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Pugsley

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Blog Entries posted by Pugsley

  1. Pugsley

    (Traction) motoring on

    By Pugsley,

    The first of the traction motor assemblies is approaching completion, just the fitting of the motor gear to go now (I'm not counting the axle assembly as part of the motor unit - I've still got to thread all 12 parts of those!)
     
    Side view of the motor assembly:

     
    The first one has been close to disaster a couple of times, due to me not really having a clue how best to put them together I've now worked out the best sequence for doing it, which should make the next 5 go together a lot quicker.
     
    End view of the motor asembly:

     
    I've also discovered another design fault - I've made the bracket fit the motor extremely accurately, however I hadn't taken into account that the shaft bearing of the motor protudes from the casing by about 0.5mm, which meant that the bracket wouldn't fold square. I've now had to drill the hole for the motor shaft out to 4mm, so it sits nicely in the support frame.
     
    View of the motor with wheel, giving an idea of what is visible behind the wheel. With the gears painted black, it shouldn't be too bad :

    It's all a (fairly steep at times) learning curve, I guess
  2. Pugsley

    37/7 Progress

    By Pugsley,

    An even greater lack of imagination with the title for tonights update, on the plus side it is a little more descriptive of what's actually occuring!
     
    Since last time Hornby class 50 buffers have been substituted for the Bachmann ones, which are too spindly IMO. To do this, twist the heads slightly to the right and pull, the head should come out with the spring. Drill down the Bachmann buffer housing with a 2.3mm drill, which will loosen the bond of the adhesive holding them in place. A little tug with a pair of pliers should bring the housing away - the Hornby buffers are glued in the holes left.
     

     
    The bogies have also been narrowed and the sideframes moved up slightly. Cut both sideframes off with a razor saw, inboard of the brake shoes, then file 0.3mm off each side of the keeper plate moulding. When reassembling, glue the sidframes back on so that the bottom of the brake shoe assembly is level with where they attach to the keeper plate. This moves the sideframes up about 1mm, and narrows the bogies by 1mm, improving the appearance.
     
    Next up - the paint shop!
  3. Pugsley

    3rd time lucky

    By Pugsley,

    This is it for a while now, I promise! The more I use these oils, the more I like them, and the more I'm getting to grips with using them. The 3rd wagon is by far my favourite of the ones I've done recently, it just looks that bit better than the others.
     
    I've used a photo of a different tank as a guide for this one, for a bit of variety:
    http://www.flickr.co...57603195747980/
     
    The model:

     
    I've used the same techniques that I've developed over the other two wagons, but have added more artificial highlights and shadows on the underframe, and on the roofwalk. Again, the underframe was exclusively oils, with talc added as required to matt the finish, the same was done to the bufferbeams.
     

     
    The base grime under the filling hatch was created by loading the tiniest amount of paint onto the brush, then rubbing it gently over the barrel. The streaks were added with a small brush, then worked into the barrel by tapping and scrubbing until the desired effect was achieved.
     

     
    I think a rake of these will look rather nice in the oil terminal on the layout, which I really should get on with building...
     
    More as and when!
  4. Pugsley

    455 Progress

    By Pugsley,

    I've made a bit more progress with the 455, with all four bodyshells assembled. The bodyshells go together quite well, but I have had to do a fair bit of fettling to get the ends to line up properly with the roof and the sides to line up properly with the ends. No major surgery was required, just a little judicious filing here and there, particularly the vertical section of the rebate in the sides, where it meets the end of the roof.

     
    All 4 cars with filler applied around the ends, awaiting rubbing down. The most time consuming part of the last couple of weeks has been the removal of all the raised details around the windows and the doors - only necessary when using Jim's etches (which I'd recommend, as it moves the detail of the model into a whole other level). There are also a couple of other good reasons to use the etches, but more of that another time.
     

