Dan Hamblin Posted March 18, 2011 Share Posted March 18, 2011 There are two lugs on the cab sides down in the corner nearest the firebox foundation ring. I found that sticking some spacers under them prevent the screws from pulling the cab assembly downwards and thus bending the running plate down. I took a load of photos when I carried out the surgery, but I don't think I took one that clearly showed where I fitted the spacers. Suffice to say it is now straight but I haven't yet managed to refit the cab seats and boiler backhead gauges! Regards, Dan Link to post Share on other sites More sharing options...
davidw Posted March 18, 2011 Share Posted March 18, 2011 Having had the body off the A2, I have analysed the cause of the sloping rear running plate. I will be interested to hear people's views on my analysis which explains both the sloping rear running plate and the loco/tender step height difference. Suffice to say it is not pretty, i.e. not particularly fixable without some quite major surgery.... There are two 'heights' of the rear running plate, the one at the bottom of the firebox S-curve(lets call it H), which appears to correspond to the Tender running plate height, and the height at the rear of the cab (lets call it H1). The height H is held by the screws running into the bottom of the front of the firebox. When on the chassis, there is a small gab between the cartazzi frame and the running plate, of about 0.5mm. The drop towards H1 begins shortly to the rear of this. There is a slight gap between the rear of the firebox (where it meets the cab) and the running plate. Importantly, there is no gab between running plate and cab at this point, nor is there any gap between the inside of the top of the firebox and the 'rim' around the front of the cab. Assuming that height H is correct, I would propose that the cab piece itself is TOO TALL. when screwed up, the force of the screws screwing into the firebox drive that part of the running plate home (achieving H), bending the casting between the S-curve and the cab. I am assuming the height of the cab roof is OK - raising it up by 0.5mm or so would made the windows too high above the firebox, and roof too high relative to the safety valves. The only solution it would seem would be to remove some material from the bottom of the cab. This would then lose a row of rivets, and damage the paint. The rear of the body would then need packing by a similar amount. What is interesting is that in all other respects, everything sits true. The main running plate has no fore-aft height difference. There are some small plastic washers supporting the rear of the body to achieve H1 (else body would lean back), so some design adjustment may have been made, but it appears to have been designed such that with this 'error' everything lines up. In other words, I would suggest that if a raw chassis casting was mated with a raw running plate (no boiler/cab etc), the running plate assembly would lean back on the chassis. Ideally therefore, assuming H is correct, the cab should be shorter (by about 0.5mm), the cartazzi should be higher (by about 0.5mm) to increase the height of the rear of the chassis (thereby 'supporting' the firebox front), which would also +/- line up the loco and tender steps. This may be a legacy of using the A1 cab, but it suprises me that a) this wasn't picked up at the CAD stage, and B) everything seems to be true in other, either by accident or forced design. If reason b, this would indicate reason 'a' was noted, but bodged rather than corrected!. If people feel photos or diagrams may help, I will post if I have a moment. Feedback on this analysis, and alternative analysis welcomed. p.s. Not the first time Bachmann have had cab problems, Every 8750 pannier body I have has the cab distorting the plastic running plate. Easily corrected by removing material from inside the firebox (allowing more space for the rim on the front of the cab). It really is a fractional amount of material (despite leading to a 1mm bend in running plate), and the running plate springs back when cab is removed. Photo's/diagrams would be helpful. Link to post Share on other sites More sharing options...
Bon Accord Posted March 18, 2011 Share Posted March 18, 2011 There are two lugs on the cab sides down in the corner nearest the firebox foundation ring. I found that sticking some spacers under them prevent the screws from pulling the cab assembly downwards and thus bending the running plate down. I took a load of photos when I carried out the surgery, but I don't think I took one that clearly showed where I fitted the spacers. Suffice to say it is now straight but I haven't yet managed to refit the cab seats and boiler backhead gauges! Regards, Dan Dan, Sounds interesting, would you be able to add a couple of shots to the gallery showing the model with the straightened footplate? Link to post Share on other sites More sharing options...
