Nu Cast 2021 Pannier - Construction

[Erudhalion]

The wheels are all insulated and the brakes don't touch the treads.

 

The motor occasionally does move a bit, but stops immediately, so it doesn't look like it is due to things being accidentally soldered together.

 

Update: The thick plottens: I've removed the wheels and gearbox, and now the motor runs fine when I touch the battery to the pickups.

Edited April 27 by Erudhalion

[hayfield]

Some none-Insulated wheel(s) ? Check whether one wheel has lost its insulating ability if all are insulated, or it may be the pickups ?

Edited April 27 by hayfield

[Erudhalion]

After much poking and probing, it turns out it was the pickups touching the frames and the brake rigging at various points. I ended up shortening the front pair and replacing the middle, amd now there are no shorts.

 

However, it now runs rather slowly. It doesn't sound to me like the motor is struggling, and in fact if I connect the motor directly to the battery it runs faster. I think I might check the electrical resistance of the pickups to see if that is the problem.

[John Isherwood]

10 minutes ago, Erudhalion said:

After much poking and probing, it turns out it was the pickups touching the frames and the brake rigging at various points. I ended up shortening the front pair and replacing the middle, amd now there are no shorts.

 

However, it now runs rather slowly. It doesn't sound to me like the motor is struggling, and in fact if I connect the motor directly to the battery it runs faster. I think I might check the electrical resistance of the pickups to see if that is the problem.

 

I use microbore PTFE tubing to prevent pickups touching bits that they shouldn't.

 

CJI.

[Erudhalion]

I've got a box of heatshrink tubing which I was thinking of using for that purpose. Unfortunatley I left it in Italy and forgot to pick it up last time I was there. Very irritating.

 

However, the pickups at the moment don't seem to touch the chassis, even accounting for any wiggling up or down caused by the wheels turning.

[John Isherwood]

2 minutes ago, Erudhalion said:

I've got a box of heatshrink tubing which I was thinking of using for that purpose. Unfortunatley I left it in Italy and forgot to pick it up last time I was there. Very irritating.

 

However, the pickups at the moment don't seem to touch the chassis, even accounting for any wiggling up or down caused by the wheels turning.

 

Heatshrink tubing is far too rigid.

 

Google 'PTFE microbore tubing', and choose the one that has a bore to suit your size of pick-up wire.

 

Talking of which - what size of wire are you using?  Phosphor bronze  I assume?

 

CJI.

[Erudhalion]

58 minutes ago, cctransuk said:

Talking of which - what size of wire are you using?  Phosphor bronze  I assume?

 

0.3mm, but as to the kind of metal I'm not entirely sure, it's the pickup wire that came with the kit. I would have said steel, but I took to solder reasonably well, which leads me to think it it might not be.

 

I've just done some more testing and I think the slow running is mainly down to dirt on the wheel treads and the ancient Lima track I'm using. If I connect the battery directly to the pickups it runs fine, it is only if the wheels themselves are involved that it slows down.

[Siberian Snooper]

I use a fibreglass pencil to clean wheel treads. Give your rails a good clean, too.

 

 

 

 

[St Enodoc]

27 minutes ago, Siberian Snooper said:

I use a fibreglass pencil to clean wheel treads. Give your rails a good clean, too.

 

 

 

 

And the backs of the flanges, where the pickups rub.

[Erudhalion]

Well, I've discovered why it was running so slowly... the battery I was using to test it was neary flat.

 

With a fresh battery it now well, at least on straight track. Curves however, ate another matter.

 

I've been testing it on a 430mm curve (around setrak 2nd radius) and it occasionally manages not to derail, as long as the body is on to keep thing on the track.

 

I've got enough sideplay as far as I can see, so my plan of action is as follows:

 

1) Give the coupling rods a tiny amount of extra sideplay, as they seem to be flexing a little, and

 

2) Reduce the pressure the pickups exert on the leading and trailing wheels.