     
    The other thing that I noticed is that the cab roof finishes straight across in the kit, leading to a 0.5 (ish) overhang in relation to the end of the sides. This needs to be eliminated by gently filing the roof section from a point just left of the corridor connection to the outside edge - the real things curve at these points. Hopefully it is visible in the pic above.
     
    Next job is to finish sanding down the first application of filler, before skimming over with a second layer and gently sanding that back.
     
    On the plus side, judging by the level of interest so far, I don't think anyone will be announcing an RTR 455 any time soon Anyone want to buy some Replica Mk1's and some MJT parts...
  5. Pugsley

    A brief glimpse

    By Pugsley,

    After what seems to be a very long time, the heavyweight 37 is finally finished. Unfortunately, I can't say too much about the methods used at the moment, as it is scheduled to appear in a future issue of BRM. So, all I can post at the moment is a couple of teaser pics to prove that I am actually achieving something from time to time:
     


     
    I'll put some more pictures up once the magazine is out.
     
    It hasn't turned out quite as well as I'd hoped as some of the materials and techniques used are a bit experimental, but it's still looking quite good, IMO. It has been good practice for the big 37 though, which I really need to overcome my fear of painting, which is the biggest barrier to progressing with it. Well, that and the fact that the first run didn't go so well, but I think that's down the back EMF being enabled on the chip which got confused by the signals from 6 motors. I now need to build a small length of track to use my rolling road on, so I can hook it up to the Powercab and start tweaking CV's. There'll be more of that in a later update.
  6. Pugsley
    Due to a varnish malfunction, what used to look like this:

    Now looks like this:

     
    And what used to look like this:

    Now looks like this:

     
    The moral of this story is, if you're using a varnish for the first time, don't use it on anything important. On the plus side, I now get to try the filter technique on the TTA, and set myself a huge challenge in replicating this:
    http://www.flickr.co...57603195747980/
     
    I wanted to do it before, but wasn't sure how I was going to do it. Now, these oils seem to be perfect for this kind of thing, so I'm going to give it a go.
  7. Pugsley

    A little pick-me-up

    By Pugsley,

    Slow progress continues with the bogie project, although the end of the first one is in sight, and as can be seen from the background of the pics below, the second is coming on quite nicely. It's taken me a little while to work out what I was going to do with current collection, but have settled on a fairly simple setup that picks up from 4 wheels on each bogie. I may add pick-ups to the centre axles at a later stage, but figured I'd try without to begin with, as it's easier!
     
    This is the final design of pick-up:

     
    It consists of an 11mm long piece of phosphor bronze strip, with a contact pad of brass soldered to one end. I've done this as I've read about phosphor bronze causing pitting on steel wheels if used in direct contact, the brass should alleviate this problem. For the first two I did, the strip is then folded in two, about 2/3rds of the way along. The second axle set was folded in half, which seems to work a little better.
     
    The collector arm is now a bit springy, helping to keep it in contact with the wheel, and is soldered to a piece of 0.7mm nickel silver wire, for strength. This, in turn, is soldered onto an L shaped bit of brass, soldered to the front face of a bit of copperclad paxolin. The whole assembly is glued on to the cross member of the bogie frame, as below.
     

     
    They're proving to be quite effective, although they haven't been tested on a track yet, I've tested the continuity using a multimeter and all is working as it should. They appear quite unobtrusive now and should be even harder to spot once painted. I was a bit worried with putting them on the outer edges of the bogies, but I think I've got away with it....
     


     
    There's not much more to do to this one now, although I need to cast some new brake gear for it. The kit includes lost wax cast brake shoes, which do sit very close to the wheels once assembled. With the kit, as designed, this isn't a problem as the metal parts fit into the resin bogie moulding. Unfortunately this is not going to work with my etched chassis as there will be a serious risk of short circuits through the bogie frames, so I'm going to make a copy of the kit parts in resin. I have used the kit parts on the outer mounts though, as these mount to the resin frames.
     
    It's all looking rather crowded now, and that's before the rest of the brake gear has gone in!
     

