Pinkmouse Posted January 9, 2010 Share Posted January 9, 2010 Christian, have a look here. It's even got a nice animated pic halfway down the page! Link to post Share on other sites More sharing options...
alcazar Posted January 9, 2010 Share Posted January 9, 2010 Can I refer you to MRJ, I can't remember which issues, but it was the Finney A4 build, in 7mm scale. I have both issues in the loft if it would help? Link to post Share on other sites More sharing options...
Horsetan Posted January 9, 2010 Share Posted January 9, 2010 ....I am now starting of the valve gear and shown below is most of the parts for one side of the loco. I really do not know where to start here.... This is one where following the original Finney instructions should stand you in good stead. BTW (although too late now, I suppose) I probably wouldn't have removed all the parts from the fret like that until I was ready to use each one in turn, because you then lose sight of the part numbers, making cross-referencing with the instructions a bit more difficult..... Link to post Share on other sites More sharing options...
dikitriki Posted January 9, 2010 Share Posted January 9, 2010 I am now starting of the valve gear and shown below is most of the parts for one side of the loco. I really do not know where to start here, I have laid out these parts not only to illustrate what goes into the valve gear but also so that I may have a better understanding of how it all works. This particular aspect of the model has been troubling be for a while now, I think I need a crash course in how a steam loco works! Hi Christian I am sure you will have loads of different answers, but for what it's worth, my approach is always as follows.... * build the expansion link and radius rod (exactly as the instructions). Make sure you have free movement here before going any further. * attach the eccentric rod to the bottom of the expansion link. * scratchbuild from brass a second cover for the return crank/eccentric rod bearing (like a funny shaped washer), but drill a hole right through. This will enable you to capture a bolt head in the cover and attach the cover to the eccentric rod. * work out how you are going to attach the return crank - solder or bush and tap. Check this for fit and trim the crank pin. * attach the return crank to the eccentric rod. This gives you one half of the valve gear. The second half.... * build the valve spindle * attach valve spindle to combination lever. * build the union link, but bend it to make the forks a little more pronounced. * attach the combination lever to the union link. * attach the union link to the drop link on the crosshead. Now attach the two halves together at the combination lever/radius rod join. * attach the reversing arms - the radius rod should slide freely through them, running on the central pin. Teaching granny to suck eggs, but do make sure there is more than enough movement in each of the joins. Sit back and watch your creation work - and post the pictures! Richard Link to post Share on other sites More sharing options...
Christian Posted January 9, 2010 Author Share Posted January 9, 2010 have a look here. It's even got a nice animated pic halfway down the page! Thanks for the link which I have found really useful, I think that I can now grasp just how the valve gear works and also have a good understanding of the terminology used. I am sure you will have loads of different answers, but for what it's worth, my approach is always as follows.... * build the expansion link and radius rod (exactly as the instructions). Make sure you have free movement here before going any further. * attach the eccentric rod to the bottom of the expansion link. Thank you for your thoughts on this one Richard, it would seem a logical order of assembly for the valve gear. And so after studying the parts and various pictures I have made a start with the expansion link / radius rod assembly. I have followed the instructions with the exeption of the link pivot which I have fitted to the expansion link rather that the support bracket. The reason for this alteration is that I did not want the pivot to foul with the radius rod. This assembly was a joy to build and the radius rod slides freely with in the expansion link. I have added some simulated hax nuts to improve the appearance. The assembly has been temporarily fitted to the support bracket as a trial fit. Next I shall move on to the eccentric rod and return crank. The kit includes a small rivet to make this joint but I think I shall improve on this. Link to post Share on other sites More sharing options...
Horsetan Posted January 9, 2010 Share Posted January 9, 2010 ^ Lovely. Link to post Share on other sites More sharing options...
