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greenglade

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  1. Evening chaps/chapesses.. I've spent this morning giving the workshop a good clean and maintaining the machines ready for the next round of work. I did also find time to fettle the inside connecting rod, I think that I'll call this finished, there's the odd blemish but nothing that stands out and hell, I have to call it a day somewhere>.. Actually I think it's smoother than the coupling rods although I do still intend to revisit them nearer the completion of the model. Work done, other than the tidying up was to drill the oilways in both ends. For the little end, I have done my own thing, Don's states to drill a No.41 hole, I have drilled a No.57 and opened it out for a short depth using a 41 to act as a reservoir. The big end as mentioned previously has been drilled/tapped 6BA for the spare oil cup that I had to hand. Later, I'll make a sprung lid for this cap to keep any grime/ash out. The idea being that if sprung I should be able to prise the lid open using the oil can nozzle to oil which will then close itself, considering the access to this I think this may be a wise move. From what I can tell with the oil cup fitted it's not going to hit anything during it's arc, I'll know for sure once the rod is fitted. 3 pictures to show a little more detail, I have laid the rod on the chassis to show it's size, which is probably close to 10" in length. View along the top Side view And close up of big end Tomorrow I'll make a start on the next piece to the puzzle, not entirely sure what I'll choose, all will be revealed soon... Pete
  2. good day, all... The inside connecting rod is nearly there, all machining operations have been undertaken and shaping completed. Jobs left to do are to drill/tap the big/little end oil ways and to give it a final file and polish. Alas my files are now a little past their best, too many times getting mixed up for which metal they were intended for...lol, I also need some new 3M sanding pads, Xmas is close, perhaps a hint to the children... So although the rod is more or less finished, I will revisit it for a final finishing exercise later. Ok, so the 'how did I do it? stage... I will state that for the entire fabrication of this connecting rod I have not done as Don suggested, I have done what seemed the best method for me with the tools available. Continuing from where we were Tuesday I began machining the flute, I first machined a section down the middle parallel to the middle of the rod. The picture shows the first side so machined, I have cut to a depth of 0.080 taking care either end not to go too far. For the little end, extra thought is required to allow for the fact that this end still needed to be machined to a thinner width. Once the first side was done I then removed the rod from the jig and flipped it to the other side, leaving the jig in place and thus set for doing either side. I then adjusted the angle of the jig for machining the first angle, once the vice was tightened I tapped a small panel pin under the jig to stop the possibility of it moving during machining, wasn't really needed but instilled a little more confidence in having a solid obstacle under the jig for support. As with the middle, once the first side was done the rod was flipped for the other side. The other angle was just a repeat of before but with the jig now tilted the other way. With the roughing out of the flute now done this left the final machining operation of reducing the thickness of the little end. For this, I just held the rod in the machine vice and reduced the little end from 0.343 down to 0.312, the metal being taken off equally from either side. The rod isn't level here as the rotary table, which I still need to use, was in the way but not important for this operation as it has no effect on the job in hand. with the machining finished it was time to get dirt, oh and sore fingers, I haven't taken pictures for the various stages but will describe how I tackled this shaping by hand. I first scribed a line from the flute edges, top and bottom, around to where it meets the big end, small end is now finished after thinning the little end down. With this done I then used a cutting disc in the Dremel and carefully cut a line just inside the scribed mark. Changing from the cutting disc to the sanding drum I began to form the concave shape. This took a number of goes, alternating between each side to keep them even. I cut the sanding drum insert down to half it's width so that I didn't accidentally mark the other side. Once I was happy with the shape and that the previous marks from the cutting disc had been blended in I then changed to a floppy abrasive disc for the final shaping/polishing. As I said, I will return to a final file/polishing session to remove any remaining marks once I have got some new files/sanding pads to do it. Two last pictures, first is the rod assembled, note that I have now machined the proper nuts. Oh and while talking about the nuts, one operation that I had forgotten to add was to machine a round recess into the rod, top and bottom, for the turned part of the nut to fit into up tightly against the rod tab, This again was done by hand using a small sanding drum and a small cutter, it wasn't possible for me to use a counter bore here. Plus I have also now been profiled, ie rounded off, the rod tabs and blended this curve into the lower part of the strap as per the P2 photo I showed previously. Hope I have forgotten anything else... Lastly, the component parts that make up the inside connecting rod on a Gresley Pacific, as noted I have followed the design as used for my chosen era, ie no strengthing rib around the back of the strap. I have however done two things, first the strap thickness around the back where the later rib was added, I have increased this for extra strength. Second, in the drawing that Eddie sent me of the correct rod, it shows two sets of fastening nuts, assumingly they lock against each other, both plain, ie, no turned section. I have used the later type as I think that it will lock better against the rod tab, it's also easier to use than trying to lock two together if required in service, I will use threadlock on final assembly. Pete
