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jcredfer

Light Switches? ... Turning the Tables...

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Hi Julian, a nice neat job which will be a nice addition to the layout. Best wishes to you and your family for Christmas and the New Year, Adrian

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Hi Adrian,

After seeing various videos which showed a number of alternative solutions for motor driven Peco tables, I was very much minded to take particular care over the build.  Noise was a feature which was often mentioned, most mentioned the Well having a "saggy bottom" in need of support and a couple claimed the wheels wobbled enough to fall free of the rail. 

 

The noisy motor / gearbox comments made total sense having picked up a Clearbox Motor at a show for a mere £7.  Their instruction leaflet says it's designed especially for schools, CDT and science project work.  For such use it is very clever, being simple to change the gear ratios and see the gearbox working through the polycarbonate case, but it is by that same case, a perfect soundbox.  That left a very simple choice, to look for a more suitable motor / gearbox or risk the neighbours suspecting my daughter was being murdered, any time the TT was used.  It was also, inconveniently, 6 V max.  The noise tests in an earlier Post show how the eventual choice was made.  A clear case of "ye pays yer money or fit the earplugs".

 

The wobbly wheels and the saggy bottom were less clear, as neither resonated with the Peco assembly instructions.  Firstly Peco make it very clear that the TT Bridge is intended to run on the wheels at either end, not the central axle.  How then can there be sufficient weight on the wheels on top of the rail at the well edge to distort the centre of the pan such that it needs substantial support?   :no:   The axles for the wheels are 2.4mm Dia steel, with the wheel boss being 2.5mm thickness, which did give slight wobble, but didn't look like enough for derailment.  I took care to check each wheel and bearing mounts for fit before glueing them together, leaving the axles free to be able to push them out for easy replacement.

 

A look at the Bridge [deliberately made first] included attempts to distort it and revealed a very strong rigid structure perfectly capable of carrying more than a couple of pounds.  That left the Well structure, made from 3 identical segments which fitted together with thickened, castelated, edges.  Putting the segments together in pairs gave rise to what seemed like a small clue.  Whilst the floor of the Well seemed to fit nicely, where the walls were meant to meet there was a small gap, less than 1mm.  A look back again at some of the videos, showed that also to be the case in several, clue two.  Those small gaps might allow the walls to distort inwards when weight was applied to the TT, thus the appearance of a saggy bottom.  The Magnifying Glasses showed a tiny bit of flash along the castellated floor edges.  With those as the only clues, I determined that the Well should be glued together along finely fitted edges, with no gaps at all.  So once satisfied all the flash was cleared the 3 parts were placed together with a further check for complete fit and then turned upside down on a flat surface.  I wound a long piece of wire, two turns round the outside rim and tied it off, such that a screwdriver could be inserted for a Spanish Windlass and then snugged.  Revell liquid plastic glue was run along the entire length of the joins and left to set.  Once dry, the TT was placed right side up and the inside of the joins had the glue applied along their length and left for 24 hours.  There seems no inclination for the Bridge to touch the Boss at the centre of the well, even when weight is added to it and I can see no movement anywhere on the walls or floor of the Well. No wonder railway travellers get constant reminders to "Mind the Gap!"

 

Kind regards and I hope you and yours have a delightful restful Christmas. 

 

Julian

Edited by jcredfer
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New Alloys [Go faster / smoother], tighter fit on the axles and less friction.  A bit of paint next.  :paint:

 

45941301304_2f91abce2f_c.jpg

 

Regards

 

Julian

 

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A little more progress.. The inside of the Well is now wearing it's basic coat and will get a misting of dirt and a ring of ash dust where the firebox passes around the Well.  The 3 x drain grids stood just over 1.5mm above the surface of the Well base.  That didn't look at all good, even 'though most grids vary above or below the level of the surface they drain, dependant on how many pints the workman had for lunch, 6 inches really didn't look right.  I turned them over onto some Blue Tac and applied a coarse emery board to the under side of each grid.  They now lie at a more reasonable level. 

 

 40028925663_8cacec087d_c.jpg

 

The outer lip is due a coat of cement colour soon and the polarity change ring can then be fitted.  The polarity change ring made a couple of clicks as the Bridge spring-contacts went over the 2 gaps, between the copper contacts on the ring.  There were 2 plastic pillows, presumably to lift each of the contacts away from the contact it was leaving, but when it had passed over the pillow, it came down with a clunk on the other side.  I tried to rub the pillow down, as it really wasn't that large, but that wasn't as easy as it sounds, causing some damage to the copper strips.  I then applied some Revell liquid plastic glue and left it to melt / soften the plastic pillows.  The flat side of a screwdriver was pulled across the pillow from the outer side, towards the centre, which pretty much flattened the pillows.  I now have to hope the rounded ends on the contacts will not bridge the gaps between the copper strips.

 

46993883581_397b7ff1d4_c.jpg

 

Regards

 

Julian

 

Edited by jcredfer
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Hi Julian, the turntable is looking really good, and the extra effort that you are making for smooth running and painting will pay dividends in the finished result. All the best Adrian.

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Temporary wiring was used to test the TT motors, which has now been replaced. The Decoder is now permantely soldered in, as are the TT Bridge power connections and a Resistor, Capaciter Filter [the little blue job on the Well floor] added to the TT Bridge connections, to safeguard against spikes which may be formed as the Bridge Rail contacts slide round to change the polarity of the Bridge rails.

 

The power supply connects through a screw type choccy block connector, attached to the brass arm [right side in the picture]; all the remaining connections are soldered to connectors fixed to the Motor Unit. It is now possible to remove the Motor Unit in it's entirety, leaving the DCC power wire input soldered to the TT Bridge, in the centre of the Well.

