Little Muddle

[Mick Bonwick]

7 minutes ago, KNP said:

He’s still smiling though.....

 

 

Or is it case of grin and bare it?

[The Johnster]

Lima were not half bad at plastic mouldings, especially for 'cheap and cheerful' models, but it all went a bit cheap and miserable below the running plate.  The 4575 was one of the less appalling ones, but the lack of chassis detail, steamroller wheels, and cab filling motor let it down, and the slow running performance was at best achieved in spite of rather than because of the drive.  The motor is actually a pretty good performer, but it is far too big and the spur gears introduce far too much friction for it to ever run really well in the model.  

 

If I may make some suggestions... if you can remove the sliding cab shutters, not an easy task i'll admit but possible, and replace them in the closed position this will further obscure the view of the motor; a dab of matt brown or black over the shiny brass carbon brush spring holders helps as well.  New wheels, to replace the solid backed Lima pony and trailing, and new driving wheels if you can manage it  will 'lift' the model, as will etched brass number plates and new buffers of course.  But the biggest issue is that 2mm too high sit of the body on the chassis, which will be horribly obvious as a mismatch of buffer heights and show the model up drastically if it is ever positioned alongside a Bachmann small prairie.  It is particularly noticeable in the gap over the rear pony wheels.  

 

It's a good project though and I'm keeping an eye on your progress, good old fashioned knock about hacking about to improve poor RTR and make it at least passable as a 'layout loco'.  These things can be picked up cheap as chips as shows, if we ever have shows again!

[The Johnster]

17 minutes ago, KNP said:

butt cheek reduction to ensure he cleared the cogs.

Could do with some of that meself!

[KNP]

A couple of quick snaps of the Prairie out and about showing off the new crew, strategically placed in an effort to conceal the large lump of a motor....

 

 

 

 

Edited March 25 by KNP

[Harlequin]

Hiding in the trees like that and up on it's toes it looks like a startled deer!

 

 

Edited April 29, 2020 by Harlequin

[KNP]

 

Edited April 29, 2020 by KNP

[checkrail]

5 hours ago, The Johnster said:

Lima were not half bad at plastic mouldings, especially for 'cheap and cheerful' models, but it all went a bit cheap and miserable below the running plate.  The 4575 was one of the less appalling ones, but the lack of chassis detail, steamroller wheels, and cab filling motor let it down, and the slow running performance was at best achieved in spite of rather than because of the drive.  The motor is actually a pretty good performer, but it is far too big and the spur gears introduce far too much friction for it to ever run really well in the model.  

 

If I may make some suggestions... if you can remove the sliding cab shutters, not an easy task i'll admit but possible, and replace them in the closed position this will further obscure the view of the motor; a dab of matt brown or black over the shiny brass carbon brush spring holders helps as well.  New wheels, to replace the solid backed Lima pony and trailing, and new driving wheels if you can manage it  will 'lift' the model, as will etched brass number plates and new buffers of course.  But the biggest issue is that 2mm too high sit of the body on the chassis, which will be horribly obvious as a mismatch of buffer heights and show the model up drastically if it is ever positioned alongside a Bachmann small prairie.  It is particularly noticeable in the gap over the rear pony wheels.  

 

Nice job on that prairie Kev. Talk about making moonbeams out of cucumbers!

 

Seem to remember some article in a mag (MRC?) yonks ago (in, or even before, the days of Crownline detailing kits) where someone had converted Lima's 4575 into a flat-topped 45xx (which of course you already have).  But his observations apply to both variants. He removed the upper body from the footplate and took something like 2mm off the bottom all round.  The excess height, IIRC, was due to the height of the installed Lima motor, but he carved some plastic (?) off the top of it and got it to sit at the right height without compromising its running.

 

 

[The Johnster]

That would do the job, and you may have to take a bit of material off the inside of the cab roof as well.  The video shows what these crude Lima mech are capable of if they wheels and pickups are kept scrupulously clean and the spur gears are all in alignment, but I reckon she'll demand that you pay attention to such matters quite a bit to keep her running like that.  I'd be even more tempted now to pick one up if it was cheap at a show; that performance is all right for auto work, which 4575s do in my location and period.

[Neal Ball]

For an old Lima loco it’s doing really well @KNP I bet your really pleased.

