Old Bill Posted July 21, 2020 Share Posted July 21, 2020 22 hours ago, Rootes75 said: Its a lovely read seeing this progress. You are too kind. I am glad you are enjoying it though. It is the only reason for doing it! Steve Quote Link to comment Share on other sites More sharing options...
Old Bill Posted July 21, 2020 Share Posted July 21, 2020 21 hours ago, andypugh said: Did you consider that they might be chaplets? Pretty sure they are not. They just look like surface marks as if something had been left in the sand. I have seen chaplets and they were much more obviously separate components. Also there is nothing obvious to support just there. I may yet be provem wrong! Steve Quote Link to comment Share on other sites More sharing options...
Old Bill Posted July 27, 2020 Share Posted July 27, 2020 They are re-decorating our production office at work and I got a call to say they were getting rid of an old picture and would I like it? It turned out to be a framed general arrangement drawing for the Dennis Subsidy A chassis! I took their arms off... Steve 3 Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted July 27, 2020 Share Posted July 27, 2020 Very nice! You just wonder what else is lurking around in old Offices around the country! Quote Link to comment Share on other sites More sharing options...
nz2 Posted July 27, 2020 Share Posted July 27, 2020 Another photo please, square on Doug Quote Link to comment Share on other sites More sharing options...
Old Bill Posted July 27, 2020 Share Posted July 27, 2020 Hi Doug. This is square on but the reflection is terrible! Steve 1 Quote Link to comment Share on other sites More sharing options...
Rootes75 Posted July 27, 2020 Share Posted July 27, 2020 Very nice and good news that it is with you rather than being put in a skip! Quote Link to comment Share on other sites More sharing options...
Citroman Posted July 28, 2020 Share Posted July 28, 2020 (edited) Yesterday there was an antiques program on tv a couple had a little russian home tabernacle in silver. They had the plan throwing it in the bin, but it got sold for 800 euros... People are stupid. I did fish the complete construction drawings of our local coal mine from a waste paper stack on the road side. Edited July 28, 2020 by Citroman 1 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted July 30, 2020 Share Posted July 30, 2020 (edited) Pattern making continues and now I am into core boxes. As you can see, there are two cut-outs in the back with return flanges, necessitating a core box each. The flange requires that the core protrudes outwards to create it. This is the side of the box with the flange tucked underneath. I drew out the profile on the drawing board which helped a lot in aligning it all. The front and side I glued together as a seperate piece. It must disassemble to be able to release the sand core. And the same for the other side. The whole lot is held together with over-centre catches. The water overflow boss was glued into the bottom. The prints on the main plug and the two boxes. The right hand one has two bosses for water outlets. Now onto the big core. I plained up some timber left over from a lorry body and the base is an old table top. Nothing is wasted in this household! The filler neck requires a cylindrical boss so I glued up two blocks and screwed them together before drilling the hole. The angles on the blocks were all cut on the chop saw. That is a marvellous tool. Nice straight cuts with controllable angles and the ability to trim them accurately to length. I cut rebates at the corners and set some plywood over the joints to strengthen them. They proved their worth when I dropped one and suffered no harm! A trial lay-out. All of the loose parts were then dowelled together and secured with over-centre catches. Just to add a bit more challenge, the inside of the tank has a baffle arrangement for the return flow. This puzzled me for a while but is quite straightforward as long as I can get the bits in the right place! The main shape of the baffle is screwed onto the bottom board. The interior will be part of the fourth core, supported through the return flow hole. All clipped together Dismantled and pulled back from the core to aid removal. One more core box to do. I shall be glad to see the back of this one. There is saw dust everywhere! Steve Edited July 30, 2020 by Old Bill 6 Quote Link to comment Share on other sites More sharing options...
David Herbert Posted July 30, 2020 Share Posted July 30, 2020 I think that the internal baffle is to deflect cold water being poured into an empty radiator from going down the pipe into the heads. Instead it tops up the radiator itself displacing hot water in the radiator into the cylinders via the water pump, hopefully reducing the risk of cracking a cylinder casting with thermal shock. Nice woodwork too ! David 1 Quote Link to comment Share on other sites More sharing options...
mattinker Posted July 31, 2020 Share Posted July 31, 2020 11 hours ago, David Herbert said: I think that the internal baffle is to deflect cold water being poured into an empty radiator from going down the pipe into the heads. Instead it tops up the radiator itself displacing hot water in the radiator into the cylinders via the water pump, hopefully reducing the risk of cracking a cylinder casting with thermal shock. Nice woodwork too ! David I very much doubt that it was to prevent cracking, boiling water will still crack an engine! More for better flow in the rad. Matthew Quote Link to comment Share on other sites More sharing options...
