MERG Kit 75 Servo4

I received my kits from MERG today, so set about building the first of 2 Servo 4's I need to automate my two twin track level crossings. MERG are out of stock of the "Hector" kits which perform the train detection and communicate with the Servo 4 boards, so that'll have to wait a while. I completed and tested the first, all ok and ready for programming (that's another story!), but halfway through the build my Antex soldering iron began playing 'hot 'n cold' with me, much to my annoyance when you're trying to solder to a PCB. Checking with my multimeter showed an open circuit (the iron is only 18 months old and hasn't had that much work), traced to the mains lead where it enters the iron, so had to dismantle the iron, cut back the lead to remake the connections, and guess what??? You need a soldering iron to repair the soldering iron!!! (Good job I have several!). Yep, the connections to the element are soldered on, just unbelievable! Anyway, with repairs carried out, first board completed and tested, so at least the second one should go together even quicker (about an hour) than the first. MERG are going to email me when the 'Hector' kits become available again, so the build may stall for a while. As part of this project, I also bought a number of 3D printed servo brackets to go under the board, one under each gate (4 per crossing) is needed, so below is a pic of a bracket with servo fitted. There is also a cam which can operate an optional microswitch for barrier lights etc if needed, although with gates, I won't need this.
Keith.

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My layout isn't broken down into sections Paul, so can't monitor it with that kit. As I use the Lenz system, it has a very fast short circuit cutout so not felt the need to go down the sectionalise route. The only time I've had a fault cutout was when I bought an uncompleted M7 kit which needed motor, gearbox and suitable wheels. Having parked it on the layout for scenic value 'til I got around to finishing it properly (it's still not completed!) I then found I had a fault. Eventually, I realised that the fitted wheels were not insulated from each other side to side, hence the short circuit......Doh! Removing it cleared the fault.
Incidentally, I have half a dozen combined infra red emitter/detectors marked "RPR220" and wondered if you'd ever come across these and whether I could use them with the dual Hectors when I eventually get them? I gather that the Express Models level crossing automation setup uses these, and as they're an 'all-in-one' component might be easier to fit.
Keith.

 

Completed and tested the second Servo 4 kit today so now the projects on 'standby' until the 'Dual Hectors' become available!
Keith.

 

Oh-oh, another recruit to the MERG cause (otherwise known as the dark side!). We're taking over by stealth!!!

Keith.

 

As a further update to my present progress with this project, I received and built the two 'Dual Hector' boards, and experimented further with the 'RPR220' infrared detector heads, which worked fine. Eventually I arrived at my hoped for setup by 'parallelling-up' two sets of detector heads, and linking the switching connections such that if a train passed over any of the four detector heads, all four servo's operated to open the crossing gates. As I have a number of projects 'on-the-go' at any one time, I now have to get around to mounting the servo's under the layout, coupling the servo's operations to the gates themselves. Regarding the servo setup, I downloaded the MERG software to the 'spare' Windows laptop, bought a USB to Serial adaptor, basically I guess because the MERG setup box was 'out of stock' and I couldn't be bothered waiting, and set the servo's that way. All I need now is the time to complete the actual installation. Now I'm retired, I wonder how I ever found the time to fit work in!!! Keith.

 

I've never found a need to clean circuit boards (well, new ones anyway!) before soldering, as using 'Ersin' multicore resin solder seems to do the job without problems. I have a 7lb drum, given to me when working on a smelter in the early 70's, and I don't expect to run out of solder before I 'kick me clogs'! I have experience of gas torch soldering of both large electric cable lugs and plumbing fittings, both of which I normally used stick solder and "Fluxite" brand paste flux for, but not used any of the 'new-fangled' liquid fluxes, some of which I gather are made from or with pig poo (urea!!). Not yet having attempted building any white metal or brass loco models, I don't have any experience of low melting point solders either.
As an aside, can I ask what you are intending using the 'Servo4' board for Roger? I have now succeeded in fitting the four servo's under the gates of the first crossing, and worked out how to use four sets of infra-red detectors (one in each of 2 tracks, at each side of the crossing) with the "Dual Hector" board controlling the "Servo4" board and operating the gates, just have to 'fine-tune' the operation since it's still a bit too speedy in the way the gates open and close. My second set of boards test ok and operate independently, but only 3 of the 4 servo's operate when connected together. Fortunately, MERG have a local meeting at the Midland Railway Centre, Butterley, which is about 6 miles down the road from me this coming Saturday and I've booked onto this. Having pre-warned them about my problem, they are going to try and solve it for me. I'll let you know how I get on.

Keith.