  8. Pugsley
    In the last post, I wrote about the track and wiring putting me off doing anything with the layout. I don't think that was the case in the end, the lack of progress with the layout was another symptom of my wider modelling malaise but I'm really glad I went down the route that I did in getting somebody else to do the bulk of the track and wiring.
     
    This update is long overdue in a couple of ways. One in as much as that this is the first update to this blog in two years, and the fact that the layout came back to the South West last year, and attended the annual SWAG members day as a last minute 'work in progress' demonstration.
     
    Looking along the length of the layout, from where the fiddle yard will be, down to the end. The VEP is stood where the main platform will be, with the oil terminal off to the left and the bay platform to the right:

     
    Simon has done a cracking job on the track and the wiring, I'm glad I asked him to do it for me. There's a little bit left for me to do in terms of laying a bit of track on one of the terminal sidings and a bit more wiring, then I can get on with the installation of the third rail.
     
    A wider view of almost the whole of the layout:

     
    I don't expect progress to be particularly rapid, there's a few workbench projects I want to get out of the way first, including the tanks that are currently on my workbench, and the 455 which is definitely going to be required for the passenger service on the layout. However, the intent is there and I'm thinking about what I need to do to get it completed for the first time in years, which can only be a good sign.
     
    I need a few more tankers to fill these sidings:

  9. Pugsley

    A milestone moment!

    By Pugsley,

    I'm feeling rather pleased with myself this afternoon, as it all appears to work! I've spent the last few modelling sessions constructing the axleboxes and their stirrups and fettling the equalising beams to fit.
     
    After the test assembly appeared to be successful, I couldn't resist plonking the body on top to see what it looked like, and it looked rather good IMO.
     

     
    Everything appears to be OK in terms of width across the bogie - nothing looks out of place there. There is an issue with one of the springs being slightly out of alignment (obvious in the pics), but a careful bit of work with a file on the mounting stud will sort that out. I've resigned myself to lightly gluing the springs in position, instead of relying on a friction fit anyhow.
     

     
    The ride height appears to be ok, in as much as in its current state the distance from the ground to the bottom of the body is less than I had allowed for the overall height of the bogie, so by the time the secondary suspension is installed it'll be at the right height. I just need to find out what that height is, as I don't appear to have written that down anywhere...
     

     
    What it has highlighted though, which I did kind of expect, is that I'm going to have to add a fair bit of weight inside the model to get the springs to ride at the correct height. In the photos above, the model is sitting at pretty much the maximum downtravel of the axleboxes, the idea is that the normal position will be at half travel, so the wheels can go up and down with the undulations in the track.
     
    It needs a bit of tweaking, but at least I've proved to myself that I haven't been wasting my time!
  10. Pugsley

    A Quick Update

    By Pugsley,

    I dunno where time goes these days - one minute it's Christmas and the next it's Easter! Still, I can offer a quick update on the 37 project - it is structurally complete and painted, with a few little bits to add before the weathering commences in anger. This is how it is at the moment:
     

     
    The biggest problem at the moment seems to be a ride height problem at the No.1 end, this is currently riding some 2mm too high, which although it doesn't sound a lot, is enough to make it look a little odd. I'm not quite sure what's causing that at the moment, but I'm hoping it won't be too hard to sort.
     
    Some of it has been weathered though:
     

     
    I had to do the fan before fitting the (rather nice) Shawplan grille, otherwise there was no way of doing it later.
     
    Tom - This is about the best I could get of the ripple effect now it's painted. I think I could have done it a bit more now, as the paint has increased the subtlety of the effect, but it's a very fine line to overdoing it!
     

     
    Edit - Image upload now working!
  11. Pugsley
    Railex has managed to do what several other shows have singularly failed to do this year, and that is to inspire me enough to get on with this layout. I've also got Chris Nevard to thank, as reading the description of Combwich in the programme sparked a Eureka moment - expanding foam filler!
     
