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Jo NZ

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Everything posted by Jo NZ

  1. Now I have the engines and carbs printed, it's time to start on fitting the engines into the chassis. The engines have plates bolted to each side to allow for fixing, like this... Except, of course, for the rear right hand mount which supports the handbrake and gear-change cross shafts and is like this The engines have a variety of supports. The rear of the rear engine is supported on hangars to the top of the chassis, and in my ignorance I supposed that all the supports were like that... no chance! There's an angle across the chassis between the engines that the front engine hangs off. Added to that the front of the rear engine hangs off the front engine by a couple of steel straps. The front engine is offset from the rear, presumably to align the chain. With me so far? more pics,,, Making the carbs was important to align the front engine as the inlet protrudes through the bodywork, so it needs to be outside the chassis. Bolster had a problem with keeping the engines in sync, and originally used a jockey wheel to keep the chain taut between the two motors. A friend of his came up with an ingenious way of adjusting the front engine to keep the chain tight without the power sapping jockey wheel. There are no details... From the photos I have, I think it works like this. There are two adjustable rods from the front engine to the front chassis rail. When these are tightened up, the front engine pivots on it's rear mount and tightens the chain, as the sprocket moves forward. The chain. I found that the easiest way to join a short chain was to cut down a spare jig (you get heaps) otherwise the chain has a mind of it's own I think that the chain is about right in pitch, but it's way too wide. I'm happy to live with that, when the body is on it will be difficult to see. A couple more views from underneath Next will be to sort out the gearbox mount and rear axle swing arm. Another voyage of discovery....
  2. Grand Prix Models made a 1/43 version. This is the first one built of the Totip car...
  3. Agreed. Irony seems to have dropped off the collective psyche. (Not to mention satire....)
  4. If you have updated Chitubox you need to reset the default printer in settings. When you set it to a Mars 3 the file format will change to .ctb HTH
  5. There is a raised script on top of the SU float chamber - It says "S.U. Adderley Park Birmingham" and it's curved to fit the top. Like this Fusion 360 has recently been upgraded to easily etch or raise lettering on curved surfaces. Unfortunately only on single curves, and the float chamber lid is part of a sphere. I tried a 2d engrave of the lettering but it didn't look right. I was discussing this with the guy who gave me the original 3d model and he offered to do it for me! Said - it's my job, I do this sort of thing every day. I sent off the 3d model of the lid and it came back with the script on it - marvellous! Then I discovered that there are two different lids - they are handed with fuel inlet being effectively mirror imaged. That isn't a problem, however the script won't mirror... I solved it by taking a spherical cut of the lid, leaving only the script, and then joined it to the mirrored lid. It seems to work - and - it is just readable in 1/8 scale. I have been printing parts as I go along, and because I've got big fingers and the parts in 1/8 scale are small, I've printed them in 1/4 scale as well. It's much easier to see where any fit problems are, and also how to split the parts for assembly and painting. I've started to model the rocker gear, but I have a feeling I'm going to be making four different rockers... The model so far - this a test piece, so I've only painted it for a quick look.... Drive side Timing side Carbs and inlet manifold (a deep breath when I fitted the manifolds - there is a gap between them - just). And the first valve rocker. The whole thing is split into 3 components so that it can be assembled. I still have no idea how the full size ones are fitted.... As you can see, there are castellated nuts! I had no idea they were standard in Fusion so I started to make my own - see the timing gear on the back of the crankcase. Then I did a search and found them - and in Imperial sizes too. Jo PS - looking at the pictures I realise that I have the SU script upside down. Ho hum....
  6. I don't know if it's still relevant, but a very long time ago I laid out the positions for the fuel pits at Christchurch airport in NZ. The refueller has a finite hose length, so the distance from the pit to the refuelling nozzles under the wing must be within this length... bear in mind the restrictions on aircraft position to access skybridges , not hit the terminal etc. I spent a while with scale cutouts of aircraft, circles from fuel ports and possible positions for the pits. Air NZ was running DC10s at the time, and told us that the parking layout would allow for Jumbos and DC10s to alternate. No reason to have a row of 747s, in other words. We dug up the tarmac, installed the pits... and then AirNZ announced they were changing their international fleet to 100% 747. Sigh...
  7. The original film was made at MGM studios, Borehamwood (Elstree). Model Lancasters ran down a wire to drop their bombs into a water tank. I'm told that this rig was right beside Elstree Way, so easy to see. Peter Jackson, AFAIK, won't make the movie if the name of the dog is changed...