  3. seems that I'm on a bit of a roll this week so will post this update covering the machining of the rod sides now, the next update, hopefully, weeks end could well see the completion of this important piece to the jigsaw. Might still have the little end bearing to do and the big end bearing shells but otherwise, I might just get the thing finished... So here's how I tackled this stage, it's basically the same as for the coupling rods for those who have been following the progress for a while, I'll go through it again here though for those who missed it. The first picture shows that one side ( R/H side as I wanted to finish with the other side, reason why coming up) has already been completed, as can be seen, the jig is now sitting vertically in the machine vice and checked to be true. Having checked the drawing I noted that the width of the rod midsection needs to be 0.281, IIRC this meant that I needed to remove 0.031 from either side. For the stop points fore and aft, I went by eye first, taking note of both Don's drawing (no dimension given) and the photo that I posted on the new rod for the P2. Once happy with the positions and allowing for the fact that as the cut got deeper the distance would increase I noted the DRO readings and proceeded to cut metal. The aft position being most critical as the edge of the cut is in line with the rod tabs, hopefully, you can see this in the picture. also worthy of a mention is that both buttons were trimmed so as not to interfere with machining. Here's the rod now machined both sides, that didn't take long did it? I got very lucky here as after a rummage through my cutters I found this one which was brand new, in its box and untouched, it was like chalk vs cheese, cut like going through butter, one day I'll invest in a decent tool cutter/grinder... one day...lol So, things to point out, with the first side machined, before doing the other side I searched for some suitable shim to pack the back to stop any possible flexing, this involved two sheets of brass shim. Now, the reason that I wanted to do this side last was so that while at this setup I could machine the big/little end faces for the oil points. This can be seen in the picture, I may go off script with the big end and add an oil cap with lid for two reasons, one to give a larger capacity of oil and second to make it easier to reach the oiling point once the loco is built. I can't see there being any height restrictions involved but will take a closer look later. As it happens I have a couple of 6BA oil cups spare, leftover from those I fitted to the front bogie for extra oiling of the axle boxes. I'll add a lid, perhaps something that's sprung loaded, we shall see. Lastly a picture of the setup for what I'm going to be doing tomorrow, the cutter is the same as used for the coupling rods, it had lost it's sharpness after that mammoth task but I have tried to use an oil-stone while running the lathe in reverse to bring back some form of sharp edge, followed by a little hand work, it certainly seems much sharper, fingers crossed. Barring any disasters, I hope to get the machining finished over the next two days middle cut first and then the jig propped up using the digital scales for doing the angled cuts, if my fingers hold out I may also get all of the hand filing/grinding done by Friday, might be a tall order but I will try. Oh and one last thing to point out, I have now changed to the Clarkson auto-chuck for doing the fluting operations. Cheers Pete
  4. I have now completed the machining or the basic profile, there's still some hand filing to do on this but I'll do this after all other machining operations have been completed. A few pictures to show where I am... First up doesn't really need much text, it's the shaping of the little end which was very similar to the big end. This time though I had to set 'X' to zero and use 'Y' as the arc is much larger than for the other end. I now moved on to the angle from big to little ends, the rod was bolted on to the plate/jig in the vertical position and using the digital scales I checked it was level. I then rested the scale on the rod to measure the angle, as can be seen, it's not very much. Next, I measured the width of the small end neck which was IIRC 0.430, this needs to be 3/8 (0.375) and so I halved the difference and scribed the edge as a guide, I marked both sides but will only use the first, once down to the line I zeroed 'Y' to repeat for the other side, choosing to flip the rod over rather than try to match the same 0.6 degrees on a swivel vice. BTW, I just approximated this gradient and then checked by running a cutter (not powered) along the edge and adjusted until happy that the angles matched. For the big end, I also needed to note where to stop cutting for the flair of the rod, Don's drawing states that at 1 3/32 from the face of the bolt tab the rod is 1/2" wide, I, therefore, marked out accordingly and noted the DRO readings for both ends as I proceeded. The large cutter in the picture was used to line up the angles, not for cutting. This is how far I got tonight, the step seen near the big end will be done by hand once I have machined the sides and the fluting. this is my next job.... Pete
