RMweb Gold Bucoops Posted August 10, 2017 Author RMweb Gold Share Posted August 10, 2017 (edited) Struggling a bit with this valve gear - think I need some decent prototype photos (probably got something somewhere!). The instructions say the expansion link is outside the eccentric rod. But I'm thinking that's wrong? The plan sort of shows it inside. I've done it outside as per the wording (red circle). Best pic I can find is of the Hattons O gauge 3D printed one - http://hattonsimages.blob.core.windows.net/mediaimages/A3_3D_03.jpg which clearly shows it outside. The other end (yellow circle) also doesn't clear the nut for the crank pin - assuming it's similar to a V2 it needs to be cranked outwards? http://www.rmweb.co.uk/community/index.php?/gallery/image/22614-sjt-1270jpg Does anyone have a decent closeup of this part? And just for good measure I read last night that using un-insulated wheels (on one side only of course) isn't compatible with DCC - whilst I don't know if I'll ever use DCC I want to be "ready" so at some point will have to buy 3 wheels... Edited August 10, 2017 by Bucoops Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted August 16, 2017 Author RMweb Gold Share Posted August 16, 2017 (edited) As a little break from the motion conundrum I knocked up a pair of Gresley bogies using MJT kits. Went for compensated ones but not sure I really need them. Bit fiddly, and managed to lean the body of the iron on one of the white metal castings which blobbed it a bit when re-doing some of the brass soldering but once painted it won't be immediately obvious. I have some old kirk kits somewhere these would work on. Going to have another look at the A1 again now edit: just noticed from the pic it looks like you can see the brass frame past the sides - side on you can't. Possibly should have cleaned the castings up a bit better though, although again it's much less obvious side on. Edited August 16, 2017 by Bucoops Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted August 24, 2017 Author RMweb Gold Share Posted August 24, 2017 Not much to report - have re-done the expansion link to eccentric rod joints but to get any further I think I need to mount the bracket to the frames. And I need a chunk of brass for that and I don't have one suitable So more shopping! Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted August 25, 2017 Author RMweb Gold Share Posted August 25, 2017 While waiting for the chunk of brass strip, I've started on the cab. Ran out of time to put the other side on (had to do some work, how rude!). Quite happy with the soldering on this so far - very little leakage through to the outside. 2 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted August 25, 2017 Author RMweb Gold Share Posted August 25, 2017 Other side now on - again pretty happy with the soldering. The sides aren't *quite* flat and one of them peeps over the front by about half it's thickness. Clamped it and re-heated it, but still ever so slightly proud. I think it will do though, it really is tiny. For grins I put the footplate, boiler and cab together - looks the part I think? Haven't touched the footplate in a while - and it would seem the no clean flux isn't - it's gone a bit green in places! Cleaned that off now. 3 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 7, 2017 Author RMweb Gold Share Posted September 7, 2017 Had a week off work but back this week. Brass arrived so have fitted a piece to screw the motion bracket to. Still not really worked out how to fix the loose bits - mainly really not sure what to do with this bit as it doesn't apparently fit anywhere. Looking at pictures it just dissapears into the gloom... So back to the superstructure - and got some fiddly bits done, in this case the splashers. They still need trimming to size. Pleased with myself that I remembered to ensure there was a left and right of the front ones! Link to post Share on other sites More sharing options...
