having used them myself, the methods I've adopted when assembling a whole train's worth of wheelsets may be of some interest. A few initial points: First, I believed the design of the mould forced the moulded centre section of the...
by andrew jukes
Thu Jun 19, 2014 9:52 am
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

Jon Price wrote: … all bets are off with regards to the bodges we have to apply to make things run properly. If we make accurate track then as far as I can tell the suspension requirement is infinitessimal (the real thing does not bounce up and down like a kangaroo). So either produce accurate track...
by andrew jukes
Tue Jun 17, 2014 9:28 am
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

Just a footnote on the Coronation + Deltic: Apart from three special 'track circuit detectable' bogies (which are still bare metal - another reason for not providing pictures), the coach and loco bogies are all rigid. The coaches originally had plain bearings (and Golden Age's now very nice P4 wheel...
by andrew jukes
Sun Jun 15, 2014 5:12 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

I've been cheating a bit. The train is at should be (four twins + observation car) but I have a Deltic on the front!

When I have Empire of India hauling the train (and someone here with a decent camera) I'll aim to post some pictures.

Regards

Andrew
by andrew jukes
Sun Jun 15, 2014 3:35 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

But, Martin, why go to all this trouble? Funnily enough, P4 wheels are designed to work with P4 track and P4 track is designed to work with P4 wheels. Derailments are largely about attention to detail and checking and measuring track and rolling stock when they occur so that each derailment source i...
by andrew jukes
Sun Jun 15, 2014 1:28 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

Russ said or a parallel-sided block (Exactoscale, although no longer made under the new C&L regime) I have discussed with Pete Llewellyn the possibility of having another batch of these made (probably without the big central cut-out for gearboxes to save cost). If you are using the gauge to asse...
by andrew jukes
Fri Jun 13, 2014 1:16 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

Martin said: [quote]"stock fitted with EM wheels widened to P4 - and it all works just as well" are true - I do, and it does.[/quote - but not using the recommended back-to-back setting of 17.75mm (and only using selected brands of EM wheels). You say you don't care greatly about these iss...
by andrew jukes
Fri Jun 13, 2014 10:38 am
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

In case anyone might be interested in the information that Andrew requested: Thank you Martin, that is helpful. I had suspected that a back-to-back of 17.67mm would be what you were using with your chosen EM wheels (I have a Studiolith gauge too - it measures 17.68mm using my micrometer). Effective...
by andrew jukes
Wed Jun 11, 2014 10:49 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

The frustrating thing about this oft-repeated discussion is that Martin keeps telling us about how EM wheels 'work' on P4 track without ever telling us properly either what the benefits might be or giving a complete framework of the standards he is working to (an equivalent to Digest 1.2). For examp...
by andrew jukes
Mon Jun 09, 2014 7:27 pm
Forum: Steam Locomotives
Topic: Wheel profiles
Replies: 113
Views: 26620

Re: Wheel profiles

I generally agree with the points made earlier by Keith and Philip, but would like to add some comments about the way the standards have evolved. If you are a P4 newbie, work to the P4 standards, preferably using a back-to-back gauge measuring 17.75mm. This dimension is at the upper end of the range...
by andrew jukes
Wed Apr 30, 2014 3:05 pm
Forum: Coaches and NPCS
Topic: Width of Gresley Bogies
Replies: 9
Views: 6320

Re: Width of Gresley Bogies

Interestingly, ten Golden Age wheelsets weigh 35gm, whilst ten Exactoscale wheelsets weigh just under 15gm. With 28 wheelsets in the train, I'm around 56gm better off already!

Just like the real thing, there can be a surprising amount of weight to be saved in wheelsets.

Andrew
by andrew jukes
Wed Apr 30, 2014 11:28 am
Forum: Coaches and NPCS
Topic: Width of Gresley Bogies
Replies: 9
Views: 6320

Re: Width of Gresley Bogies

Here is an amusing twist to this earlier concern of mine. The Coronation has been running on my layout, with no problems at all from the very nice Golden Age P4 wheelsets (train seen at Welwyn North in shot 4 on the C&L homepage). The appearance and finish of the train are excellent and the only...
by andrew jukes
Sun Apr 20, 2014 11:29 pm
Forum: Steam Locomotives
Topic: The Great 3F build off
Replies: 197
Views: 72096

Re: The Great 3F build off

This arrangement will react the torque - but because the reacting force is vertical it will produce a change in the loading of the driven axle. David Knight's arrangement in contrast, looks like a horizontal link, pivoted at both ends (one end is hard to see), so is likely to ensure the reacting for...
by andrew jukes
Sun Mar 16, 2014 9:38 am
Forum: Lathe Work
Topic: Sick Unimat
Replies: 28
Views: 12009

Re: Sick Unimat

Terry, not sure why you thought the suggestion was anything other than to mount the 24V DC motor in place of the existing one. As I recall (I haven't had to do this myself), most of the discussion was about how to mount the pulley on the new motor shaft and obviously how to bolt the motor to the exi...

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