Any Question Answered

[queensquare]

Hi,

 

Bit late to the question on this thread, but as Products officer I have been loaned an N class by one of the Wealden group members to attempt an etch for the rods. As Chris has said, you could use the Pannier rods to get something started as I am only at a very early stage with the artwork. However, the Farish valvegear is a fair bit chunkier than the Dapol ones, and while I'm happy leaving the valve gear on the Dapol Brit and Schools, the Farish N does look rather thick.

 

As I have mentioned in the Products thread the intention is to make most rod sets available either as private members products such as Nigel Hunt's LMS stuff, or direct via the Association if unavailable elsewhere.

 

So no deadline yet - I'm finishing off the Castle bits and bobs - but I don't want to leave the N too long.

 

regards

Nigel (putting head in noose again!)

 

Splendid news, I look forward to those arriving. I have an N waiting to add to the North Cornwall roster and also a Castle - 5098 Clifford Castle to go with Kimberley Hall!

 

Jerry

[Nig H]

Hello everybody,

 

I'm getting on with my first loco chassis, I've put the frames together and I've got the crankpins fitted, but now I've got to this bit of the instructions:

 

11. Now add the wheels to the chassis. The drive axles should have the final drive gear offset on an gear muff on the opposite side to the gearbox. The worm wheel stub axle should have the 30T worm wheel centralised, and a 14T spur gear offset. The wheels and stub axles are fitted in the usual 2mm manner (see the available notes on this from Bill Blackburn for details).

 

Does anyone have a link to the notes from Bill Blackburn they can share? Does anyone have any tips for getting gears onto gear muffs straight and level?

 

Thanks in advance

 

Simon

Hello Simon,

 

I can't say that my method of getting gears on muffs is the best but I can't think of anything better. You could start with chamfering the edge of the muff slightly then ease the gear over this chamfer. Place the gear on a hard flat surface and gently tap the muff down onto the gear so the muff gradually moves inside the gear. Continue until the muff is flush with the gear against the flat block. An alternative I sometimes try is to introduce the muff into the hole in the gear then squeeze the muff fully home between the jaws of a vice. If you want the gear in the middle of the muff, open the jaws of your vice slightly more than the diameter of the muff, position the gear over the gap in the jaws and tap the muff down until the gear is in the position desired.

 

I don't know what Bill said in his notes but I suspect it might be based on the assumption that you use the wheel quartering tool. For this method the axles fit very tightly in the muffs and I believe its almost impossible to remove the axles (if required) once they have been inserted in the muff. I use a different approach because I prefer to be able to take things apart of testing some aspect of the chassis is the build progresses. I prefer to have the axles a good snug/ tightish fit in the muffs, with the axles being glued inside the muff once I am happy with quartering etc. I therefore open out the hole in the muff with a broach until I am happy with the fit of the axles, but first I file flats along the muffs, one on either side. This makes holding the muff easier. I also drill 1mm holes about 2mm either side of the centre of the muff from one side to the other. These are for little drops on superglue for attaching the axles. The position of the holes might need changing for muffs with gears. I usually now file a flat in the end of each axle to act as a key for the glue. 

 

Hopefully the attached pic shows some of this.

 

I hope this helps.

 

Nig H

[Chris Higgs]

Hello Simon,

 

I can't say that my method of getting gears on muffs is the best but I can't think of anything better. You could start with chamfering the edge of the muff slightly then ease the gear over this chamfer. Place the gear on a hard flat surface and gently tap the muff down onto the gear so the muff gradually moves inside the gear. Continue until the muff is flush with the gear against the flat block. An alternative I sometimes try is to introduce the muff into the hole in the gear then squeeze the muff fully home between the jaws of a vice. If you want the gear in the middle of the muff, open the jaws of your vice slightly more than the diameter of the muff, position the gear over the gap in the jaws and tap the muff down until the gear is in the position desired.

 

I don't know what Bill said in his notes but I suspect it might be based on the assumption that you use the wheel quartering tool. For this method the axles fit very tightly in the muffs and I believe its almost impossible to remove the axles (if required) once they have been inserted in the muff. I use a different approach because I prefer to be able to take things apart of testing some aspect of the chassis is the build progresses. I prefer to have the axles a good snug/ tightish fit in the muffs, with the axles being glued inside the muff once I am happy with quartering etc. I therefore open out the hole in the muff with a broach until I am happy with the fit of the axles, but first I file flats along the muffs, one on either side. This makes holding the muff easier. I also drill 1mm holes about 2mm either side of the centre of the muff from one side to the other. These are for little drops on superglue for attaching the axles. The position of the holes might need changing for muffs with gears. I usually now file a flat in the end of each axle to act as a key for the glue. 

