Jump to content

imt

RMweb Gold
  • Content Count

    631
  • Joined

  • Last visited

Community Reputation

246 Good

1 Follower

About imt

Profile Information

  • Location
    Newcastle upon Tyne

Recent Profile Visitors

259 profile views
  1. Nigel: Well true to their word, the courier arrived at 11.05 am and this is my first VERY CRUDE attempt with 3.3k ohm through the hole resistors using your suggested method. Held in place with a crocodile clip whilst one end wrapped round the axle and then stuck to the wheel. I used Bondic, instant curing under blue light. The other end was cut back and stuck to the wheel with NO contact with the axle. To keep things secure a drop of fast acting CA was put on the resistor package where it was close to/touched the axle. I then used Bare Conductive paint and the success of that after maybe 10 mins is in the second photo. The AIU is top left and the small red smd led can just be seen. No connection to the products named - they just do what it says on the tin. Now, the result is a bit of a mess, and I will get better, it's crude but it works. I have a spare pack of metal wheels which I can practise upon. There are some problems in that the led flickers with movement - improved by cleaning the track but I obviously need to get that paint/blackening off the wheel. Iain: Thank you for your continued encouragement. I understand your method and I have seen YouTube videos showing it. My problems are physical, knobbly finger joints and damaged sight. Now I am sure that there are many with worse problems than I and who do much better. I agree that those who can would find your method easier. The second part of the delivery is 1206 size SMDs and I WILL try again. Thank you both for your help and encouragement.
  2. I have had a message from the resistor supplier apologising for the delay and saying the 3.3k in two styles will be with me by noon tomorrow. I'll start with your through the hole idea first because it seems to me to be the less open to my clumsiness. I'll have a second go at the SMD approach too but that seems more chancy. I have just had a clumsy quick swing at the task as you suggest using a 4.7k through the hole and it worked quite easily. its just held in place at the moment but it does the job with no apparent current draw. I'll keep you informed.
  3. So it's not necessarily too much paint, but probably paint in the wrong place Nigel? I was trying to put paint onto the silver pads but not below the SMD. Perhaps I moved too quickly to do it, I tried to let the paint "dry out" a little before I used it so it didn't flow too much. Presumably make sure I leave it longer next time. I have just looked at the ampmeter - 0.3 amps as soon as I put the wheelset on the track and it heats quickly. So this is a short?
  4. Well that was fascinating. Something new I almost got right, and then it went wrong (again!). The 4.7k ohm through the hole and 1206 smd packages arrived to day, so this afternoon, with much trepidation, I set out to have a go. Firstly the 4.7k through the hole resistors DO actually register on the NCE AIU, so (even though I intend to use the 3.3k ohms when they arrive, as my mentors Iain and Nigel have advised) I thought I'd see whether I could make up a resistor set. I scraped the paint off the axle and at each end above the insulating bush. My attempts with CA on the through the hole type was not encouraging. they simply would not stick, the CA to metal was OK but not to the resistor. BUT the 1206 size SMDs looked doable, I could see them and I could pick them up with my "open the wrong way" tweezers. And I managed to stick one at an angle across the insulating bush so it touched the wheel and the axle. I then used my "Bare Conductive" paint along the axle to the other side and up to the opposite wheel, and then from the top of the SMD to the wheel it was touching. So far so good. Gosh I may be able to do this! Then I tested the resistance. It was over 10k but falling (?) and when it got down to about 4 I put it on the track and hey presto the AIU "saw" it. Go for celebratory cuppa and newspaper read. on return found that the wheelset was very hot - it would have melted a plastic bogie. Now the resistance is negative - if that's possible. I was generous with the paint. Is that what I did wrong or is there something else? Or maybe many something elses! Feeling happy that I can do this, just need guidance to get it right.
  5. You are quite right Iain, and had I not started travelling down the NCE route 7 years ago I wouldn't be using their gear now (the old "How do I get to Tipperary? Well I wouldn't start from here" joke) I have quite an investment now and I didn't feel like trying mix and match. I decide that I'd finish this layout as I started - and at 76 there may never be another. The problem with NCE is it's all old designs and no development - but at least it does what it says on the tin. IF I were starting again I would probably go with Digikeijs - European, broadening range and well documented. But others would no doubt differ. Iain
  6. Thanks Iain. I hadn't thought of that. At the moment I don't have lights or additional decoders, though I do keep thinking about it - especially for my 101 and 108. Presently the BOD process is taking up my time and pocket money!
  7. OK I'll stop panicking Nigel! Thanks. I THINK I understand all that. The 3.3ks should arrive tomorrow so I can start testing from there. I intend to have a reistor set at each end of the two carriage subsets which make up my rakes. My maximum length is 5 carriages (6 a real push) and the extra coach would tend to be a an RU or similar in the middle or a BG for parcels on the end. These extras would probably have a resistor set at each end. The maximum my fiddle yard and station can hold would be less than 2 dozen "carriages" and that would mean the same number of resistor wheelsets (given that some are 121s (need none) or 117s (need 1 at end) and most are in 2 carriage subsets with 1 resistor each end). So I think I am in the .25amp load area - or 2 sound locos idling! I'll think through how to manage the freight later. My SB5 is 5 amps so I won't hit the maximum, and my 3 power districts and accessory bus have 1.75amp limiters. Thanks very much, I have learned a lot, and I hope others will find this useful too. I'll let you know how I get on.
