Clem Posted August 8, 2015 Share Posted August 8, 2015 I thought I'd put a quick post on here as I've just completed the EM Conversion of the Bachmann K3. First of all I need to thank Pete Hill for his initial guidance on how to tackle this slightly awkward conversion. As usual, it was hugely helpful. The Bachmann K3s are pretty fine model representatives of the real thing with one or two slight deviations. The main problem visually concerns the driving wheels which are a scale 5 foot 4 1/2 inches as opposed to the 5 foot 8 inch prototype. I wanted to convert to EM so I thought I'd take the opportunity to replace the wheels with Gibson 5' 8" wheels at the same time. I used 1/8 inch axles (on Pete's advice) which required the opening out of the slots very slightly (they were slightly oversize for the original 3mm axles, anyway). I bushed the coupling rods for the outer 2 axles to fit neatly on to the Gibson crankpins and made the crankpins for the centre axle out of 2.5mm brass rod drilled and tapped to 14BA. The difference in size of the driving wheels effectively pushes the chassis up by about 0.6mm so I reduced the body bearing surfaces on the top of the chassis by that amount, including the cylinder mount. Getting sufficient clearance for the driving wheels to prevent shorting was interesting..... But successful. I'm not sure that there's much metal below the running plate where the wheels are but it's all good. I fabricated a wider dummy front for the pony truck. She certainly runs better than she did in OO. Anyway here (below) is the result. The engine was weathered early today and is now all but finished. I may not be able to get to the computer for the next few days so if there are any queries I will attempt to answer them as soon as possible. Best Wishes Clem Link to post Share on other sites More sharing options...
Horsetan Posted August 10, 2015 Share Posted August 10, 2015 Finer wheels make all the difference. Link to post Share on other sites More sharing options...
Clem Posted August 15, 2015 Author Share Posted August 15, 2015 Finer wheels make all the difference. I agree. But the correct size driving wheels make even more of a difference. It's been quite rewarding doing this conversion - thanks again to Pete Hill for advice given (and the confidence that it can be successfully done). But having done one, I'd not hestitate to do another, although you have to be careful when establishing the driving wheel clearance under the running plate. I think they are a pretty good solution to K3s numbered 61870 upwards. I'll use South Eastern Finecast to do any of the earlier ones so I could choose the correct cab and have right hand drive. One of the reasons I posted this, was to see if anyone else had tackled it - it's always interesting to see different approaches to the same problem/project. one more thing, on the painting - although I'm reasonably happy with the finish, I'd like to do a cleaner one next time - not quite so heavy on the weathering and a little more of Bachmann's very acceptable lining visible! Link to post Share on other sites More sharing options...
Clem Posted August 26, 2015 Author Share Posted August 26, 2015 I couldn't resist placing a quick piccy of my model of one of Colwick's muched loved J6's here. The only connection with the K3 is that it was weathered at the same time as 61896 above (that's my excuse and I'm sticking to it!). I've just got a new canon compact camera (as my old one broke) and this was taken by way of testing it out. Quite pleased! The depth of field is pretty good considering it's all automatic. I built this engine in the 1980's in OO. It's had a P4 chassis and now has an EM chassis which I completed a couple of months ago working in parallel with the K3 conversion. This engine acquired a tender cab in 1958 but as my modelling period is 1954-1956 it has been built without it. Colwick had about 20 J6s at the time and they could be seen on anything from coal, fitted freight, pick-up goods, local passenger and even excursions to Skegness and Mablethorpe. It was a sad day when 64219, Colwick's last J6, was condemned in 1961. Link to post Share on other sites More sharing options...
Redgauntlet1946 Posted April 30, 2016 Share Posted April 30, 2016 Hi, A bit late but I am also trying to convert a K3 to EM using Gibson Wheels. My problem is the width around the rear crosshead guide support and the lifting arm. I can't see how to increase the width to clear the crankpins without major surgery. Could you give a bit more detail on exactly how you achieved this? Does it in fact need major surgery or is there an obvious solution that I can't see? My minimum radius is 36 - 48 inches. Your K3 looks superb by the way! Regards Ian Link to post Share on other sites More sharing options...