jdb82 Posted September 7, 2017 Share Posted September 7, 2017 Had a week off work but back this week. Brass arrived so have fitted a piece to screw the motion bracket to. Still not really worked out how to fix the loose bits - mainly really not sure what to do with this bit as it doesn't apparently fit anywhere. Looking at pictures it just dissapears into the gloom... IMG_20170907_084940 - Copy.jpg So back to the superstructure - and got some fiddly bits done, in this case the splashers. They still need trimming to size. Pleased with myself that I remembered to ensure there was a left and right of the front ones! IMG_20170907_085017.jpg Soon I'm going to be getting to the point of soldering up some fairly fiddly bits on my model - what have you been using to hold the small parts of brass together to stop them moving when you introduce the iron? Burnt fingers or just tweezers and gravity? They look really good, and I imagine if I try that there would be bits of brass sticking out all over the place! 2 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 7, 2017 Author RMweb Gold Share Posted September 7, 2017 Whatever I can find! By far the most useful is a toolmakers clamp. Similar to this: http://www.ebay.co.uk/itm/Proops-1-x-2-Toolmakers-Clamp-M0210-/352004246679 Masking tape as well gets used a lot. For the splashers I taped the clamp to my heatproof board, opened the jaws enough to use as a backstop for the curved splasher tops when sat on their side, then slid the splasher side into place and held it there with a small piece of tape. Then splashed some flux on and with a very hot iron (400c) gently poked at it with the solder on the tip of the iron. A couple I had to do a couple of times. For other bits I've used fingernails, the opposite end of the flux brush, scrwedrivers, pliers, whatever.Needle files are quite good as they also grip a little bit. Hope that gives some ideas? Yours is 7mm? So some of the bits a little bigger than 4mm - but no doubt still some fiddly stuff! Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 8, 2017 Author RMweb Gold Share Posted September 8, 2017 Hmm, oh to still have access to a surface grinder. Would have made the next job easy. The top of the cylinders need to be flush with the footplate valance. On the real thing it looks like the valve tuck behind the valance, on the model the valance is so thick that's not going to happen. I *think* I will remove the top of the valves so they are level with the top of the cylinders. I don't think I will be able to thin the valance sufficienly unfortunately. Might have to find my dremel. This should test the quality of my soldering! Link to post Share on other sites More sharing options...
jdb82 Posted September 9, 2017 Share Posted September 9, 2017 Whatever I can find! By far the most useful is a toolmakers clamp. Similar to this: http://www.ebay.co.uk/itm/Proops-1-x-2-Toolmakers-Clamp-M0210-/352004246679 Masking tape as well gets used a lot. For the splashers I taped the clamp to my heatproof board, opened the jaws enough to use as a backstop for the curved splasher tops when sat on their side, then slid the splasher side into place and held it there with a small piece of tape. Then splashed some flux on and with a very hot iron (400c) gently poked at it with the solder on the tip of the iron. A couple I had to do a couple of times. For other bits I've used fingernails, the opposite end of the flux brush, scrwedrivers, pliers, whatever.Needle files are quite good as they also grip a little bit. Hope that gives some ideas? Yours is 7mm? So some of the bits a little bigger than 4mm - but no doubt still some fiddly stuff! Yep, mine is 7mm. I'm finding even this fiddly, so goodness knows how you put together 4mm kits! Thanks for the ideas - I'll give'm a go. I'll see what I can find by way of a toolmakers clamp....I live in Brunei at the moment, so sourcing your 'less standard' DIY tools is somewhat challenging! Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 9, 2017 Author RMweb Gold Share Posted September 9, 2017 I do get the shakes sometimes with the little bits! The toolmakers clamp is very versatile. I've even used it for bending to 90 degrees, as a surface to flatten bent bits etc. I just bought the cheapest I could find but yes I imagine postage to Brunei can be a bit of a hinderance. Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 14, 2017 Author RMweb Gold Share Posted September 14, 2017 Getting there - Still needs some tweaking and the footplate bows a little but getting a lot closer. AND just for good measure the wheels roll a lot smoother. Bonus lol 2 Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 19, 2017 Author RMweb Gold Share Posted September 19, 2017 A small but significant (for me!) bit of progress. I found some fantastic pictures of a 7mm A3 here - http://www.rmweb.co.uk/community/index.php?/topic/6510-finney-a3-spearmint/page-2 - really hoping that Christian one day finishes documenting the build as the quality is fantastic. So I've now drilled through the centre of the valve case and passed the valve rod into them. And now the union links are connected to the crossheads. So for the motion, all that's left is the return crank then the reverse gubbins. Link to post Share on other sites More sharing options...
timbowilts Posted September 19, 2017 Share Posted September 19, 2017 Reading this thread convinnces me that my deciion to model GWR ws the right one :<) Tim T Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 19, 2017 Author RMweb Gold Share Posted September 19, 2017 What it should convince you is that whenever someone says start with an inside cylinder loco - do it! There was no decision to do LNER - the rest are insignificant Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted September 22, 2017 Author RMweb Gold Share Posted September 22, 2017 Little bit more progress, I've dropped the motion bracket down a bit, but the cylinders need to also move down a touch too (I was half expecting it as the piston rod was slightly above the axle centreline and it looks like it should be inline. Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted October 2, 2017 Author RMweb Gold Share Posted October 2, 2017 Been rather busy, so not really achieved anything. Think I still need to drop the cylinders slightly, but it's starting to get a bit close to cutting all the way through the frames. Probably time to remove some from the cylinders... Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted October 17, 2017 Author RMweb Gold Share Posted October 17, 2017 Lost a bit of momentum on this one. Still struggling with the valve gear so have returned to the body for a bit, starting with soldering the splashers on and doing a bit of cleanup. Got to probably trim some bits out of the boiler to make it fit. Link to post Share on other sites More sharing options...