    I'd been wrestling with how I was going to achieve the landscape that I desired, and this, combined with some flue tape (like gaffer tape only much, much stickier) is the answer. I considered blocks of extruded polystyrene, I have some left over from Chittle, but cutting it to the right dimensions and angles seemed like a lot of, messy, work. So, I've set about laying the tape over the areas to be foamed, then covering it in foam. I need to get some more, however, as the small can didn't go as far as I thought it might have.
     

     

     
    The foam will be carved to shape with an old kitchen knife. I also managed to pick up the last track components I needed and have now laid all of the sleepers, with the exception of the bay as that is a little close to the area being foamed, and once that stuff is stuck it's not going anywhere!
     
    More terraforming updates soon.
  12. Pugsley
    After yesterdays trials and tribulations, one of the first things I did this evening, once home, was to turn the boards around to see how it would look viewed from the opposite side to the original plan.
     

     
    I think it works better - I'm much happier with the appearance of the layout now, it just works better IMO.
     
    The mugs and herb jars are the storage tanks, the CDs are the loading canopy and the coasters are a small office building. The Bachmann boxes by the far wall are a low-ish relief building for an industry that shares part of the oil terminal yard.
     
    I've taken the opportunity to check out the photographic angles as well, and it's going to work much better this way round. Here's a rough idea of how the layout will look from a distance:

     
    And some of the possible angles:



     
    I'm happy now that it's showing a bit more potential
  13. Pugsley
    Follow these links for the other stages of this project - I've had to trim the number of entries in the index box, to the right:
    Part 2 - More Gronk progress
    Part 3 - It doesn't look much different, does it?
    Part 4 - End of side 1, please turn over
    Part 5 - Side 2
    Part 6 - End of side two - approaching the end(s)
    Part 7 - Nearly the end(s)
    Part 8 - The finished article
     
    I know its in the archive, but seeing as this is still a current project, I'd better move it over here.
     
    Based on this photo:
    http://web.ukonline.co.uk/railscans/pic ... 000310.jpg
     
    The model started life as Dick Hardy, but I wanted to do something different with it. I started this ages ago, and it was intended for the later period on Chittle, but now I've got rid of the layout (and the rest of the stock), I'll probably put this one up for sale once finished - I still want to do it justice though.
     
    This was how far it had got previously:
     

     
     
    Renumbered, and the black window surrounds and cab door that the Hornby model came with have been painted grey, with a mix matched to the factory finish. I'd also renumbered it with Fox transfers, and changed the warning flashes to the early type (I'd originally planned to do it in 1998 condition, which wasn't much different). It needed fading, and the roof and sides need to be done separately - executive dark grey is a funny colour when faded, it goes a kind of tan colour. Departmental grey, however, just gets lighter.
     

     
     
    At this stage the roof has been faded with washes mixed up from Humbrol 110 and 34. The sides have been attacked with white gouache washes. The numbers have been removed, as the fading virtually obliterated them. I'll put them back later, probably after the first grime layer has gone on - as they're plastic, the oily dirt from the fuel doesn't stick to them.
     
    The downside of using this wash technique is the wash gathering in all the detail, and looking very wrong. Since trying this method on the 08 (after using it with some success on my blue 33) I've decided it's a technique that is better suited to smooth sided vehicles. Undeterred though, I pressed on to see what would happen once some grime had been run into the panel lines:
     

     
    And to be quite honest, it looked more than a bit pants. So, I decided that it all had to come off (the beauty of gouache) and that the only way to get the overall fade would be to do a spray fade. I left the gouache washes that I had already put on the yellow on both ends, as I wanted that more faded than the black. A bit of maskol to protect the glazing, the roof masked off, and it was ready to go:
     

     
    The gouache hasn't gone completely, but it doesn't matter as the sprayed fade will even things out. I used Vallejo off-white, heavily thinned with a little screenwash added in the mix to help the surface tension. this was sprayed at relatively high pressure, and just dusted on, and built up gradually.
     

