Isambard Kingdom Brunel Posted January 15, 2013 Share Posted January 15, 2013 I am in the process of converting a 14xx with a comet chassis from OO to P4, the loco was a good runner on OO track with a lenz chip using my Select as a controller. It was fitted with Romford wheels which I have removed, I replaced them with Gibson P4 equivalent and it still ran well despite not having the coupling rods fitted. My problem is the huge gap between the wheels and chassis about 60thou on each side. Now my cunning plan: I have part of a perseverance 14xx chassis, basically just the etch containing the frames and brakes. If I lay 40 thou plasticard on the existing using epoxy can I fit the perseverance frames over the sides after cutting out space for the hornblocks to work. The other reason for using these is if they are insulated from the main chassis, maybe I could fit the pick ups to this which would save running a bus bar from a piece of copper clad. in my naiavety I can't see a problem with this, providing they are completely insulated. What do you think? Is this feasible or am I being a complete numpty and missing something? Link to post Share on other sites More sharing options...
tender Posted January 15, 2013 Share Posted January 15, 2013 I'm not familiar with the Comet or Perseverance chassis, but have built a High Level 14xx chassis which goes together very nicely (in P4, EM or 00). Something worth considering maybe. Ray. Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted January 15, 2013 Author Share Posted January 15, 2013 Thanks Ray, that will be my next project. I have a Hornby 14xx which has been converted using Ultrascale wheels, but it does not run very well. I want to keep the body which has been upgraded and put it on a High Level Chassis. Unfortunately its all about funds (isn't it always) I also need to build a Comet B set, preferably two sets which means the lottery bals need to drop. I bought this 14xx off ebay very reasonably priced ( a real bargain) with the intention of converting. Link to post Share on other sites More sharing options...
Miss Prism Posted January 15, 2013 Share Posted January 15, 2013 My problem is the huge gap between the wheels and chassis about 60thou on each side. Plate the frames with plasticard. Link to post Share on other sites More sharing options...
hayfield Posted January 16, 2013 Share Posted January 16, 2013 Terry I have converted a K's 00 gauge chassis to EM simply by glueing 1mm plasticard to both sides and drilling out the axles holes, then fitting Romford wheels with EM gauge axles. Cant see any problems, but I would measure the difference between P4 and 00 gauge spacers, subtract the thickness of the etched sides then make up the difference with plasticard. I would leave a bit of room for the thickness of the glue and at worst fit the odd spacing washer, better to be slughtly under that too wide Link to post Share on other sites More sharing options...
Horsetan Posted January 17, 2013 Share Posted January 17, 2013 Overall width for a P4 chassis tends to be about 16mm, so that should give you some clues about how much widening you need if you're using overlays. Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted January 20, 2013 Author Share Posted January 20, 2013 I managed to fit the overlays, and then discovered that one of the hornblocks had come loose. Hopefully I have managed to replace that. I have fitted the front pair of drivers and the trailing wheels. I now need to file a flat on the axle to enable the gear to fit and then we can fit the motor and drivers. I have some coaches to build but I think a High Level Chassis is needed to replace the one on 5816 Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted February 10, 2013 Author Share Posted February 10, 2013 Well its taken a while, but. I now have a working P4 Chassis, my one concern is that there is still some side play in the driving wheels. Is it possible to get washers with an 1/8" orifice or should I make my own, and howw much sideplay should there be? I still have to fit pickups I am thinking of top acting wipers using Phos Bronze wire? Link to post Share on other sites More sharing options...
Stringfingerling Posted February 10, 2013 Share Posted February 10, 2013 I converted my ancient 14xx to EM gauge many years ago. Romford used to do the washers, so perhaps Markits do? I once bought a pack of assorted 1/8" washers with very fine gradations of thickness; sadly I can't remember where from, but I'm sure you'll be able to find some. For pickups I've used brass wire successfully but I think it was either Iain Rice or Guy Williams that recommends soldering on a very short length of gold wire for the actual contact points. I'm not sure if your chassis is compensated, sprung or rigid, if either of the former and you need to allow for vertical movement of the driving wheels, I think it's a good idea to have a good length of wire for the pickup , perhaps with an omega loop so it can move readily, while staying properly in contact with the wheel but without putting much frictional pressure on it. Also if you are using a chassis with some form of vertical play in the hornblocks my inclination would be to mount the pickups so that they act on the front or rear of the wheels rather than the top where they may tend to restrict the vertical travel or act as springs, interfering with your chosen suspension system, or possibly losing contact when the wheel is at the bottom of its travel. When the Flexichas system first became popular I remember seeing photos of models clambering over matchsticks left on the track - not very prototypical. I think Guy Williams knew what he was talking about when he recommended quite a small amount of travel; this would have one benefit amonst others of making it easier for your pickups to stay in contact, wherever they are mounted. Good luck with it. Link to post Share on other sites More sharing options...
