Search found 75 matches

by Crepello
Wed Jun 14, 2017 12:40 pm
Forum: Trains: Model and Prototype
Topic: Thoughts on Motors
Replies: 74
Views: 18612

Re: Thoughts on Motors

I've nothing against bevels, but they do require very precise positioning on both axes. Yes. You can achieve anything from Portescap whirr to Hornby-Dublo Co-Bo whine. In applications where the motor is remote from the driven axle, driving via a shaft to a floating right-angle gearbox, the lack of ...
by Crepello
Thu May 25, 2017 9:09 pm
Forum: Layouts and Operations
Topic: Brettell Road
Replies: 535
Views: 109749

Re: Brettell Road

Didn't this start as a relaxing sideline to the Main Project? Seems to have turned into a textbook example of mission creep!
by Crepello
Sat May 20, 2017 10:09 pm
Forum: Steam Locomotives
Topic: Any Wheel and size!
Replies: 79
Views: 12028

Re: Any Wheel and size!

decauville1126 wrote:My son did some custom wheel centres for me which were printed using Shapeways FUD.

Without photos, that's just a tease!
by Crepello
Sat May 20, 2017 9:51 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

Will L wrote:So again, how is your equalising system going to address something like my O4 2-8-0?

Or indeed anyone's 9F. A good head start for Andy might be to acquire one of the Dave Bradwell chassis kits, and show us a photo of what he has to leave out, and what he needs to put in to obtain his improvements.
by Crepello
Wed Apr 26, 2017 10:06 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

proto87stores wrote:I would suggest that low force wire linear tensioning is not a contributing factor in sliding CSB suspension operation.

Why are you worrying so much about friction in the supports then??
by Crepello
Wed Apr 26, 2017 12:57 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

There's also the consideration that the friction generated in the changing of the suspended wire length only leads to changes of wire tension. These tensile forces (one each side of an axlebox) then need to be resolved into their vertical components to arrive at the contribution to axlebox load pert...
by Crepello
Tue Apr 18, 2017 4:20 pm
Forum: Control Concepts
Topic: Maximising Adhesion using Electronics
Replies: 21
Views: 4115

Re: Maximising Adhesion using Electronics

With multiple motors in a loco, possibly one per axle, it might be feasible to compare the voltage and current draw for each, and rein-in whichever is accelerating due to loss of adhesion.
by Crepello
Tue Apr 11, 2017 9:34 am
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

The 4 point body mounting would then instead be on the fulcrum centres of the additional upper side beams and the fulcrum centres of the two transverse beams. In that way the chassis also handles moderate twist, but still fully equalizes. To be as analytically thorough as you wish the springing con...
by Crepello
Wed Apr 05, 2017 8:30 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

But sprung suspension systems cannot produce equal weigh distribution in the dynamic phase - only when the system is static can that be so. Neither do rigid beams! When a beam rotates to a new equilibrium point, it must necessarily be due to unequal moments at its ends. No. If has has unequal loads...
by Crepello
Tue Apr 04, 2017 11:28 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

Alan Turner wrote:But sprung suspension systems cannot produce equal weigh distribution in the dynamic phase - only when the system is static can that be so.


Neither do rigid beams! When a beam rotates to a new equilibrium point, it must necessarily be due to unequal moments at its ends.
by Crepello
Fri Mar 03, 2017 8:01 pm
Forum: Road Vehicles and Figures
Topic: Ethnic diversity and other things
Replies: 11
Views: 3307

Re: Ethnic diversity and other things

I think I saw my first West Indian face taking a breather from shovelling as a quaint 'toy-town engine' passed me spotting near Marshmoor, ECML in the late 50's. I was young, but old enough to read "Return to Ashburton Grove" on the wagons. So that would probably have been a J6 on the Ashb...
by Crepello
Sun Feb 19, 2017 9:13 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 67603

Re: Flexi Chassis an Appreciation

Recently I dug out of one of my boxes the Scalefour Society Locomotive Springing Unit, a set of etchings together with a couple of pages of instructions. I never used it, because I didn't understand it, and because I was at the time firmly wedded to compensation, which I did understand. This was, I...
by Crepello
Fri Jan 13, 2017 4:15 pm
Forum: Coaches and NPCS
Topic: Reclaiming Damaged or Generally Unacceptable Coach Wheels
Replies: 30
Views: 6556

Re: Reclaiming Damaged or Generally Unacceptable Coach Wheels

That's a rather sad story. Exactoscale "doing a Rover" ?
by Crepello
Fri Jan 06, 2017 11:38 pm
Forum: Coaches and NPCS
Topic: Reclaiming Damaged or Generally Unacceptable Coach Wheels
Replies: 30
Views: 6556

Re: Reclaiming Damaged or Generally Unacceptable Coach Wheels

John Fitton wrote:I think I will have to do a financial accounting here and see what the loss would be by chucking the misfits.