G-BOAF Posted March 19, 2011 Share Posted March 19, 2011 There are two lugs on the cab sides down in the corner nearest the firebox foundation ring. I found that sticking some spacers under them prevent the screws from pulling the cab assembly downwards and thus bending the running plate down. I took a load of photos when I carried out the surgery, but I don't think I took one that clearly showed where I fitted the spacers. Suffice to say it is now straight but I haven't yet managed to refit the cab seats and boiler backhead gauges! Regards, Dan Interesting, does that mean there isn't enough headroom for the backhead with gauges on? Pics of where you put the spacers (indicating where they are, if you can't acually show them). I will post some diagrams of my theory soon. Link to post Share on other sites More sharing options...
Dan Hamblin Posted March 20, 2011 Share Posted March 20, 2011 No problem, but I haven't got time to edit the photos at the moment and add captions so these are straight off the camera! As delivered. Bent footplate clearly evident. First bit of the stripdown - body off and cab plus backhead sections removed. Note the raised metal platform with two holes. The screws holding the backhead and cab structure to the footplate go up through these holes. Cab on its own. You can just about see the lug I refer to on the drivers side in the shadow. I removed a bit of excess plastic from the front of the cab as well as I experimented with different methods for repairing the bent footplate. I also had to file off the back of the handrail stanchions as they were pushing the cab sides outwards. Backhead and cab. You can see that some material has already been filed off to make it fit, presumably on the production line as that is what it looked like after I disassembled it. The seats and most stuff along the top of the backhead is still off of my model, principally because I haven't had the chance yet to refit it! Cab backhead loosely refitted to show the relationship between it and the footplate (the latter bent back to the correct form). The fallplate has not been added, but sits in the thin slot above that for the drawbar. See the gap at the front of the backhead between the bottom section and the footplate? This is where the cab structure lugs go and with space remaining the overall design means that screwing the screws tight into the backhead pulls the whole strucutre downwards at the back. Bit counterintuitive as you would expect the front to go down first. Reassembled. Not perfect by any means - compared with the original look there is now a small gap between the cab front and firebox cladding, but I would rather have the straight footplate. Comparison with the tender. Hope this helps. Regards, Dan 3 Link to post Share on other sites More sharing options...
micklner Posted March 20, 2011 Share Posted March 20, 2011 Much better , well done Link to post Share on other sites More sharing options...
Bon Accord Posted March 20, 2011 Share Posted March 20, 2011 Thanks for those Dan. I've just dug my BP out of the box (I'm in between layouts at the moment!) and given it a good eyeball in comparison with your photos, and it does seem that the droop on your model (in original shape) is much worse than on mine, in comparison mine almost looks like yours post modification. What did you use as a spacer? I've got another 2 A2's (BB and AHP) and whilst AHP is the same as BP, BB has a bit of a droop and the left-hand cab number isn't square. I can't help but wonder why they've painted the tender shoulders on both BB and BP black as they should be green - a mistake not made on their A1's. Looks to me like a few failures in quality control at Bachmann, not that it's a huge problem to me as the A2 is a fine model, but annoying in the niggling sense all the same. Link to post Share on other sites More sharing options...
Dan Hamblin Posted March 20, 2011 Share Posted March 20, 2011 Spaces were a bit of a bodge made out of some spare sections of plastic cut to size using a craft knife. They worked so well that I decided to leave them in there. I've been thinking a bit more and remembered the conclusion I came to when I found out what the problem was. The cab backhead, being cast metal, does not flex. Combined with a slightly assymetrical shape and a lack of support for the footplate means that tightening the securing screws and thus closing the gap at the front forces the back of the footplate downwards. This creates the bent footplate. It should be easily fixable by making the plastic lugs on the cab structure thicker I think. Regards, Dan Link to post Share on other sites More sharing options...
G-BOAF Posted March 20, 2011 Share Posted March 20, 2011 Think you've hacked it there. Well done, much better explanation than mine, mostly because it works!! the 'lip' between firebox and cab is, I see, on the firebox, this is, I now remember, how the A1 was done. Now that the rear of the cab is 'higher' (since slope is gone), Did you pack the rear body-chassis screws? Link to post Share on other sites More sharing options...
