Any Question Answered

[65179]

I'd go with epoxy rather than superglue Justin. CA isn't conductive in the absence of a conductive filler, but it's not the nicest stuff if heated.

 

Simon 

[justin1985]

39 minutes ago, 65179 said:

I'd go with epoxy rather than superglue Justin. CA isn't conductive in the absence of a conductive filler, but it's not the nicest stuff if heated.

 

Simon 

 

Thanks Simon - yes good idea. I had thought CA for ease of removing the motor if I ever need to again, but went with a thin bead of epoxy, as you suggest.

 

Justin

 

[65179]

A good tap in the right place and an epoxy bond can be broken easily enough. I've had to do it more often than I'd like when trying to get coreless motors nice and straight on a tender chassis.

 

Simon

Edited October 5, 2020 by 65179

[justin1985]

I'm sure I saw some discussion about turnout blade joggles in 2mm recently, but I can't find it again now.

 

I seem to remember it was concluded they're not often prototypical. However I've always ended up using them so far, as it seems the only way to avoid wheels hitting the end of the blade.

 

Does that mean I've never filed my blades thin enough?

 

Justin

[2mm Andy]

58 minutes ago, justin1985 said:

I'm sure I saw some discussion about turnout blade joggles in 2mm recently, but I can't find it again now.

 

I seem to remember it was concluded they're not often prototypical. However I've always ended up using them so far, as it seems the only way to avoid wheels hitting the end of the blade.

 

Does that mean I've never filed my blades thin enough?

 

Justin

 

The discussion re. joggles was on the 2mm Virtual Area group - look at the messages on/around 21st September.

 

Andy

[richbrummitt]

What would be a sensible adhesive for our SRBP (copper clad) sleepering to paper for a permanent bond?

[Geordie Exile]

12 hours ago, justin1985 said:

I'm sure I saw some discussion about turnout blade joggles in 2mm recently, but I can't find it again now.

 

I seem to remember it was concluded they're not often prototypical. However I've always ended up using them so far, as it seems the only way to avoid wheels hitting the end of the blade.

 

Does that mean I've never filed my blades thin enough?

 

Justin

 

There's also reference to/discussion of joggles in the Track book (Ch 5) and methods to shaping them and the blades.

 

[Ian Morgan]

11 hours ago, richbrummitt said:

What would be a sensible adhesive for our SRBP (copper clad) sleepering to paper for a permanent bond?

 

I have found double-sided sticky tape to be pretty permanent unless cut into very narrow strips

 

[richbrummitt]

23 minutes ago, Ian Morgan said:

 

I have found double-sided sticky tape to be pretty permanent unless cut into very narrow strips

 

Did you have any issues with ballasting (and the sticking of) subsequently?

[Caley Jim]

2 hours ago, richbrummitt said:

Did you have any issues with ballasting (and the sticking of) subsequently?

On Connerburn I laid the track (plain rail on chairplates on pcb sleepers) on 1" wide double sided tape and then sprinkled on coarse sand as ballast.  It's still secure 50 years on!  (photo taken in 2009)

 

 

Jim

[Caley Jim]

16 hours ago, justin1985 said:

Does that mean I've never filed my blades thin enough?

Switches need to be filed to pretty much a knife edge.   Something I've never seen mentioned (IIRC), though, is making sure that when you fit the switch the tip doesn't end up producing a slight tightening of the gauge.  I put a set in the curved stock rail and fit the first switch into that, placing a button gauge at the tip of the switch between it and the opposite stock rail.  I then lay the second switch so that its tip is in line with, and certainly no further from the crossing than, the first.

 

In theory the taper on the flange of the wheel should guide it over the tip of the switch by moving the wheel slightly away from the stock rail, but if the flange of the opposite wheel is hard against the other stock rail, this can't happen.

 

If your switch tip is too thick, then you can reduce it by gently rubbing its inside face with a fine file while it is hard against the stock rail.  Only file in a 'trailing' direction and slightly chamfer the top inside edge.  This is probably heresy, in which case I would ask Your Honour to take multiple other such offences into account!  

 

Jim

Edited October 9, 2020 by Caley Jim

[Chris Higgs]

1 minute ago, Caley Jim said:

Switches need to be filed to pretty much a knife edge.   Something I've never seen mentioned (IIRC), though, is making sure that when you fit the switch the tip doesn't end up producing a slight tightening of the gauge.  I put a set in the curved stock rail and fit the first switch into that, placing a button gauge at the tip of the switch between it and the opposite stock rail.  I then lay the second switch so that its tip is in line with, and certainly no further from the crossing than, the first.

