RMweb Gold nickwood Posted February 15, 2015 RMweb Gold Share Posted February 15, 2015 I have a very nice, completed Blacksmith's kit of the GWR Steam Railmotor. Unfortunately one side of the valve gear has shed a pin which has got lost. Whilst I'm quite good at finding ways of repairing things I'm at a loss as to how best effect a repair of this. I have never built any valve gear so am not familiar with the techniques used to rivet the two pieces together. The photo shows the two parts that need joining. I think I'm probably fortunate to some extent in that they are accessible. One thought I've had is to use one of the thin track pins and cut it to the length required and then rivet it in place. The valve gear is quite intricate and fragile so I am wary of using any method that needs some element of force. I presume the pins are normally rivetted with some sort of special tool. If I need to get a tool what do I actually need to get. As I would probably have no further need of it afterwards is there another way? Any help or advice would be appreciated. Link to post Share on other sites More sharing options...
RMweb Premium Siberian Snooper Posted February 16, 2015 RMweb Premium Share Posted February 16, 2015 Rivets are normally closed by hammering. The head end is rested against something solid (an anvil or another hammer) and the other end is then formed using a dolly. For something that small just a few taps with a hammer should do. Valve gear rivets are available from Alan Gibson Workshop. The alternative is to use a brass pin and solder a small washer to it. Link to post Share on other sites More sharing options...
cobach47 Posted February 16, 2015 Share Posted February 16, 2015 use a small brass pin and washer and instead of soldering flatten the end of the pin with pliers to hold it Link to post Share on other sites More sharing options...
buffalo Posted February 16, 2015 Share Posted February 16, 2015 Coincidentally, I have one of these sitting on the bench in need of much more care and attention than yours. Without seeing one it is difficult to appreciate how small they are. The hole in the eccentric rod where it joins the expansion link is only 0.6mm diameter, so the 0.8mm Gibson rivets would be too large. It would also be very difficult to access the back of the rivet to flatten it. I reckon the pin and washer approach is your only choice here. Nick Link to post Share on other sites More sharing options...
richard i Posted February 16, 2015 Share Posted February 16, 2015 dont forget the paper put between the two rods so that they do not solder together and have some movement room, remove it once the solder joint is made. Link to post Share on other sites More sharing options...
RMweb Gold nickwood Posted February 16, 2015 Author RMweb Gold Share Posted February 16, 2015 Thanks to all for the suggestions, they're very helpful. From what has been suggested I think using brass wire and washers is the way to go as the thinnest track pins I can find will not go through the hole. As Nick has said, and I've double checked the Gibson rivets are too large at 0.8mm diameter 0.45mm is the largest diameter wire that will pass through the two holes as things stand. I could possibly open the holes out a little to use 0.6mm wire perhaps but I'm not sure it is worth the risk. I will need to make some washers from some thin brass strip somehow. It might be a week or two until I get the opportunity to have a go but it should be an interesting exercise. I'll post some results up in due course, if i get it to work. Cheers Link to post Share on other sites More sharing options...
RMweb Premium Siberian Snooper Posted February 16, 2015 RMweb Premium Share Posted February 16, 2015 Thanks to all for the suggestions, they're very helpful. From what has been suggested I think using brass wire and washers is the way to go as the thinnest track pins I can find will not go through the hole. As Nick has said, and I've double checked the Gibson rivets are too large at 0.8mm diameter 0.45mm is the largest diameter wire that will pass through the two holes as things stand. I could possibly open the holes out a little to use 0.6mm wire perhaps but I'm not sure it is worth the risk. I will need to make some washers from some thin brass strip somehow. It might be a week or two until I get the opportunity to have a go but it should be an interesting exercise. I'll post some results up in due course, if i get it to work. Cheers I would suggest cutting slivers off of a piece of brass tube with the internal diameter that is the same size as the diameter of the wire you are using. Link to post Share on other sites More sharing options...
