Any Question Answered

[lambiedg]

On 24/08/2022 at 02:00, Winchat said:

 

Nigel

 

You probably need a barrel jack to wire connector.  Connection is self explanatory.  I have attached a photo of one but I am not sure where you would get one in the UK.

 

Kind regards

 

Geoff

 

 

 

 

I got mine from Mr Bezos

[Nig H]

On 24/08/2022 at 02:00, Winchat said:

 

Nigel

 

You probably need a barrel jack to wire connector.  Connection is self explanatory.  I have attached a photo of one but I am not sure where you would get one in the UK.

 

Kind regards

 

Geoff

 

 

 

 

Hello Geoff,

 

These look like they will work so I've bought some from ebay. Thanks everyone who offered help and advice - much appreciated.

 

Nigel Hunt

[Izzy]

13 hours ago, Yorkshire Square said:

 

The boss is part of the anodised axle and therefore should be electrically insulated. In the unlikely event that the anodising has worn away on both bosses the 12V would still need to arc across the 0.3mm gap.

 

Have you checked the wheesets for non-continuity across the wheelsets? You might just have a faulty set.

 

Hi Tony,

 

Being a bit dense, when I originally had this problem it never occurred to me that the axles should be incapable of passing current. I have a couple of spare 3-071's - new/unused - so I've just tested them, and if the MM probes are touching the inside faces of the bosses, but not elsewhere, both of them will pass current without any resistance value. Plain axle ones I have without gears do not. There is no electrical path I can find between the actual wheels. I presume the glue used is an added insulation layer so I'm surprised there is one through the gear joint/s.  If I had realised this shouldn't happen, I would have raised the issue back then. So very sorry I missed it. Apologies. In normal use with the Farish plastic bogies it's not an issue of course, just with these 3-axle bogie with the larger PB area that allows contact with the rear of the bosses.

 

Bob

[Wotan]

2 hours ago, Izzy said:

 

Hi Tony,

 

Being a bit dense, when I originally had this problem it never occurred to me that the axles should be incapable of passing current. I have a couple of spare 3-071's - new/unused - so I've just tested them, and if the MM probes are touching the inside faces of the bosses, but not elsewhere, both of them will pass current without any resistance value. Plain axle ones I have without gears do not. There is no electrical path I can find between the actual wheels. I presume the glue used is an added insulation layer so I'm surprised there is one through the gear joint/s.  If I had realised this shouldn't happen, I would have raised the issue back then. So very sorry I missed it. Apologies. In normal use with the Farish plastic bogies it's not an issue of course, just with these 3-axle bogie with the larger PB area that allows contact with the rear of the bosses.

 

Bob

So I’m guessing I did have a point after all? It did completely baffle me what was wrong and rather regretted bringing it up as I was doubting myself after yesterdays responses……

but thank you Bob 

[Chris Higgs]

22 hours ago, Wotan said:

Well now here’s the thing and perhaps after banging my head against a wall all day trying to be understood this might clear things up

i measured the distance between the boss of the association wheels and that came out on my set as 6.45mm 

 

the distance between my beefed up pick ups on this Farish model on the middle axle space came out at 6.77mm 

therefor I deduce it will certainly not help having a further barrier of kapton/sellotape 

the bosses clearly are a problem as the chassis stands 

perhaps that’s enough of this saga now ???

michael 

 

As 6.77mm  > 6.45mm they shouldn't fit anyway.

 

So best I think you look for another approach. The axles were designed for, and worked well with the Farish chassis as they were at that time. The boss was deliberate to avoid the wheels slopping from side to side. 

 

As has been mentioned they are anodised and should not short out anyway. But if they are constantly rubbing in a chassis that is too wide for them perhaps it has worn off.

 

Chris

 

[Chris Higgs]

7 hours ago, Izzy said:

 

Hi Tony,

 

Being a bit dense, when I originally had this problem it never occurred to me that the axles should be incapable of passing current. I have a couple of spare 3-071's - new/unused - so I've just tested them, and if the MM probes are touching the inside faces of the bosses, but not elsewhere, both of them will pass current without any resistance value. Plain axle ones I have without gears do not. There is no electrical path I can find between the actual wheels. I presume the glue used is an added insulation layer so I'm surprised there is one through the gear joint/s.  If I had realised this shouldn't happen, I would have raised the issue back then. So very sorry I missed it. Apologies. In normal use with the Farish plastic bogies it's not an issue of course, just with these 3-axle bogie with the larger PB area that allows contact with the rear of the bosses.

 

Bob

 

The anodising was made so that there would be no conductivity between wheel and axle, and if tested (I don't know if they are) it would be in that area. They would not be tested between the inner faces of the bosses, as it was not necessary to have insulation at that point. Or so we thought at the time...