 

{NB. The polarity change is needed as when the loco drives onto the TT Bridge, the left-hand side of the loco will be on a positive supply rail, but when rotated through the 180 deg, the left-hand side of the loco will be facing the opposite [negative charge] rail.  But you all knew that didn't you.}

 

32326839507_3f303e51f0_c.jpg

 

Topside looks like this and and rotates very quietly indeed.

 

32212733667_0d35671c73_c.jpg

 

LMR 2-8-0 Austerity got a celebtatory turn, just to be sure and check the TT Bridge rail connections.  Actually, it got several...   Sshhh!!!

 

46240547705_2fbf1381ee_c.jpg

 

Regards

 

Julian

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Hi Julian, that looks really good, time well spent to get it looking that good. All the best Adrian.

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Turntable... ??

 

 

I was rather hoping to throw some light on the topic and thought these might help...

 

 

 40364624613_09cd81e64b_z.jpg
 

 

Regards

 

Julian

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Now, that's a bit more light on the idea...

 

Never soldered anything quite that small, ummm...

 

40374831263_fa1b9bb25a_c.jpg

 

A couple more to do, yet.

 

Julian

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Hi Julian, that looks like a job for a steady hand and no interruptions from mobile phone calls or people cold calling trying to flog you double glazing. All the best Adrian.

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10 hours ago, westerhamstation said:

Hi Julian, that looks like a job for a steady hand and no interruptions from mobile phone calls or people cold calling trying to flog you double glazing. All the best Adrian.

 

All that is of little problem compared to the shaking hands, so lots of BluTak, as well as the clamp and both hands on the Iron, so the Zigs on one hand counter the Zags on the other.  :blink:

 

I have a slightly larger board to solder up, so I thought I would have a practice on a few of these.  They are only £1.50 each and, being separate, any errors would be easier to spot on individual boards.

 

Regards

 

Julian

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After a little of this...

 

Grid_Holes_3.JPG.824260fc93e8e591984d0c7075c4196b.JPG

 

Which ends up like this...

 

Grid_Holes_2.JPG.0a8c046bc93f90feb80a3e4001097c3e.JPG

 

I can now get to fit one of the PCBs I was working on

 

Regards

 

J

 

 

 

 

 

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You will probably already know that the Peco Turntable has a Polarity changer under the Bridge, so when it turns the polarity is correct to move onto the track it faces.  That's good and works fine, well almost.  Where the polarity swaps there are 2 small gaps [picture below], to ensure it doesn't cause a short, between the two contacts.  As a sound fitted loco rotates on the Bridge, the sound will cease for a couple of seconds as that gap is traversed and then start again.  I'm filling the gap in the sound with a simple Simmer sound from a PCB.  Loco drives on, chuffing nicely and stops, leaving it simmering.  The TT starts rotating and at around the 90deg point the simmer stops, so the PCB simmer will cover up the loco silence, until power is restored to the loco.  Further TT rotation will fire up the loco and turn the PCB off.  What could possliby go worng??

 

46993883581_397b7ff1d4_c.jpg

 

These are a selection of the small PCBs I used for practice soldering on a PCB.  The sound making PCB I eventually made is on the top left, with the little red handles and what I will eventually fit under the newly converted religeous Grid. in the TT Well, is on the right.

 

47628808861_67fcaa8cd8_c.jpg

 

The one I made from a kit had adjustments for the volume and the chuff rate.  What I didn't know, was that the minimum chuff rate wasn't zero, so a simple Simmer wasn't possible.  The other one has volume and also the 2 x green wires are feeds, which sense the track voltage and start the chuffs at an adjustable rate.  It sounds like this...

 

47628371711_2193a49375_z.jpg

It's Hisssssterical.    :(

 

If you look carefully at the pencil at lower left, it is pointing to a Meccano brass collar [remember them?].  Power for the PCB will run thtough a contact on one side of the collar.  Another pick-up will contact on the diagonally opposite side of the brass collar.  Whilst these 2 x pick-ups are in contact with the brass collar, the Simmer will play.  However, I want the sound to stop playing, when the TT Bridge is lined up with the tracks, as the Loco will be making it's own sounds to run on / off the TT.  In order to stop the PCB sound, there is an insullated stripe down one small section on the brass collar [my daughter will probably not notice that some of her nail varnish has contributed to silencing the PCB].  This simply cuts the power, until the TT Bridge starts to rotate again.  Once it has gone 180 deg, the insullated stripe is under the opposite pick-up, so power gets cut again, so the loco can leave with it's own sound again.

 

Regards

 

J

 

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I bought one of these, Austerity 0-6-0ST LMR livery.

48624908482_2593e3322a_z.jpg

In the box, is one of these and there is no relevant paperwork to answer what it might be.

 

48213404921_2047176b6a_z.jpg


I don't suppose anyone might know where it is supposed to fit?

I looked under it, but can't see any blank spaces asking to be filled. Is it possibly a representation of the Coal Bunker shutter?

Regards

Julian
 

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6 hours ago, westerhamstation said:

Hi Julian, I hope this link might give you some clues as to what it is. All the best Adrian.

http://www.rtmodels.co.uk/4slp050 rt models 4mm scale dj models austerity j94 detailing sheet.pdf

 

 

Thank you Adrian, that is a lovely set of etched parts, a small contribution to RT Models may soon be on it's way. 

 

I had a reply on Facebook, apparently the plastic bit which came with the LMR 0-6-0, is meant to be fitted under the boiler, to represent valve gear.  Looking at it, it will need some research and a bit of modification before it reaches the parts beneath.

 

Best wishes

 

Julian

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