RMweb Gold nickwood Posted February 16, 2015 Author RMweb Gold Share Posted February 16, 2015 I would suggest cutting slivers off of a piece of brass tube with the internal diameter that is the same size as the diameter of the wire you are using. You might be right but either way it will be fiddly Link to post Share on other sites More sharing options...
ozzyo Posted February 16, 2015 Share Posted February 16, 2015 Have a look for dress makers pins, you only have to sort out how to fix it in place. Link to post Share on other sites More sharing options...
RMweb Gold nickwood Posted February 16, 2015 Author RMweb Gold Share Posted February 16, 2015 Have a look for dress makers pins, you only have to sort out how to fix it in place. Do they take solder? Link to post Share on other sites More sharing options...
ozzyo Posted February 16, 2015 Share Posted February 16, 2015 Do they take solder? Yes very well. Link to post Share on other sites More sharing options...
RMweb Gold nickwood Posted February 16, 2015 Author RMweb Gold Share Posted February 16, 2015 Yes very well. Just raided the wife's sewing box and the diameter of all her pins are too big. Probably about 0.8mm. Ah well! Back to the wire and washer idea. Link to post Share on other sites More sharing options...
Dazzler Fan Posted February 17, 2015 Share Posted February 17, 2015 Has anyone filed a drawing of this etch with any of the Etchers, viz. PPD Ltd.? Noel Link to post Share on other sites More sharing options...
david.hill64 Posted February 17, 2015 Share Posted February 17, 2015 You can also get dome head brass rivets with 0.5mm diameter shafts from that well known emporium amongst other places. You can put the rivet through from the non-visible side, through a piece of writing paper with a hole that is a tight fit around the rivet (and possibly with a drop of oil - not too much - then the other link. Flux the rivet and end of the link. Solder the link to the rivet, taking care not to dwell with the iron. You can then cut back the rivet, file flush and remove the paper. You should now have a nice free moving and secure joint. As the rivet head is not much larger than the rivet shank, you need to make sure that holes in teh parts to be joined are not too big, but it sounds like you don't have that problem. Link to post Share on other sites More sharing options...
Coach bogie Posted February 17, 2015 Share Posted February 17, 2015 Just raided the wife's sewing box and the diameter of all her pins are too big. Probably about 0.8mm. Ah well! Back to the wire and washer idea. You can get thinner ones. I found thin and nickel plated a few years back and have been using them ever since. Some 0.6 here in steel http://www.amazon.co.uk/Korbond-25-Professional-Dressmaker-Pins/dp/B007TKDP5G/ref=sr_1_fkmr1_1?ie=UTF8&qid=1424159886&sr=8-1-fkmr1&keywords=dressmakers+pins+brass Similar to those that I have. They are shorter and sold specifically for hemlines in 0.6mm dia. http://www.amazon.co.uk/Hemline-Dressmakers-Fine-Long-Pins/dp/B003ZVP7OA/ref=sr_1_fkmr1_2?ie=UTF8&qid=1424159886&sr=8-2-fkmr1&keywords=dressmakers+pins+brass Engine below used dress maker pins as the rivets were missing when I bought it. Mike Wiltshire Link to post Share on other sites More sharing options...
John_Hughes Posted February 17, 2015 Share Posted February 17, 2015 When I built one as a commission a few years back I substituted Peco track pins, which are dead straight. As a general rule I don't like rivets, so I do this quite often! The sequence is this: scrape the blackening off the pin, gently ease the various holes with a broach if necessary to get a good running fit (you don't want any wobble here!), shorten the pin as required, push through the components so that the head is at the front including oiled Rizla paper to avoid the whole thing seizing up, solder at the back and clean up. Go at it carefully, and it takes hardly more time to do than to describe! Link to post Share on other sites More sharing options...