 

In theory the taper on the flange of the wheel should guide it over the tip of the switch by moving the wheel slightly away from the stock rail, but if the flange of the opposite wheel is hard against the other stock rail, this can't happen.

 

If your switch tip is too thick, then you can reduce it by gently rubbing its inside face with a fine file while it is hard against the stock rail.  Only file in a 'trailing' direction and slightly chamfer the top inside edge.  This is probably heresy, in which case I would ask Your Honour to take multiple other such offences into account!  

 

Jim

 

I was looking (I don't know where or when) at a modern FB switch and it had a chamfer on the top edge. The don't have to be knife-edge at the bottom.

 

Chris

[£1.38]

8 hours ago, Chris Higgs said:

 

I was looking (I don't know where or when) at a modern FB switch and it had a chamfer on the top edge. The don't have to be knife-edge at the bottom.

 

Chris

That's my theory too. Both the flange and the tyre are tapered on the wheels, so only a very small part of the wheel is ever in contact with the rail.

 

 

I file the end of my point blades down to a thinnish profile, but still slightly blunt, before fixing them in place. Only then, do I file a gentle taper to the top of the tips of the point blades, getting them to merge with the top of the stock rail. That should be all you need for smooth running. The bottom of the point blade has no impact at all on the running of trains, so can be left relatively blunt.

 

Here are some diagrams on Templot to illustrate what needs to be filed away

 

https://85a.co.uk/forum/view_post.php?post_id=19573

Edited October 9, 2020 by £1.38
add

[justin1985]

20 hours ago, Caley Jim said:

Switches need to be filed to pretty much a knife edge.   Something I've never seen mentioned (IIRC), though, is making sure that when you fit the switch the tip doesn't end up producing a slight tightening of the gauge.  I put a set in the curved stock rail and fit the first switch into that, placing a button gauge at the tip of the switch between it and the opposite stock rail.  I then lay the second switch so that its tip is in line with, and certainly no further from the crossing than, the first.

 

12 hours ago, £1.38 said:

Here are some diagrams on Templot to illustrate what needs to be filed away

 

https://85a.co.uk/forum/view_post.php?post_id=19573

 

Many thanks for the tips chaps, really appreciated! I'm always learning with 2mm!

 

Putting a set (bend) into the switch rail to put the planed section back into alignment had completely passed me by, but makes a lot of sense when you think about it!

 

So far I've only got as far as the vee and the straight stock rail. I did put a very slight joggle into the stock rail - using the slot in single etch thickness method from the Track book, but then largely flattened back out again, so it's very subtle indeed. I'll give the switch rails that I've prepared a bit more attention to thin them down further.

 

J

 

[Izzy]

If you chamfer the top leading corner of the switch blade at 45degrees, so it sort of rounds off a bit, this helps to ‘lead’ the root radius of the wheel tyre into the switch. N gauge wheels with their NMRA RP25 curvy profile have less problems here because of the large root radius which keeps the bulk of the flange well away from the side of the rail. The 2FS profile by comparison has little in the way of a root radius, almost a sharp corner angle, so it’s easier for the bulk of the flange to run up against and catch the rail side/front edge. 
 

Izzy

[Caley Jim]

1 hour ago, justin1985 said:

Putting a set (bend) into the switch rail to put the planed section back into alignment had completely passed me by, but makes a lot of sense when you think about it! 

Read my post again, @justin1985. The set is in the curved stock rail, NOT the switch.

 

Jim 

[justin1985]

4 hours ago, Caley Jim said:

Read my post again, @justin1985. The set is in the curved stock rail, NOT the switch.

 

Jim 

 

Yup, understood Jim.

 

It was the Templot forum post linked by @£1.38 advocated putting a slight set into the blade itself:

 

"Put a set (that's a bend to you and me) in the rail at the planing length so that the end of the rail is aligned where the running face was (the picture should make this clearer). This location of this set is important since this affects the switch angle." [My emphasis]

 

I'm sure this is written with larger scales in mind, but the principle sounds sensible?

 

J

[Caley Jim]

That's not something I've seen advocated before so have never used.  You should be able to make it out in this photo on the top stock rail of the turnout on the right. 

 

 

My switches are all loose heel, so a set in them wouldn't be possible.