Clem Posted May 3, 2016 Author Share Posted May 3, 2016 Hi Ian, Sorry it took a while to get back to you. It seems like quite a while since I did the K3 - blimey was it only last Summer? At the moment we're going through a painful house extension which limits my modelling and more to the point limits my access to the K3 which is locked away not very accessible. Yes, I seem to remember it initially running a bit like Hop-along Cassidy for the reason you quoted although I thought it was the coupling rod that was catching. I think I modified the support to provide clearance. If you can hang on for a couple of days, I'll try to get in to inspect it to remind myself how I did it. Also, I think I made notes of the conversion and if I can lay my hands on those, I'll share them with you. Best Wishes Clem Link to post Share on other sites More sharing options...
Redgauntlet1946 Posted May 4, 2016 Share Posted May 4, 2016 Hi Clem, Thanks for your response, I'm not in much of a rush at this end. I set aside a day to have a go as I'd been lead to believe it was straight forward but the conflict between ability and ambition seems to have caught me out. I'm trying to concentrate on track laying at the moment but short diversions have a theraputic effect and obviously I need a running loco when the track is in a condition to be used. So I'm happy to wait on your convenience. Regards Ian Mersey507003 I'm no expert but... If you are talking Steam then - Yes you can move the wheels outward on their axles. OO wheels are 14.5mm back to back, EM are 16.5mm. I know some people have done it but you have to ensure the the wheel profiles meet EM specifications or else you will have difficulty at turnouts etc. Also as you are reducing the depth of travel of the axle into the wheel it is problematic ensuring the wheel alignment is still true. A lot of ready-to-run wheels have flanges that meet the spec but the wheels are wider so that gives clearance problems which would make my difficulties above even worse. The best I could suggest is get a Back to Back gauge and give it a try. If it works Job Done. If not buy a set of Gibsons. If you pick a model for which Alan Gibson has a conversion available there is a selection of How to Do It downloads on his web site. I have no experience with Diesels but I think they will be much more straight forward Ian Link to post Share on other sites More sharing options...
Clem Posted May 5, 2016 Author Share Posted May 5, 2016 Hi Ian, A quick update... I've found my K3 notes but unfortunately they peter out before I got to the end of the project , so no mention of precisely how I got over the offending slide bar support. I hope to get into the garage (layout room) at the weekend and I'll have a look at my solution - perhaps take a photo if it's going to help. I usually try to take notes on projects but often the 'doing it' part takes over and I forget to write it up for posterity. I'll have to be more disciplined!! Hopefully a further update at the weekend. Hi Mersey507003 Yes I would second all what Ian has said above. It's adviseable to talk to as many EM modellers as possible before starting. It's a big subject (but well worth persuing in my view) and you will pick it up as you go along. You can pull the wheels out to 16.5 back-to-back on some RTR locomotives (I use a GW wheel puller to preserve the quartering) but in most cases I replace the existing wheelsets with Alan Gibson (or other make) as they tend to be finer and thus ride better particularly through pointwork. However, I've still got a couple of locos that ride ok with proprietary wheels pulled out and that method can work in one or two cases. If you do go down the road of pulling wheels out, you need to make sure when you replace the wheel set in the axle slot, that you put some kind of spacer each side between chassis and wheel to reduce side play. It's crucial that outside cylinder engines have virtually no sideplay on the front axle as clearances are minimal behind slide bars and the crankpins will foul the slide bars if there is side-play. Also, a lot will depend upon the lengths of the axles. In some cases there simply isn't enough support for the wheels once widened and replacements become the only solution. If you replace wheel sets then you need to learn how to accurately quarter wheel sets. Again the GW press can be a big help here although it can be achieved by lining up spokes in wheels by eye. If you're a steam modeller then probably best to start with an inside cylinder engine - something like an 0-6-0. Hope this helps Clem Link to post Share on other sites More sharing options...
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