Don't forget there could well be takers for the tyres alone!
by Crepello
Mon Sep 05, 2016 8:38 pm
Forum: Starting in P4
Topic: gearbox designs for sprung BO-BO or Co-Co bogies
Replies: 42
Views: 9729

Re: gearbox designs for sprung BO-BO or Co-Co bogies

If I were to do another project like this, I'd use a central motor with long driveshafts to transfer boxes on the outer ends of each bogie to minimise driveshaft articulation. You are homing in on a configuration described around 1975 in a P4 Society newsletter. The infuriating thing about 'doing i...
by Crepello
Fri Jul 15, 2016 4:07 pm
Forum: Guest Book
Topic: Britannia driving wheels from Ultrascale
Replies: 7
Views: 2831

Re: Britannia driving wheels from Ultrascale

I understand Ultrascale have been doing commissions for European diesel and electric conversions so probably using existing diesel wheels with gears to match the model a bit like their BR diesel conversions only these wholesalers are buying hundreds of them at a time to sell on to modellers. There ...
by Crepello
Tue Jun 07, 2016 3:23 pm
Forum: Where to Find?
Topic: 24mm's / 6' Wheels 20 Spoke with 12" Crankpin Throw
Replies: 27
Views: 4823

Re: 24mm's / 6' Wheels 20 Spoke with 12" Crankpin Throw

Now there seems to be a viable alternative for wheel centres, 3D printing, of more interest would be the durability of the material used and its resistance to the common lubricants we use. How stable is it and is there any chance over time of shrinkage? It's precisely from this that springs frustra...
by Crepello
Tue Jun 07, 2016 1:41 pm
Forum: Where to Find?
Topic: 24mm's / 6' Wheels 20 Spoke with 12" Crankpin Throw
Replies: 27
Views: 4823

Re: 24mm's / 6' Wheels 20 Spoke with 12" Crankpin Throw

It is a bit disappointing to have to rely on tyres supplied as a favour rather than being listed as a catalogue item. Doesn't reassure, that they might not be forthcoming for a subsequent project.
by Crepello
Wed Apr 27, 2016 2:07 pm
Forum: Layouts and Operations
Topic: Ouse Viaduct/Balcombe/Lewes project
Replies: 118
Views: 44676

Re: Ouse Viaduct/Balcombe/Lewes project

or "How We Out-Retfored Retford".
by Crepello
Thu Apr 14, 2016 12:45 pm
Forum: Guy Rixon
Topic: Coaches with wooden armatures
Replies: 29
Views: 5817

Re: Coaches with wooden armatures

Do you know any aeromodellers? I'm thinking in terms of either a heavyweight doped tissue, or one of the iron-on self adhesive films such as Solarfilm. This latter has a startup overhead, hence my nod towards finding a friend with the kit already.
by Crepello
Wed Mar 23, 2016 11:04 am
Forum: Coaches and NPCS
Topic: GWR E147 B set
Replies: 45
Views: 11696

Re: GWR E147 B set

If you look closely at the drawings in John Lewis' coach plan book you will find a consistency in the outlines of the Collet roofs which is not matched by the way the end elevations are dimensioned. This suggests to me that the DO had templates made to ensure that each of the GA drawing they drew h...
by Crepello
Tue Mar 22, 2016 9:44 pm
Forum: Coaches and NPCS
Topic: GWR E147 B set
Replies: 45
Views: 11696

Re: GWR E147 B set

The story I heard - from a very good source - is that the GWR GAs were sent to the workshop, and have only occasionally survived. Surely the super-organised GWR D.O. drew and traced their GAs on linen for durability, and simply used the reprographic technology of the time to produce such copies as ...
by Crepello
Fri Oct 23, 2015 7:20 pm
Forum: Wagons
Topic: 7 mm wheels for Realtracks FLA container flats
Replies: 14
Views: 3593

Re: 7 mm wheels for Realtracks FLA container flats

Tony, IMHO, Society policy for a long time has been to avoid competing with trade suppliers, Hi Keith, I can confirm that you are absolutely correct on this - it remains Society policy to not compete with products that are available elsewhere in the market. That is especially the case when manufact...
by Crepello
Mon Sep 21, 2015 7:35 pm
Forum: Exhibitions
Topic: Scaleforum 2015
Replies: 123
Views: 33689

Re: Scaleforum 2015

When it comes to totting up the attendances, it would have been +1 for Sunday, but for the fact I received a call bearing unwelcome news as I approached the outskirts of Aylesbury, and had to divert to other matters.
by Crepello
Fri Aug 28, 2015 10:30 am
Forum: On My Workbench
Topic: Manning Wardle wheels
Replies: 34
Views: 8267

Re: Manning Wardle wheels

If Alan Gibson can also supply tyres on their own then it does open up the opportunity of filling the gaps of wheels that are not available. I asked the requisite question at Railex. The answer seemed to be a grudging "Yes, but only if you mention this conversation." I guess the margins a...

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