!!

Not Registered?

Welcome!  Please register to view all of the new posts and forum boards - some of which are hidden to guests.  After registering and gaining 10 posts you will be able to sell and buy items on our N'porium.

If you have any problems registering, then please check your spam filter before emailing us.  Hotmail users seem to find their emails in the Junk folder.


Thanks for reading,
The NGF Staff.

Author Topic: My new locomotive works...  (Read 56109 times)

0 Members and 1 Guest are viewing this topic.

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #705 on: September 02, 2019, 11:07:33 PM »
Thanks guys.  :)

I've changed my thoughts about the gearing and motor since yesterday. I'm now leaning towards one of Sven's 7mm coreless motors and a 1:25 reduction. Sven's motors are 5,000 rpm slower than Nigel's ones and the N1 would have a theoretical top speed of around 84mph with the revised gearing (I can also have a flywheel). However, I need to resolve how I'm going to mount the rear pony, or if I'm going to make it fixed, before proceeding further.

Therefore, with this playing on my mind and the need to fill up an etch sheet before I can do anything, I decided to start another loco body.



This one is a ground up redesign of my old C12 4-4-2. My existing version runs on a Dapol 14xx chassis and is a bit of a jack rabbit! I'd also like to increase the weight available for traction. The original CAD is a little basic compared to my more recent efforts and the file has become unstable on the latest version of my CAD software. It's taken a little while to get to this stage; one of the problems when you've got drawings with most of the dimensions on it!

It'll eventually become 4511, a Hitchin based locomotive. The like below takes you to a picture of it at King's Cross in 1938.

https://mikemorant.smugmug.com/Trains-Railways-British-Isles/LNER-and-BRE-and-BRNE/LNER-pre-grouping-locomotives/GNR-locomotives/i-7QbxWds/A

« Last Edit: September 02, 2019, 11:09:31 PM by Stevie DC »

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #706 on: September 03, 2019, 05:08:26 PM »
The C12 has progressed a little today. However, this afternoon I turned my attention back to the C1. Those with good memories will recall that I'd hacked about a Dapol Hall chassis and fitted it with Britannia driving wheels (the biggest that would fit). The bogie and cartazzi truck wheels are the largest bogie wheels Farish produces while the tender wheels are Peco Collett spares. The motor (Nigel Lawton 8mm) is mounted in the tender and drives the loco using the Hall's drive shaft.

The issue has been getting the weight distribution right. Too far forward and the rear loco wheels jump of the track. Too far back and it won't haul anything (or even itself). I tinkered with it just before I went on holiday and resisted the urge to throw it against the wall! I decided to take a slightly more scientific approach and came up with this.



Nothing special, just a piece of tufnol with the center acurately marked out and a piece of 2mm brass rod taped underneath. The photo is deceptive as it is not quite perfectly balanced and will fall to one side after a couple of seconds (I was just quick with the camera!). However, it seemed sufficient for my purposes. I unsoldered the wires to the tender and placed the loco onto the board. This showed that the loco was badly tail heavy and so I disassembled the chassis and added as much weight as I could up front. This didn't cure the problem and so I had to carefully remove lead from the rear of the locomotive (superglued into place!). The body now showed that the weight fell between the splashers but I had forgotten to account for the weight of the chassis!

Back apart again and more weight removed from the rear of the loco. Eventually, I got the weight to fall slightly in front for the center of the two driving wheels, which puts most of the weight over the wheel with the traction tyre. I then reassembled the loco and gave it a quick run along a temporary test track.



An unscientific test of briefly holding the tender to prevent movement showed that the traction tyre was gripping both forwards and backwards. I've still got a couple of changes to make, but I'm happy that things seem to finally be on the right track now.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4985
  • Country: gb
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #707 on: September 03, 2019, 07:57:55 PM »
My existing version runs on a Dapol 14xx chassis and is a bit of a jack rabbit!