 

Chris

  

[Yorkshire Square]

5 hours ago, Chris Higgs said:

 

The anodising was made so that there would be no conductivity between wheel and axle, and if tested (I don't know if they are) it would be in that area. They would not be tested between the inner faces of the bosses, as it was not necessary to have insulation at that point. Or so we thought at the time...

 

Chris

  

 

Chris, I've just tested multiple wheelsets, both from Central Shop and from locos that I've converted. On all of them the axle is completely insulated. I'm not sure exactly how the anodising process is undertaken, but I'd be very surprised if it only anodises each end of one axle rather than the whole piece.

[Nigelcliffe]

17 hours ago, Yorkshire Square said:

 

Chris, I've just tested multiple wheelsets, both from Central Shop and from locos that I've converted. On all of them the axle is completely insulated. I'm not sure exactly how the anodising process is undertaken, but I'd be very surprised if it only anodises each end of one axle rather than the whole piece.

 

The whole axle is anodised, and fairly thick.   It is possible that a wheel may short from wheel to axle if the anodising was a bit thin from the factory, but that should be rare.    They can be easily tested (quick buzz on a multimeter continuity setting).  

 

It sounds like the problem is due to Bachmann changing a detail in their chassis.   As advised elsewhere, raising the matter with the shop directly will get someone to look into it and propose a solution.  Usually that would require borrowing a loco from the person with the problem to study and consider different approaches.     From the photos posted I can see several solutions, but would need to see an actual loco to evaluate which were the most sensible - I'm sure anyone else who's done 2mm product development would be the same, need to actually see the real thing, not just look at photos.  

 

 

- Nigel

 

 

 

[Chris Higgs]

21 hours ago, Yorkshire Square said:

 

Chris, I've just tested multiple wheelsets, both from Central Shop and from locos that I've converted. On all of them the axle is completely insulated. I'm not sure exactly how the anodising process is undertaken, but I'd be very surprised if it only anodises each end of one axle rather than the whole piece.

 

It would get anodised everywhere. But that is not the same as saying it needs to be anodised everywhere. You would only test that it worked where it was needed i.e. where the wheel is attached. Because there was some implication in previous posts that if it conducts between the bosses that that wheelset is somehow faulty. It isn't, as that feature was not in the design spec.

 

Chris

 

[Yorkshire Square]

Okay, having reread the various posts and looked at the photos, I see that I misread the measurements and as Chris stated 6.77mm (measurement across wipers) > 6.45mm (distance between bosses), it looks like the bosses sit into the cut outs of the wipers and are likely rubbing on their outer edges rather than their faces. The simplest solution would be to cut the wipers back so that they don't foul the bosses. I think this has already been suggested. See below:

 

 

I'd suggest a 4 1/2" disc or maybe smaller...

Edited August 26, 2022 by Yorkshire Square

[2mmMark]

On 26/08/2022 at 23:47, Yorkshire Square said:

Okay, having reread the various posts and looked at the photos, I see that I misread the measurements and as Chris stated 6.77mm (measurement across wipers) > 6.45mm (distance between bosses), it looks like the bosses sit into the cut outs of the wipers and are likely rubbing on their outer edges rather than their faces. The simplest solution would be to cut the wipers back so that they don't foul the bosses. I think this has already been suggested. See below:

 

 

I'd suggest a 4 1/2" disc or maybe smaller...

 

What about a very thin slice of empty Biro tube, with a small cut in it to make a split washer so it can be slipped over the axle?  Should stop the wheel boss touching the pickup.

[Laurie2mil]

You used to be able to get very thin fibre washers with a 1.5mm diam hole, which were very useful for taking up a bit too much slack, and in this case could act as insulators.  they could be filed even thinner.  Don't know if they're still out there: cannot remember where I got them  from  - it was 30+ years ago - maybe the Assocn shop then?

[bécasse]

2 hours ago, Laurie2mil said:

You used to be able to get very thin fibre washers with a 1.5mm diam hole, which were very useful for taking up a bit too much slack, and in this case could act as insulators.  they could be filed even thinner.  Don't know if they're still out there: cannot remember where I got them  from  - it was 30+ years ago - maybe the Assocn shop then?

I certainly had some (and some with a 2mm ø hole too) which suggests that they were once available from a trader, Branchlines perhaps?

[nick_bastable]

possibly Peco fibre washers 🙄

[Yorkshire Square]

The issue won't be solved by washers as the boss appears to be sitting inside the cut-out on the wiper assembly. The only option is to make the cut-out larger so that it doesn't intermittently scrape against the outside rim of the boss. See below - wheels and gears omitted for clarity:

 

 

 

[Wotan]

Thank you for clearly stating the issue I tried originally to raise.

michael 

[Intraclast]

Beginner's question I'm afraid, but I've done alot of searching of the forum and convinced myself that the answer is easily findable. I found some information at larger scales, but am not sure if its the same in 2mm.