 

I hope this will reduce the forces pushing the wheels sideways and cure the problem.

 

Update: Success! It can now navigate 2nd radius curves without too many problems.

Edited April 29 by Erudhalion

[St Enodoc]

2 hours ago, Erudhalion said:

I've got enough sideplay as far as I can see, so my plan of action is as follows:

 

1) Give the coupling rods a tiny amount of extra sideplay, as they seem to be flexing a little

Make sure that the side rods allow the wheels to take up the full amount of sideplay you have provided.

[Captain Kernow]

On 29/04/2024 at 07:56, Siberian Snooper said:

I use a fibreglass pencil to clean wheel treads.

I use cellulose thinners, applied with a cotton bud. Dirt runs away from that, screaming into the night...

 

[Erudhalion]

Not much progress over the past few days, I do have this rather inclement closeup of the cab front/boiler backhead, which I will try and tidy up before soldering to the body.

 

There were two options, one with smaller windows and this one with larger ones. Looking at period photos, this one looks like it was by far the most common, at least on the pannier tanks.

 

I soldered on the variuous details provided in the kit (lubricator, regulator, gauge glass) but had to fabricate a new regulator handle, as I think there was a casting flaw on that piece.

 

I also fabricated a firehole door to close the hole provided for the original gearbox. It isn't exactly to scale, but it gives an impression. I think it will look fine once the crew is in the cab as well.

 

I will probably have some more gaps to fill, as it doesn't seem like the bevels on the bottom match up with the splashers all that well.

[Erudhalion]

I am presented with a bit of a conundrum.

 

 

This is the piece out of which I'm supposed to form the three fire iron supports for the back of the bunker. The instructions simply state "fold up the fire iron supports". There is this drawing as well:

 

I might be missing something, but I'm not sure how to go about this, considering that if I follow the diagram literally, I'm going to end up with six angular hooks.

 

I've cut out one of the six strips to try folding one and see if it looks promising, but it doesn't.

 

My only idea is that maybe if I fold the outer strips along the half etched areas, that will bend the strips into the proper round hook shape, bit if anyone can shed some light on this, I would be very grateful.

[John Isherwood]

19 minutes ago, Erudhalion said:

I am presented with a bit of a conundrum.

 

 

This is the piece out of which I'm supposed to form the three fire iron supports for the back of the bunker. The instructions simply state "fold up the fire iron supports". There is this drawing as well:

 

I might be missing something, but I'm not sure how to go about this, considering that if I follow the diagram literally, I'm going to end up with six angular hooks.

 

I've cut out one of the six strips to try folding one and see if it looks promising, but it doesn't.

 

My only idea is that maybe if I fold the outer strips along the half etched areas, that will bend the strips into the proper round hook shape, bit if anyone can shed some light on this, I would be very grateful.

 

I am guessing that you have material for six hooks, as you surmise.

 

What would result if you curved the strips in opposite directions at the two 'fold' lines - would that produce the reverse curve of the fire-iron hooks?

 

CJI.

[Erudhalion]

14 minutes ago, cctransuk said:

What would result if you curved the strips in opposite directions at the two 'fold' lines - would that produce the reverse curve of the fire-iron hooks?

 

Maybe the short end needs to be bent about 90° in one direction to form the part that goes into the locating hole, while longer part needs to be bent the other way to form the hook.

 

That might work, but I'm still not entirely sure.

[John Isherwood]

1 minute ago, Erudhalion said:

 

Maybe the short end needs to be bent about 90° in one direction to form the part that goes into the locating hole, while longer part needs to be bent the other way to form the hook.

 

That might work, but I'm still not entirely sure.

 

Perhaps the double fold is to produce a thicker fixing 'pin' to go into the hole?

 

CJI.

[micklner]

Cut a piece of paper double (or bigger)  the etch size , and then fold up and see what happens .

 

Or you simply  have a missing etch.

