Search found 82 matches

by Crepello
Sat Jun 02, 2018 11:50 am
Forum: Product Information
Topic: Ultrascale Updates
Replies: 55
Views: 11687

Re: Ultrascale now closed to new orders

more recently I've seen some directly printed steel wheels of superb quality for 2mm scale (metal printing at iMaterialise.com). So, I wonder what the quality and longevity of an injection mould produced this way might be? Could be fine for the cosmetic variations in driving wheels, which I would h...
by Crepello
Mon May 28, 2018 12:07 pm
Forum: Product Information
Topic: Ultrascale Updates
Replies: 55
Views: 11687

Re: Ultrascale now closed to new orders

I haven't noticed any speculation, unhelpful or otherwise, so far in this thread!
But concern about our continued ability to pursue our chosen activities is understandable, particularly as supply from other sources has become problematic.
by Crepello
Mon Jan 22, 2018 12:35 pm
Forum: Guest Book
Topic: Flexi Chassis an Appreciation
Replies: 467
Views: 79606

Re: Flexi Chassis an Appreciation

Yes. This repeats a query I posed a while ago: how can 4 non-co-planar wheel contact points be translated into 4 co-planar beam pivot points, merely by taking the mean of adjacent wheel contact points?
by Crepello
Mon Jan 08, 2018 10:15 pm
Forum: Track and Turnouts
Topic: Securing supplies of track components
Replies: 31
Views: 7111

Re: Securing supplies of track components

I suspect the Exactoscale working screw couplings relied on Malcolm Cross's contacts in Switzerland. But I share your disquiet about the future of the range above railhead height. Some outlook statement would be appreciated.
by Crepello
Sun Jan 07, 2018 3:24 pm
Forum: Trains: Model and Prototype
Topic: What back to back setting do you use?
Replies: 195
Views: 42830

Re: What back to back setting do you use?

To end on an interesting note, a distant (geographically) friend who had always modelled in OO but recently built several locos that run on "London Road", has just announced he has built a loco with Markits wheels and Markits P4 axles, that runs perfectly on a S4 (not P4) layout at anothe...
by Crepello
Mon Nov 13, 2017 2:20 pm
Forum: Exhibitions
Topic: Railex 2017
Replies: 26
Views: 6372

Re: Railex 2017

I understood that on the Little Bytham portion of the main line the large pacific expresses regularly hit 80mph (and greater) and I think that this capability is one of the governing criteria for his model. Isn't this the portion of line where Mallard achieved the record? To achieve this it is a ne...
by Crepello
Wed Oct 25, 2017 7:16 pm
Forum: Tools and Techniques
Topic: Slow TV
Replies: 9
Views: 2808

Slow TV

The BBC4 'Slow TV' strand at this instant has a chap handcrafting a WIndsor chair in his shed. "Complex and time-consuming" they say.
As this could equally apply to, say, an etched kit, or a track formation, what would it take to get some of our work featured I wonder?
by Crepello
Wed Jun 14, 2017 12:40 pm
Forum: Trains: Model and Prototype
Topic: Thoughts on Motors
Replies: 74
Views: 21696

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: jim s-w
Topic: Brettell Road
Replies: 574
Views: 134678

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: 15267

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: 79606

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: 79606

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: 79606

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: 4850

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: 79606

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: 79606

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: 79606

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: 3865

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: 79606

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: 7757

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: 7757

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: 11391

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: 3176

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: 5662

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: 5662

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.

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