 

I'm preparing to convert a Farish Jinty and I'm thinking I need to paint the wheels (mk5) before I start. What is the best way to go about this without an airbrush?  Should I chemically black them (presumably masking off the tire tread - I've not used chemical blackening before) or etch prime and paint with rattle cans? Or should I use a brush?

 

Many thanks

 

Mark

[Caley Jim]

Since the centres are 3D printed stainless steel, they can't be easily chemically blackened.  I paint my wheels by cutting circles the diameter of the tread in some card the same thickness as the tread, push the wheels into the card and then spray with a rattle can.  You might get a wee bit of bleeding onto the tread, but that's easily removed by lightly scraping with a craft knife.  Keep the card for future use with the same size of wheel!

 

Jim

[queensquare]

I do a variation on what Jim does. I run a bit of Maskol around the tyre and push the wheels into a block of balsa and spray with a rattle can.

Dont forget to fit the crankpins first!

 

Jerry

[Intraclast]

Thanks Jim and Jerry, very helpful.  And thanks for the crankpins comment as I probably would have got that wrong.  Time to buy some rattle cans.

 

Mark

[edit - spelling]

Edited September 4, 2022 by Intraclast

[jonas]

Morning, can anyone help with rewheeling Dapol IOA / JNA (and Farish MAO) wagons for 2mm?

 

Is there a suitable wheelset available as a straight swap?

 

Thanks!

[martin580120]

Hi folks,

 

I'm working on the Association J94 replacement chassis as my first forray into loco building and have reached the point where I need to add gears. The instructions refer to the old imperial gears. I'd guessed the metric gears and found they didn't fit, or reach each other. I picked up half a dozen other sized gears yesterday at the NEAG 40th Anniversay show but have had similar issues:

 

32T (3-397) seems to clash with the section of etch that holds the worm in place. There is sufficient NS to trim some of it away, is this something that needs done? The 28T (3-396) has the same issue, whilst the 25T (3-395) won't reach the worm.

I tried two 16T gears (3-391) but they won't meet. I tried another couple of gears and found the only ones that met were the 25T (3-395) and 18T (3-392).

 

Other point to note is I am planning to use DCC so can limit the motor using the chip (a Zimo MX616)

 

All of this is pre-amble to a couple of questions I suppose:

1. Am I using the right gears here? Have I missed something, or is this a (vaguely) sensible gear arrangement and I'll need to cut/file a channel into the etch to accept the proposed gear off the worm?

 

2. If so, does it matter which way round the two gears that will drive the rear axle go? The diameter of the 25T gear is close yo that of the wheels, so I'm not sure about it sticking out the bottom of the loco?

 

3. If I have messed this up, is there some table/article/RM web post somewhere that gives equivalency between the old and new gears to prevent me confusing myself in the future? My intended next project is a 3F chassis, so I can see me going through this again...

 

If I need to buy other gears, I'm quite happy to, somehow a bush has fallen out and I've lost it, so another pack of them will be needed in the near future, so making the order up to £20 would be ideal.

Edited September 11, 2022 by martin580120
I can English good me...

[Nigelcliffe]

There's a table of gear centres for all the different types in the Member's Handbook (distributed in Dec 2020, or to new members who joined since that date).   With that you can work things out, rather than lots of guesswork.  

 

The instruction diagram for the J94 says 14:18 M0.4 - so metric "coarse" gears, and thus standard shop items.  (14 gear first, 18 gear on the axle of the wheels ).     

 

You seem to be trying to find a metric "fine" set which fit, consulting the tables suggest 25:18 may be close-enough on mesh centres.

 

Yes, it matters which way round you fit them.  25 first followed by 18 second will mean "loco goes much faster" and 18 first, with 25 second will mean "loco goes much slower".     Obviously clearance for wheels or other chassis parts needs to be considered - a J94 has 8.5mm diameter wheels, so the final gear needs to be 8.5mm outside diameter or less (again outside diameter is in the tables).   

 

 

- Nigel

 

 

[Nick Mitchell]

30 minutes ago, martin580120 said:

32T (3-397) seems to clash with the section of etch that holds the worm in place. There is sufficient NS to trim some of it away, is this something that needs done? The 28T (3-396) has the same issue, whilst the 25T (3-395) won't reach the worm.

 

 

These gears you mention are not worm gears - they are spur gears, and the wrong pitch.

Not only will they not reach the worm properly, they will also not mesh with it.

 

You need a 3-367 30T Skew cut 100DP gear for this.

[martin580120]

Thanks Nigel and Nick. That explains why that's not working then!