Podhunter Posted October 17, 2017 Share Posted October 17, 2017 I read last night that using un-insulated wheels (on one side only of course) isn't compatible with DCC . Nonsense. DCC requires a two-wire electrical connection from the track to the input of the decoder. That part of the connection is no different to connecting a motor to the track for DC control. Current collection is made by the pickups from the insulated wheels on one side and the electrical connection from the non-insulated wheels via the chassis. When fitting a DCC decoder, the red & black wires to the decoder are connected to the pickup/chassis, the same way as you had connected a DC motor. The grey/orange wires from the decoder connect to the motor. Some older motors (e.g. the X04) have one insulated connection and one implicit connection through the metal body of the motor. Since the motor is fixed to the chassis it receives current via the uninsulated wheels and live chassis. There is a separate wire from the insulated motor connection to the insulated wheels pickups. That is the arrangement that won't work for DCC: it's not the live loco chassis that's the problem, it's the live motor frame. Most modern motors (e.g. Mashima) have two insulated connections and the motor frame or can is not connected, and are fine for DCC with a live chassis. Link to post Share on other sites More sharing options...
hayfield Posted October 17, 2017 Share Posted October 17, 2017 Some older motors (e.g. the X04) have one insulated connection and one implicit connection through the metal body of the motor. Since the motor is fixed to the chassis it receives current via the uninsulated wheels and live chassis. There is a separate wire from the insulated motor connection to the insulated wheels pickups. That is the arrangement that won't work for DCC: it's not the live loco chassis that's the problem, it's the live motor frame. Most modern motors (e.g. Mashima) have two insulated connections and the motor frame or can is not connected, and are fine for DCC with a live chassis. Just put a bit of plastic tubing (stripped from a piece of wire) on the non insulated side, both brushes are insulated from the live chassis, no cost solution. Makes no odds if the frame of the motor is uninsulated, as a can and open frame motor (Anchorage etc) bodies touch live chassis without any issues, as far as I know this is fine for DCC operation Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted October 17, 2017 Author RMweb Gold Share Posted October 17, 2017 Apologies - I re-read where I got it from (which was a DCC based thread) - it's ANY model with a live chassis and metal buffers/couplings. If one is connected to one rail, and touches another that is connected to the other rail - sparks. Link to post Share on other sites More sharing options...
hayfield Posted October 17, 2017 Share Posted October 17, 2017 Apologies - I re-read where I got it from (which was a DCC based thread) - it's ANY model with a live chassis and metal buffers/couplings. If one is connected to one rail, and touches another that is connected to the other rail - sparks. I guess its the same in this instance for both DC and DCC, normally the couplings keep stock apart, and most wagons and carriages have insulated wheels. Excellent point to consider though Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted October 18, 2017 Author RMweb Gold Share Posted October 18, 2017 I guess its the same in this instance for both DC and DCC, normally the couplings keep stock apart, and most wagons and carriages have insulated wheels. Excellent point to consider though Yes it's both DC and DCC - I confused myself so it's only fair I confused everyone else as well Link to post Share on other sites More sharing options...
hayfield Posted October 18, 2017 Share Posted October 18, 2017 Rich Don't worry, as someone who has modelled for years I have never had this issue, though I can see it could be an issue and perhaps if I wish to build my locos to be DCC compatible it would be wise to insulate both sets of wheels. Back to your issues with the valve gear, you have chosen one of the harder types to build as a first build, cannot help you with this one Link to post Share on other sites More sharing options...
RMweb Gold Bucoops Posted October 18, 2017 Author RMweb Gold Share Posted October 18, 2017 I think i'd prefer to err on the side of caution and try and stick with insulated wheels throughout. Markits are doing their best to prevent this though, still waiting for a response several weeks later... I have certainly given myself a baptism of fire with this kit! Link to post Share on other sites More sharing options...
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