KalKat Posted February 17, 2015 Share Posted February 17, 2015 Lacemaking pins are frequently finer too ...... http://www.ebay.co.uk/itm/40mm-x-0-59mm-200-pins-STAINLESS-STEEL-LACE-MAKING-BRIDAL-WEDDING-SATIN-PINS-/181658525565?pt=UK_Crafts_Lace_Making_ET&hash=item2a4bb11f7d http://www.ebay.co.uk/itm/17mm-x-0-45mm-Small-Head-400-pins-HARD-STEEL-BOBBIN-LACE-LACEMAKING-PIN-/181660958202?pt=LH_DefaultDomain_3&hash=item2a4bd63dfa or brass..... http://www.ebay.co.uk/itm/14mm-x-0-60mm-1000-Count-FINE-BRASS-MODEL-MAKING-CRAFT-HOBBY-PINS-/171684285573?pt=LH_DefaultDomain_3&hash=item27f92e4c85 Edit to add brass Link to post Share on other sites More sharing options...
RMweb Gold 57xx Posted February 17, 2015 RMweb Gold Share Posted February 17, 2015 Nice find KalKat. I spent ages trying to find brass pins to make up some Masokits screw links. All I kept turning up were the nickel plated steel pins that Mike linked to on Amazon above (not brass despite the Amazon search term used!). Not sure what I'd do with the other 976 pins after making up 12 sets of screw couplings though Link to post Share on other sites More sharing options...
KalKat Posted February 17, 2015 Share Posted February 17, 2015 They are jolly useful for all sorts of other things too. I've used them to build up assorted injectors and valves etc. Link to post Share on other sites More sharing options...
davidbr Posted April 12, 2015 Share Posted April 12, 2015 My apologies for being late -I have only just come across this thread whilst looking for something else. Nick, It would seem from your first image that you have not got the links connected correctly. I can't see the front end properly but there should not be a diagonal connected to the reversing crank at the bottom of the G iron. I hope the attached helps you see what I mean. Link to post Share on other sites More sharing options...
bgman Posted April 12, 2015 Share Posted April 12, 2015 All my etched valve gear is still in the box! I need a load of mojo to tackle it .....one day maybe? (The body is 90% complete and just waiting to be dropped onto the motion ) hey ho ! Link to post Share on other sites More sharing options...
davidbr Posted April 12, 2015 Share Posted April 12, 2015 The hardest part of the valve gear is starting. After that, it gets easier. However . . . do look at pictures, identlfy the bits on the fret and make sure you know what goes where BEFORE you cut anything out. There is a mistake on the fret (though the gear still goes together) with the combination lever, the vertical bit right by the cylinder block. It is too long so the union link which connects to the bottom points downwards when it should be parallel to the ground. Be careful, too, distinguishing between the reversing crank and gear return crank. One goes on the bottom of the G iron and the other the rear wheel crankpin. On the fret, the latter has a D shaped hole (you are meant to file a flat on the crankpin) which is easy to overlook which I did, but fortunately the two parts are about the same size. I have made three lots of this valve gear from the original Mallard etch and am now working on a fourth, a test etch for the Blacksmith model. I strongly recommend having a look at GWR Steam Railmotors by John Lewis. If anyone wants some help, send me a message and I will see what I can do. Link to post Share on other sites More sharing options...
Mad_Hatter Posted April 12, 2015 Share Posted April 12, 2015 Link to post Share on other sites More sharing options...
Administrators Phil Parker Posted April 12, 2015 Administrators Share Posted April 12, 2015 I have one of these on the bench at the moment. Will use brass pins and solder as I have in the past. I don't use oiled Rizla papers though, kitchen aluminium foil works better for me. Also, coat anywhere you DON'T want the solder to be with permenant marker, solder only sticks to clean surfaces. You can remove the marker with turps later. Link to post Share on other sites More sharing options...
davidbr Posted April 12, 2015 Share Posted April 12, 2015 I have one of these on the bench at the moment. Will use brass pins and solder as I have in the past. I don't use oiled Rizla papers though, kitchen aluminium foil works better for me. Also, coat anywhere you DON'T want the solder to be with permenant marker, solder only sticks to clean surfaces. You can remove the marker with turps later. Very good suggestions, Phil. I haven't come across foil being used. I also brass pins but have honed my soldering so that I rarely use any washer or pen. I use a pointed iron bit, NOT tinned, with just a few molecules of solder. I also file the pin heads down to virtually nothing (just enough to stop the pin going right through) and insert the pin from the BACK. Link to post Share on other sites More sharing options...
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