G-BOAF Posted March 20, 2011 Share Posted March 20, 2011 p.s. regarding the gap under the cab - The packing clearly goes under the backhead casting, but did you put it under both the casting and cab lug, or between casting and cab lug. I would have thought the latter wouldn't have changed the height of the cab at all (but clearly might cause problems for backhead controls against the cab roof!) Also, I note there is still a gap between the running plate rear of the firebox. The 'rim' at the rear of the firebox touches the running plate - I am wondering if it protrudes below the firebox slightly. But again, congrats on the explanation and repair job! Link to post Share on other sites More sharing options...
Dan Hamblin Posted March 20, 2011 Share Posted March 20, 2011 No need to pack the rear screws - they already had two thin clear plastic washers on them (from memory). I can't remember now which side I put the spacer! It definitiely had to go one side because of the position of the lugs. I will get around to re-fitting the cab gauges etc. but they might require some thinning down as it definitely seemed like there was less space in there than before. I agree that there are a few more gaps that have opened up, but the overall effect is much better and hopefully when running on the clubs exhibition layout they won't be as noticeable. This is definitely the ready to run model which has required the most work despite being brand new. Mechanically though it is sound. Regards, Dan Link to post Share on other sites More sharing options...
G-BOAF Posted March 29, 2011 Share Posted March 29, 2011 Dear Forum Hot of the press – midnight oil burned! Working on my original theory, two dismantled A2s, and Dan Hamblin’s analysis.... I have solved the Bachmann Peppercorn A2 Sloop, completely, gone*. I will be posting a step by step blog when time allows (hopefully in the next few days) I will flesh out description, but wanted to show you some proof pics! NOTE:, box on which loco resting may not be entirely flat, tender and loco potentially at fractionally different angles, but running plate IS level! Cab running plate now at same height as buffer beam running plate at front, both fractionally higher than tender running plate (off track). NOTE: Orange running plate LINING IS NOT STRAIGHT, and DOES SLOPE UPWARDS! I will post a blog link when said item is written, and a copy posted off to Bachmann! If anyone is desperate, PM me, and I will see what unillustrated prose I can muster!) IMHO, rear end looks MUCH better, cab top overhang now sites nicely lined up above top tender recess, powerful looking beast! Cab will need slight straightening, along with some work on the backhead – not difficult, all will be explained. Main running plate preserved completely level (+/- 0.05mm according to my Callipers). *actually, a chance that I’ve gone **fractionally** too far the other way! Enjoy, sorry for garish flash-illuminated pictures. Alpha Foxtrot (p.s. Yes I do know about the bent axlebox retaining detail on the cartazzi on this example!) Link to post Share on other sites More sharing options...
davidw Posted March 29, 2011 Share Posted March 29, 2011 okay - how did you do it? Link to post Share on other sites More sharing options...
G-BOAF Posted March 30, 2011 Share Posted March 30, 2011 Bending (of rear footplate), packing (under rear footplate), and filing* (of backhead, and cab supports on the footplate casting). Although as can be seen in my second picture, the rear end is 0.5mm too high. I think I've now got the front footplate and rear footplate to agree within 0.05mm**, which is probably within the error of undulation of the flat surface I am working on! Full guide to follow at the weekend. *not yet done - when model reassembled first time, it was clear this was causing the problem - because I was back to square one! Pics are from dry run mk2!!, haven't yet reassembled fully **be interesed to hear from people for whom this margin of error is too much - I decided to cut my losses and not waste another HOUR over 0.05mm! Link to post Share on other sites More sharing options...