 

Hopefully the attached pic shows some of this.

Duchess tender draw beam.jpg

 

I hope this helps.

 

Nig H

 

 

I think Bill's notes were written before the quartering tool was thought of, and came along at the same time as the Mk4 wheels (the current ones) which is quite a while ago now. But I recall he did ascribe to the tight muff method and his advice on how to get them off was to melt the muff away with a soldering iron. A bit pricey these days.

 

I put my gears onto muffs by using the vice method described here.

 

I bought a set of closely spaced drills (1.5mm, 1.51mm, 1.52mm etc) to open muffs up as I generally find a broach just gets stuck. That was before I started 3D-printing muffs.

 

Chris

[richbrummitt]

The Mk4 wheel notes were about 15 years ago.

[2mm Andy]

I think Bill's notes were written before the quartering tool was thought of, and came along at the same time as the Mk4 wheels (the current ones) which is quite a while ago now. But I recall he did ascribe to the tight muff method and his advice on how to get them off was to melt the muff away with a soldering iron. A bit pricey these days.

 

I put my gears onto muffs by using the vice method described here.

 

I bought a set of closely spaced drills (1.5mm, 1.51mm, 1.52mm etc) to open muffs up as I generally find a broach just gets stuck. That was before I started 3D-printing muffs.

 

Chris

 

The drills are available here;

 

https://www.drill-service.co.uk/products/drills/jobber-drill/d-hss-jobber-drill/

 

I bought the 1.51mm, 1.52mm, 1.53mm and 1.54mm sizes. No connection other than as a satisfied customer.

 

Andy

[Mr chapman]

Hi,

 

Bit late to the question on this thread, but as Products officer I have been loaned an N class by one of the Wealden group members to attempt an etch for the rods. As Chris has said, you could use the Pannier rods to get something started as I am only at a very early stage with the artwork. However, the Farish valvegear is a fair bit chunkier than the Dapol ones, and while I'm happy leaving the valve gear on the Dapol Brit and Schools, the Farish N does look rather thick.

 

As I have mentioned in the Products thread the intention is to make most rod sets available either as private members products such as Nigel Hunt's LMS stuff, or direct via the Association if unavailable elsewhere.

 

So no deadline yet - I'm finishing off the Castle bits and bobs - but I don't want to leave the N too long.

 

regards

Nigel (putting head in noose again!)

Top stuff I'll buy a couple when they arrive, no rush! Should be able to make one good'un out of them

[MrSimon]

Thank you for the advice all!

 

I had a slight panic before asking on here because when I tried the first wheel on and I couldn't get it back off, and I couldn't get the big cog on straight (it's almost as if the hole was smaller than on the small cog).  I've got the drill bits on order

 

 

I got this far but when I turned the axle with the worm on (i used an off-cut of worm so I didn't ruin the bit I needed for the motor) I could feel the gears grinding in the same place each rotation.  I need to order a new muff, the one I got the gear onto is a pretty chewed up and then I opened it up too far so it spins on the axle...

 

One final (for now) question:  Do I take the wheels back off to paint the chassis?  I've got the crank pins soldered on and coupling rod ready to try quartering the chassis when the new muffs come, but when it's all finished and running well do I then take the wheels back off or leave them on and paint under them?

 

Thanks again

Simon

[Chris Higgs]

Thank you for the advice all!

 

I had a slight panic before asking on here because when I tried the first wheel on and I couldn't get it back off, and I couldn't get the big cog on straight (it's almost as if the hole was smaller than on the small cog).  I've got the drill bits on order

 

SAM_1585.jpg

I got this far but when I turned the axle with the worm on (i used an off-cut of worm so I didn't ruin the bit I needed for the motor) I could feel the gears grinding in the same place each rotation.  I need to order a new muff, the one I got the gear onto is a pretty chewed up and then I opened it up too far so it spins on the axle...

 

One final (for now) question:  Do I take the wheels back off to paint the chassis?  I've got the crank pins soldered on and coupling rod ready to try quartering the chassis when the new muffs come, but when it's all finished and running well do I then take the wheels back off or leave them on and paint under them?

 

Thanks again

Simon

 

You need to be sure you have used the correct muffs. The cheap ones (3-100) are designed only to use on axles without gears, and are not guaranteed to be concentric (and often they are not). Using these is pretty much asking for your gears to bind, and they are too large to fit the metric gears anyway (see below). The more expensive ones are turned to make sure they are concentric, which is vital for gears to work.

