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  1. C

    Scale Model Vertical Maytag. Any Info?

    These look A LOT like the south bend projects model engine
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    Electric car plant

    If you count the total bird killed by wind turbines that's a very small number, compared to other factors(skyscrapers and cats). Unfortunately if you look at the species of birds in that number the pictures get darker, as mainly big and endangered bird (that have very low reproduction rate) are...
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    Engine sucks but will not blow

    Piston OD have a big influence on compression and also ring gaps, while ring groove depth is not as important. Working on old two stroke motorbikes, usually there's about 1mm of radial play behind the rings on a 50mm bore, but tenths on the ring gap and piston clearance can make the difference...
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    Unusual variations on two-stroke head design.

    Sometime you need to start off a blank page... could be the good one. As the PTFE and JB-weld insert I think they could have contributed to overheating because of the very poor heat conductivity compared to aluminium, as the piston get mostly cooled by its contact with the cylinder wall (lacking...
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    Unusual variations on two-stroke head design.

    I'll try to give my view on your points. 1)the double reflecting cone will cause a lot of diffraction nullifying the effect of the waves (the interaction is the same of waves on a river, that reflect and move in a completely different way than the water flow). the gas flow will easily double...
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    Unusual variations on two-stroke head design.

    I understand the limit that Owen have, as space requirement has always been an issue for 2stroke motorcycles (look at the crazy design of some multi-cylinder motorcycles) As for the tailpipe I didn't explained myself very well, given also that I never gave to much of a thought about that, making...
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    Unusual variations on two-stroke head design.

    Hi, based on my knowledge and experience I think the folded cone won't work very well. To explain my conclusion I'd like to clarify the internal physics of a tuned pipe First, you have to consider two properties as separated: gas pressure and waves. You want to get rid of all the exhaust gas...
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    G-Code error HELP!

    Could it be the machine skipping the end point of an arch? I had kind of the same problem on a CNC mill when we started using CAM with dynamic milling, crushed a 40mm cutter in the side of a 200mm steel cube it was contouring (could not air run as it was over 1 hour even whit max feedrate. It...
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    is alluminium or brass better for steam engine pistons

    The problem is that aluminium have a very high sliding friction and even at relative low speed can get sort of gummy and seize. On modern engine low piston weight is much more important given the high rpm and the bad friction quality is compensated by using a lot of oil, but there are still a...
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    Effective muffler for a two-stroke model aeroplane engine.

    Having calculated and built many two stroke tuned pipes and played with old moped "pot" mufflers, I can tell you that exhaust pulse timing is much more important than the back pressure. If you run a two stroke with a stub pipe (back pressure basically zero) you will rev it only to less than half...
  11. C

    Counterweighting with "heavy metal"

    Even a wood mold will work for lead, as the melting temperature should be around 250-300°C. Old tin(lead) soldier were cast in rubber molds
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    Counterweighting with "heavy metal"

    Many two stroke motorbikes use hard lead insert in holes drilled in the crankshaft shoulders. The same type found in old wheel weights, very easy to cast and machine, with a fairly good strength.
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    why people like low speed hit and miss engine?

    Looks like the governor has the weight are pivoted to close to the swinging mass, needing more a faster speed to work. Also having the governor on the camshaft work at half the crankshaft rpm, needing twice the mass to have the same effect. And making thicker flywheel will give more inertia...
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    Vacuum Rotor

    Aluminium would only be trouble as the expansion rate is very different than the cast iron of the cylinder, making it wery hard to run.
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    New member

    Hello Peter From the pictures your casting look very similar to the vices I used at my previous workplace. If you are interested I can try and make drawings for it. Unfortunately I moved recently and I don't have a PC with me, but I enjoy hand drafting so it will not be a big issue (just a...
  16. C

    Stuart Turner Compressor

    Probably there was a more "sketched" assembly drawing as with Stuart current kits. About the valves, it has only a delivery valve (12) in the head and the intake is through a port between the cylinders, uncovered at the bottom of the stroke
  17. C

    No longer a UFO - Gearless Hit and Miss

    Ciao James Li trovi sulla rivista "Home Shop Machinist" 1993 vol.12 N.3-4-5-6 (Devrai cercarla usata perché non so se ci siano state ristampe) PS. Aggiungi la traduzione in inglese anche se da google ;)
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