  8. Well thanks Iain and Nigel. But I have been thinking (again?) and would like a further response. As I told you I was putting 3 * 10k across the piece of track I was using to test the whole BOD idea, and that was resulting in an "occupied" light from the AIU. You explained that meant that I needed 10000/3 (special case as all 10k) or 3.3k. Then I had this horrible thought in the middle of the night!. If I put 2 * 3.3 on the first and last wheelsets on a coach what would happen - would this mean that the coach would not be recogised because 2*3.3/2 is less than I need? So I did an experiment this morning with 3 10k close together and they registered occupied as you would expect. I then slid one half an inch away from the other 2 - still occupied. But at about an inch not occupied any more. So it seems to me in my ignorant state that a 3.3k ohm resistor at either end of the coach will be ok - but will it? They will both (and maybe including a loco) be in 1 BOD block. How about short UK waggons when in a rake? Am I just panicking unnecessarily or are there more gotchas to trip over??
  9. Never was much good at physics - but I managed to fly alright without that knowledge. I have ordered some of those too - so I should have it bracketed. I'll let you know what transpires. Thanks for all your hlep Nigel - as usual.
  10. So as I read the kind replies, what you are saying is that I am using TOO BIG a resitor at the moment and that's why a single one doesn't work - adding resistors actually LOWER the overall resistance. Hence using Nigel's simple sums (thanks so much for the simple I need it) I need to buy 4.7k resistors since I have (and intend to keep) 2 turns. As usual RTFM, but I didn't really understand it when I did! I know you mean well when you keep reccomending SMDs - I really cannot get on with them so I will get some 1206 to try and also order the smallest 4.7k "through the hole" I can get and see which I manage with best. They are as cheap as chip - ugh!
  11. I expect this is an oft asked and answered question, but I cannot find the answers using Google or RMWeb search - so here goes. I have a layout controlled by JMRI and using NCE products for power supply and other electronics. I want to move on to Block Occupancy testing so I have acquired the necessary additional hardware - an NCE Auxilliary Input Unit and some BD20 occupancy sensors. I am at the stage of testing before upending my layout to perform surgery undernesth to add the detectors where necessary. I have used my stand alone loco programming track to loop in a BD20 on one of the supply wires and to see how things go. Now a DCC loco is detected and an LED shows on the AIU. It's a Bachmann 08 and it draws about 0.1 amps when just sitting there. So that's OK: locos on the layout will be "seen" and the software can react to that. But of course I want the whole train, or the odd rake of coaches left in a platform, or the whole length of a DMU to register appropriately. This means resistor/resistive wheelsets and there the problems begin. I know nothing of electronics. I am quite good at other things but sadly not electonics, brain surgery or rocket science. I have found some YouTube episodes describing how to use SMDs for this purpose. I bought some but they were so small that I couldn't get on with them - damaged eyesight and arthritiky fingers. As you will all know, magnifiers are all very well but they insist on magnifying the tweezers too! So I bought some "through the hole" VERO type resistors (10k ohm) which I can see and have nice pieces of wire that I can solder to things. My intention is to CA the resistor to the axle and then solder the wires to the back of the wheels above the insulating bushes. In my test before doing anything permanent mode I thought, drop one of those accross the rails and see if it's detected. But it wasn't. Uh? If I put 3 or so on they were. So I thought must have bought the wrong size - multimeter says 10k oms. Maybe its insufficient contact area. Try holding resistor accross wheel set. Still doesn't register. Clean "blackening" off the wheelset - resistor still doesn't register - but I can read 18 volts AC across both of them. Power OK. What am I doing wrong? What is it I don't know/understand? I don't want to waste hours making up wheelsets that won't work. HELP ME PLEASE - I DON'T CARE HOW MUCH YOU LAUGH AT ME.
  12. It's the PLs that are the problem. Train tech with cover most (though not all) of your needs IF you can live with a GPL at the foot of the signal. The Train-Tech ones are quite neat, but you couldn't stick them onto a post as they have a long underbaseboard "tails" for the connections/DCC gubbins. CR Signals USED to make things up for you but their Facebook page seems to indicate that they are running down and not doing much any more, which is a shame. I don't have the eyesight or manual dexterity to do what is needed, nor the hundreds of pounds to buy the deluxe models, so I used what I could get.
  13. Indeed, and quite why you would want an SI with only one indication I cannot think. I expect someone will tell me.
  14. Just to complete the picture can I remind people of CR signals (https://www.crsignals.com/) whom I have used in the past. No connection just a satisfied customer. Their prices are reasonable and (they used to?) will build to requirements - e.g. PLS and a JI on a 3 aspect signal - but NOT SI's, if you need those the ONLY supplier is Absolute aspects for whom you need deep pockets. Their contact details are on their web page. You DO need to provide DCC controllers as they are straight DC lights. I used Train-Tech SC1 and 2 successfully on their kit.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.