  5. Last update for this week... I have now made the jig and the two buttons and their associated parts for holding the rod to both the jig and the rotary table. The first picture just shows the jig, this is the same one as used for the coupling rods, I have machined away most of the deep cuts from when profiling the other rods, I've dome this as I need this face flat to hold in the vice. As you can see I didn't bother removing the deeper cuts from when testing the various woodruff cutters for the fluting. In this picture, the surface is now flat and square. Next up was to fit a large 1/2" thick plate to the old jig to hold the connecting rod which BTW is longer than the coupling rods, hence why the added part. In this picture, we can see the plate now attached to the old jig and the accurately positioned two mounting holes drilled/tapped for the rod to be held by. This setup has had a little thought put into it for all machining operations for this particular part. In this position, I can machine the top and bottom angle for the rod, I can work out the angle by repositioning this jig so that it sits upright in the vice and using the digital angle scale can get an approximation of the angle required, I just then need to swivel the vice to said angle and cut. When it comes to the fluting which also needs to meet this angle I'll again set the jig upright in the vice and with the digital scale sitting on the rod lift the appropriate end until the angle reads zero. The fluting for each side will be done in 3 stages, the middle first and then top and bottom meeting the two angles required. This will be much clearer when I get to do this next week. The bolts for mounting the rod are 6mm for the little end and 8mm for the big end, this allows me to hold them properly and also be able to fit the two sized buttons. here I have now accurately machined the two spacers which I have also tapped 6 and 8 mm and held the rod in place. Of course, all drilling was done square to the bed to ensure the rod is running parallel along 'X' once held in position, same goes for the plate fixed to the original jig. I have also drilled/tapped extra 8 mm holes ready to clamp the rod down during machining. With the jig ready I then turned my attention to profiling the two ends beginning with the big end. As can be seen, I made a start on machining the curve, the uneven part to the left is just where I have cut away excess metal ready to flair the curve of the strap into the rod itself, this to be done by hand. I've included this picture to show how I held the work in the rotary table, two buttons with the lower one seen here having a spigot that's larger than the nut below. The spacer in the rod as mentioned is also threaded so when all tightened they were not going to come loose and I'm happy to say, they didn't. The spigot was held tightly in the rotary table chuck and with the large button between both chuck and job it was very stable. For the little end, I'll need to be careful although I have made the bottom button larger than the required top which is to size for the required rad. BTW I didn't bother hardening the buttons, I saw no point as they are a one time only use. last picture to show that the rear of the big end cap/strap has now been roughed out. Once all machining is completed I have some more shaping to do here as the rod tabs need rounding which then flairs into the strap itself. I also need to machine the top of the oil housing, I'll do this when the rod is set vertically in the vice. Next week I'll start with the little end profile and then tackle the angles, should be fun... Pete
  6. Drilling the little and big end holes... To do this i held the rod in the machine vice and packed up either end with timber, I also packed out the narrower end of the rod when held in the vice to keep it running true along the 'X' axis. I did a few passes before starting to drill to ensure all was correct. Before starting I wanted to get a feel for how the rod was looking when the two holes were plotted. I began at the little end lining up with the centre mark of the ring and advanced along 'X' by 8.5938 to arrive at the big end. the first picture shows where this ended up, I was very happy to see this, things were boding well for today's operation, what could go wrong? Now that I was happy with the position I first centre drilled the big end... I then opened up the big end by step drilling up to 5/8th and then before changing over to the boring head, I went back to the little end to drill this out to 9mm. Here I had a problem, my fault, I mistakenly picked up a very small centre drill and began drilling as if I had the larger size that I had begun with. Using the same force as before this led to one outcome, yep, the damn tip broke off in the job. The tip was too deep to chisel out using a punch and after thinking for a while of a way around this I decided the only thing that I could do was to turn the job over and drill from the other end, this time starting with the correct centre drill. I was reluctant in doing this as it meant resetting the job but didn't really have