 

Jim

[nick_bastable]

59 minutes ago, Caley Jim said:

That's not something I've seen advocated before so have never used.  You should be able to make it out in this photo on the top stock rail of the turnout on the right. 

 

 

My switches are all loose heel, so a set in them wouldn't be possible.

 

Jim

is that a Barry slip gone north ?

 

Nick B

Edited October 10, 2020 by nick_bastable

[Caley Jim]

2 hours ago, nick_bastable said:

is that a Barry slip gone north ?

Ha! Ha! No!  It's two turnouts dancing toe to toe!

 

Jim

[Donw]

On 08/10/2020 at 22:29, justin1985 said:

I'm sure I saw some discussion about turnout blade joggles in 2mm recently, but I can't find it again now.

 

I seem to remember it was concluded they're not often prototypical. However I've always ended up using them so far, as it seems the only way to avoid wheels hitting the end of the blade.

 

Does that mean I've never filed my blades thin enough?

 

Justin

 

I did quite a bit of the posting about them on the VAG  I could forward them if I have your email.

Don

[Donw]

5 hours ago, justin1985 said:

 

Yup, understood Jim.

 

It was the Templot forum post linked by @£1.38 advocated putting a slight set into the blade itself:

 

"Put a set (that's a bend to you and me) in the rail at the planing length so that the end of the rail is aligned where the running face was (the picture should make this clearer). This location of this set is important since this affects the switch angle." [My emphasis]

 

I'm sure this is written with larger scales in mind, but the principle sounds sensible?

 

J

 

That very much sounds to me as though the blade has been incorrectly filed.  A simple way to remember is 9ft or A switch blades file at 1/24  12ft or B blades file at 1/32  15ft or C blades files at 1/40.  The code 40 rail is 0.5mm head width so for a B blade mark 16mm from the tip and file an even taper from the mark to the tip. On the straight stock rail side the blade should meet with the planned taper snuggly against the stock rail for the whole taper. On the curved stock rail you put a set in at the same angle and the curve then starts the same distance from the set (i.e 16mm for a B switch. This of course is a council of perfection and you may not get it as accurate as you would like. However a blade that just touches at the tip will be wrong and may be tight to gauge just after the tip. Obviously a blade where the tip isn't touching is even more wrong.

Don

[£1.38]

12 hours ago, Donw said:

 

That very much sounds to me as though the blade has been incorrectly filed.  A simple way to remember is 9ft or A switch blades file at 1/24  12ft or B blades file at 1/32  15ft or C blades files at 1/40.  The code 40 rail is 0.5mm head width so for a B blade mark 16mm from the tip and file an even taper from the mark to the tip. On the straight stock rail side the blade should meet with the planned taper snuggly against the stock rail for the whole taper. On the curved stock rail you put a set in at the same angle and the curve then starts the same distance from the set (i.e 16mm for a B switch. This of course is a council of perfection and you may not get it as accurate as you would like. However a blade that just touches at the tip will be wrong and may be tight to gauge just after the tip. Obviously a blade where the tip isn't touching is even more wrong.

Don

Jim and Don, have a proper look at the link I gave. The impression I get is that you are misunderstanding the concept. What is described there is a pretty common way of doing things, even in the likes of S7 and P4. It ensures that the blades fit snugly against the stock rails just like the prototype - and in my experience is an excellent way of doing things.

https://85a.co.uk/forum/view_post.php?post_id=19573

Not quite the same for modern times, where curved planing of point blades is now the norm. IIRC that only happened in the UK from the early 1960s though.

[Izzy]

I’m afraid I don’t see the need or desire for this. If the blade is planed at the correct deflection angle it should sit up against the stock rail with the closure rail sitting in the right place. Otherwise either the latter won’t be in the correct position or there will be a kink. Seems odd to me so I have to wonder what I am missing/failing to understand.

 

Izzy

Edited October 11, 2020 by Izzy

[Laurie2mil]

I don’t think you’re missing anything, Izzy. The Templot link explains how the modern prototype does it, which is impractical in 2FS. Keep it simple is my advice: a set to the planing angle in the curved stock rail, a 5-thou jiggle in the straight stock rail, and “plane” the switch blade straight and vertically to the switch angle, aiming for 0.1 - 0.125mm at the very tip. 
Sometimes I just can’t get it to sit as smoothly against the stock rail as it should - and that is the only time I would put a file along the top inside corner of the switch - just until it’s all smooth and to gauge. 
Laurie Adams