Nick Dunhill's Workshop - Royal Scot from a JLTRT kit

[Hobbyhorse]

To be fair, it's probably not the wheels or the concept, it's the machinist or the Loctite they used has failed. I use Loctite 603 which seems to have more grip.

For the clarity, of the two sets that haven't slipped, one came from Mr Dowling of this parish the other was unknown and in the kit box.

I’ve had similar problems as well, but only with wheels machined not by Alan Harris or my self.
Alans and mine are all assembled without any adhesives with the correct reamed fits on axles to castings.
I’ve used and machined them since the ninety’s and haven’t had any problems and have enough castings for future projects. The problems I’ve found on unknown machinist wheels are poorly fitting axles to castings and rusted telescopic axles. One tip is to degrease the telescopic axles and add a tiny amount of copper grease, which doesn’t degrade and has worked for me. These are my first choice of wheel, which are all double insulated and if machined correctly and looked after provide a good set of wheels. My latest build on here Three Green Boxes gives a good rundown of them.

Simon

 

[mickoo]

I suspect some are not tapering the axle and insulated bush, not a problem for carrying wheels, but essential for drivers if you don't want them to shift.

Even with perfect machined wheels, they're still a big time soak for commercial builders, almost invariably you need to make removable brake gear and the taper pin will almost never line up with the gear box final gear, resulting in drilling a new hole and moving it, and, it'll never line up with inside motion, so more faffing around there with new pin locations and drilling.

Cosmetically they're not a lot different from Slaters wheels once painted, the axle screw is the biggest give away and that can be depressed/covered and made to look like a solid axle in far less time than all the above work load.

I can concede a bonus for the likes of Mark Woods wheels with profiled spokes front and rear, you could argue that you cannot see the rear anyway (easily); but flat backed AGH I personally struggle to justify the cost and work load.

On the other hand, I wouldn't try to dissuade those that like/prefer them, each to their own.

 

[Nick Dunhill]

It's done and at the painters.

I had to make a little folding tool to make the lower curve in the smoke deflector. The etching needs to be supported to stop it billowing out where the lower hand hold is.





I decided a belt and braces approach and insulated the whole loco chassis from the body, and did similar with the tender. I added pick ups to the insulated wheels, in an attempt to keep the electrons under control. Painting will help. I test ran the loco and all was fine, Its an analogue loco, so no decoder to hide.

I was in the process of stripping the loco and giving it a final wash when a couple of things happened.

Firstly Warren rang to point out that there were no balance weights on the wheels. None in the etches either I discovered. Turns out that Scots were rough riders, and the balance weights were constantly modified to try and reduce this. Luckily I had pics of this loco, in the era required, from both sides. The balance weights had extra plates, roughly welded on (looks like my MIG welding in the photos!) and filled with lead. I made some, it took a couple of hours.



Secondly, the postie delivered some nameplates from Diane Carney. She'd etched me some mounting plates for the nameplate and crest as well, and I attached them to the front splasher.

Here it is, in pieces, ready to be packed and taken to the painters. There's a lot of components!



I think it was a really good, and highly detailled kit, let down by the lack of component ID in the sketchy instructions. More after painting.

 

[Nick Dunhill]

So I spent the majority of this week reassembling the Scot. Unfortunately I can only give you a sneaky-peak as the felt-pen operative put the painted roof of the loco in another box of my bits, so I can't fit it until next week.

 

[timbowales]

Drool.........

 

[Ian@StEnochs]

I never saw a Scot that clean & shiney!

 

[john lewsey]

Your models really are an inspiration Nick.
John

 

[Fitzroy]

The model looks absolutely fantastic Nick.

Mikoo, Re Loctite on AGH wheels, am I right in assuming its being used to hold a tufnol insulating ring? Because if it is, it will likely ultimately fail. Loctite is really only meant for metal to metal bonds. It would be better to use a smear of araldite I think.

 

[Nick Dunhill]

The quartering (well 120°) on all 3 drivers of this loco didn't match. It was a big problem, as 120° crank locos are much more sensitive to inaccuracies. I had to reset them by breaking the bond between the (stub) axle and tufnol bush.

I would have much preferred the drivers to be supplied without the telescopic axle/tapered pin set up. I much prefer a tapered axle/interference fit, and like to quarter by eye, lining up spokes. You have to set end float and fit bearings first. It's much easier than you imagine.

As I said earlier in this thread, in my experience the tufnol bush often fails, and quartering is lost. IMHO rim insulating is much better, no tufnol to fail, and electrons kept away from the chassis.

Retainers (mine is Loctite 603) don't work on tufnol bushes. Retainers work by expanding and tightening an interference fit. Tufnol is plastic so will deform/fail. I use a good quality superglue on tufnol.

Make sure there are no tight spots (rod and axlebox centres MUST match exactly, and quartering spot on) or the tufnol/axle bond will fail even more quickly.

 

[Nick Dunhill]

Paint by Warren Haywood