 

In the video, how do you stop the LED flicker showing?

 

I did a video a while ago using my DSLR to show the sound on one of my locos and the flicker was so bad I deleted the video.

 

Thanks, Neal.

 

 

[KNP]

51 minutes ago, Neal Ball said:

For an old Lima loco it’s doing really well @KNP I bet your really pleased.

 

In the video, how do you stop the LED flicker showing?

 

I did a video a while ago using my DSLR to show the sound on one of my locos and the flicker was so bad I deleted the video.

 

Thanks, Neal.

 

 

 

This video was done my iPhone 7 which seemed happy to film under LED's whereas my Panasonic TZ100 flickered like a good 'en.

No doubt there is a good technical reason for this but I haven't found out yet.  

I also noticed that the phone, because of it's size of lens, had a greater depth of field and was easier to hold whilst operating the controller.

A phone clamp for my tripods has been ordered and in future this will be my preferred way of doing a video's of the layout.

[KNP]

Last of the station views, but this time a bit further back

 

 

Edited March 25 by KNP

[Worsdell forever]

1 hour ago, KNP said:

...A phone clamp for my tripods has been ordered and in future this will be my preferred way of doing a video's of the layout.

 

That's chickening out, go on, make one...

[Neal Ball]

2 hours ago, KNP said:

 

This video was done my iPhone 7 which seemed happy to film under LED's whereas my Panasonic TZ100 flickered like a good 'en.

No doubt there is a good technical reason for this but I haven't found out yet.  

I also noticed that the phone, because of it's size of lens, had a greater depth of field and was easier to hold whilst operating the controller.

A phone clamp for my tripods has been ordered and in future this will be my preferred way of doing a video's of the layout.

Thanks Kevin. I did some research and it’s all down to the recording rate on the DSLR. There are tutorials about changing the recoding speed to suit the LED but my camera was having none of it! 
 

I decided against using the phone at the time, I wanted to demonstrate the sounds and needed my hand free for the controller.

 

I will need more practice I think.

 

Thanks again, Neal.

[AY Mod]

2 hours ago, KNP said:

This video was done my iPhone 7 which seemed happy to film under LED's whereas my Panasonic TZ100 flickered like a good 'en.

No doubt there is a good technical reason for this but I haven't found out yet.  

 

It's all down to the phase of the fluorescent lights at any point compared to the shutter speed used in the video. Normally fluorescents are 100Hz here so there's a 100 on/off cycles per second; not enough for us to notice but a camera may do so (again based on the shutter speed being used). The only way to mitigate against it is to be able to manually control the shutter speed (and the fps) within the video) to ensure there's a consistent number of cycles within frames. Therefore shutter speeds of 1/100, 1/50 and 1/25 should end up with equal cycles/light whereas anything in between gives an uneven number. In the earlier video it starts off OK and then starts phasing over the viaduct onwards once the camera has automatically adjusted the shutter speed due to light levels. I've managed to achieve far worse results on occasions! The annoying thing is it's often not discernible on the camera screen but it certainly is when you get back to base.

 

It makes still photography look easy by comparison.

 

[Edit - sorry, you did say LEDs but the same principle applies]

Edited April 30, 2020 by AY Mod

[Darwinian]

As LEDs are DC is it not possible to smooth the supply to the LED lighting, thus eliminating the pulses which presumably originate from the AC conversion. 

Afraid my knowledge of electrics isn’t enough to suggest how.

[Harlequin]

If there's a "dimmer" involved the "brightness" control of the LEDs is probably implemented by Pulse Width Modulation (PWM). That is, turning the LEDs on and off very fast and varying the amount of time they are on vs. off.

 

So if the LEDs are not on full brightness it's more likely that a camera will pick up the on and off states, depending on the PWM frequency, the camera frame rate and "shutter speed". (I have the feeling that even on "full brightness" the PWM circuit will still turn the LEDs off for short periods, but I'm not sure about that.)

 

The frequency of the PWM circuit doesn't have to be related to mains AC frequency at all. You can buy PWM LED dimmers with a range of frequencies, 100-400Hz are common but you can get much higher frequency dimmers specifically to avoid flicker with electronic cameras.