G-BOAF Posted May 4, 2011 Share Posted May 4, 2011 Dear Forum Thanks for waiting, especially various people who have messaged me asking for an explanation. Parto f hte reason why it took so long was that when I said at the end of april I had fixed it, I actually hand't, some more adjustment, namely in the cab area, was called for, along with thinner packing (0.25 instead of 0.5mm) Finally done the step-by-step, and accessible below. Sorry if the tone is a bit patronising at time, in part I wrote it for myself!!! http://www.rmweb.co.uk/community/index.php?/blog/411/entry-6555-Bachmann-a2-cab-sloop-fix/ BP is now on display, looks great and in the process of getting OHL flashes. Pics of an early 2000's A2 will follow at some (unspecified!) point! 1 Link to post Share on other sites More sharing options...
silverlink Posted May 8, 2011 Share Posted May 8, 2011 Many thanks for this well put together article, looks as though I'm going to be very busy as my 'Haymarket Cross' layout now has ten of these great loco's on it !!! Cheers silverlink Link to post Share on other sites More sharing options...
micklner Posted October 21, 2011 Share Posted October 21, 2011 A H Peppercorn now with correctly painted Handrails and Sand fillers. Etched work plates added and finished in Satin Varnish to get rid of the awful original shiny finish. 1 Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted October 22, 2011 Share Posted October 22, 2011 Arghh, testing my powers of resistance to the limit. It looks fabulous even if slightly off the road in the Cartazzi zone... There are so few in the class that they are all going to be covered soon enough, so it is my determined plan to hold off for the Kylchap fitted Happy Knight, Bronzino and Velocity in late crest. And possibly Sugar Palm in a weak moment... Link to post Share on other sites More sharing options...
Betty's Husband Posted December 31, 2011 Share Posted December 31, 2011 Having caught the railway modelling bug again after an 18 month absence (and being very pleased to have done so) I purchased the A2 Tudor Minstrel. I just want to say thank you to G-BOAF and Dan for their work on correcting the cab sloop problem. By following their work and reading the superb 'how to' guide from G-BOAF I have been able to straighten the footplate and eliminate the sloop (there is less than 0.1 mm on both sides and the cab looks far more square). I am not skilled enough to have worked this out for myself so to have a guide to be able make a massive improvement to this model is much appreciated! I now have a couple of questions regarding the LNER apple green livery. I see that micklner has painted the handrails green on AHP and I assume this is also correct for Tudor Minstrel (it is apple green but with British Railways on the tender circa 1948). However are the sandboxes supposed to be green on TM also? Using the only references I have, (which are black and white!) I can see that AHP in LNER apple green did have green sandboxes, but in a picture of 60535 Hornets Beauty in BR apple green I am sure the sandboxes are black. Does anyone have any better info on this matter before I get my paintbrushes out? Thanks, and all the best for 2012! Link to post Share on other sites More sharing options...
RMweb Premium Hilux5972 Posted January 1, 2012 RMweb Premium Share Posted January 1, 2012 Do the Blue Peter's come with a certificate? If so mines missing! As per above video, have you checked under the foam lining of the lid? Link to post Share on other sites More sharing options...
RMweb Premium Hilux5972 Posted January 1, 2012 RMweb Premium Share Posted January 1, 2012 Have you checked under the foam lining, as in the above video, in the lid WRLPG? Link to post Share on other sites More sharing options...
robmcg Posted January 23, 2012 Share Posted January 23, 2012 (edited) Two new versions now at Hattons. Looks to me as if the BR late crest version at least may have an acceptable running plate below the cab? Level, I mean... Edited January 23, 2012 by robmcg Link to post Share on other sites More sharing options...
davidw Posted January 23, 2012 Share Posted January 23, 2012 Tender livery and cylinders are now correct. Link to post Share on other sites More sharing options...
S.A.C Martin Posted January 23, 2012 Share Posted January 23, 2012 Couple of questions fellas (my apologies) Can anyone confirm the shed name on last years Tudor Minstrels bufferbeam, please? Regarding the new ones on Hattons, is the apple green a double chimney but without the multi valve regulator? Am looking to get an apple green A2 for a planned conversion and am pondering the choices available. Thanks in advance. Link to post Share on other sites More sharing options...
micklner Posted January 23, 2012 Share Posted January 23, 2012 Tudor M no shed name. If you mean Sugar Palm it didnt get the multi regulator till 1949 , only ever seen a nearside shot , should be out soon !! 1 Link to post Share on other sites More sharing options...
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