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Fryers Lane - Speedlink in the '80s (P4)


Mark Forrest
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I suspect that under load the wire won't behave as you think Mark. The bit of wire that runs parallel to the servo arm may not move with the arm.

 

Either that or constantly twisting the wire will cause it to eventually fail.

 

Or C something completely different...

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Im Back

 

post-6677-0-50462500-1440339945_thumb.jp

 

 

Mark, etc

 

remove the front bracket and replace with some sheet, large enough to cover the rectangular hole that your operating wire is currently going through and the two front bolts holes

 

in the sheet we need to drill two fixing holes to match the bolt holes and we need to drill small hole 1mm should do, at the front so that the small hole is above the centre of the rectangular hole that your existing wire goes through

 

Remove the bracket with the servo in it and bring it forward so that the front face of the servo horn is in line with the back of the 1mm hole, murphy's law states that the existing holes in the servo bracket are now in the wrong place, to fix the servo in place but you should be able to sort that

 

 

Now you just need a operating wire with short 90deg bend to go between end hole in servo arm (servo arm vertical) and through the 1mm hole in the plate so that it engages with the sliding part of the tortoise plate, making sure that it isn't too long otherwise it will scrape on the underside of the baseboard

 

The operating wire needs to be restrained from coming out of the servo arm, bush made of sleeving and attached with super glue would work

 

The actuating wire needs to be Piano wire or Guitar wire so that it bends  to give the same effect as omega loop when the point blades come to the stock rail

 

Ideally the servo arm needs to move about 60deg (+-30 of centre) which will make it a lot easier to set up you can alter the arc of servo movement by lifting the servo bracket using longer bolts and spacers if necessary

 

The piece of sheet could be some thick plasticard 

 

for the wire I would try .4mm piano wire or No 24 guitar wire

 

Geoff

 

 

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I suspect that under load the wire won't behave as you think Mark. The bit of wire that runs parallel to the servo arm may not move with the arm.

 

Either that or constantly twisting the wire will cause it to eventually fail.

 

Or C something completely different...

 

I should have said why

 

Chris you are correct in your that the wire wont behave correctly it would need another bearing point, as soon  as you put load on the wire it would bend out of the way were it is bent at 90deg

 

Also the movement at the tie bar end would be the same as the movement at the servo arm end about 1.5mm max making it very difficult to set up the servo ending in unreliable results

 

Geoff

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Following Spam's corn store, I presume you hand scribed all the corrugations.

No chance.  Can't spend too much time on buildings, they get in the way of the important things in life, like wagons.  I will be throwing these together with little or no care or attention to detail in the hope that nobody looks past the wagons positioned in front of them.

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A slightly frustrating morning out in the garage working on the layout.  Two of the servos refused to move when I connected the wires as a makeshift switch.  At first I thought I must not have set the control board up correctly, so laptop out to the garage connected up to the board, only to find I needed new (Windows 10) drivers for the USB to serial adapter that talks to the board. The Wi-Fi doesn't reach that far so back indoors, took a bit of searching, but I did find the right driver and installed it.  Back out to the garage and all the settings seemed correct, but still no movement.  Swapped them around onto different sockets and still no good so was beginning to think I had two dead servos - which seemed odd as I had tested them all before.  

 

Then I thought to try them without the extension cables I had bought, and guess what - both were fine.  Test meter out; to find that two of the four extension leads I bought don't have one of the wires connected end to end.  So need to get a couple more cables ordered tonight.

 

After a set back like that the temptation is to pour another glass of red and forget about the layout.  Except that it is now less than a month until the layouts exhibition debut, so no time for slacking!  There's a 37 on the workbench awaiting new buffers and a couple of low relief buildings for along the back that need sorting out.

 

Mark

 

The connections at the end of the leads are crimped onto the wire then it is pushed into the housing which should lock into place, it could be that they haven't locked in the housing and have pushed back, check this by pulling the offending wire to see whether it comes out, if it does reinsertion could cure the problem

 

Geoff

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No chance.  Can't spend too much time on buildings, they get in the way of the important things in life, like wagons.  I will be throwing these together with little or no care or attention to detail in the hope that nobody looks past the wagons positioned in front of them.

 

I promise to look past the smelly diesels and modern wagons and to closely inspect all and any buildings.

 

Hope this helps...

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I've not looked at the Traintronics product, is that £22 for a servo control board? How many servos does each board handle or is that a cost per turnout?

 

Mark

 

Just had a look at the TT300 it's just a slow motion point motor that can work on DCC or analogue, so that's £22.50 per point motor !!!

 

silly money when you can research what's available using the internet

 

Geoff

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Following Geoff's description I've reworked the servo mount and this is what I now have:

post-6677-0-15593400-1440450727_thumb.jpg

 

The aluminium mount sits upon a slab of copperclad with a 1mm hole drilled in it at the centre point of the tie bar, the wire passes through this and into the tie bar.  Simple but effective, works a treat; thanks again to Geoff for pointing this out.  Thinner but stiffer wire is on its way, ready to be fitted at the weekend.

 

The layout is attending Scaleforum as a work in progress, but I'm keen to move it along as much as I can by then.  Here are the two buildings I was working on last night placed roughly in position.  The ground level between the backscene and the track will be slightly below track level.  This is currently in removable sections of foamboard allowing me to take sections away from the layout (which is out in the garage) to work on them in the comfort of my modeling room.

post-6677-0-08982000-1440450731_thumb.jpg

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