Chris Gilbert Posted November 19, 2012 Share Posted November 19, 2012 Ok guys Β how the kin el do I get the body off an Athearn CF7? Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 19, 2012 RMweb Gold Share Posted November 19, 2012 Chris Β Just got my Florida Central one out - undo the screws holding in the couplings. Β The screws need a bit of help with a pair of pliers as you unscrew them as they do get stuck. Β Once out, pull the couplin box out of the body and the chassis will drop out Β Ian Link to post Share on other sites More sharing options...
Jez Posted November 19, 2012 Share Posted November 19, 2012 Chris, should just be able to take the coupler boxes off and the body-shell should just slide off - beware of short wires on the headlight bulbs though. Β Jez Link to post Share on other sites More sharing options...
Chris Gilbert Posted November 19, 2012 Author Share Posted November 19, 2012 Done it the decoder that had been fitted was jammed in. When I first ran it, it made a loud clicking noise... Looks like the decoder was pushing down on the motor and causing problems... Β runs nice for a Ready to Roll loco... Β Thanks both... Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 19, 2012 RMweb Gold Share Posted November 19, 2012 Ah yes, had this with a number of these Athearn mechs - quite often the wires get pushed onto the fly wheels and etc. Β Ian Link to post Share on other sites More sharing options...
Chris Gilbert Posted November 19, 2012 Author Share Posted November 19, 2012 Next problem anyone notice the fuel tank short out on point work? Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 19, 2012 RMweb Gold Share Posted November 19, 2012 Not had that problem but I did reprofile the tank. I cant rmember what I did to it though. Β If I remember, I will bring it with me to Warley. Β Ian Link to post Share on other sites More sharing options...
warbonnetuk Posted November 20, 2012 Share Posted November 20, 2012 Chris Β I've done 2 CF7's and left the tanks unmoleseted but had no probs with shorting. Mine have run over PECO Code 75 and 83 with the stock wheelsets Β Likewise with Ian I can bring the current CF7 with me at the weekend for reference Β Dan Link to post Share on other sites More sharing options...
long island jack Posted November 20, 2012 Share Posted November 20, 2012 Not had that problem,my cf7 had a short on the circut board,had to hard wire the decoder in,also had a problem with the bulbs, replaced them with leds Ray Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 20, 2012 RMweb Gold Share Posted November 20, 2012 I replaced the board with a Digitrax board. That works fine. However when plugging in a Sound bug its fried two of them. Β I have a Tsunami decoder that wouldn't fit in another loco so it may well get that fitted now I have it to hand. Link to post Share on other sites More sharing options...
Chris Gilbert Posted November 20, 2012 Author Share Posted November 20, 2012 Ok it's not the fuel tank that is shorting out....cos I can see daylight all the time. But every time it moves over point work it shorts... Β I'm going to try my Santa Fe CF7 to see if its my point work ... I will report back Link to post Share on other sites More sharing options...
long island jack Posted November 20, 2012 Share Posted November 20, 2012 Check the back to backs one of my wheel sets was a bit narrow and every now and then it would short on the point work,i've found with some athearn the axles can be a bit loose where they fit in to the gear,drop of super glue sorted that. Link to post Share on other sites More sharing options...
F-UnitMad Posted November 22, 2012 Share Posted November 22, 2012 My CF7 has a Tsunami sound chip that seems to short every so often, quite randomly it seems, not in particular locations. It's a bit annoying; the loco stutters, then carries on, the engine noise cuts out then comes back in as if throttling down from notch 8, the lights go off and stay off, and I have to reset them. It's not a good advert for DCC sound, and I don't know what the problem is. Link to post Share on other sites More sharing options...
Prof Klyzlr Posted November 22, 2012 Share Posted November 22, 2012 Dear F-Unit, Β Are we sure that it's a _short_ circuit or an _open_ circuit? Β Happy Modelling, Aim to Improve, Prof Klyzlr Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 22, 2012 RMweb Gold Share Posted November 22, 2012 My CF7 has a Tsunami sound chip that seems to short every so often, quite randomly it seems, not in particular locations. It's a bit annoying; the loco stutters, then carries on, the engine noise cuts out then comes back in as if throttling down from notch 8, the lights go off and stay off, and I have to reset them. It's not a good advert for DCC sound, and I don't know what the problem is. Β I have had this before on an Athearn loco . I think its the way the power picks up from the wheels through the bearings that sit in the trcuk frames. An Amtrak P42 did this. I eventually bought a newer one second hand cheaply and swapped thetrucks over and it now runs fine with the Loksound decoder in it. Β Ian Link to post Share on other sites More sharing options...