RMweb Premium TimC Posted January 10, 2010 RMweb Premium Share Posted January 10, 2010 Very tidy work there! Also good to see you loco will be in forward gear - too many built in mid gear. Following the build with interest. Link to post Share on other sites More sharing options...
alcazar Posted January 10, 2010 Share Posted January 10, 2010 It does look good doesn't it. Is the finish due to the glassfibre brush? It looks very realistic for steel, even though made from nickel silver. Link to post Share on other sites More sharing options...
Christian Posted January 10, 2010 Author Share Posted January 10, 2010 Is the finish due to the glassfibre brush? It looks very realistic for steel, even though made from nickel silver. It is coming up alright but not the final finish yet. I use files of finer and finer grades, wet and dry paper 320 + 1000 + 1200 and the assembly is then finally buffed up with a brass wire wheel fitted to a mini drill. I find that the glass fibre brush whilst great can be a little too course for the final finish. Using nickel silver is proving very enjoyable to work with compared to brass and I have found it great to solder. I am currently working on the return crank and eccentric rod, making the joint work properly is proving very tricky. Hopefully I shall do an update later. Link to post Share on other sites More sharing options...
alcazar Posted January 10, 2010 Share Posted January 10, 2010 Jsy shows that taking your time and taking care can produce excellent results. Link to post Share on other sites More sharing options...
Christian Posted January 10, 2010 Author Share Posted January 10, 2010 OK, I seem to be getting somewhere now. Spent the day building the return crank / eccentric rod. The kit includes a tiny rivet which is supposed to pass through both the return crank and the eccentric rod, the rivet head is then covered with a brass plate. I did try to build the assembly in this way and it did kind of work but once I had soldered the brass cover plate to the eccentric rod, the return crank binded up badly. I scraped this method and had to dismantle the assembly and clean it up ready to try something different. I rather liked (Dikitriki's) method of using a bolt housed inside the cover plate and fabricating a washer to make the gap, so this is the method I shall use. When I build the other side I shall photograph all of the steps that I used and post them on the 'Building O Gauge Online' website, but basically I have made up a washer out of 0.6mm brass scrap with a 1.6mm hole in it. This is then fitted to the eccentric rod and a 14BA brass bolt with the head filed flat sits in the 1.6mm hole, the brass cover plate is then soldered in place and the washer then shaped to match the cover plate, the 14BA bolt should move freely. A 14BA brass nut is then fitted the rear of the return crank and filed down so that it is just proud of the return crank. The bolt from the eccentric rod is now threaded through the return crank nut and soldered in place, the excess bolt then removed and filed flat. The result is a perfectly formed and free moving joint. The return crank has been taped 12BA and is screwed onto the crank. Not too sure if this is the best way or whether to add a scrap of nickel to the back of the crank to give it some thickness. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted January 10, 2010 Share Posted January 10, 2010 Looks like the gear on FS when prepared for static exhibition in 1925, really lovely. I should have thought you would be better building up the outside face of the return crank with a cover to conceal the screw, as this component had no visible fixings. Link to post Share on other sites More sharing options...
Michael Delamar Posted January 10, 2010 Share Posted January 10, 2010 this is making me want to get on with a nice big steamer in O fabulous work Mike Link to post Share on other sites More sharing options...
Christian Posted January 13, 2010 Author Share Posted January 13, 2010 I have finally managed to finish one side of the valve gear which proved far more difficult than I first imagined. As explained earlier I had already fitted the expansion link, radius arm, eccentric rod and return crank which all worked well, however I realised that once the radius arm is fitted to the combination lever, union link and connecting rod, the whole assembly would then not come appart again. Therefore I decided that some form of bracket would be required to join the cylinder and slidebar assembly to the expansion link support bracket so that the whole cylinder and valve assembly could be removed in one piece, so I made up a bracket with some scrap nickel silver fret. I also realised that I would not be able to remove the connecting rods from the slide bars once the valve gear was connected so I spent some time giving a final finish to the slide bars and detailed them with some simulated hex nuts, the rear most hex nuts also hold in place the end stop which I made from some 1mm square brass stock. The combination lever was then attached to the valve stem and I encountered my first disaster as I had managed to solder the joint solid and this was the first of three joints that would come off the combination lever. I had to dismantle this part and start again fortunately the second attempt proved more sucessful. The rest of the joins were made up with great care as I was convinced that the last join would go wrong and I would again have to start all over again. The assembly is now fitted to the frames and connected up to the wheel crank for a test run. All the motion moves very smoothly and the final result is very satisfying. I have not done anything to improve the return crank yet, this needs a little more thought. Meanwhile I now have to repeat the entire process on the other side which I hope will be a lot easier now that I know what to do and what not to do. Link to post Share on other sites More sharing options...