     

     
    It's looking much better by this stage. It needs a bit more work on the battery and exhauster boxes on one side, and a bit on the solebar of the other, but that can be done with gouache.
    Once the dirt starts to be added:
     

     
    It starts to look more like it should from the photo. Numbers have been added again, but from Modelmaster this time - I'm disappointed with how yellow the Fox transfers go.
     
    The griming/highlighting needs to be finished on both sides, and then it'll be onto the underframe. I haven't yet decided what technique to use on the underframe - my variation on Martyn Welchs' method, or another idea I've been cooking up, similar to that I use for buffer grease. Hopefully I'll make a decision soon
  14. Pugsley

    And So It Begins

    By Pugsley,

    What better to do on a sunny Saturday, then to put some good music on and break out the water mixable oils:
     

     
    So far, I've made a start on the No. 1 end nose and the roof, working along to the other end. This is just the initial colouring, there's more to come once this is dry in a couple of days. The whole weathering job is going to take quite some time, I think, as not only is it much bigger than anything I've done before, I'm going to have to put more in the way of details in, if it's to look as good as I want it to.
     
    More as it happens
  15. Pugsley
    Links for the next chapters of the saga:
    26 - Getting somewhere at last!
    27 - OMG, I think it's going to work!
    28 - Getting there slowly
    29 - Quick bogie update
    30 - More bogie progress
    31 - Spring bounce
    32 - A milestone moment!
    33 - Doing a jig
    34 - Back to life...
    35 - Mocking....
    36 - I dont believe it!
     
     
     
    I decided to finish another 'quick win' task before starting on the bogies - fitting armrests to the seats included in the kit.
     

     
    The armrests are filed from 1x2mm Evergreen styrene strip, to more or less the shape and size in this picture:
    http://briandaniels.fotopic.net/p61285107.html
     
    Next up, bogie assembly!
  16. Pugsley

    Back to life....

    By Pugsley,

    Back to reality. I've given the virtual world a bit of break for the minute, instead turning back to the 37 bogie in the, possibly vain, hope that I'll have one assembled for Telford.
     

     
    The picture above shows the last of the motors undergoing final adjustment (cf. bodging) and testing before assembly. I am pleased to confirm that they all actually work, having been tested on my ancient Hornby controller.
     
    More soon!
  17. Pugsley

    BOGIES!

    By Pugsley,

    No, I've not been shouting that word in libraries in homage to Dick and Dom, but I've actually started work on the springy bogies of 415.
     
    Quite a productive weekend has seen me prepare the 42 teeth gears for fitting onto the axles and make a start on the axles themselves.
     

     
    The gears originally had a 2mm hole in the centre. I enlarged these by drilling 3.5mm, 4.3mm and then reaming to 4.74mm for an interference fit on the 3/16ths axles. Which brings me, neatly, to the axles themselves.
     
    The original plan was to have solid, one piece, axles, but further thoughts turned to how I was going to set the back-to back measurements effectively, with all of the traction motor gubbins in the way. The solution is to have the axles in two halves, which will screw into one another, allowing for adjustment.
     
    One half is 23mm long, drilled 2.5mm and will be tapped M3. The other half is 28mm long, but has 5mm turned down to 3mm, ready for threading M3. Once the axles are assembled, I'll see how the threadlock holds, if it's not sufficient I'll drill through the two halves and taper pin them.
     
    Next jobs are to thread the spigots and tap the holes in the other halves, before drilling and reaming the wheels to 4.74mm.
  18. Pugsley
    As the pictures in the printed magazine haven't shown up some of the subtle effects that can be achieved with the oil paints as much as I'd like, I've taken the liberty of putting the pictures used in the article, plus a couple of bonus ones, here. I'm not including the words though - this is in addition to the article, not instead of it
     
    Click each photo for a larger view.
     