CraigZ Posted November 22, 2012 Share Posted November 22, 2012 My CF7 has a Tsunami sound chip that seems to short every so often, quite randomly it seems, not in particular locations. It's a bit annoying; the loco stutters, then carries on, the engine noise cuts out then comes back in as if throttling down from notch 8, the lights go off and stay off, and I have to reset them. It's not a good advert for DCC sound, and I don't know what the problem is. Β That almost sounds like it's picking up power from just one truck. To really get to the bottom of it, remove the trucks and make certain that there's not a layer of lube on the truck bolster or frame bolster. To really get to it, solder a wire from the bearing plate on each side of the truck up to the circuit board or decoder board. Link to post Share on other sites More sharing options...
rayf2496 Posted November 22, 2012 Share Posted November 22, 2012 Hi Chris Sorry you have been having problems with the CF7, I took the shell off before I sent it to check which decoder was fitted. Must have caused it to snag- sorry!. Re the shorting issue, it never had any problems on my Peco code 83 pointwork. BW Ray Link to post Share on other sites More sharing options...
Prof Klyzlr Posted November 22, 2012 Share Posted November 22, 2012 I have had this before on an Athearn loco . I think its the way the power picks up from the wheels through the bearings that sit in the trcuk frames. An Amtrak P42 did this. I eventually bought a newer one second hand cheaply and swapped thetrucks over and it now runs fine with the Loksound decoder in it. Β Ian Β Dear Ian, Β A recent poster to the MRH formum stated a similar issue, and actually started tearing the trucks apart, fully ready to start soldering in a load of (what turned out to be) un-necessary bearing<>bearing<>pickup<>PCB wiring. Β When a _methodical_ diagnostic approach kicked in, it was quickly discovered that the wheelsets on the loco in question, (which was BTW a 2nd hand CF7), had been worn to the point that the stock Ath NS plating was gone, and the underlying brass was the running/pickup surface. A replacement of the wheels with polished-steel wheels (a la older BB Ath) improved the situation markedly, and replacing with NWSL solid NS wheels is on the cards. Β Point being, the Ath design generally is very rugged, and there is usually little reason to go pfaffing around with the axle/bearing/keeper-plate pickup system. (I'm not saying it _can't_ go wrong, check for hair and scenery wrapped around the axle/bearing area!, but best to check the _basics_ before just wildly wielding the soldering iron...) Β Willy Occum was onto something... Β Happy Modelling, Aim to Improve, Prof Klyzlr Link to post Share on other sites More sharing options...
Prof Klyzlr Posted November 22, 2012 Share Posted November 22, 2012 That almost sounds like it's picking up power from just one truck. To really get to the bottom of it, remove the trucks and make certain that there's not a layer of lube on the truck bolster or frame bolster. To really get to it, solder a wire from the bearing plate on each side of the truck up to the circuit board or decoder board. Β Dear Craig, Β AFAIK the Horizon era Aths use trucks which are directly-wired to a DCC-ready PCB??? (All of my Horizon-era SW1500s have wired-trucks ex-factory), Β IE if it's a Horizon-era Ath, the truck<>frame contact point system has already been eliminated... Β Happy Modelling, Aim to Improve, Prof Klyzlr Link to post Share on other sites More sharing options...
F-UnitMad Posted November 23, 2012 Share Posted November 23, 2012 Thanks chaps for the help & advice with my CF7 problem. No idea if the problem is a 'short' or 'open' circuit problem - how does one tell the difference? I doubt it's worn wheels or bearings - it was a new model, but a look at the trucks wouldn't go amiss. IIRC the wiring is a more modern job than the old Blue Box style with steel strips; there was a PCB, at first I fitted a TCS chip to the supplied jumper plug, but replaced the whole lot when I got the Tsunami. Interesting info about the old sintered iron Athearn wheels... I know for one thing they give a better tractive effort than modern wheels!! Link to post Share on other sites More sharing options...