any other option. Anyway, here's the picture of the big end being opened up to 5/8th before the mishap. I'm happy to report that drilling from the other side worked, first centring and then step drilling out to 9mm. The first drill did hit the broken tip but just pushed it clear (most of the metal around it had been removed with the chisel) and since it was only small, had no effect on the overall little end hole. Thank god for that... The picture shows the rod with both holes now to size, as can be seen the big end hole was completed with the boring head and gave a nice finish which is spot on for both distance from the little end centre and between the rod tab, this will be seen better once I part the two pieces which won't be for a while yet. Last picture to show the rod removed from the vice and on lying a flat surface. A have a couple of things to do next, I need to make up a jig including spigots with 8.5938 distance between centres to hold the rod securely for machining the profile. The same spigots will be used to hold the rod in the rotary table for machining the two ends. I will machine the ends first, then the face profile while holding the jig flat, once that is done the jig will be held vertically (on it's side) for the side profiling. this is basically how I did the coupling rods, I'll hopefully get the first part done before the weekend. Thanks for looking Pete
  7. Continuing with the connecting rod... I then machined the strap recess for the rod tab to fit into, this was a tight fit, here the rod sits a little proud of the strap. Once removed from the vice a small tap with a hammer made it a good fit. Now we come to an error that I made which I duly fixed and then discovered that I didn't need to fix it at all...lol The next picture shows the strap now pushed fully home onto the rod and as can be seen, I have placed it more or less central to the rod. What I hadn't realised is that the step on the top of the strap (you can just see where I have begun to machine a slight step to replace that which I removed earlier, mainly due to one corner being burnt off during the laser cutting process). After getting to this stage and looking at a recent picture of the new P2 rod I could see that this step's top edge should have been placed at the top of the rod tab, hope that makes sense? This would have been more obvious if the tabs on the rod hadn't been the same length making me think that the strap fitted central to them. So if you look at this picture you'll see that once I got to this stage I realised that the top part of the strap didn't have enough material on it for the rib that is shown on Don's drawing. IE: the centre of the rod tab into the strap when the big end hole is drilled left no material for the strengthing rib. Not a problem I thought, a quick trip to my son's for him to give a fillet of weld around the back edge using his brand new all singing all dancing fancy welder, resulting in this. great I thought, I'm back on course to produce something like this picture of the new inside connecting rod for P2 Prince of Wales. As it happens just in time I received another email from Eddie this morning giving some more very helpful details on the 1934 crosshead and also a drawing and article on the 'correct' inside connecting rod for 4472 in my chosen era. You see, the design as drawn by Don is the one designed to stop an issue of the strap parting a little doing service, to cure this they added a rib around it's back edge, yes you guessed it, the very rib which I had just had some weld added for me to be able to machine to Don's drawing......oh the joy's of Model engineering....many thanks again to Eddie in helping me keep the model as she should be for the late 30's and thus there will be no rib on my strap, shame as it looks great. This picture also helps to show how the rod will hopefully look when finished, as can be seen 4472's rod tabs will be rounded off as seen here to a height of where the step starts on the strap top and blended into the bottom. My rod will look very much as seen here, but without, of course, the rib, I will add a little extra metal to the back of the rib to avoid the issues seen in the 1920 rod design which is what was fitted to 4472 in the late 30's Next job was to drill/tap the strap 2BA ready for the studs that I needed to turn up. Here we have the two studs duly turned, these were loctited into the strap and left to cure, short thread end going into the strap. This gets me to this stage, I need to counterbore the rod where the studs are as they are being pushed out a little, the stud positions are as drawn, ie, very close to the rod, not central in the strap ends, most of which will be rounded off later. The two brass nuts are what I have will as a temporary fix for the nuts which will need turning up with a section that fits into the counter-bore. This will become clearer later. With the strap bolted up tight ( I have used some K&S tube to mimic how the proper nuts will be when done)II clamped it down to the mill bed and started to rough out the thickness from 0.390 to the required 0.343, this of course is the thickess part of the rod which is only at the big end, the rest will be reduced much further but to ne able to do that i first need to machine all of the rod (both sides) down to a common thickness. I can hear some saying, 'why not use a flycutter' I think this next picture explains why. I needed to be able to hold as much of the rod down flat as possible. I looked at a number of ways to machine this rod, (unlike the coupling rods i needed to get the faces flat before drilling the two holes which i could then have used to fix to a jig) including using the vertical slide on the lathe, I didn't like any of them and settled for this rather laboured method and why no flycutter was used. This is the last picture for tonight, the thickness is approx 5 thou oversize to allow for final filing/polishing once the rest has been machined to profile. First thing tomorrow I'll spend some time setting the rod up on the mill bed and drill both little and big end holes, once that is done I'll make up another holding jig as used for the coupling rods so that I can finish profiling and then get onto reducing the centre section, little end and finally do the fluting, still a few days work left there I suspect. Thanks for looking in chaps, more soon... Pete