Have you considered retro-fitting a coreless drive to the 14xx, as in the current NGS journal? Seems this could be a good way to improve the existing loco.

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #708 on: September 03, 2019, 09:29:29 PM »
Have you considered retro-fitting a coreless drive to the 14xx, as in the current NGS journal? Seems this could be a good way to improve the existing loco.

I have but I'd like to get some more weight over the driving wheels. While the change of motor will free up some space, leaving the whole area available for weight would potentially be better. Besides, this is something I've wanted to try for some time now.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4985
  • Country: gb
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #709 on: September 03, 2019, 09:32:43 PM »
I have but I'd like to get some more weight over the driving wheels. While the change of motor will free up some space, leaving the whole area available for weight would potentially be better. Besides, this is something I've wanted to try for some time now.

Sure, but to make a useful loco out of this one, I'd have thought this would be economical - with the size of the prototype a good flywheel could be added to give both mass and performance. I'd have thought that filling the smokebox with lead and the bunker with lead would give a loco capable of pulling more than the prototype.

Also, check the springing of the rear 14xx wheels - they can be overdone which doesn't help.

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #710 on: September 03, 2019, 09:37:46 PM »
Sure, but to make a useful loco out of this one, I'd have thought this would be economical - with the size of the prototype a good flywheel could be added to give both mass and performance. I'd have thought that filling the smokebox with lead and the bunker with lead would give a loco capable of pulling more than the prototype.

Also, check the springing of the rear 14xx wheels - they can be overdone which doesn't help.

Thanks Alan, I'd like see through spoke wheels as well and a correct wheelbase. To be honest, I'll probably sell the existing one.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4985
  • Country: gb
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #711 on: September 03, 2019, 09:46:19 PM »
Thanks Alan, I'd like see through spoke wheels as well and a correct wheelbase. To be honest, I'll probably sell the existing one.

Understand regarding the spokes, though wheelbase wouldn't bother me too much.

I will need to revisit mine and improve the motor. Shame I don't know the original builder - I re-wheeled, re-motored, detailed and re-painted her from an ageing LNER black; but the core is an exquisite scratchbuild. Shame I think I picked the weakest of the motors I have to fit to it (literally a rouge I think, as the Bachmann 5 pole is generally a good unit)!



Hopefully the original builder would approve of her refurbishment.

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Newportnobby

  • Global Moderator
  • Trade Count: (+68)
  • Full Member
  • *****
  • N Gauge Society Number: 21962
  • Posts: 32608
  • Country: england
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #712 on: September 03, 2019, 09:47:26 PM »
Nice job on the C1, Steve. It appears to run very smoothly and quietly.

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #713 on: September 03, 2019, 09:51:00 PM »
Understand regarding the spokes, though wheelbase wouldn't bother me too much.

I will need to revisit mine and improve the motor. Shame I don't know the original builder - I re-wheeled, re-motored, detailed and re-painted her from an ageing LNER black; but the core is an exquisite scratchbuild. Shame I think I picked the weakest of the motors I have to fit to it (literally a rouge I think, as the Bachmann 5 pole is generally a good unit)!



Hopefully the original builder would approve of her refurbishment.

I remember when you got that Alan. It is an exquisite bit of work and I think that the original builder would have very much approved of what you've done with her. Hopefully you'll sort out the motor issue in due course.  :)

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #714 on: September 03, 2019, 09:53:30 PM »
Nice job on the C1, Steve. It appears to run very smoothly and quietly.

Thank Mick, it's taken a lot of work to get it to this stage! The original fixed bogie has gone and has been replaced with a Farish bogie with a scratch built connecting bar and fixed directly to the underside of the body. It seems to hold the track well enough.