andypugh Posted July 31, 2020 Share Posted July 31, 2020 40 minutes ago, mattinker said: I very much doubt that it was to prevent cracking, boiling water will still crack an engine! It was 19-umpteen. A lot of engineering was based on rules of thumb and common beliefs. The baffle might have been intended to address a problem that did not exist, to address a problem that did exist, but ineffectively, or to address a real problem effectively. It is very unlikely that anyone then would have bothered to _test_ which of those it was. Even now, where a car company might have more test vehicles than a total pre-war production run, a lot of stuff gets put in on the basis of "it probably does no harm" or a quick back-of-the-envelope FE analysis. 2 Quote Link to comment Share on other sites More sharing options...
nz2 Posted August 1, 2020 Share Posted August 1, 2020 A thought as to the radiator baffle; When an engine is working very hot there is a danger when checking the water level. Hot water can splash up through the filler cap opening. The baffle would redirect water reducing this splashing. A second point could be as an indicator as to how fill a radiator should be. A check on two radiators here show no triangular baffle but a circular shaped additional casting positioned vertically instead. Doug Quote Link to comment Share on other sites More sharing options...
Old Bill Posted November 8, 2020 Share Posted November 8, 2020 I am not much of a wood worker and was getting a bit fed up with it so I gave it a break and did some other things. However, the feeling has come upon me again and it is time it was finished off. I took it to see a pal who has much more experience of this kind of work than I and he made a couple of points. One was that he didn't think the badge would draw very well, particularly around the points in the letter 'N'. I therefore applied some wax fillet around all of the letters. This comes in strips and, if it is warm enough, simply pushes into place using the ball tool. It took some patience but worked well. I put some filler in the letter 'N' and then dressed it off afterwards, tapering it upwards to the end of the points. We also had some discussion about the internal baffle feature. he didn't think it would work very well as there is no key to align the core so I took the wedge out and made up a removable piece of wood and another core box for a pice that could be dropped into the hole. The upper piece is screwed into big core box with wing nuts and the lower part is the box for the piece of sand that drops in. The original, non-located core box, now needed some adjustment. A couple of coats of Bondaprime. Ready for the foundry! I had planned to take it to Devon this weekend but have been kyboshed, unfortunately. Next trip down will be anybody's guess. Oh well. I can start on the bottom tank pattern now. Steve 🙂 9 Quote Link to comment Share on other sites More sharing options...
alsfarms Posted November 9, 2020 Share Posted November 9, 2020 Steve, That is nice craftsmanship. I am guessing that the radiator is to be cast in aluminum? Do you have the sides in pattern form yet? What is your plans for the core? If I stay with the Riker project, I will need to build the radiator for that truck also. Al Quote Link to comment Share on other sites More sharing options...
Old Bill Posted November 9, 2020 Share Posted November 9, 2020 Hi Al. As you can see from the earlier pics, the lorry was fully functional. When Dad rebuilt the radiator, he replaced the sides by using the originals as patterns with some bits glued on to give a machining allowance and replace the broken bits. These are still fine. We are also fortunate in that the original core is in wonderful condition and needed only a few of the gills straightening out when he first did it. However, the aluminium tanks have corroded right away and, although we got a few years out of them, have now had it completely beyond repair. Hence the need for new ones. I am not much of a woodworker and have not done anything as complex as this before but one has to have a go. Our Thornycroft has a complete new radiator but for that one, I bought a share in the pattern that was professionally made for Hampshire Museums Service. That pattern has produced at least six sets of castings which are now scattered around the country. I had the gills made by a radiator repair company and threaded them on the tubes myself before returning them to be soldered into the tube plates. Unfortunately, they have stopped doing that sort of thing so I will have to look somewhere else for the next lot. If you take a look through the Thornycroft thread, you will find the whole story in there. Steve 🙂 1 Quote Link to comment Share on other sites More sharing options...
andypugh Posted November 9, 2020 Share Posted November 9, 2020 3 hours ago, alsfarms said: What is your plans for the core? If I stay with the Riker project, I will need to build the radiator for that truck also. Are you following the 1908 Dennis thread? Ben is building an entire radiator from scratch there, too. 1 Quote Link to comment Share on other sites More sharing options...
alsfarms Posted November 10, 2020 Share Posted November 10, 2020 Nice craftsmanship Ben is doing on the radiator. I would need to study and read up in order to build the shell and then all the core pieces to make it all function as it should. This is a great forum to study and enjoy! Al Quote Link to comment Share on other sites More sharing options...