Edited May 7 by micklner

[Jeff Smith]

I just use thin brass strip for lamp irons etc - bent using needle-nosed pliers.  Stuck on with superglue before painting.

[DCB]

On 29/04/2024 at 21:00, Erudhalion said:

Well, I've discovered why it was running so slowly... the battery I was using to test it was neary flat.

 

With a fresh battery it now well, at least on straight track. Curves however, ate another matter.

 

I've been testing it on a 430mm curve (around setrak 2nd radius) and it occasionally manages not to derail, as long as the body is on to keep thing on the track.

 

I've got enough sideplay as far as I can see, so my plan of action is as follows:

 

1) Give the coupling rods a tiny amount of extra sideplay, as they seem to be flexing a little, and

 

2) Reduce the pressure the pickups exert on the leading and trailing wheels.

 

I hope this will reduce the forces pushing the wheels sideways and cure the problem.

 

Update: Success! It can now navigate 2nd radius curves without too many problems.

You are doing very well as my Bachmann  64XX with the same wheelbase is a bit marginal on 2nd Radius.  Do you think  your pickups will work reliably with that amount of travel.
How do you plan to paint the chassis?    

[Siberian Snooper]

Here's my solution to the fire iron conundrum

 

https://www.dartcastings.co.uk/dart/L122.php

 

They're a little bit chunky, but a lot less faffing.

 

 

 

[Erudhalion]

I already have a set of fire irons, or I might have gone for that set.

 

I'll try out with a piece of paper to see if I can work out what I'm supposed to do, and if that fails I'll just bend them up by hand.

 

Here are a few pics after yesterday's efforts:

 

 

The cab and bunker are both in one piece, but they aren't soldered to the footplate yet. In the second pic you can see the new cab floor with the springs which I removed from the origonal pieces which were meant to be attached to the boiler.

 

The right-hand side of of the bunker wasn't quite the right shape and left a bit of a gap where it was meant to form the corner above the flared section, but I managed to fill the gap with solder and file it into shape.

 

One problem remains, however: neither the cab nor the bunker sit properly on the footplate:

 

With the bunker I'm the right hand side and the back sit fine, but as you can see, there is a bit of a gap on the left. I could either file down at the back and on the right until it all looks good, but I risk losing the lines of rivets around the bottom. An alternative is to solder it as it is and fill the gap with solder and if necessary file it so it isn't too obvious.

 

On the cab, things are a little more complex as I still need to mount a handrail knob to the cab side which is meant to line up with the ones on the tanks. If the cab sides were to be resting on the footplate, these handrail knobs would be too low. There is also the fact that there isn't that much space between the bottom of the windows in the spectacle plate and the top of the tanks.

 

The gaps here are bigger too so if I fill them with something it would be more obvious, so I'm not sure of the best way to solve the issue.

 

I've also hacked off the old injectors, and have ordered some brass ones from Alan Gibson, as well as brass door darts and whistles.

[St Enodoc]

3 hours ago, Erudhalion said:

With the bunker I'm the right hand side and the back sit fine, but as you can see, there is a bit of a gap on the left. I could either file down at the back and on the right until it all looks good, but I risk losing the lines of rivets around the bottom.

The whole footplate doesn't look quite straight and level in the first photo, which might be affecting the fit. Is is too late to do anything about that?

[Erudhalion]

You are right, it isn't quite straight and level. I will try and correct it as much as possible, and that might help a bit.

 

However, the problem with the bunker and cab is more to do with the fact that the bottom of the two don't sit on the same level. I lined up the tops of the back and sides of both cab and bunker because I didn't want gaps under the roof or steps in the corners of the bunker.

[Siberian Snooper]

I agree some of the parts only fit where they touch, I have had numerous attempts at assembling the Armstrong bunkers and I still haven't achieved satisfaction. I have consumed several more cups of coffee than usual, as I have a cuppa when I boil the kettle to separate the parts.

The Collet style bunker I found slightly easier to assemble.