Polar Star Posted December 4, 2009 Share Posted December 4, 2009 Finney A4 - S7, 7mm scale 33mm gauge - A rivetting problem by polar star original page on Old RMweb __________________________________________ Comment posted by alcazar on Mon Sep 28, 2009 1:08 pm Thanks very much for the response, once again. Yes, please, PM me details of Mr.Penn-Sayer so I can contact him with a view to sorting this out in my head, at least I have to say, I found the wheels very realistic, which was why I asked if they were AGH. In the MRJ article, the builder used AGH wheels and they didn't really jump out at me. The photos of the built A4 and the build on the DJH website, DID though, and theirs is built on Slater, so I am still tyrying to decide Finney or DJH. (Unfortunately, in the meantime, my car has decided it no longer liked it's big-end bearings, and, being an Impreza, is likely to cost me bigtime, so any model-buying is definitely on hold at the moment ). As regards the Slaters screw: can't it be disguised at all? I suggested palsticene, (excuse spelling?) in an earlier thread, I used to use it with Romfords: press platicene into the ends of the axle, smooth with a finger and dimple the end of the axle with a sharp point. Would that work? __________________________________________ ??? posted on Mon Sep 28, 2009 1:38 pm Time to get back to the tender and the rivetted strips which fit along the top edge of the outer frames. Martin Finney notes in his instructions that rivetting of this strip might elongate the item and he suggests leaving the strip in the fret during the rivetting process. So that is what I did with the result in the photograph here. Lots of nicely formed rivets on a strip which is meant to be flat - what is not easily seen in this picture is that the strip has curved in two directions, from the side view the strip has the shape of a banana. The next step was to gently remove the curve which is seen in the photo and for that I used finger and thumb, stroking the curve out. After achieving a strip which would lay flat I used a metal ruler and smooth faced pliers to get a straight edge to the top of the strip. At which point the strip was found to be 0.5mm - 1mm longer than required. Cutting the excess from one end is not an option for the elongation occurs across the entire length of the part and hence the distance between the notches in the strip no longer matches the separation of the angle brackets on the tender frames (see an earlier post for a picture of the frames). So the strip and frames were aligned mid-way between axles 2 and 3... and each notch in the strip was made longer until every bracket would fit into the corresponding notch. To get the very ends of the strip to align with the frames and to preserve the rivets in the vertical portions of the strip, I cut the strip into three parts (between bufferbeam / drag beam and adjacent tank bracket), soldered the long part of the strip onto the frames and then adjusted the two small parts to fit. All this would have been easier if the drag beam had not been folded down. Peter __________________________________________ ??? posted on Mon Sep 28, 2009 1:52 pm alcazar wrote: Yes, please, PM me details of Mr.Penn-Sayer. I have to say, I found the wheels very realistic, which was why I asked if they were AGH. In the MRJ article, the builder used AGH wheels and they didn't really jump out at me. The photos of the built A4 and the build on the DJH website, DID though, and theirs is built on Slater, so I am still tyrying to decide Finney or DJH. As regards the Slaters screw: can't it be disguised at all? I suggested palsticene, (excuse spelling?) in an earlier thread, I used to use it with Romfords: press platicene into the ends of the axle, smooth with a finger and dimple the end of the axle with a sharp point. Would that work? Unless I am mistaken, the DJH kit is supplied without wheels so which wheels to use ought not to influence the choice of kit. If you choose the kit from Martin Finney and wheels from Slater's do remember to state that the wheels are for a Finney kit as the kit assumes bogie axles of 5/32" diameter (which Slaters can supply). I have some engines under construction with Slater's wheels and the screw head can be disguised with a circle of 5 thou plastikard secured with something like UHU or Photomount. When the sticky has dried then the edge of the plastic disk can be blended into the boss with wet and dry. Peter __________________________________________ Comment posted by alcazar on Mon Sep 28, 2009 3:40 pm Thanks for that. Could the strip, above, have had the rivets half-etched? __________________________________________ ??? posted on Mon Sep 28, 2009 4:59 pm alcazar wrote: Could the strip, above, have had the rivets half-etched? You are asking me to comment on an aspect of the design for the kit in which the choice - emboss the rivets or half-etch the strip - was made by Martin Finney. I do not have his experience and skill in kit design and indeed I am unlikely to ever know how to make that choice. Might there be a different way of achieving the result and in a way that is more predictable? Probably as I can think of several alternatives, however those alternatives might not be acceptable to either the kit designer (greater effort to produce the design) or the kit purchaser (too fiddly / time consuming). As it stands, I have got the strips in position and looking ok. regards, Peter __________________________________________ Comment posted by alcazar on Mon Sep 28, 2009 5:02 pm OK. I see your point. PM'd you back by the way I'll let you get on with the build now, or it'll be Christmas before you get any further. __________________________________________ Comment posted by 28ten on Mon Sep 28, 2009 7:23 pm Seeing as the subject of wheels has come up I thought somebody might be interested in this shot of the castings as they arrive and a finished F/S wheel I have recently finished for a local commission, you can see the taper pin in the background Here is the S7 form tool used to create a profile I must say i do like the quartering jig, I will have to make something similar AGH wheels are my preferred option but I do use slaters for tender wheels and occasionally for loco wheels. __________________________________________ Comment posted by Western Star on Thu Oct 01, 2009 9:13 pm In view of the interest shown in the crank pin jig, on thread and via PM, I have asked Mr. Penn-Sayer if he would consider making a small number of the jigs for those who wish to turn their own wheels. Paul has replied to say that expressions of interest are welcome and that he has several months of work outstanding on other modelling projects at the moment. He asked that I mention that the jig as illustrated can do:- S7, FS , left and right lead, 90 degree and 120 degree separation for outside crank pins plus cross drilling of an axle for taper pin. Following the wheel photos of "28ten" I remembered that I had some incomplete AGH wheelsets which were intended for the Cartazzi axle of Merlin (which is being built on this thread by Peter aka Polar Star). So here are some photographs which show a partially turned casting, a completely turned casting and a turned casting mouted on an axle (with a Tufnol bush for the axle),. regards, Graham __________________________________________ Link to comment Share on other sites More sharing options...
3 link Posted December 4, 2009 Share Posted December 4, 2009 Fantastic !!!! I was wondering if you would bring this most interesting thread over to the new site. All the best, Martyn. Link to comment Share on other sites More sharing options...
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