  8. No sir....except for backhead fittings and the dome and loco brake shoes all castings have been completed...I think?...it's mostly solid bar stock work from now on...:)
  9. Inside connecting rod I'm fairly busy with family commitments this week but have found a little time to make a small start on the inside connecting rod, my thinking is to get the inside motion done first as it's relatively easy, well not in as far as the components are concerned but in relation to there being much fewer when compared to the outside cylinders. The items concerned are the connecting rod, crosshead (thanks to Eddie, I now have a copy of his superbly drawn LNER crosshead for 1934 which is what we think can be seen on the few photo's available for the late 30's),2:1 lever, pin, bearing, valve spindle/bobbin and valve connecting rod and their connecting pins. These will be what I'll concentrate on the most but may well do a few other bits and pieces to break up the amount of machining involved, we shall see. You may recall that Malcolm (MEL) laser cut my blanks for me, I think that I mentioned before that I am in two minds as to whether this makes life easier or not, it certainly involves a lot less swarf but needs more care in setting up as you have no flat datum to start with. The first picture shows the blank as supplied, this particular blank is cut very close to the final dimensions, closer than I would like which makes life a little harder and setup is crucial. I spent some time looking at this blank working out how best to mark out and begin, the method I arrived at is probably not the best but I couldn't see any other way of tackling this particular part. I began by splitting the two parts, scribing a line down the middle of the rod and roughly marking out the big end tab, using the scribed line as a guide I held the blank level in the machine vice and machined the end tongue that will fit into the strap recess. The picture shows the blank after this had been completed. Best I show how I held the blank and also state that the tongue depth is critical, requiring a distance between centres of 8 19/32 " I have no way of accurately measuring this at this stage so I have used a rule and dividers to get it as close as possible. Once I get to the drilling of the little and big ends I will start from the big end joint (split bearing) and then advance along 'X' by 8.5397 (more likely to be 8.5398 as my resolution is 2 microns)to give me the exact distance between centre's required. I'll cover this in more detail when I get there. I wonder if the reason that Don states for the piston rod length 'check to place' is to allow for any discrepancy in the rod? Here we have one side near to size, I used a small engineer's square to line up the blank to ensure it was horizontal and tightened very tightly, once I got to this stage I rechecked the distance from tongue to little end centre, it was 15 thou oversize which made sense as I still hadn't reached a clean edge on the 3/8 step back to the bolt tabs from the tongue edge(centre of big end hole). the top of the tab has been left oversize for now, I'll finish this when the strap is attached. I also machined the front face of the tab leaving it 6 thou oversize for now. We now have the rod end machined to size and moving onto the strap which is also seen here. Two changes here, I have made the width of the tongue a little larger, about 40 thou and the strap blank as seen will have it's joining face machined flat, removing the step as it's too large for my liking and there's more than enough meat on the strap blank to do this, as it stands it impeeds the bolt location. Reason for widening the tongue is to give more meat on the tips of the hole once it's been drilled, I don't really like them going to a 'point', especially as the hole centre will be by eye just as much as by measurement having no datum to measure from, one of the con's vs the pro's of using a cut blank, this will become clearer later. This picture is just to show that I have machined away the step on the joining face of the strap. This is where I have left things for tonight, I won't be back in the workshop till next week. The strap blank was, of course, clocked for it's centre point and here I have begun to machine the 3/8 deep slot for the tongue to be a tight fit. I'll get on with this on Monday. To summarise, once I have drilled/reamed the big end/little end holes I'll do as with the coupling rods and mount them onto a solid steel base for the profiling and fluting, lots more work to do on this little gem... More soon Pete
