May not be much help but Dorman long list the following: http://www.unipartdorman.co.uk/assets/semaphore_signal.pdf BRS-SM 28/4 BRS-SM 28/5 BRS-SM 28/6 So dimensions are given in http://www.unipartdorman.co.uk/assets/086_009029.pdf and http://www.unipartdorman.co.uk/assets/086_009031.pdf for the cir...

The paint spec for the arms was quite thick, so as a suggestion (and I don't have access to such!) would be to powder coat? I guess it would have to be a white base coat and then the stripes would have to be stencilled on somehow..and the red/yellow fronts painted.... spraying it all would probably ...

As Keith asked, here is a link to a large video (about 84 meg) converted to MPEG 4 (no sound) from my phone http://people.bath.ac.uk/ccsrip/gl5/modbustest.mp4 It shows only one slave being controlled by a two-wire bus, commanding three servos independently or together. The slave is powered via a 9v ...

Hi all, to comment on a few comments. Arduino Micro. If you're sure that's what we need, I can get them, just let me know, but, the Farnell site points out specifically if using more than 12V the voltage regulator may overheat and damage the board . Not sure how this ties in for your requirement fo...

Can you not use the base to act as the heat sink? I think it's the same as 0 volt if using one on the 78 or 79 series. Just try to minimise the amount of work the regulator has to do, this will keep the heat down. I would not mind seeing the video but it's way over 10 meg not sure it would email? Y...

Here is a prototype setup (small images below) - it's got three servos attached to prove we can drive more than one arm. I did actually solder it to veroboard as I think a custom PCB is an unnecessary expense. I am re-thinking the veroboard approach though, just a small one to hold the voltage regul...

So since last post I've spoken on the phone to Jonny and much to my relief he's doing all the hard work and sorting out all the locking - it's cut the problems in more than half. I've got a master and two slaves doing my bidding (and video to prove it!) but I've run out of components. Jonny sent me ...

Thanks for the detailed explanation Richard. A couple of points. You say we only need 3 input lines. I hate to disrupt things, but we were assured that we needed only two signal wires, two for power, and three for manual control, so we now have 50 off, seven pin sockets to suit. Do we now need 9 pi...

No news on the electronics. Jonny, Richard? I'll explain the point I am at. Mostly trying to find time to get anything done! So when it was originally suggested I got involved in the programming of an programmable electronics board, Johnny suggested the Ardunino Leonardo, I haven't been to previous...

I can fairly easily thread rod - I have some welding rod, but we best stick with a consistent supply so it's all the same if you're the quartermaster Dave :-) I have a post you gave me at Gilling - I would guess the exact length of rod for the U-bolt will be calculated by maths or by empirical means...

Richard, I could help with the 'U' bolts. Are they all the same size or are there different widths or lengths? If you can send me a drawing with all dimensions and preferred material I'm sure I could ease the burden! Steve. I don't have drawings either - anyone? To my knowledge there would be two d...

Doug supplied some for his ground disc signal kit, turquoise colour, I seem to remember him referencing it in his articles in Engineering in Miniature. Of note perhaps is that those old style 3D glasses with the red and blue-ish lenses aren't too far off, but the cheap lenses are film not thicker pl...

Just a note to add as we're powering the boards/servos, it looks like we going to need a "daughterboard" to hold the voltage regulator(s), we'll need a tap off to power the arduino and servos, as well as the lamps, so we'll have to join up some of the electronics if we're going ahead with modbus (ne...

Richard, thanks for the offer with U bolts. Will you be able to do the cutting, trimming and threading as well, or will you need someone else to help? I reckon there will be about 150 to make! The pipe bender arrangement sounds good, you can then change wheels to make U bolts for the two diameters ...

I can help out with U bolts, although as I don't have any kind of mill any former would need to be supplied to me, I guess something like a pipe bender arrangement would make for consistency... so just a bar with a stop bending round a slight clamp pin? I could knock one up out of bar stock I suppos...

Got the jitters? Going back a few years we did fit a small unit between the rc receiver and the servos on some of our production models at work. This was done to try and smooth out the survo movement coursed by interference. Maybe a survo smoother might help, most model shops should be able to get ...

Looks good Dave, wouldn't mind having a go at one of these myself if we're doing a kit-of-parts (Royal "we" there :D ), does it need a jog to assemble? You mentioned the servo choice. I guess it's the logical option as it is what is used at Ryedale. Their posts produce quite a quite snap on/off. You...

I had started thinking about how signal control is to be done with the Arduinos, and it did occur to me we might be re-inventing the wheel - this is of course before I started looking into other possible solutions. The one that came to mind was Digital Command Control (DCC) - this already provides a...

Since all signals seem to be covered by the existing members of the group, can I then elect to make "spares"? And to be honest since I'm "down South" an don't get up to Shildon they probably will be. I'd be interested in doing two, maybe something a bit more fancy than a single post so a "Type 2" an...

If you want some close up photos of BR arms, you could do worse than check eBay, they come up from time to time, and what I didn't appreciate before I saw a drawing was the spectacle plate is pressed rather than cast. The links below show the welded stop on the back plus details like the "BR" letter...