Minesweeper Posted January 3, 2010 Share Posted January 3, 2010 (edited) What eyes! I've made them a little over length - but the holes have been carefully measured - so I hope that they are in exactly the right place! No pre-assembly! Tony Edited January 3, 2010 by Minesweeper Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 3, 2010 Author Share Posted January 3, 2010 Four other parts of the Coupling need to be made and these are the Coupling Shaft Bronze Blocks. The Coupling Shaft Pins are located within these and they are designed to tilt slightly in use as needs be to compensate for any movement within the Coupling Tubes. The finished overall dimensions for these "bronzes" is 1 3/8" x 1 3/8" x 1". Some years ago, we saw an off-cut of a Bronze Bar for sale on an Auto Jumble stand at the Great Dorset Steam Fair - it measured 3" in diameter and was about 10" long and cost £25. We had no specific use for it at the time, but bought it as we thought that it might come in useful one day! And several years later, it has! Two slices of 1 3/8" length have been taken off it with the band saw with a small allowance for final machining. The two slices have to be split longitudinally but these were turned in the lathe to exact finished length before splitting them to save machining them in that direction when they were in halves. They were then cut again longitudinally with the band saw after that turning to final length. . The four halves then have to be roughly taken to the finished sizes but with final machining allowances included by either milling or with the band saw. Whilst the band saw was in use, a further slice was taken off the bronze bar for the nut on the Water Pump which will be required shortly. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 3, 2010 Author Share Posted January 3, 2010 Once the blocks have been taken down to their final finished overall dimensions, the following machining operations remain to be done. A curved bevel of 2 1/16" radius has to be machined on the top surface to allow for any movement when in use. The centre of the bronze has to be bored out to 7/8" diameter to take the Coupling Shaft Pins and the oil passage ways have to drilled. Steve will machine the 2 1/16" radius in Leicester - he has our Rotary Table with him up there - but I have drilled and tapped the blocks 3/8" BSF through the centre of the blocks just where the 7/8" holes will eventually go, so that he has the means through that to bolt the thing down whilst machining the radius. Boring them out to 7/8" after that operation will just take that threaded hole away. We need a piece of 7/8" diameter Silver Steel for the Coupling Shaft Pins - and uncannily, I have this in stock already. Many years ago, there was a firm called "Whistons", who have long disappeared from the scene, who dealt mainly in Surplus Stock and I think that it is as long ago as 1975 - or even before that I bought a box of "mixed Silver Steel" from them. It was mainly in small diameters of up to about 3/8" maximum - but included was one 13" length of 7/8" which I thought that I would never use...................... Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted January 3, 2010 Share Posted January 3, 2010 I'm sitting here thinking that whatever you paid for the raw material and the workshop machines you have certainly saved it back on this project alone. If I needed something like this and I could find the drawings I would just pay someone to make it, but this coupling wouldn't be a £5 bill, now would it? I traded on my amphibious GPA just because I didn't have this sort of workshop capacity - but more of a sheet metal working emphasis. Gone to a good home though. Quote Link to comment Share on other sites More sharing options...
phil munga Posted January 3, 2010 Share Posted January 3, 2010 I've just gone through the last few pages to find a drawing showing these parts for the coupling , I know there's one on the last page but thought there was a better one showing these bronze parts of the gearbox input drive shaft ,, anyhow there was a page that I missed don't know how , but that clutch is quite some size which often is hard to gauge without another object or person next to things to show the actual size , so after that page thought I'd go back a bit more to see if I'd missed anymore - and ended up on page 44 the diff rebuild , seeing all them cogs and working out and understanding how it all works , just great fantastic Keep up the good work and keep thanking whoever found the drawings Quote Link to comment Share on other sites More sharing options...
42 chevy Posted January 4, 2010 Share Posted January 4, 2010 I am just in awe at the work you gents are doing. Everyday I check to see if you made new postings on your project. It inspires me to keep working on my project. John Gott Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted January 4, 2010 Share Posted January 4, 2010 Many thanks, Phil and John! Tony Quote Link to comment Share on other sites More sharing options...