 

Added to this the old Imperial gears have a 1/8" hole (3.2mm) whereas the new metric ones are 3.0mm bore. So you need to know which you have bought and use the appropriate gear muffs. Apparently we don't do 3-102 any more so if you have imperial gears you will need to use 3-102b, putting Imperial gears on the 3.2mm end or metric on the 3.0mm end. I am only guessing but if you think one gear has a smaller hole than the other that just might well be.

 

Forgotten to paint your chassis? Oops. Well, Iain Rice reckons that if you have got to the point where you can run it you can set it off and then spray paint using your airbrush. Because the spokes are in motion you should end up painting the whole area behind the wheels. All you have to do then is get the paint off the motor, gears and everywhere else that it has gone. Overall my advice is to paint the frames before you put the wheels in. That means anything you do afterwards such as the brakeblocks has to be glued rather than soldered, but that is probably not such a bad idea in any case.

 

Chris 

Edited May 31, 2018 by Chris Higgs

[Nig H]

Thank you for the advice all!

 

I had a slight panic before asking on here because when I tried the first wheel on and I couldn't get it back off, and I couldn't get the big cog on straight (it's almost as if the hole was smaller than on the small cog).  I've got the drill bits on order

 

SAM_1585.jpg

I got this far but when I turned the axle with the worm on (i used an off-cut of worm so I didn't ruin the bit I needed for the motor) I could feel the gears grinding in the same place each rotation.  I need to order a new muff, the one I got the gear onto is a pretty chewed up and then I opened it up too far so it spins on the axle...

 

One final (for now) question:  Do I take the wheels back off to paint the chassis?  I've got the crank pins soldered on and coupling rod ready to try quartering the chassis when the new muffs come, but when it's all finished and running well do I then take the wheels back off or leave them on and paint under them?

 

Thanks again

Simon

 

Hello Simon,

 

I usually paint the chassis without the wheels. I add as much of the brake gear as possible to the chassis before painting. Paint the wheels at this point too, if not already done. You can still solder the brake hangers and pull rods in place after re-assembling the painted wheels on the painted chassis. I'd scrape away any paint from the outside face of the brake hanger bracket first. If any paint work gets damaged when you solder the rest of the brake gear in place, it can easily be re-touched when you paint the brake hangers and pull rods etc.

 

Nig H

[DavidLong]

Simple question. An Association 03 chassis with 7mm Chinese motor. Runs absolutely fine and in reverse is almost silent while in the forward direction sounds like a miniature coffee grinder. Why in one direction but not the other? Any ideas?

 

David

[Izzy]

Hi David,

 

Is there much shaft end float? Just wondering if in the 'coffee grinder' direction it's the commutator bottoming on the back plate through force from the gears. With these motor types there is of course no end bearing so care needs to be taken to ensure they have little or no end float/pressure to stop them doing this or chewing up the brush 'fingers' by excess pressure.

 

regards,

 

Bob

[DavidLong]

Hi David,

 

Is there much shaft end float? Just wondering if in the 'coffee grinder' direction it's the commutator bottoming on the back plate through force from the gears. With these motor types there is of course no end bearing so care needs to be taken to ensure they have little or no end float/pressure to stop them doing this or chewing up the brush 'fingers' by excess pressure.

 

regards,

 

Bob

 

Interesting thought, Bob. How to eliminate the end float though?

 

Edit just to add that an 04 and 08 exhibit the same problem although the noise is slightly less. With the 04 it is also in the forward direction, the 08 going in reverse.

 

David

Edited June 1, 2018 by DavidLong

[Chris Higgs]

Interesting thought, Bob. How to eliminate the end float though?

 

Edit just to add that an 04 and 08 exhibit the same problem although the noise is slightly less. With the 04 it is also in the forward direction, the 08 going in reverse.

 

David

 

If you make sure the worm cannot float much within the cantilever gearbox that will help. But I am tending to think about the dog clutch approach to decouple the motor from the worm.

 

Chris

[DavidLong]

If you make sure the worm cannot float much within the cantilever gearbox that will help. But I am tending to think about the dog clutch approach to decouple the motor from the worm.

 

Chris

 

They don't use the gearbox, Chris, as it has been removed and meshing takes place via the height of the motor mount. Bob did this on his 04 and 08 chassis' so I'm not alone in using this method and he doesn't seem to have the noise problem. It's also a pretty stndard method across the scales. Surely it shouldn't be necessary to go to the faff of dog clutches to solve it. Your most recent etches which you have been illustrating don't include the gearbox.

