Scalefour Forum

I could well award that an ok, Julian. Your shim washer saves it by spreading the force from the small diameter end of the tightened flangeless crankpin over a larger area so that it doesn't slowly sink into the plastic wheel boss with time and let the return crank loosen. A drop of shellac and it m...

It just so happens that I'm working on my Hornby B1 body at the moment. Replica managed to get the wheels in their B1 with the bottom face of the platform (actually the valence edge) at the correct height but it was over scale thickness so the top was high. As a result I produced a correct chassis w...

That seems very good - I was just raising the point as I once had significant differences in days gone by and they were very easy to measure. Just something to be aware of, really. Perhaps this is one less issue to worry about in future, although worth bearing in mind when digging out some old stock...

.......and quieter.

DaveB

Dave, have you compared the diameters of the original and replacement wheels? The prototype had a tight spec. on this as any significant difference meant the loco was trying to tear itself apart with one bit attempting to go faster than another. I'm not sure what the limit should be as just dividing...

Thank you. I believe shellac is an old clockmakers trick - I don't suppose there were any young clockmakers then. Returning to the laminating problems, I found that even Slaters solvent made my walls warp and have to use Di-limonene. Only explanation I've come up with is that I use blocks of alumini...

Don't know why you glued the screw in the wheel, Julian, is this standard out there? If the screw was loose you could adjust the ret crank angle this way. Of course it probably improves the security of the crank fixing so there you are. Doesn't sound as if white spirit should shift shellac but try i...

Some comments on crankpins following my biased views on adhesives which start on the Crab pages. They're only loosely connected to matters arising from Dave Holt's fine 9F. The Sharman crankpin is very restricting and I've done my best to avoid it. You solution DaveH is possibly the only way to go. ...

Normally you would be able to unwind the remaining piece of screw from the back of the wheel, Julian, so do I conclude that this has also been nutlocked in place? All through my career I've been suspicious of these adhesives and especially so when outside their 12 month shelf life. There's a lot of ...

You could take the opportunity to test the strength of the joint as there's unused samples available for destructive testing. Anyway, you've found a way to win and that's all that matters. With the flatter crossings you're doing well to avoid burning the point off with the torch, although the meltin...

Humbrol seem to have fought back against this one as the last time I tried thinning their paint with B&Q turps it just went into lumps. Any chemists out there to explain....or suggest a way out?

DaveB

Misunderstanding there, Julian. Without checking as it would be pointless, for return crank mounting I believe I had suggested a tapped version of an Ultrascale long crankpin or, more clearly, a home made crankpin using the Ultrascale design. Perhaps the "long"was missing as front crankpin...

Perhaps just put much less solder on - no fillet. The silver solder would be strong enough for a butt joint so it isn't going to break, it's probably stronger than the rail.

DaveB

Perhaps shave the boiler bands down a gnat's - a thou' is about scale thickness.

Cheers,

DaveB

Indeed it's all about adjustment, WillL and I don't think it perverse to adjust the c of g. Some find it easier to turn a screw, others apparently not. An approximate balance point can be predicted before building a loco, even with weight bearing carrying wheels. What I often find impossible is gett...

I think you'll find that wood moves far more than metal, Noel, particularly with humidity and temperature, too. See Google. I have vague memories of an American article which was circulating a while ago and which pointed this out. Anyway, it was just an excuse for having gaps at baseboard joints whi...

I remember hearing that when one of the Burnley engines was preserved the engine-man was very peeved that the museum people chucked out his sofa and ripped up his carpet. Doesn't sound as if your man would kip on the floor but I have no idea what was normal.

DaveB

You've missed the point, Julian. Springing gives vital sound insulation by decoupling the mass of the body from the track so a sprung loco will always be quieter than a compensated one - unless the beams are bendy or the springing is one of those strange systems where they run bottomed out. Difficul...

I'll repeat my assertion that having 2 different downward acting springs is not sound engineering design. The fact that one is probably much greater than the other doesn't really excuse it as there are other ways of implementing the pick-up function so the compromise is totally unnecessary. In any c...

Now that this thread has settled, it's a good opportunity to remind a generation spared the task of routinely dismantling their car engine the need to number axleboxes and hornguides so that the chassis can be re-assembled with these bits in the same place and orientation every time. Each axlebox wi...

But first stick the bottle to something so you can't knock it over.

DaveB

I'm not looking at the time, despite having quite a bit of trackwork, just following my chosen prototype, that's all. Most of my blades were milled in batches which is quite quick once set up but I see from this thread that I should have used a 12 deg tapered cutter on a single taper rather than a b...

To design a kit chassis that has removable wheelsets it's just a matter of not etching the springs on the bottom of the frames but including them on a keeper plate which also holds the axleboxes in their hornguides......or hold your bearings in their slots if you really must have a fixed axle. Not d...

A question which relates to the current discussion on the position of the starter: my rather basic understanding suggests that, as drawn, the ground discs only give a proceed with caution indication. Surely this would mean the driver proceeding through the entire block section at reduced speed unles...

Paul, I'm fascinated by your magic formula for wagon weight which I've never seen before - was it in a very early issue of the standards or have I just missed it? The NMRA always specified their vehicle weights in this way but they had an initial constant. They recommend 1 oz + 1.2 oz per inch for a...