Rootes75 Posted November 10, 2020 Share Posted November 10, 2020 I really like the work on the Dennis letters, that is going to look superb when cast. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted November 10, 2020 Share Posted November 10, 2020 I do hope so! Steve Quote Link to comment Share on other sites More sharing options...
Old Bill Posted December 13, 2020 Share Posted December 13, 2020 (edited) The radiator pattern making continues with the bottom tank. As you can see, this is extremely poorly as well. When you say that something is patched up, this one really is! I decided that the split line should be through the centre line of the bosses and so cut the main blocks and flange and also some prints for the water flanges. As the end bosses are also split, I screwed two blocks of wood together before turning them in the trusty Myford. I have a very nice wood turning lathe but I am not very good at it so for accuracy, I use the Myford! This is how the assembly should look. There are webs beneath the bosses so I have attached them to one side only and rebated beneath. The moulder will have to brush the sand out of the rebate when he does the second half. Gusset cut to profile. To create the inside requires a big core so I glued up some timber for the print. All laid in place and looking promising. However, I still have this feature and it has been perplexing me for weeks. Whoever drew it certainly didn't think of the poor guy who had to make it! I could leave it off and still have a functioning radiator but it wouldn't be right. The trouble is that I can't read the casting to see how it was done. Normally, I can but this one is a puzzle. Well, it is going to have to be done with a core so I have made up some blocks as prints. I am working on the core box now and will let you know how I get on. I shall be glad to see the back of this one! Steve 🙂 Edited December 13, 2020 by Old Bill 5 Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted January 24, 2021 Share Posted January 24, 2021 I have just purchased a photo of a Dennis WO Subsidy lorry in civilian use. It shows the lorry crossing Conwy suspension bridge which certainly makes for a nice photo. The lorry is operated by Co-Operative Wholesale Society Ltd 1 Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 26, 2021 Author Share Posted January 26, 2021 We could of course done one of these subsidy conversions. We had a spare back axle, wheels and length of chassis, but we would never have got it in the shed. 5 Quote Link to comment Share on other sites More sharing options...
Citroman Posted January 27, 2021 Share Posted January 27, 2021 Just reverse it in with a bit of speed...😁 Quote Link to comment Share on other sites More sharing options...
Old Bill Posted February 7, 2021 Share Posted February 7, 2021 Well, it has been a while since I posted anything. This lock-down is a bit of a nuisance but we carry on. I have continued with the radiator bottom tank pattern. Next task was to partially drill a hole through the water outlet flanges. This will give a boss in the sand on which the main central core can sit and leave a hole in the tank. A bit of tidying up with some filler. Time to glue it up! More filler and wax fillets. On to the core boxes. The first was quite simple and produces a cylinder of sand to hollow out the bosses at the ends. I started off by dowelling two pieces of beech together and then drilling through. I used a boring bar to bring them to size. The main core is a rectangular lump with radiused ends. I couldn't put any draft in this one so I made the sides removable to get it out. The bottom section has the corner radii to follow the line of the tank. This time, I made a special tool to help install the leather fillet material and it worked quite well. A bit of filler in the corners where I didn't do a very good job with the leather. Now the tricky ones. I agonised over these corners for months but eventually came up with this solution. The square section drops into the core print on the end of the main plug. To get the tricky return flange, there are two pieces glued in and a removable sliding piece to pull out. I do hope the moulder can sort it out! Filler again for the fillets. Left and right hand of course. Painting at last! The usual two coats of Bondaprime, polished with wire wool to get a good surface. Finished at last! I am glad to see the back of these. They have gone on too long and I would much rather be cutting metal! Thinking ahead, these castings are just too big for my dinky mill, no matter how I look at it so I have bought a Bridgeport type turret mill. The trouble is that it needs to reside in the space behind the lorry. However, the lorry is immobilised due to a lack of radiator! To get it out of the way, I lashed up a bucket and a couple of bits of hose just to let me start it and run for a few minutes. It worked OK but boiled up pretty quickly! Success! Mill installed and awaiting arrival of the castings. A trip to the foundry beckons when we are let out again. I'll keep you posted how I get on! Steve 5 Quote Link to comment Share on other sites More sharing options...
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