Dazzlerofkernow Posted November 28, 2020 Share Posted November 28, 2020 (edited) Hi all, I have an issue with my Bachmann class 66, i have not had it that long, already have a couple of Hornby 66's. the Bachmann is derailing on Hornby points, i took a video here: have been searching and reading and trying the various fix's I have set the back to backs on the wheels to 14.4 using a gauge and it does not seem to be snagging the pocket, have also tried adding a washer under the boogie to raise it up a bit. any help which what im missing? Cheers Daz Edited November 28, 2020 by Dazzlerofkernow Link to post Share on other sites More sharing options...
MartynJPearson Posted November 29, 2020 Share Posted November 29, 2020 Is there anything obvious happening at the other end of the bogie, particularly with respects to the track leading up to the points being level? I've had an issue with Bachmann class 47s where they didn't cope well with the points being on a gradient compared to the next bit of track, causing one end of the bogie to lift. Link to post Share on other sites More sharing options...
johnb Posted November 29, 2020 Share Posted November 29, 2020 Are the bogies free to turn and lift? 1 Link to post Share on other sites More sharing options...
wasdavetheroad Posted November 29, 2020 Share Posted November 29, 2020 Is it a standard 440mm radius point?, if so it looks like the wheel flange is riding up over end of the 'V' Link to post Share on other sites More sharing options...
Ouroborus Posted November 29, 2020 Share Posted November 29, 2020 As above. The leading wheel spins without forward movement, then you have movement and it derails. Just before it spins you see the flange (left side as you view it), ride up on your track. But the question now is why isn't the bogie negotiating the point as it should. Does it do this on any other similar point? Interesting watching the video whilst wearing headphones! Link to post Share on other sites More sharing options...
RMweb Gold ITG Posted November 29, 2020 RMweb Gold Share Posted November 29, 2020 (edited) Probably a little obvious but does this happen when the loco is running in same direction through the point but opposite way round? Or indeed, what happens when loco runs through point in opposite direction? The answers may give some clues....... In my limited experience, and not with this loco, but when an odd loco didn’t like a point that others were ok with, (but others points and this loco combinations were ok) I found on a couple of occasions, the issue seemed to be the point was not sitting quite flat - I’d managed to lay it with a slight twist, due to untrue baseboard. Edited November 29, 2020 by ITG Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 29, 2020 Author Share Posted November 29, 2020 Hi Thanks for all the reply's will try to answer all of them, first up its a standard Hornby R8072 and it happens on a few of these, could it be just too small a radius? (im still building the main layout, this is a tamp layout on a board on the kitchen table) I have some express pecos to go on the main layout. this happens in both directions and the bogies are free turning, I have added a washer on the top of the bogie's to make them a little higher so they dont snag the frame. as for the watching with headphones, in the slowmo it makes quite a thump as it comes back down! lol not sure what it is that's making it hit the V of the points but does seem to do it on all of them, its a great runner on a loop but does not seem to like changing tracks :P Cheers Daz Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 29, 2020 Author Share Posted November 29, 2020 yea that could be it, im using a combo of set track and flexi on the layout im building. but my temp kitchen table layout is all set track. saying that though the 66 goes round a 2nd radius curve fine, just seems to be the points Link to post Share on other sites More sharing options...
dasatcopthorne Posted November 29, 2020 Share Posted November 29, 2020 Could it be that the centre pair of wheels have their side to side movement restricted? Link to post Share on other sites More sharing options...
smokebox Posted November 29, 2020 Share Posted November 29, 2020 Those wheels look quite thick, so it may work better if you reduce the back to back down to somewhere near to 13.9mm, which was the standard that Hornby used in the not too distant past. 3 Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 29, 2020 Author Share Posted November 29, 2020 2 hours ago, dasatcopthorne said: Could it be that the centre pair of wheels have their side to side movement restricted? I will check this as that is one thing I have not checked is how freely the middles move. Link to post Share on other sites More sharing options...
Chrisr40 Posted November 29, 2020 Share Posted November 29, 2020 Does the 66 have sand pipes ? if so are these bent out of line and fouling the track / points ? Link to post Share on other sites More sharing options...
dasatcopthorne Posted November 29, 2020 Share Posted November 29, 2020 Fix a strip of plasticard 10thou ish to the rail side of the checkrail. Dave. Link to post Share on other sites More sharing options...
dasatcopthorne Posted November 29, 2020 Share Posted November 29, 2020 Are you sure the gauge is 14.4mm? Could it be a 14.8mm Double0gauge Association one? Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 29, 2020 Author Share Posted November 29, 2020 6 hours ago, smokebox said: Those wheels look quite thick, so it may work better if you reduce the back to back down to somewhere near to 13.9mm, which was the standard that Hornby used in the not too distant past. That's an interesting idea, I wonder what the standard wheel thickness is... I checked with me gauge and a set of calipers, I saw a post about the plasticard on the checkrail might have to get some and give this a go. Also the centerwheels are free to move left and right they are not stuff at all. Link to post Share on other sites More sharing options...
RMweb Gold ikcdab Posted November 29, 2020 RMweb Gold Share Posted November 29, 2020 Mmm not sure that narrowing the checkway with platicard is going to help. If it is only this loco then the problem is with the loco, not the track. In that case, the b2b are just too wide. As suggested above, you need to double check and narrow them ever so slightly. Link to post Share on other sites More sharing options...