I also had to use Alan's dodge of placing a washer on one of the gears to obtain a reliable mesh.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4985
  • Country: gb
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #715 on: September 03, 2019, 09:57:01 PM »
Hopefully you'll sort out the motor issue in due course.  :)

It runs fine, but just cogs really badly from pole to pole at low speed, not at all like this motor in general. Not a high priority, and in the running fleet still, albeit like many is awaiting the ultimate project layout.

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #716 on: September 06, 2019, 12:34:36 PM »
I've been playing around a bit more with the C1 but I've become dissatisfied with the tender pickup arrangement. The current arrangement using very thin phosphor bronze wire rubbing on the backs of the wheelsets. Unfortunately, no matter how much I adjust them they produce quite a bit of drag. A split frame arrangement looks more appealing at the moment but what to do about the wheels?

I have a set of Farish split frame tender wheels but found that the axle diameter is only 1.2mm - too small for the 1.5mm inside diameter bearings I have available. The Peco wheels use 1.5mm diameter axles but have plastic centers. I started thinking about how I could make the wheels live to stub axles and experimented on a spare set of wheels I have.

First I filed a notch into the rear of the tyre using a on of the edges of a fine square file.



Next I shaped a piece of 0.12mm phosphor bronze wire into an "L" shape and placed it into a tiny slot cut into the center of the wheel using a piercing saw and a fine blade (two strokes max). Then, using a piece of wire, a tiny amount of superglue was placed on the back of one of the spokes (as far away from the tyre as possible) and the wire was temporarily secured in place. Some bluetack was used as a temporary jig, liquid flux applied to the slot in the tyre and solder applied (very quickly as to not melt the plastic) to secure the wire to the rim of the tyre.



I then cleaned up the joint using a fine sanding stick and finished off the back of the wheel using 1200 grit wet and dry paper.



From the front, the wheel looks unaltered.



I then cut some 1.5mm axle steel to length and cleaned up using files. I also put a chamfer on each end of the axle length before pressing it to the wheel, holding the stub axle in a pin chuck.



The resulting assemblies are electrically live between the tyre and the axle and just need a plastic muff to finish off.

Online Dr Al

  • Trade Count: (+49)
  • Full Member
  • ***
  • Posts: 4985
  • Country: gb
  • Gender: Male
    • Awards
Re: My new locomotive works...
« Reply #717 on: September 06, 2019, 01:14:43 PM »
I assume these are spare PECO Collett tender wheels - if so, conductors can be bought for a pittance from Peters Spares:

https://www.petersspares.com/peco-38313-collett-contact-disc-tender-wheel-black-electroless-nickel-plate-pk2-n-gauge.ir

They work very well, are completely invisible, and just clip into the inside edge of the wheel behind the spokes. I've used them on a recent UM tender wheel conversion where I fitted PECO tender wheels instead and needed a side of wheels to be conductive with complete success.

Cheers,
Alan
Quote from: Roy L S
If Dr Al is online he may be able to provide a more comprehensive answer.

“We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.” – Dr. Carl Sagan

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #718 on: September 08, 2019, 11:58:16 AM »
I assume these are spare PECO Collett tender wheels - if so, conductors can be bought for a pittance from Peters Spares:

https://www.petersspares.com/peco-38313-collett-contact-disc-tender-wheel-black-electroless-nickel-plate-pk2-n-gauge.ir

They work very well, are completely invisible, and just clip into the inside edge of the wheel behind the spokes. I've used them on a recent UM tender wheel conversion where I fitted PECO tender wheels instead and needed a side of wheels to be conductive with complete success.

Thanks Alan, I'll look into those.

Offline Stevie DC

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 2120
  • Country: 00
    • Awards
Re: My new locomotive works...
« Reply #719 on: September 08, 2019, 12:00:31 PM »
I spent a bit more time this morning on the redesigned C12.



Still plenty to do, but it is getting there.

 

Please Support Us!
November Goal: £60.00
Due Date: Nov 30
Total Receipts: £25.00
Below Goal: £35.00
Site Currency: GBP
42% 
November Donations


Advertise Here
anything