Chrisg Posted January 4, 2010 Share Posted January 4, 2010 Amazing work & I'm just worring about maching a banjo bolt :shake: Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted January 4, 2010 Share Posted January 4, 2010 I am very pleased to see the progress with the universal joints. Great job being done of them. Ben Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 4, 2010 Author Share Posted January 4, 2010 Steve has now completed the shaft for the Water Pump - this has been machined in Stainless Steel instead of mild steel as was the original. We had encountered a problem with the mild steel Pump Shafts on our two Autocars because of rust - and then subsequent leakage around the gland nuts because of it - so have opted for Stainless Steel this time. The only really complicated part with this one was the machining of the spline with our limited equipment. Steve made a "dummy" spline up first of all on a piece of scrap mild steel, just to ensure that his calculations were correct and that it would fit - and after a tiny bit of easing it went nicely into the drive. So, then confident that it would be OK, he went ahead on the far more expensive piece of stainless steel, now completed and as seen in the picture - it has yet to be tried but it should be alright. Again, an element of luck came into this with the "cutter" - Tony went to an Auction a couple of years ago to buy something completely different and there was a small Hessian bag of brand new milling cutters and slitting saws on offer there which he bought for "peanuts". The cutters were then divided up between Tony and Steve - and Steve made a holder for his by adapting an old Slab Cutter which had come with his Mill and which was really of no use to him in its original form. It was the first time that this "cutter" and holder was used when milling this spline. Steve has some bits of the Universal Joint in Leicester at the moment to finish off - Tony still has the Coupling Shaft Pins to make, and then it will be full speed ahead on the Water Pump. Steve is making a fresh pattern for the Water Pump "elbow", and we have delayed taking the last lot of patterns to the Foundry for casting until the final pattern is completed so that they can all go together. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 4, 2010 Author Share Posted January 4, 2010 Whilst pottering in the shed over Christmas, Steve came across the cylinder drain taps which had been patiently awaiting their turn for cleaning repair and refitting. The taps themselves were fine and a good clean and greasing were sufficient to bring them back. However, the rear one had been mounted on a banjo fitting in order to keep it clear of the oil pressure gauge pipe. This was a steel fitting which promptly sheared off when an attempt was made to extract it. Rather than make a new fitting, Steve just drilled it out and then silver soldered a new threaded piece into the end. That seemed to work OK so it was screwed back in but with graphited grease this time! That's one more small job completed. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 4, 2010 Author Share Posted January 4, 2010 With the thought of running the engine in the not too distant future, our thoughts have now also turned to the Exhaust Pipe as we never had one. Some substantial steel tube will have to be bent up and this was something else that Steve "eyed" up over Christmas. Tony made up the Silencer some time ago - the pictures were posted at the time but were "lost" when the Forum disappeared temporarily. If anyone wants to see them again, then they can be posted once more. Whilst looking at the exhaust system, Steve thought that there should be a centre support bracket but could find no trace of one. A couple of days later whilst rummaging through a box, he found this bracket, beautifully labelled by Tony as to what it was and where it went! Steve looked in the location described and found the missing holes so there was that mystery solved! Several old Dennis chassis have now passed through our hands and have nearly always been stripped of anything that would be of any use to us. When the last one arrived which was the one with the differential in it and which had come from the seaside chalet at St. Ives in Cornwall, these remains of the exhaust pipe centre bracket were still on it. They were rescued to be a "pattern" and put to one side (and forgotten!) until they were needed. Something else to make up! Quote Link to comment Share on other sites More sharing options...
Great War truck Posted January 6, 2010 Author Share Posted January 6, 2010 The photos of the exhaust mostly disappeared during the forum crash a while back, so i thought it would be useful to remind you of what we have done. Sorry if you have seen some of these photos before. All we had from the original Silencer was the remains of the two cast iron end plates and front elbow casting - all well beyond redemption. But we also obtained a copy of the original silencer drawing. From the information then available, Steve made up the patterns for the two new end plates and the elbow which were then cast at our local foundry. A suitable outer steel tube was rolled up by a local metal fabricator and welded along the seam for us, and a piece of stock tube was purchased for the inner perforated silencer tube and suitably drilled with dozens of holes and blanked off in the centre. We had the two hanging brackets which came from one of the other chassis'. The tail pipe is a standard part available at any Autoparts supplier. Quote Link to comment Share on other sites More sharing options...
