Any Question Answered

[D869]

3 hours ago, richbrummitt said:

I've a chimney to do for the pannier tank. At the moment though I'm stuck with a problem of a motor that won't turn the wheels. I've a few ideas to try but looking for the next distraction to have a break from that aspect and don't feel motivated to do the injectors yet.

 

Alternatively... you have a CNC milling machine, so you can tell it to cut the base of your boiler fitting...

 

[Lacathedrale]

What happened to my wheels? They are association brass wheels with steel rims, were painted with acrylic and mounted into a chassis, then removed, and touched up with more acrylic. I placed a cigarette paper with a dab of oil over one of the crankpins (otherwise very clean), and then set the whole lot (including loco body, con rods, etc.) in a tin. Upon return - this is what I see!

 

I can wipe off some of the brown with a cotton bud dipped in lighter fluid but it looks like the paint has crazed and bubbled over - both layers were cured and had been sitting on my work bench for some time - it seems the catalyst was being put in the tin?

 

 

[richbrummitt]

Could the blistering of paint have been the result of lighter fluid treatment or was it like that upon removal from the tin? 

 

The brown appears top be rust. The tyres are steel and too much moisture can easily cause this, especially in a damp environment such as a garage. You may be able to polish it out with fine abrasive. Reducing the humidity and or protecting the steel should prevent future occurrences. I've had the same happen with loco wheels and even rolling stock wheels. I have a humidifier in the workshop since last year - as recommended by a number of 2mm friends. 

[Chris Higgs]

55 minutes ago, Lacathedrale said:

What happened to my wheels? They are association brass wheels with steel rims, were painted with acrylic and mounted into a chassis, then removed, and touched up with more acrylic. I placed a cigarette paper with a dab of oil over one of the crankpins (otherwise very clean), and then set the whole lot (including loco body, con rods, etc.) in a tin. Upon return - this is what I see!

 

I can wipe off some of the brown with a cotton bud dipped in lighter fluid but it looks like the paint has crazed and bubbled over - both layers were cured and had been sitting on my work bench for some time - it seems the catalyst was being put in the tin?

 

 

 

I did have a case where I put some Association rims in a a sealed bag with some 3D-printed wheel inserts and the rims rusted like crazy. I guess the inserts relased water.

 

So I would just clean the rims off and see how it goes. They are steel and will rust in suitbale environments. Alan Gibson 4mm wheels do the same.

 

Chris

 

Chris

 

 

[Donw]

Perhaps using some VPI/VCI paper when storing wheels or models would be worthwhile.

 

Don

[CF MRC]

I don’t have a rust problem in my current 2mm workshop as it’s indoors. However, I do chemically black wheels before painting - this is quite good at preventing rust.  I usually polish steel  wheels before using them in a chassis. A smooth surface has less pits in it to start the corrosion process.  Any rust on your wheels will clean off easily with a scratch brush. 
 

The paint looks like it’s a goner; it should be stripped and replaced.  I suppose lighter fuel might lift acrylic paints, if used in volume.   Might be worth using a black acrylic primer from a rattle can to paint them (cut some card with slots to mask off the bearings/gears). 
 

Tim

[Lacathedrale]

Thank you all for the help - I've stripped and repainted (acrylic) and left out uncovered to see what happens next. My workshop is a garden summer house that's weatherproof and well insulated but I suppose is fairly suceptible to damp being of timber construction. I have a small space I could use for a workshop indoors - maybe that is going to be a better choice in the long run.

 

[richbrummitt]

Unfortunately (for wheels) the UK is generally humid. If you still have problems then dessicant or even a dehumidifier would be good. I was quite surprised how much water the dehumidifier took out in the first week or so of switching on. 

[Lacathedrale]

Thanks @richbrummitt and @CF MRC - i've got a dehumudifier too and I've been running it for a few hours a day and it's pulling out about a cup of water each time - hopefully this helps. In the meantime I stripped and repainted - hopefully there'll be more luck this time!

 

I've got a two part question re: track soldering - previously I used salami slices of lead solder and that worked well, switching to solder balls and liquid flux a little later. I'm now trying to get the one-piece etched chairplates from shop2 working on PCB track and just wondering if I should look into solder paint? I've got some rather thick solder paste, but I'm finding it quite hard to apply in repeatable measures.

 

Secondly, I'm just about finished with my bottle of Carr's green flux that I've had for donkey's years. Before I go about trying to find a direct replacement, are there any better suggestions?