Prof Klyzlr Posted November 23, 2012 Share Posted November 23, 2012 Dear Chris, Β - An "open" circuit is where a wheel breaks contact, is dirty, or otherwise _stops_ conducting electricity. Β (IE the "circuit" from - Power supply/booster - thru the "wires"/track-buss+rails+wheels - to the "Load"/decoder+motor - and back again Β is not complete) Β Typical symtoms are that the downstream item (motor, LED, decoder) simply stops working (no power). but NB that _only_ the loco experiencing the "open circuit" should stop, all others should continue operating. Β In the case of "intermittent/short-sharp open circuits", the mechanical flywheel effect may carry the loco over the "dead spot", with the result that the electronics "stop (no power) and (re)start again" relatively quickly. Β Considering the sheer maths that a HO loco which has a 6" long wheelbase, (4-axle GP roadswitcher or similar), Β and has 4-pickups per rail, needs a piece of dirty track at least 6" long to create a complete "open circuit" condition, (IE _all_ possible paths of wheel/rail pickup are "open circuit" simultaneously, it only takes _one_ pickup to be "making circuit/contact" at any given moment to keep things moving...) Β NB that we are considering the "open circuit" issue from the loco side of the wheel/rail contact equation. Now, before anyone says "...it only takes 2 turnout frogs, on the same rail, the same distance apart as the trucks are, to create a "open" condition, not a complete 6" of dirty track...", Β I would counter that - there was at least 3 conditions in that sentence, which _all_ have to be met, in order to cause a "open circuit" condition (remember Willy Occum...) - the issue shifts to poor/mis-wiring of the turnout frogs, which is a different fault condition altogether... Β Β Β - In contrast, a "Short" circuit represents a situation where the power feed is not making it to the target device, but is finding "a way home" before getting to the intended destination. Β (IE instead of the "circuit" being - Power supply/booster - thru the "wires"/track-buss+rails+wheels - to the "Load"/decoder+motor - and back again Β it's Β - Power supply/booster - thru the "wires"/track-buss+rails+wheels - thru the "short-circuit" - and back again Β The "motor+decoder" misses out on being part of the "circuit", and thus misses-out on recieving any power... :-( ) Β In the common case of a model loco, the power comes up one rail, and _instead_ of being sent thru the decoder/motor, on it's way home via the other rail, it is "short circuited" directly to the other rail (the decoder/motor misses out on recieving the power). Β Common symtoms in this case are similar to an "open" circuit, except that with a sudden "very heavy load" in the circuit, (A "short circuit" creates a situation where the power supply is demanded to give _everything_ it's got and more, instantaneously) Β the power supply/booster can't handle the "massive sudden spike" in load, and shuts-down to protect itself (or the self-protection system/fuse/circuit-breaker fails, and the "magic smoke" gets let out!) Β As such, when one "load" in the circuit, (or specific loco in our case), presents a "short circuit" condition to the Power-supply/booster, _all_ locos fed by that power-supply/booster are affected, and _all_ will likely audibly/visually/mechanically reset... Β Β Hope this helps... (If not, my apologies, delete and move on... ;-) ) Β Happy Modelling, Aim to Improve, Prof Klyzlr Link to post Share on other sites More sharing options...
RMweb Gold Scottish Modeller Posted November 23, 2012 RMweb Gold Share Posted November 23, 2012 Hi all, Β Ref to the comment about 'Older Sintered Iron Wheelsets - Athearn' Β A long time ago - I thought this was a possible solution and potential new 'Best Practice' which I stared to follow. Β Long enough ago to to be able to say 'this is NOT a long term solution' at all. Β The 'Older Sintered Iron' wheelsets are themselves prone to deterioration by electrical contact - think 'Spark Erosion' - when run on DCC. Β Yes - these wheelsets improve things with DC power. Β However - Since changing to DCC - experience shows that the locos with replaced shint wheelsets of with this type are more likely to have electrical problems. Β I have an older SW1500 that I changed over which literally 'ate' the wheelsets on DCC. Since replacement with new shiny wheelsets I've had no problem. Β Thanks Link to post Share on other sites More sharing options...
Jon Grant 4472 Posted November 23, 2012 Share Posted November 23, 2012 Try soldering thin red and black wire to the truck pickups, rather than trusting the dodgy connection between the truck and chassis block. Take care to get the red/red and black/black wires matched up to the correct sides otherwise you will fry the decoder Β Jon Link to post Share on other sites More sharing options...
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