  10. Final update for the week and yes I have fitted the middle cylinder securely in the frames although is push really came to shove I'm sure that it wouldn't take much to remove it again. I spent some time looking through all of the drawings, in particular, the draincock arrangement and could see no reason to put it off any longer. before doing so I took an accurate measurement of the distance between the port outer edges and noted it for later. To aid timing and bobbin alighnment I will leave off the front and rear covers so that I can check when making the bobbin that all ports are covered when centrally placed. Yes, I can still fit them while in the frames. Ok, so on to the work for today, mostly logging what needs to be done next, I'll go through that at the end, but I began by lapping the front cover guides for the valve crossheads. I did this by using the jig that was used for soldering the parts together and some fine grade auto valve lapping paste. I held the jig in the vice and worked the guide up and down until a nice sliding fit, the valve crossheads are still to be made so I can now make them a good sliding fit once I get to do them. Picture shows the setup... Next, I repainted the cylinder with the high-quality radiator paint that my son had introduced me too, for this I loosely fitted the two steam chest covers and the piston cover, the aim being to protect the mating faces of all. I placed the front cover jig in it's guides to protect them also as can be seen here. And we now have the cylinder where it belongs using fresh new 6BA CSK screws,. A few jobs done here, the middle cylinder mounting holes were CSK deeper as some screws had been just proud of the surface and I also CSK the lower screws for the smokebox/saddle as I had forgotten these all those years ago when making the frames. Well actually, not so much forgotten as hadn't noticed that they need to be CSK as the outside cylinder flange plates bolt up over them, this is why I have to fit the smokebox before the outside cylinders. Once all this was done, I masked up and resprayed the area satin black to remove all blemishes left during recent construction. So, what's next, well the list is endless even just for getting to the stage of fitting the smokebox, which BTW still needs to be stripped and re-painted. I think it's only when you get to this stage that you realise just how much work has to go into a live steam model of this size, even putting aside all the extra detail i have planned it truly is a daunting task that still awaits my attention. Here's a small list of my next jobs.. Drain cocks: Bowden cable+ outer sleeve to be routed Drain cock main shaft and pulleys, I'll leave the cab detail for now Links between the 3 cylinders Cross shaft and mounting trunnions for it Draincocks themselves Middle cylinder connecting rod, bearings, piston rod (to adjust) plus crosshead 2:1 gear lever, plus it's pivot and bearing, connecting rod, middle cylinder valve crossheads, bobbins, spindle plus the connecting rod between them. Main vacuum pipework to buffer beam Oil piping from lubricators to cylinders, both steam and for the valve guides/slide bars Gravity sanding box and pipework (push/pull rod system can be left till later) That lot is daunting enough but still, before fitting the smokebox I have to repeat this twice more over for the outside cylinders and considerable more including timing and running on air. Cleary I am certifiable as are all you other ME hobbyists....the joke is on all of us....:) See you guys again soon.... Pete
  11. will do, but it's always asking a point in case I'm forgetting something... so many parts on this thing that this is very possible... cheers Pete
  12. I wasn't going to post again until tomorrow but I have a question to ask so will get the details for today out of the way first. First I have now machined the other outer motion bracket to size, I had slightly more to remove for this side but not much. Pictures shows that the inclinometer for this side shows 0.3 degrees. this picture just to show that both sides are now done and things are now getting exciting although I can't mount the outside cylinders permanently just yet, more on that in a minute. few weeks back when I was fitting the liners I mentioned making up a tool to measure the distance between their outer edges for the bobbins. Someone asked if I could show what solution I came up with (sorry I forgot who?) It's pretty simple and material-wise involves K&S brass square tubing, I have used a number of sizes and slide them into each other for strength for both the inner and outer portions. For the innermost I bent the end over 90 degrees and crushed it flat and then reinforced with some solder, this was then soldered into the next size up permanently joining them together, this gave me the inner sliding part. For the outer, I ground/filed off a section leaving just one flat edge and bent that up 90 degrees, this was then reinforced on it's leading face (the one not needed to measure) with a smaller section of brass tube, another tube the next size up was soldered over this for its length and again at the far end of the tube yet another tube was soldered over that. This was just to give enough meat for a hole to be drilled/tapped 6BA for a locking screw. The final job was to file down the sides of the two 'tabs' to give more movement within the port and thus help when the two ports didn't line up with each other, hopefully, that makes sense. Here's the tool in question... A view from beneath to show the two tabs, the operation is simple enough, I just place the inner section into the steam chest until the first tab drops into the far port, I