 

[Caley Jim]

I use Carrs 188 solder paint for all my track and etch construction.   the only times I use a stick of solder is to re-enforce a joint or bend line or fill a small gap.   It has its own flux and it's well nigh impossible to put too much onto the joint.  Apply it with a cocktail stick or similar.  Don't be concerned to create and even layer as you would with paint.  when you apply the iron it will flow through the joint.  For trackwork, place a spot on each sleeper where the chairplate is to go , hold the chairplate in place with an old pointed object (broken drill in a pin vice, old tweezers, cocktail stick)and apply the iron to the pcb beside it until the solder flows. Same when your soldering on the rail.

 

For etched kit construction, you don't need to tin layers before soldering them together.  Just apply solder paint to one of the opposing surfaces, fold the two tightly together and apply the iron to the outside of one surface, moving it slowly over the whole area.

 

Jim W

[Laurie2mil]

We all do everything differently, William, and I guess my basic advice is experiment and settle on what works best for you.  Jim's method patently works - have a look at his Kirkallanmuir if you haven't already.  I'm still varying (?developing?) my technique after some 22 switches (how I have counted points since pocket-money days) using a combination of Easitrac "plastic" sleepers and chairs, and soldered pcb sleepers with the etched chairs. 

 

I still use the same basic technique for the etched chairs as in my article in the 2MM Magazine (I think last year), but I now use 0.6mm solder balls and liquid Rosin Flux.  All parts  are well-cleaned first (pcb sleepers and etched chair frets  with the scratch brush and  the rail degreased  by wiping with alcohol).  I position the etched chair between rail and sleeper and press down on the rail to hold it with a small screwdriver (all assembled "dry"), place a small blob of the flux to the side of the chair with a syringe and small needle, and solder with 3-4 solder balls using a 1mm bit at 375-400 degrees.  The rosin flux flux has  2 key advantages: it wets superbly, flashing through all the nooks and crannies between the rail/chair/sleeper, and it is non corrosive and so does not need cleaning to prevent corrosion continuing afterwards (although I guess paint is likely to adhere better if you do).  Hold the iron on until you see the solder flash right across the chair (1-3 seconds); the flux wets so well that the joints are made sleeper-chair and chair-rail at the same time.  When happy with the position, bend the claw of the chair in towards the rail, and you can add another couple of solder balls to fill in the gap here and strengthen the joint further if you wish. 

 

Chris Bentley introduced me to this flux, and using it with the solder balls has transformed the neatness of my soldered track with the push-through etched chairs.   I got my flux from Circuit Specialists Europe who were very efficient:

https://www.circuitspecialists.eu/review/product/list/id/362/category/113/

it isn't cheap (c. £19 for 100ml - it needs a courier as the Post Office won't take it) - but it goes a very long way.  5ml syringes and small needles can be bought from RS Components, amongst many places.

 

So there's 2 ways of doing it!  Good luck,

 

Laurie Adams

 

[Lacathedrale]

Excellent both, thank you! I'll try both and see how it pans out.

 

I will also review the chairplate articles in the magazine, I was looking through the archive USB and couldn't find them, I didn't think to check non-archival issues. I too am attempting a hybrid construction inspired by what @justin1985 has shown me.

 

 

[Laurie2mil]

You're welcome.

 

The etched chair article was in the 2mm Magazine August/September 2018 issue (!), pp. 74-82.  If you have difficulty finding it, I can email you my draft in WORD privately, which might also allow a little more  enlargement of the photos.

 

I'm currently building a curved cross-over (2x D12 points) and include a few photos of that in progress;  they're taken with an iPhone so have their technical limitations, but hopefully add to the discussion.

[queensquare]

Great stuff Laurie, good to have you on here contributing. I find that if you stick to just hanging out in the 2mm corner of the thread it doesn't eat up too much time!

 

Jerry

[Donw]

Nice work laurie, lovely to see the sort of pointwork used by full size lines. Turnouts like D12 are rarely seen in model form.

 

Don

[Jim T]

I’m working at home which has the benefit of a new workbench desk in the living room, so zero commute after a day designing the Chiltern Tunnel for HS2. I’m trying to use the time to progress my 2mm wagon fleet, but I’m stuck with an HTV (21t mineral hopper). The body is the NGS kit and the chassis is s3-258, one of the Fencehouses etches available from the Association shop.