7mm Mick Posted January 14, 2010 Share Posted January 14, 2010 I have finally managed to finish one side of the valve gear which proved far more difficult than I first imagined. As explained earlier I had already fitted the expansion link, radius arm, eccentric rod and return crank which all worked well, however I realised that once the radius arm is fitted to the combination lever, union link and connecting rod, the whole assembly would then not come appart again. Therefore I decided that some form of bracket would be required to join the cylinder and slidebar assembly to the expansion link support bracket so that the whole cylinder and valve assembly could be removed in one piece, so I made up a bracket with some scrap nickel silver fret. I also realised that I would not be able to remove the connecting rods from the slide bars once the valve gear was connected so I spent some time giving a final finish to the slide bars and detailed them with some simulated hex nuts, the rear most hex nuts also hold in place the end stop which I made from some 1mm square brass stock. The combination lever was then attached to the valve stem and I encountered my first disaster as I had managed to solder the joint solid and this was the first of three joints that would come off the combination lever. I had to dismantle this part and start again fortunately the second attempt proved more sucessful. The rest of the joins were made up with great care as I was convinced that the last join would go wrong and I would again have to start all over again. The assembly is now fitted to the frames and connected up to the wheel crank for a test run. All the motion moves very smoothly and the final result is very satisfying. I have not done anything to improve the return crank yet, this needs a little more thought. Meanwhile I now have to repeat the entire process on the other side which I hope will be a lot easier now that I know what to do and what not to do. Hi Christian, nice to see the valve gear coming on so well, I wish I had the time to get some modelling done but working nights and feel like death warmed up !! What measures did you take the second time round to prevent the joint being soldered solid?? Do you apply oil/grease/paper to the area where you dont want solder to run or is it just flux in the right place?? Hope progress continues a pace, best regards Mick Link to post Share on other sites More sharing options...
Christian Posted January 14, 2010 Author Share Posted January 14, 2010 What measures did you take the second time round to prevent the joint being soldered solid?? Do you apply oil/grease/paper to the area where you dont want solder to run or is it just flux in the right place?? Hello Mick The method I used on further sucessful attempts was to pin the joint together with the 0.8mm wire used for the pivot ensuring that it is a tight fit. The loose hole in the middle is opened up a little more so as to allow plenty of free movement. I then put some oil, using a needle and suringe, on the free moving joint and allowed it to penitrate. The tinyest amount of flux is placed on the pin, a blob of solder on the soldering iron and the iron is then quickly dabbed on the joint. The excess wire is then cut away and then filed smooth. This worked fine for the remaining joints. As had been said many times before, the advantage using metal and solder is that everything can be taken apart, cleaned up and started again. Maybe frustrating but worth the effort. Work now continues on the valve gear for the other side. Link to post Share on other sites More sharing options...
Scale7JB Posted January 14, 2010 Share Posted January 14, 2010 That really is looking lovely... some very beautiful etches for the valvegear.. I must get myself a Finney kit at some point !! Keep up the good work JB. Link to post Share on other sites More sharing options...