hold that there and pull back the outer section until the second tab drops into the closest port, by pulling the two against each other and locking the screw I now have the distance required. I then carefully remove the tool by lifting directly up until it touches the other side of the liner and remove the tool. Doing it this way the tabs aren't knocked during removal. The last job is to measure the distance between the outer faces of the tabs with a vernier. The ports on one cylinder are just slightly out of line for the tool so I will do this a number of times before being happy, once decided on the sizes I will turn up some bar that's a sliding fit to the decided size and double-check if I have measured correctly. BTW, all steam chests have now been reamed out to 11/16 as per drawing Now for the question, I think that I've reached the stage where I can fit the middle cylinder for the last time, I certainly need to get some parts permanently fitted or I'll never get the thing finished.. Unless there is a reason why not I plan to repaint the middle cylinder tomorrow and mount it for the last time using thread lock, along with it's top slide bar (bottom slidebars will be left until the crossheads are made and the piston rod has been machined to length). When it comes to the middle cylinder there is plenty of room to fit the bobbins and check their position while it's between the frames, the piston can also be removed which it will need to be as the rod is still overlength noting Don's note'check to place'. I have an awful lot of important parts that are near ready to be permanently fixed but can't while other parts aren't... For example, the outside cylinders share the same bottom row of holes as the bogie centre, so that is still loose but I can't fit the outside cylinders until the smokebox has been fitted and sealed along it's exhaust passage through the frames to the outside cylinders, I'll also need to make up the cylinder cladding and drill the holes to fit too. Once I have the cylinders permanently fitted I really am on a roll, so my question to you old hands at this game for tonight is...can anyone think of a good reason to not fit the middle cylinder? Draincocks and their associated cable/tubing/rig and the relief valves I believe can all be fitted in situ. Cheers Pete
  13. sorry chaps, yet another update... I've been pretty busy today and best post the details or it will be too much to write up in one go....8 photo's for today.. With the lugs sorted I could look at drilling them for the slides to fit, as I said before things in this area are very close with being able to drill these two holes. So close in fact that I have moved them out a little to save risking damage to the piston gland plate face. The first picture shows how close things are, in fact, the holes are just under the gland face, hence why I have moved them back a little. Note the slide in the picture is under its mount for working out where the holes need to go, just in case someone says I'm putting it in the wrong place.. and so, with the holes drilled I could temporarily mount the slide bars for the left hand outside cylinder and here we have another conundrum... How the hell am I supposed to fit nuts in that tight space seen in this picture? The answer will be in the following picture.. Oh, BTW, you can just see that as I mentioned before that I did grind a little of the liner edge to flare it into the exhaust passage, you can also see that I have yet to ream the liners and hone them, mustn't forget that. With these little niggles building I took another, more, closer look at the prototype and the answer was there as clear as day. If you look closely at this photo that I took 3 years ago you'll notice that the top of the upper slidebar has a step machined into it to give more room for the nuts, I will follow big brother and do likewise, problem solved.. Now that I had the slide bar sitting one the cylinder (btw both cylinders are at this stage) I could turn my attension to getting the outside motion bracket slipper machined so that I had the correct angle/position for said slidebar. The picture shows that the L/H cylinder has been bolted to the frames, along with the outside motion bracket with the slidebar held under it . 0.2 degrees, not bad... So, with the bracket held in the machine vice on it's one datum, ie the face that meets the frames I slowly took a little off and then did a trial fit, actually I must have done this about 6 times before getting a zero reading. Once I got to this stage where the angle was zero while just being held with a plastic peg I was happy and then could mark out the position for the 3 bolt holes to be drilled. End result is the cylinder is mounted with it's slidebars and motion bracket and looks in it's correct position, I won't really know how this all fits until I have made both the connecting rod and the crosshead, if there is to be any fettling I think it will be very small if at all. One other check to do before calling it a night was to see how the slidebar relates to the connecting rod position, I have to say that I'm pretty pleased with how things went today, tomorrow I'll repeat the process to the R/H cylinder and then I'll have all 3 cylinders with the slidebars connected in situ. After this, I'll need to take it all apart again...lol.... More soon Pete