 

I’m quite pleased with how it’s gone together so far (the soldering lesson from Nick’s Jubilee series of videos helped a lot) but the instructions are very generic and don’t really explain how it fits the kit - as you can see it’s currently hung up in three places so the hopper won’t sit down right on the chassis and is about a scale foot too high.

 

What have I missed or done wrong?? Do I need to modify the hopper bottom on the kit?

 

The other one (still very much work in progress) is on a modified Parkside chassis which hasn’t really saved any time and is notably too wide. It’s also quite hard to figure out how to do a roller bearing equipped wagon using this chassis.

 

Thanks in anticipation...

[Yorkshire Square]

Hi Jim

 

The chassis is indeed a Fencehouses one, but the instructions in the shop list for 2-358 (not 3-258) are actually by Chris Higgs where he refers to this item as a LMS 17'6" chassis. So you've done very well to get so far! 

 

I'll ask Bob if he has any instructions for this chassis and let you know.

 

I don't know anything about the NGS body, but what are those two bits sticking out above ribs 2 and 4? They seem to be what is stopping the chassis sitting down properly.

[PaulCheffus]

2 hours ago, Jim T said:

The other one (still very much work in progress) is on a modified Parkside chassis which hasn’t really saved any time and is notably too wide. It’s also quite hard to figure out how to do a roller bearing equipped wagon using this chassis.

 

Hi

 

its quite easy to remove the moulded axle boxes and replace with 2-476 BR roller bearing axle boxes. I’ve done this for a couple of the Parkside chassis.

 

Cheers

 

Paul

[Lacathedrale]

@Laurie2mil - are you using plastic chairs on PCB timbers? Is that performing a function (i.e. holding the rail upright/in gauge while soldering) or time-saving?

[Chris Higgs]

14 hours ago, Jim T said:

I’m working at home which has the benefit of a new workbench desk in the living room, so zero commute after a day designing the Chiltern Tunnel for HS2. I’m trying to use the time to progress my 2mm wagon fleet, but I’m stuck with an HTV (21t mineral hopper). The body is the NGS kit and the chassis is s3-258, one of the Fencehouses etches available from the Association shop.

 

I’m quite pleased with how it’s gone together so far (the soldering lesson from Nick’s Jubilee series of videos helped a lot) but the instructions are very generic and don’t really explain how it fits the kit - as you can see it’s currently hung up in three places so the hopper won’t sit down right on the chassis and is about a scale foot too high.

 

What have I missed or done wrong?? Do I need to modify the hopper bottom on the kit?

 

The other one (still very much work in progress) is on a modified Parkside chassis which hasn’t really saved any time and is notably too wide. It’s also quite hard to figure out how to do a roller bearing equipped wagon using this chassis.

 

Thanks in anticipation...

 

Yes, you need to modify the hopper bottom.  The chassis top needs to sit flush with the bottom of the side stanchions and anything on the hopper bottom that is stopping that has to be cut away.

 

As far as I can see you have two alternatives.

 

1. cut the hopper bottom into two, so you have two hoppers. Remove any protrusions.  Then glue these into the body. They should then fit nicely into the holes in the chassis

2. Build the body without the hopper bottoms, assemble that to the chassis. Then glue the hopper bottom inside the chassis.

 

Chris

Edited March 31, 2020 by Chris Higgs

[Jim T]

Hi Chris

 

Yes, you’re right.

 

I’m thinking rather than cutting away from this hopper body I’ll order a couple more and fix the Moulding for the hopper bottom under the chassis / brake unit cross member, perhaps as two separate pieces. So a brief hiatus with this is on the cards until another couple of NGS kits arrive.

 

EDIT: NGS is out of stock so done a bit of hacking about and the body near enough fits now. Fairly simple in the end, although I have a couple of tricky 45° bends to do on the chassis cross beams to fold down half etched sections which seem to be designed to support the hopper ends. It looks like this might not give me quite enough - if so I can easily cut them away or file them back to get a good fit. Pic and write up to follow in OMWB section.

 

Hi Paul

 

How did you manage to maintain free running after you cut away the axle boxes from the Moulding and replace them. On my chassis this removes the bearing surface... Did you add association bearings? If so what axle length did you use?

 

Thanks for the replies

Jim

Edited March 31, 2020 by Jim T
Updated

[Laurie2mil]

Jerry and Don - Thank you for your encouragement.  Re the choice of a 2x D12 X-over - its the consequence of modelling the station exactly to scale - whether it looks right or not!  The radius of the main lines through the crossover is 6' widening to 8'.  I'm just very lucky to have the room to do it.