DCB Posted November 30, 2020 Share Posted November 30, 2020 Its a back to back issue. loco B to B too wide for the point. the check rail should hold the flange away from the V of the frog. If the B to B is too wide the flange rides up. 2 nd radius points are marginal for 66s and the like anyway. The trouble is some locos need the wider flange way to cope with their narrow B to B some Hornby were 13.9mm approx. I regauge coaches etc to 14.25 mm approx Hornby Dublo 2 rail plastic wheel B to B with a go/ no go gauge with 14.2 and 14.5mm ends I haven't had any issues with Bachmann on Peco Streamilne points but have re gauged lots of Triang Hornby and Hornby locos to 14.25 to get them through Streamline points. I suspect the Hornby points may have wider gaps between check rail and running rail than Peco set track, Relaying with code 75 and putting the old stuff on eBay for me to buy is a possible solution. Link to post Share on other sites More sharing options...
Bill Radford Posted November 30, 2020 Share Posted November 30, 2020 I have encountered similar problems with Bachmann 66s. All 4 turns into the fiddle yard are 4th radius Peco (24" more or less) and the lead wheel derails - not the same turn for each loco! I replaced the settrack on one turn with flexitrack and this cured it (same radius!) although 66 714 Sence still has a problem running on one turn. Link to post Share on other sites More sharing options...
dasatcopthorne Posted November 30, 2020 Share Posted November 30, 2020 15 hours ago, ikcdab said: Mmm not sure that narrowing the checkway with platicard is going to help. If it is only this loco then the problem is with the loco, not the track. In that case, the b2b are just too wide. As suggested above, you need to double check and narrow them ever so slightly. You may narrow the flangeway on the check rail side a little (this is usually too wide anyway) but this will pull the wheelset away from the nose of the crossing. Try it with some card first or clear plastic from packaging. Dave. Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 30, 2020 Author Share Posted November 30, 2020 i have got some 10thou plasticard on the way to test this out, also will test bringing in the b2b to around 14/13.9 and see if that makes a difference. cheers for the replies all, will do some testing. Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted November 30, 2020 Author Share Posted November 30, 2020 so i did a little test i reduced the b2bs down to 13.9 and guess what.... no derailing! initial testing looks good will do some more testing over the weekend, looks promising! (only tested on a short bit of track with a couple different points, will test on the temp layout next time its out) Cheers Daz 1 Link to post Share on other sites More sharing options...
RMweb Premium Jeremy Cumberland Posted November 30, 2020 RMweb Premium Share Posted November 30, 2020 From the excellent video, it looks to me that the real problem is the bogie not turning enough. When the offside wheel rides up onto the vee, it immediately pulls the nearside wheel up with it, as if the bogie is incredibly rigid. However, when the offside wheel drops off the vee, the bogie twists before the nearside wheel is dragged off the top of the check rail, so the bogie is not as rigid as all that. Even when the offside wheel rides up onto the vee, the nearside wheel ought still be able to remain in the flangeway, but clearly it does not want to, so my guess is that the bogie at that point is already turning as much as it can. What is restricting its movement I cannot see. It could be the other two wheelsets or it could be something else. Clearly the point check rail gap and the locomotive's original back to front measurement (back to back plus flange thickness) are incompatible, but in some respects it does not really matter which is at fault. Reducing the back to back by 0.5 mm shifts the whole bogie 0.25 mm further to the left (in the direction of travel), and then the offside wheel is shifted another 0.25 mm away from the vee, all without changing the angle between the bogie and the locomotive. If you went and reduced the check rail gap instead, although this would also keep the flange away from the vee, the bogie would have to turn a little more, and this appears to be the thing the bogie cannot do. However, reducing the back to back is probably something of a fudge. Unless the locomotive has particularly thick flanges (about 1.25 mm), you should not need a back to back of 13.9 mm, and you might encounter a problem running through finer-scale points, if you have any on your layout or if you want to run the locomotive on someone else's (does anyone know how wide Peco flangeways are these days? I was under the impression they would not accomodate 13.9 mm back to backs). What might be worth doing is slightly increasing the back to back till you find the largest size that works. If you can get to 14.2 mm without derailing, your locomotive should run on any proprietary track. 1 Link to post Share on other sites More sharing options...
dasatcopthorne Posted December 1, 2020 Share Posted December 1, 2020 On 30/11/2020 at 20:42, Dazzlerofkernow said: so i did a little test i reduced the b2bs down to 13.9 and guess what.... no derailing! initial testing looks good will do some more testing over the weekend, looks promising! (only tested on a short bit of track with a couple different points, will test on the temp layout next time its out) Cheers Daz Daz. This was always going to work but if you run your locos on any other type of track you may well find the opposite problem in that the b2b is too narrow. Try the plasticard before altering all the locos wheels. Dave. Link to post Share on other sites More sharing options...
Dazzlerofkernow Posted December 2, 2020 Author Share Posted December 2, 2020 (edited) Cheers Dave, I have some plasticard for further testing. At the moment the only loco I'm having trouble with is me Bachmann 66 although we the offer on at hattons I'm tempted by one of theirs... (My Hornby one is perfect with no problems) Cheers Daz Edited December 2, 2020 by Dazzlerofkernow Link to post Share on other sites More sharing options...
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