Christian Posted January 16, 2010 Author Share Posted January 16, 2010 At last I have been able to finish up all of the valve gear on the other side on the loco which fortunately was much easier than the first side. I guess that making all the mistakes first time around has tought me what to do and what not to do. I have also made and fitted the 2 to 1 lever and front valve rods and made up a bracket to hold the expansion link bracket and the main cylinder assembly together. This was well worth doing as it hold everything together and can now be easily removed from the loco frames. Next to do would be the driving wheel springs followed by the brake gear. I am waiting for some cast brass springs to arrive as I do not like the look of the etched brass laminated parts included within the kit, so I cannot do then yet. Also I feel that it would be best to fit the springs before doing the brake gear as some of the brake gear will be quite delicate. So I am unsure what to do next, do I dare have a look at the footplate? Link to post Share on other sites More sharing options...
alcazar Posted January 16, 2010 Share Posted January 16, 2010 Not having built one of these, can you say which is the bracket you made? Or show it on a pic? How do you go about removing the whole valvegear, doesn't it entail unscrewing the return link? And so how do you get it a) in the same place every time, and B) to STAY in place, ie, not unscrew itself? Whose cast springs will you use? Enjoying the thread, btw, and am following it on Building O gauge too. Link to post Share on other sites More sharing options...
Christian Posted January 23, 2010 Author Share Posted January 23, 2010 Over the last week I have been doing some further jobs of the chassis. The chassis has been stripped and I have been fitting the balance weights to the driving wheels. I have also been working on the coupling rods which involves addressing the oil filler cap on each bearing. Each of the etched filler caps has been filed flat, drilled and fitted with short sections of 0.7mm NS wire, a great improvement, photos to follow. Aso work has started on the front bogie truck. This has been modified a little to include a sprung bogie side control unit. The control unit made by 'Gladiator Models' replaces the 'Finney' main spacer which is a 'U' shape channel. I have not fitted the front tie bar as yet as this shall also need to be modified for the fitting of an AWS sensor, fitted during the prototypes later life. I have also got hold of some cosmetic bogie spring of which you can see two of in the picture below. The trouble is that I have no idea which way up they go. Should they be as the left one in the photo with the beam above the axle and on top of the springs, or should they be as the ones on the right with the beam below the axle and at the bottom of the springs? I have studdied my limited resource of photos but none clearly show the bogie springs. I could also do with some better photos of the AWS sensor, guess I shall keep searching. Link to post Share on other sites More sharing options...
Horsetan Posted January 23, 2010 Share Posted January 23, 2010 ....The trouble is that I have no idea which way up they go. Should they be as the left one in the photo with the beam above the axle and on top of the springs..... Yes, that's the correct one. Link to post Share on other sites More sharing options...
alcazar Posted January 23, 2010 Share Posted January 23, 2010 Interesting, where did the bogie springs originate? Link to post Share on other sites More sharing options...
Christian Posted January 23, 2010 Author Share Posted January 23, 2010 Christian, on 23 January 2010 - 11:47 , said: ....The trouble is that I have no idea which way up they go. Should they be as the left one in the photo with the beam above the axle and on top of the springs..... Yes, that's the correct one. Thanks Horsetan that's correct. After looking at the rivet detail on the frames I can see that it matches the rivets on the spring casting. Interesting, where did the bogie springs originate? The cosmetic spring castings are supplied by Hobbyhorse. I have spent the day trying to figure out how to do the front bogie tie bar with it's ABS sensor shoe. I managed to find a fairly good photo of the prototype so set about scratch building the front tie and support bracket. The cast ABS shoe itself was found in my spares box and was originally supplied by MMP in their excellent detailing kit. Here is the finished bogie with both the cast springs and the ABS shoe and bracket now fitted. Link to post Share on other sites More sharing options...
Western Star Posted January 24, 2010 Share Posted January 24, 2010 Here is the finished bogie with both the cast springs and the ABS shoe and bracket now fitted. I very much like the clean appearance of your work and in particular how well the bogie springs have been attached to the frames (given the closeness of the spring castings to the centre platework). Please tell what method has been used for the castings and how you achieved such a good result. regards, Graham Beare Link to post Share on other sites More sharing options...
alcazar Posted January 24, 2010 Share Posted January 24, 2010 Also, what IS ABS on a loco? Link to post Share on other sites More sharing options...
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