    Intro:

     
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  19. Pugsley
    I've not really acheived much of late, I haven't really felt like doing much and the large scale 37 has stalled as there's a few expensive bits I need to buy for it before I can continue. Over the last week or two I've slowly started to feel like doing something, so thought I'd turn my attention to some of the unfinshed projects kicking around the shelves behind the workbench.
     
    The quickest win was going to be the model of 37890, that I started nearly two years ago! It's been mostly complete since June 2010, when it appeared on the Class 37 display, to celebrate 50 years of the class, at the 2010 DEMU showcase event.
     

     
    I've modified the Blue Star socket on the front to look a bit more like the real thing, this just involves rounding the top with a file. I've also fitted the bufferbeam pipework, most of which is from a Hornby Class 50 detailing pack, with the exception of the vacuum pipes, which are of unknown origin (possibly Heljan?) - it's amazing what you discover when rummaging through the bits box!
     

     
    The Shawplan windscreen etch, and flush glazing really help life the Bachmann model, as do the Hornby 50 buffers and pipes. Lowering the ride height and moving the bogie sideframes slightly inward also make a great deal of difference to the appearance. I've also added the handbrake actuators (Shawplan) and chains (Detail Associates). Transfers were from Fox, and the etched arrows and depot plaques were also from Shawplan.
     

     
    I'm happy that this is now complete - just a little weathering now, which I'm quite looking forward to as it'll be the first time that I've used the water mixable oils on a loco. More progress soon, hopefully! I really should build a photo diorama as well - something else to consider.
  20. Pugsley
    Possibly not the best catchphrase to use these days , but I thought I'd start the next 7mm scratch build project with a little quiz. Although there's still a lot to do to the Cargowaggon Twins to turn them into an actual model, rather than a collection of bits, I wanted to get another project under way in the design stage.
     
    I find that after a day at work, I often don't feel in the mood to do some actual modelling, and there's a good chance that I could cock something up through being tired. Hell, there's a good chance I could cock something up anyway! So, an hour or two of slaving over a hot computer seems a more realistic proposition of an evening, and it's much easier to rearrange virtual items than it is to rectify a physical mistake.
     
    So, ladies and gentlemen, I give you this:

     
    It's very early days yet, so I will be very impressed if anyone can guess what it is. Not so impressed to give the winner anything, though, so you'll only have the satisfaction of being correct, which can be very satisfying
     
    This is going to be a slow burn project (aren't they all!), so don't expect updates too regularly...
  21. Pugsley
    I've put a small article on the Showcase about colour variation with oils, as the format seemed to fit a little better over there. The article can be found here:
    http://www.rmweb.co.uk/showcase/?p=2289&preview=true
  22. Pugsley

    D I Why?

    By Pugsley,

    A combination of things in the title - do it yourself transfers and why am I going this far? I could have the body assembled by now, I reckon, but it is getting to a point where the extra work seems worthwhile - I just have to keep thinking 'it'll look great once it's finished!'.
     
    The transfer making wasn't as tricky as I feared it might have been. I ordered some of the clear and some white paper from Crafty Computer Paper, which comes with fairly comprehensive instructions. The first attempt didn't go exactly to plan - after 3 light coats of Klear sprayed on the ink ran after wetting the decal. Since that first attempt, I've given everything else one thin-ish coat of Humbrol Mattcote applied with a flat brush and it appears to be working much better. The signs were made up in CorelDraw based on photos I've found on t'internet.
     
    The results so far:

    The engine room bulkheads are now substantially complete - just need a little weathering before fitting. The painted flag and detonators in box effect looks a little crude but, in the context of the assembled model, should look OK. Just don't look too closely...
     
    The nose bulkhead for the No 1 end is in a similar position, although I have started on the weathering of this, mostly worn paint/shiny metal so far, using Metalcote silver (Humbrol).