 

William - in answer to your question re plastic chairs on pcb sleepers - it's to save time.  I don't pretend that the etched chairs aren't something of a pain in the a**e:  the cast brass chairs are far easier/quicker/neater but they are prohibitively expensive to use wholesale (and, I fear, may raise the rail fractionally higher than the etched and plastic chairs, so I'm reluctant to mix them with the others - fine if you're using them for the whole point).  I like to build up the crossing rail by rail, and the idiosyncratic tie-bar I use needs a secure bond between the rail and sleepers, so for these 2 areas I still solder.  The soldered chairs right through the crossing nose allow the adjustment you need to get the alignment and gauge of the point and splice rails exactly right, but there's no need to solder the stock and check rails to every sleeper at the crossing - just opposite the  wing rails "knuckle" and the crossing nose (again, to allow adjustment).  Once all the soldered joints are done on all the rails and I'm happy with their alignment, then the plastic chairs are slid into position and stuck down as the final act.  Those on the pcb sleepers are stuck down with the very runny 5" Roket cyano - a very small blob on the end of a wire placed against the join spreads under the chair by capillary action.

 

You're right that holding the rail vertically is key.  I use a full or half length of the plain Easitrac sleeper base (6 or 3 sleepers-worth) stuck down onto the template at each end of each track, which also helps the gauging at the start.  This may or may not end up being sacrificed, depending on the track plan it's mating too. 

 

Another tip (actually another of Jim Watt's tips): leave the rails about 3" (sorry, c.7.5cm) longer than the sleepers on the template you're building, and on the already-laid track it will mate up to cut the rail back c. 3 sleepers worth leaving the sleepers in situ.  When you're ready to stick down the new piece of track, trim the over-long rails accurately to length (and de-burr them) and feed them into the empty chairs.  An easy way to get a perfectly smooth line from one piece of track to another.

 

I'm saving my cast brass chairs for a short but complex unit of track (sharp point/sharper single slip/even sharper diamond all in less than 12") in a loco yard - where it will just save so much time and no risk of breaking the etched chairs by the repeated application of the iron that I know I'll need to get that lot right.  I'm glad you're making headway with the chairs - console yourself with how much you're saving by not using the cast brass ones!

 

Laurie Adams 

[PaulCheffus]

9 hours ago, Jim T said:

Hi Paul

 

How did you manage to maintain free running after you cut away the axle boxes from the Moulding and replace them. On my chassis this removes the bearing surface... Did you add association bearings? If so what axle length did you use?

 

Thanks for the replies

Jim

 

Hi

 

Basically I used a piece of 0.010” plasticard about 1.5mm square with a hole in the centre into which the association bearing is glued. The plasticard square is then glued to the inside of the axle box with the bearing fitting into the existing hole made after removing the moulded axlebox. The axle length I used was the standard 12.25mm as I used the N gauge wheels on mine.

 

Cheers

 

Paul

[Chris Higgs]

18 hours ago, Jim T said:

Hi Chris

 

Yes, you’re right.

 

I’m thinking rather than cutting away from this hopper body I’ll order a couple more and fix the Moulding for the hopper bottom under the chassis / brake unit cross member, perhaps as two separate pieces. So a brief hiatus with this is on the cards until another couple of NGS kits arrive.

 

EDIT: NGS is out of stock so done a bit of hacking about and the body near enough fits now. Fairly simple in the end, although I have a couple of tricky 45° bends to do on the chassis cross beams to fold down half etched sections which seem to be designed to support the hopper ends. It looks like this might not give me quite enough - if so I can easily cut them away or file them back to get a good fit. Pic and write up to follow in OMWB section.

 

Hi Paul

 

How did you manage to maintain free running after you cut away the axle boxes from the Moulding and replace them. On my chassis this removes the bearing surface... Did you add association bearings? If so what axle length did you use?

 

Thanks for the replies

Jim

 

You should be aware Bob's chassis was not specifically designed for the NGS body. It is the chassis part of his hopper kit which has a lovely etched body. 

 

Bob did these for me a number of years ago as I didn't fancy building 20+ etched bodies! Not sure when it became a shop item though.  

 

Chris

[Jim T]

Nice to know the history of what you’re building!

 

I’ve succeeded in marrying the plastic hopper to Bob’s chassis now (see below) so the next time this appears will be on the workbench thread.

 

Many thanks to all who’ve supplied suggestions or info about the chassis.