phil munga Posted January 6, 2010 Share Posted January 6, 2010 Very nice job , are the cast ends held together by threaded rods that go right through the silencer-if so might it have had springs on one end to help keep it all tight ? Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted January 6, 2010 Share Posted January 6, 2010 Yes, rods right through it with threaded ends. Springs not necessary - they are just done up tight. You will notice that the rods are a little over length at the moment as the cast iron ends are a tight fit in the tube and I used the extra length on the threaded end to pull them in tight with the nuts. They need to be trimmed back sometime! Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 7, 2010 Share Posted January 7, 2010 On this type of silencer the central perforated tube has a 'bung' in the middle. The exhaust gas and noise escapes from the input set of holes, rattles around the can and then passes through the exit set of perforations out to the tail pipe. However, Tony should have gone to Kwik-Fit who have Dennis Subsidy lorry slencers on the shelf - see picture. Quote Link to comment Share on other sites More sharing options...
Stormin Posted January 7, 2010 Share Posted January 7, 2010 On this type of silencer the central perforated tube has a 'bung' in the middle. The exhaust gas and noise escapes from the input set of holes, rattles around the can and then passes through the exit set of perforations out to the tail pipe. However, Tony should have gone to Kwik-Fit who have Dennis Subsidy lorry slencers on the shelf - see picture. Perhaps they're going for the performance option with the straight through silencer. Watch out for the chrome big bore tail pipe soon :rofl: Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted January 7, 2010 Share Posted January 7, 2010 You will be telling me next, Barry, that Kwik-Fit have had these on the shelf since 1918! Tony Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 7, 2010 Share Posted January 7, 2010 Very nice job , are the cast ends held together by threaded rods that go right through the silencer-if so might it have had springs on one end to help keep it all tight ? I don't think they had springs but they would certainly need something. They were probably just spring washers or, knowing Dennis now, Thackery washers. I will have to have another look at the drawing. On the subject of Thackery washers, does anyone know where we can get a few, 7/8", 1" and 1 1/4" bore? They are the very devil to find in these large sizes and we have only managed so far by salvaging originals. Unfortunately, our stock has run out and we need just a few more. Dennis used them to prevent rattle in the track rod and also the brake linkage, as shown here. Any suggestions please chaps? Steve Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 7, 2010 Share Posted January 7, 2010 Steve, on all my Dennis's up to the mid 30's the washer style which was used throughout was a thick spring washer with a central concave groove. They are stamped 'Grovers Pat." and are certainly the ones which were used on the silencer. Quite possibly these are more scarce than your Thackeray washers. The only advantage with the Grover washers are they can be made relatively simply. Barry. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted January 7, 2010 Share Posted January 7, 2010 We have managed to salvage a few grover washers for under nuts and so on but generally replace them with standard spring washers. I'm not prepared to go turning up and heat treating special spring washers so you have found the place where I draw the line! We will probably put ordinary spring washers on the silencer. However, the Thackery washers seem to be most often used as an anti-rattle device and that is what we are looking for for the remaining brake rigging and to go on the ball joints of the track rod to support the rod. Quantities needed are minute so it is not worth having any made up specially and I don't really want to make up the tooling to make them ourselves. Someone out there will have two of each size under their bench, I am sure! Steve Quote Link to comment Share on other sites More sharing options...
phil munga Posted January 8, 2010 Share Posted January 8, 2010 hi Steve, I've seen and used these Thackery type washers I'm just trying to think where and one place that seems to come to mind is the throttle lever on my Fordson Tractor but think the size would be more 5/8 , I'll have a check in the buckets of old bolts at my parents when the weather permits Quote Link to comment Share on other sites More sharing options...
BenHawkins Posted January 8, 2010 Share Posted January 8, 2010 I have a Dennis drawing that shows grover washers under all fasteners on the silencer. The bolts on flanges also have holes for 16swg lockwire. I may have a few spare Thackery washers as all my vehicles are meant to rattle. Ben Quote Link to comment Share on other sites More sharing options...
Asciidv Posted January 8, 2010 Share Posted January 8, 2010 Looking a little harder, it quite posssibly seems that my efforts at making replacement 'Grover' washers has been misplaced. An Indian washer making company seem to have them in all sizes. I have asked for a quotation. Barry. Quote Link to comment Share on other sites More sharing options...
Adrian Barrell Posted January 8, 2010 Share Posted January 8, 2010 I have a fair quantity of 1/2" Thackery washers in two sizes (outside diameter). If you need any of this size, let me know. Quote Link to comment Share on other sites More sharing options...
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