 

David

[Chris Higgs]

They don't use the gearbox, Chris, as it has been removed and meshing takes place via the height of the motor mount. Bob did this on his 04 and 08 chassis' so I'm not alone in using this method and he doesn't seem to have the noise problem. It's also a pretty stndard method across the scales. Surely it shouldn't be necessary to go to the faff of dog clutches to solve it. Your most recent etches which you have been illustrating don't include the gearbox.

 

David

 

It may be standard, but perhaps the Chinese motors just aren't of the quality to use them in this way?

 

Chris

[Izzy]

I think the problem with an issue like this is that there are so many variables that it’s often difficult to pin down. My 04/08 for example have these Chinese 7mm motors, but whether they are the same production as David’s or just similar spec...... Mine are also fitted onto the chassis with a plasticard ‘box’ around them as well as axles moving in slots. All of this could affect how resonance vibrations are transmitted through the chassis/body.

 

To restrict shaft movement I push the worm on as far as it will go. So when the end hits the motor body it acts like a limit stop. Very crude but it works okay. I still have stocks of the older, longer, black version worms with 1mm bores and I don’t know if this would work with the newer white type. Otherwise you could use the shouldered 1mm-1.5mm adapter sleeve but this isn’t a firm push fit on the shaft.

 

Bob

[2mmMark]

Maybe the solution is to make a small close fitting collar which can be slid onto the shaft and locked in place to limit end float. Looking at the Chinese can motors I have, it looks like you'll need to pull the shaft towards the front  bearing to take up the end float, then locate the collar in position with a tiny "fag paper" clearance between it and motor. A squeeze with pliers ought to be enough to fix the collar in place.

 

Mark

[DavidLong]

Thanks for the comments. I thought it may be helpful to show the chassis as it is at present. The photos show it with the body removed and it was removed from the track when it was going forwards which is when it produces the noise. As I stated it is almost silent when moving in reverse. Apologies for the flaky paintwork but I started this loco about two years ago and it has been a cause of much frustration in its running so it has suffered a lot of dismantling and reassembly! I may even build it a new chassis although, apart from the noise, it is now running rather well.

 

 

 

The 'izzy type box' is intended to have a hat added which would take the DCX76 chip. See, Bob, I do take notice of your good ideas!

The other chassis that I had mentioned was for the 08 which is destined to have a Farish body added. I'm really pleased with this so far as its running qualities are excellent. It's held up at the moment while I try to work out a way of making the outside frames removable as I'm reluctant to have them permanently attached. I actually preferred the method of them being attached to the footplate/body structure as in the Association 08. I have plans for a small fleet of 08s (green 1968/blue 1977) so I'm trying to work out assembly methods that will work consistently. More 'izzyness' on this one as well!

 

 

 

 

I may yet end up making a new pcb footplate using the Farish footplate as a pattern and attach the outside frames to it in a similar manner to the Association kit.

 

David

[DavidLong]

Association members may have seen a note in the newsletter about the laser cut ply sleepers that are being sold by York Modelmaking. I bought some of these as a trial. They are sold as 'N gauge' but are 17.5mm long which would be entirely correct for the 1:148 true gauge of 9.7mm but of course incorrect for British N 9mm gauge.

Using my Northwest Shortline Chopper I removed 0.5mm from them to give the correct 17mm for 2FS and made up a short length of plain track as a trial. If you were being really picky they are fractionally chubby for 2FS by about 0.1/0.15mm. Thickness is 0.81/0.82mm. This is how it turned out:

 

 

 

 

The staining of the sleepers didn't inhibit  the adhesion of the chairs to the sleepers using my usual mek as the adhesive. No matching strips for point timbers have so far appeared.

 

David

 

[backofanenvelope]

Hi, noob question but what do people use for gluing down pcb’s down on to a ply board. I did a cursory search but on my tiny ithingumy it’s a bit difficult. Anyway thanks for any advice and I might post a pic of my efforts later if it doesn’t look pants

[DavidLong]

Hi, noob question but what do people use for gluing down pcb’s down on to a ply board. I did a cursory search but on my tiny ithingumy it’s a bit difficult. Anyway thanks for any advice and I might post a pic of my efforts later if it doesn’t look pants

 

Ordinary PVA will be fine, used it for years.

 

David

[D869]

Ordinary PVA will be fine, used it for years.