     
    Once the nose bulkhead is weathered and fitted, I can make a start on fitting the cab detailing bits, and the LED cab lights. About the only cab detailing parts left to make now are the windscreen wiper motors - these will be fitted after the bulkhead is secured in place.
    http://www.rmweb.co.uk/community/uploads/1264621456/gallery_6668_11_33085.jpg
     
    Included in the above pic are brake indicator lights, isolating switches of some kind (I think - they're fitted above the cab doors on the drivers side), cab heaters, radio and unidentified tanks that go on the secondmans side.
     
    After finishing the cab assemblies, attention will turn to the body sides, although there is a little experimenting to be done before assembly - more of that in the next 'gripping' instalment...
  24. Pugsley
    As a further distraction from the 37 bogie project, I thought I'd do a little more to the chassis for the Nitric Acid tanks. I'm using Alibre design for this as well, which has a sheet metal function, that calculates fold sizes and the half etched fold areas based on the parameters I specify. It's taken a while to get my head round, purely because there's so much it can do, and I'm not really familiar with CAD, so I'm very much learning as I go along.
     
    There's a few hours work gone into this so far, it would have been quicker apart from the sharp learning curve, so I've redone a few things several times to get where I am now.
     

     
    It's just the outer members at the moment, the next thing I'm going to draw up and add to the assembly are the axleguards (W-Irons), I've just got to work out a foolproof way of locating them, which I think is going to involve etching through and using Scale Hardware cosmetic rivets. All other solebar rivets will be of the usual half etched and punched through variety.
     
    Although this is going to be mostly etched, I'm planning on making as much use of castings as I can, in order to reduce construction time and complexity. I'm aiming for a compromise between the JLTRT speed and ease of assembly and the MMP looks and details. Only time will tell if I can manage it!
     
    Everything appears to look OK size wise at the moment, I've scaled the buffers down and fitted them virtually. They're the right distance apart (scale 1727mm) and there's only a tiny bit of bufferbeam visible on the outer edges, just like the prototype, so I'm happy.
     
    More as and when...
  25. Pugsley

    Doing a jig

    By Pugsley,

    No, I've not taken up Irish dancing, but have had a bit of an issue with the traction motors. I've made a bit of an error when calculating the relative position of the gears, meaning that the teeth mesh too tightly, leading to tight spots if anything is even slightly out of position. Sadly, the 42 tooth gears that mount on the axle were slightly out, mostly due to the way that I'd held them in the chuck when drilling them out to fit the axle.
     
    I then tried mounting them in the chuck by the boss, but can't tighten the chuck enough to stop it moving, without crushing the boss, particularly when reaming out to the final dimension. This meant that they were always ever so slightly out of round, leading to jamming.
     
    So, thoughts turned to how I could hold the gears adequately during this operation, and how I could make it consistent across all of the gears. In the end I came up with the idea of drilling two holes in each gear, and using these to screw the gear onto a mount that would fit in the lathe chuck. To ensure that the holes were consistent across the gears, and on the mounting block, I made a drilling jig out of a piece of 0.5mm brass.
     

     
    Whilst I made one of the holes slightly off centre, it didn't really matter as the position will always be relative to the other. As seen in the photo, the jig is drilled to 5.9mm in the centre, to fit over the boss of the gear. The holes are drilled to 2.2mm, clearance size for 8BA. The jig is used to drill one hole in the gear, then an 8BA screw is slipped into the hole, to maintain the jig position, whilst the other hole is drilled.
     

     
    Apologies for the slightly crap photo, but this shows the mounting block. The centre was drilled out to 5.9mm, to fit the gear boss, then a drilled gear was used to mark out the position of the two mounting holes. These were drilled out to 1.8mm, then tapped 8BA. The gear to be drilled is fitted onto the mount, secured with two 8BA screws, then the whole assembly is mounted in the lathe chuck, gripped on the outside of the block.
     

     
    This shows the whole thing assembled, with a gear for drilling, ready to be put in the lathe. Early indications are that it has pretty much worked, although I will have to do a small bit of bodging on a couple, by filing a small amount off the teeth. Still, it's a whole lot better than previous
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