 

Edited April 30, 2020 by Harlequin

[Neal Ball]

1 hour ago, AY Mod said:

 

It's all down to the phase of the fluorescent lights at any point compared to the shutter speed used in the video. Normally fluorescents are 100Hz here so there's a 100 on/off cycles per second; not enough for us to notice but a camera may do so (again based on the shutter speed being used). The only way to mitigate against it is to be able to manually control the shutter speed (and the fps) within the video) to ensure there's a consistent number of cycles within frames. Therefore shutter speeds of 1/100, 1/50 and 1/25 should end up with equal cycles/light whereas anything in between gives an uneven number. In the earlier video it starts off OK and then starts phasing over the viaduct onwards once the camera has automatically adjusted the shutter speed due to light levels. I've managed to achieve far worse results on occasions! The annoying thing is it's often not discernible on the camera screen but it certainly is when you get back to base.

 

It makes still photography look easy by comparison.

 

[Edit - sorry, you did say LEDs but the same principle applies]

 

Thanks Andy @AY Mod, I'm going to try again with the DSLR, but given its primarily a stills, rather than video camera, my options might be limited.

 

Will give it a go.

Thanks, Neal.

[Neal Ball]

1 minute ago, Harlequin said:

If there's a "dimmer" involved the "brightness" control of the LEDs is probably implemented by Pulse Width Modulation (PWM). That is, turning the LEDs on and off very fast and varying the amount of time they are on vs. off.

 

So if the LEDs are not on full brightness it's more likely that a camera will pick up the on and off states, depending on the PWM frequency, the camera frame rate and "shutter speed". (I have the feeling that even on "full brightness" the PWM circuit will still turn the LEDs off short periods, but I'm not sure about that.)

 

The frequency of the PWM circuit doesn't have to be related to mains AC frequency at all. You can buy PWM LED dimmers with a range of frequencies, 100-400Hz are common but you can get much higher frequency dimmers specifically to avoid flicker with electronic cameras.

 

 

Thanks @Harlequin. Strangely, here in Spain, you cant buy dimmer switches at all!

[DCB]

22 hours ago, The Johnster said:

  New wheels, to replace the solid backed Lima pony and trailing, and new driving wheels if you can manage it  will 'lift' the model, as will etched brass number plates and new buffers of course.  But the biggest issue is that 2mm too high sit of the body on the chassis, which will be horribly obvious as a mismatch of buffer heights and show the model up drastically if it is ever positioned alongside a Bachmann small prairie.  It is particularly noticeable in the gap over the rear pony wheels.  

 The body has two problems,  compared to the drawing in Russel the Boiler and tanks are around 2mm too high above the running plate.  The running plate is the right height but the buffer beams are too short and the buffers are mounted too high. They should be at the bottom of the buffer beam. The whole loco was lifted 3" when the 44XX became the 45XX with 6" bigger driving wheels so they used deeper buffer beams to compensate.    Carving 2mm off the tanks etc will lose all the rivet detail, so the result may look worse or be one hell of a lot of work.  Fitting buffers in the right place and 1mm or so extra depth on the buffer beams should be a 5 minute job, 2 hours at the most.

[KNP]

Thank you for the comments on 4589, very informative and useful.

She will be parked until the sandboxes/pipework arrive then I will fit and weather the hole lot.

 

The next project will be to bring King Stephen back into the workshop for renaming to King Edward V111 plus a few other tweaks that where niggling me.

 

At the same time I will work on some trainspotters - have an ideal place for them, can you guess?

 

 

Edited March 25 by KNP

[Bogie]

Watching the grate get unloaded off the back of the truck?

[Worsdell forever]

42 minutes ago, Bogie said:

Watching the crate get unloaded off on the back of the truck?

 

Corrected for you. 

[Tallpaul69]

2 hours ago, Bogie said:

Watching the grate get unloaded off the back of the truck?

Not if they are keen spotters!

 

I suggest they might be at the end of the platform watching the shunting?

Those were the days!

 

Cheers

Paul

[Banger Blue]

Spotters - on the end of the platform at either LM or ET.

 

Bashers = flailing like a loon out of the vestibule window, shouting “Dreadful” or “M’Lordz”

(although I doubt that type of activity was around in the 30s   )

[KNP]

Looks like the start of a race, need to give Jimmy a chequered flag!!!!