Paul Cram Posted February 10, 2013 Share Posted February 10, 2013 Kean Maygib used to do the assorted washers, not sure if you can still get them. I space the sides of the chassis at 16mm and the hornblocks make up the rest so I do not need washers. This seems to be the right amount of side play. Link to post Share on other sites More sharing options...
RMweb Gold Captain Kernow Posted February 10, 2013 RMweb Gold Share Posted February 10, 2013 Glad the overlays seem to have worked, I'd also have agreed with this idea, if I'd seen the thread early enough! Which axle are you driving - the leading one presumably if it's standard 3-point compensation? In which case, I'd have minimal side play on that one, and probably no more than 1mm total on the centre axle, with perhaps similar on the rear (pony truck), as there'll need to be a bit of play for the compensation to work. As others have said, the amount of vertical movement required is really not very much at all. Any chance of some photos at some stage, please? My OO 14XX (K's kit) was the first (and probably the only) steam loco that I actually converted to P4. It turned out to be a bit of a long, drawn-out affair, and I resolved after that, that all further steam locos would be newly produced for the P4 layout. Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted February 10, 2013 Author Share Posted February 10, 2013 I am using a donor model to convert this which was bought off E Bay, this for some reason is driven off the rear driver with the leading driver compensated with a fixed beam. I don't have much vertical movement. I had to replace the hornblock, which took a couple of goes as I had never done that before. I then had to wait for some jig axles to arrive before I could set them up. originally it would not work, but I needed to thin the coupling rods as the were wider than the flanges on the coupling rod pins, so were being held taut when the nuts were screwed on. Hopefully you can understand what I mean. I have learnt a lot bodging this and will be impressed if progress continues and I actually get a runner. Link to post Share on other sites More sharing options...
Gordon A Posted February 11, 2013 Share Posted February 11, 2013 Keep at it. It is most satisfying when you get a chassis to run smoothly. IIRC Clutton - WR/BR P4 will be attending Wigan show this year. Gordon A Bristol Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted February 11, 2013 Author Share Posted February 11, 2013 Spent what seemed like a very long hour this evening trying to sort out pickups, managed to fit one side working on the flange. will try to do the other side tomorrow, What is the best way to form a coil wrapped around a 1mm rod? Used a lot of .33 brass wire trying to make one....... Link to post Share on other sites More sharing options...
Stringfingerling Posted February 13, 2013 Share Posted February 13, 2013 Are you trying to form a loop in the pickup wire? If so, Imm rod sounds too small for .33 brass wire. I would form one loop about 3mm across; this enables you to roughly double the length of the pickup wire, allowing a more gentle spring effect for contact on the rim. You don't have to put in a loop; you could just form a gentle v bend or rather a u bend, put the loop is preferable I think. The bit I found trickiest was soldering the pickup wires on to pcb mountings i used with the right amount of springiness and the right orientation; it feels as though you need several hands for the job. Sorry if this isn't what you meant! Good luck and may patience be with you tomorrow. Rob Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted February 23, 2013 Author Share Posted February 23, 2013 Has made a schoolboy error. Last week I soldered the pickup wires onto the pcb and all looked well, however, I then left the chassis until today as my good lady has spent the week in hospital. I must have not washed and cleaned the flux off as the Gibson wheels are now all corroded. Don't know if they are cleanable, but, I think I will order new drivers anyway. Link to post Share on other sites More sharing options...
Mike G Posted February 23, 2013 Share Posted February 23, 2013 Clean with a fibre glass brush and all should be well Mike Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted February 26, 2013 Author Share Posted February 26, 2013 Thanks I removed the wheels etc last night afte returning from Clatterbridge, I have given them a good glassfibre brushing and they look much better. I am going to tin the remainder of the bases for pickups then give the chassis a good scrub. I thought it may be an idea to give wheels and axles a wipe with an "oily rag", but, now think it will attract a layer of dust and other crap. Hopefully I will find time to reassemble in the next few days Link to post Share on other sites More sharing options...
Isambard Kingdom Brunel Posted March 5, 2013 Author Share Posted March 5, 2013 I finally have a running chassis, quite impressed by that as I have not built / bodged a chassis before. I bought a 00 14xx with what I believe is a Comet Chassis fitted with Mshima motor and Romford Wheels. I removed the wheel, pick ups and cleaned up the chassis. I covered the Comet Chassis with 40thou plasticard and the glued a Perseverance 14xx chassis frames to that after removing sufficient metal around the wheel bearings and the rear sub assembly. I then had to fit new Hornblocks, (something new to me) After fitting wheels and fettling the coupling rods I refitted the motor. I then had to work out how to fit pick ups (finally managed to fit them on all 6 wheels It is useful having an insulated frame. Still waiting for delivery of a Lenz chip then I can work on the body. So far so good Link to post Share on other sites More sharing options...
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