 

And sort out plenty of heavy things to weight it down while the PVA sets, plus some bits of wood, play, hardboard or whatever to spread the weight over as much of the railhead as possible.

[Izzy]

Thanks for the comments. I thought it may be helpful to show the chassis as it is at present. The photos show it with the body removed and it was removed from the track when it was going forwards which is when it produces the noise. As I stated it is almost silent when moving in reverse. Apologies for the flaky paintwork but I started this loco about two years ago and it has been a cause of much frustration in its running so it has suffered a lot of dismantling and reassembly! I may even build it a new chassis although, apart from the noise, it is now running rather well.

 

021.JPG

 

022.JPG

 

The 'izzy type box' is intended to have a hat added which would take the DCX76 chip. See, Bob, I do take notice of your good ideas!

The other chassis that I had mentioned was for the 08 which is destined to have a Farish body added. I'm really pleased with this so far as its running qualities are excellent. It's held up at the moment while I try to work out a way of making the outside frames removable as I'm reluctant to have them permanently attached. I actually preferred the method of them being attached to the footplate/body structure as in the Association 08. I have plans for a small fleet of 08s (green 1968/blue 1977) so I'm trying to work out assembly methods that will work consistently. More 'izzyness' on this one as well!

 

018.JPG

 

019.JPG

 

020.JPG

 

I may yet end up making a new pcb footplate using the Farish footplate as a pattern and attach the outside frames to it in a similar manner to the Association kit.

 

David

 

Lovely construction David, I wish I could make mine half as neatly.

 

If I have it right, when running in reverse the gearing force on the motor in the 03 would be pulling the worm away from the motor, so my original thought doesn't have legs. I do notice however that I added inner strengthening layers to the chassis around the gear layshaft areas on both the 04/08 chassis to beef them up a bit and this may well help absorb some produced vibration noise. Strangly I have found that these Chinese 7mm coreless motors run nicely 'out-of-the-box' with the default settings on the DCX 76's whereas the Farish & Nigel Lawton coreless types both need some tweaking with CV's to get the best out of them.

 

Will you be fitting stay-alives? Having now experienced the advanatge they produce even with good running locos like the 08, all my shunters will get them, and especially as I have also struggled to get really decent reliably running 03/04's.

 

In respect to the outside frames on the 08 I made a replacement footplate from thin brass shim sheet ( K&S sell very useful packs of it with a range of differing sizes), and then used point timbering strips glued to it with the OF's then soldered to them. The frames of course need isolating from the footplate, and the front/rear beams, so gaps were left. The front beams were made as a 'wrap-around' unit with the front steps and keeping a gap between the steps and frames proved 'interesting'. Plasticard between the frames then isolates the chassis from the footplate when it's all screwed together. I did post some shots on the yahoo VAG in the distant past but not sure if they are still around on the new IO VAG so have added a few here in case they may help anyone.

 

 

 

 

 

 

 

regards,

 

Bob

[D869]

Simple question. An Association 03 chassis with 7mm Chinese motor. Runs absolutely fine and in reverse is almost silent while in the forward direction sounds like a miniature coffee grinder. Why in one direction but not the other? Any ideas?

 

David

 

I've puzzled over similar issues in the past although not quite to 'coffee ginder' severity. As others have said, the main suspects must be the motor, worm and (less likely) wormwheel/spur gear assembly. End thrust is one possibility, probably the most likely but the friction between worm and wormwheel will also produce sideways thrust which will push the worm one way and the wormwheel the other. This could cause the wormwheel or spur gear to foul something.

 

Is the motor removeable? If so maybe try a different motor... or to isolate the issue... temporarily fit the motor with blu tack or whatever so that it drives from the opposite side of the wormwheel and then see if the coffee grinder effect happens in the same or the opposite direction. If it's opposite then it's the motor/worm. If not then it's further down the drive train - probably the wormwheel/spur gear.

 

Directional issues can come from further down the drive train but for a coffee grinder I think that motor is the most likely and the probability gets less as you head towards the wheels.

 

I must admit that when I did my 45xx I bought the 'dont put end or side thrust on a coreless motor' line and put a single UJ between the motor and the gearbox. This may or may not be overengineered.

 

Regards, Andy

[Caley Jim]

 The front beams were made as a 'wrap-around' unit with the front steps and keeping a gap between the steps and frames proved 'interesting'.

Tissue paper placed on the surface and then flooded with cyano-acrylate will provide insulation where clearances are tight.  Make it oversize and then trim back once the glue has gone off.

 

Jim