  8. And on to the carburettors.... There are 4 SUs, pre 1935 so not even the first"H" type, and information is very sparse. The only identifier is a stamped number on the side"1530". I had a few pictures of period carbs so started with the choke size (1 1/8") and estimated my way around the drawing. I drew one using a picture from the car, and then realised that they are all different. As the front engine is canted over, and the carbs need to remain upright, the manifold flanges are angled. The float chambers are fitted to either side, depending on the position of the carb, and the float chamber tops are also handed where the fuel union enters....and the float chambers appear to be bigger than standard, presumably because BM ran on Methanol. Here's a picture of one in situ. It illustrates the relationship between the carb and manifold quite well as it's more exposed than the others. And my random jottings...
  9. Once you have scratch-built a new one, you will, of course, find the original.
  10. Well I always thought that nothing happened unless there's a picture, so I printed a couple more and took one. Excuse the white bits, they are from the washer and will be removed....
  11. I have been printing finned cylinders for a J.A.P. V-twin and came across the same problem with warped fins (Mars 2Pro/Chitubox). I found that mounting the cylinder dead horizontal, with every fin supported, came out OK. My fins are the same thickness as yours, but I only have 13 of them to get straight.
  12. Model Motorcars have it if you search their site. https://model-motorcars.myshopify.com/products/ignition-wire-z038?_pos=1&_sid=de5581554&_ss=r
  13. Try treating it as separate projects. Engine, Gearbox, Chassis, Interior and then the body. You can display each build as you go along. Take your time, only do the next bit when you feel like it.
  14. The bezier curve descriptors were so difficult to manipulate (computer power? It was only a VAX 760 (?)) that we often gave up... Good to hear that they work nowadays. If you're going to learn Fusion 360, it's free for students and hobbyists (a bit difficult to find the free site though). I can recommend the tutorials on YouTube by Arnold Rowntree https://www.youtube.com/watch?v=LSRKJgTSS4c&list=PLFCTgdiT5-kLBNvrkUNy63Gu1tWdRuKkr. I tried several others and got confused until I found these.
  15. Most 3d CAD programs have a download feature for nuts, bolts etc. You just need to find someone who can print them.
  16. Bezier curves! What CAD program are you using? Matra-Datavision Euclid used M. Bezier's curves in the 80s. At that time they were really difficult to manipulate to get the shape you wanted. Renault used the same software, we reckoned that's why all the late 70's Renaults were such strange shapes....
  17. First print, and first time using water washable resin....
  18. I'm calling the gearbox finished, for the time being. It has errors, but when it's printed (it's only 20mm long) they are difficult to spot... The complex bit on the top is the Positive Stop Control - I'll quote "The principle of this control is a step by step change, the control lever always returning to a central or normal position. The travel of the lever is regulated by a stop in either direction and the movement is such that only one gear-change can be made at a time."... "It has been developed to provide a quick and positive gear change for racing machines, thus enabling the the rider to keep both hands on the handlebars, giving better control of the machine."
  19. There must have been something about hi-fi companies in the 70s. Rotel gave a lot of free jackets away (in cool black), but people soon stopped wearing them around the paddock because so many got asked "do you work for Rotel? They owe me money" in aggrieved voices....
  20. From working on aircraft structures for 20 years I think this is more like it.... 16 SWG = 0.064” / 1.626 mm. You are talking Imperial wire gauge?
  21. Regarding your 16swg tub - that's about 1.6mm full size. I've just printed a component that's 2mm full size in 1/8 scale, and it's a bit thin... Your skins will be 0.08mm in 1/20 scale - that's probably see through. You might want to overscale them a bit.
  22. Thanks for the reply, it really made me think! Looking at the gearbox next to the engine in the frame (all carefully positioned with blu-tak) it looks the right length. Next step is to finish the clutch mechanism and then draw the positive stop control. Wish me luck....
  23. I used to work with a nutter gentleman who had an old mini. The works car park had one space that was really narrow, and no one ever parked in it. It was just wide enough for the mini, but left no room to get out. As he was invariably the last one to turn up, he would stop in front of the space, get out, lock the car and then push it into the space, opening the boot to remove the brick which he put under the back wheel. An ealy version of Mr Bean? Anyhow I digress. Driving up the M1 he would change lanes about every mile, almost at random, so he used all three. Why? "to wear them out evenly"
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