  14. Completion of slide bars except for bolt/nuts The next job was to drill the two front holes into the bottom slide bars, starting with the middle cylinder. I first clocked one bar so that it was central and then with the opposite bar swung out of the way I used the top slide bar to correctly position the holes. Not seen here is that I used a piece of shim as a spacer for the first hole which has already been drilled in this first picture, I then zeroed this hole and advanced on 'X' by 0.187 to drill the next hole. With one side done I repeated the process for the other bottom bar by swinging out the bar just drilled, I didn't need to clock for the next bar as it's the same as the first, just zeroed 'X' again for the first hole, hope that makes sense. One picture that I forgot to take was the drilling of the brass packing pieces. I first loctited both rear and front packers to the top slide and drilled through them, once the bottom slides had also been drilled, with the packers now clamped between both slides I could machine them to width, finishing will be done with a file. The picture shows the front brass packers having just been machined, rears where done in the last update. This then brings me to the slippers for the crossheads and a bit of a story here, well two, in fact, thanks to Eddie's (MECH forum) timely intervention which I'll go into more in a minute but the first thing is a not very good batch of gauge plate from eBay. The first time that I've ordered such from there, my mistake and I won't be doing it again from that supplier. First problem was that the plate was approx 3 thou oversize, should have been 0.1562 but was closer to 0.159, no problem I thought, I'll just machine it down a little. I duly did that and it warped? was this even gauge plate I asked myself? Not to be deterred, I checked it's thickness with a mic and it was just over 0.156 along the length of the part I had cut off from the 18" bar that I ordered. So I heated it to cherry red to normalise the metal and while still, a dull red, put it in the vice to straighten it. Let it cool, polished it and to my surprise with no further work required it was a perfect fit in the bars? Sometimes life just works... Anyway, here's the part slid in between one of the bar sets. I then cut the bar into 3 sections and machined them down to a length of 1.250 each as per Don's drawing and this is where we come to the second story. Eddie kindly contacted me to say that don's drawing for the crosshead is wrong for my chosen era, IIRC it's a BR pattern circa 1948. He happens to be working on his own crossheads for his superb models of an H4 and K3, you guys need to check these out on the Tyneside ME site, true masterpieces. Thus, I then did a little research and could see that Eddie is 100% correct, and so am in the process of looking into this. Now some things I have to follow what Don has drawn to avoid any conflict later in the build, these will be the length of the slippers and the distance from bottom of the slipper to the centre of the piston rod, I may also need to look at any step within the drop link but will still be able to build a crosshead that looks like the correct pattern, it looks like 4472 shared this with the V2 and P1/2 but I'm still looking into this. I have deviated from Don anyway as his crosshead incorporates the slipper with the head, I had already decided early on to make these in two parts planning to machine a groove down the centre of the slipper and a tongue on the top of the head and then silver solder together, at least that's the plan. with the crossheads temporary on hold I will move on to the important task of getting the outside cylinder slide bars mounted to them and also to the motion brackets. I first need to drill the two mounting holes into the cylinder lugs and have to say that this is very close. My plan is to set up each cylinder and transfer the holes from the slide bars from underneath, they can't be done from above due to the steam chests being in the way. To do this I have to clean up the lug's underside and the last picture for tonight shows the first cylinder having been done. This is not critical so I just held the cylinder in the machine vice at approx 1 degree tilt to ensure I could remove the offending material leaving just the minimum to remove with a chisel so that the bar will fit up against the stop,, ie the lower bars. next update might actually have the slidebars in place, we shall see... Pete
  15. One picture to finish off this weeks progress. I have now machined the rear brass packers and drilled the holes in the bottom bars to be able to fit the parts so far made together. I have used temporary 8BA bolts and a piece of brass for the front packing, it's a little thin (0.01mm) but close enough to show how they'll look when finished. I have laid them out on one of the pictures that I took of the prototype 3 years ago at York for comparison. Hopefully, the correct thickness brass and the material for the crossheads will be here beginning of next week. What I can do while waiting though is to drill the outside cylinder lugs and fit the slides to them, I can then fit the outside motion brackets and set about mounting the slides to them, I think that's going to take a few days. I have also made a decision on the oilways for the outside slides, I will follow the prototype and fit two lines, one either side. When looking at the prototype and the refrigerator copper tube that I had in mind for the job I discovered that this is fairly close to scale, yes the union's will be larger but they will still fit and look good, or at least in my mind's eye they will.. More work but worth it, I think. cheers Pete
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