camshaft design
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ajoeiam
Well-Known Member
Not software per se but would suggest you look in a copy of the Machinery's Handbook.
(25th ed pages 2077 - 2102)
(25th ed pages 2077 - 2102)
Bentwings
Well-Known Member
Cam design in the auto world is very complicaed.you might look at comp cams.com or Crain cams.com. These are two big cam manufacturers. Most of our engines are micro compared to auto engines.
campare a 500 cu.in big block to one of our 5.0 cu inch engines . Our move very small volumes of air compared to these monsters. Then look at piston stroke of 5+ inches. , almost the height of a single cylinder engine complete. Some auto engines have valve lift higher than the entire piston stroke distance of our engines. So possibly sing basic timing might at least get a running engine. A few thousandths cam lift might make a difference. Timing will affect it some of course. As will igniti9n timing . When It gets to flame travel speed our engines would likely see it as nearly 8nstantageous. Most yard equipment engines run about 28 degrees advance. I’ve had model airplane engines with variable advance but just an auto retard for starting worked best. My hot rod rc engines worked best running at maximum power output with an inflight fuel adjustment. A simple mosque resulted in an engine out dead stick landing. So compromises had to be made. Generally something as slightly cooler exhaust temp and try to maintain this throughout the flight. Running right on the edge as we called it.
I’ve only heard of model cam grinders so even that would be an engineering challenge. Granted you could machine or grind with modern cnc but you still need to “tell” the machine what to do. I’m not sure if the tech dept of these companies could help or not. I had excellent experience in the auto racing part but small engines might be well outside their area.
campare a 500 cu.in big block to one of our 5.0 cu inch engines . Our move very small volumes of air compared to these monsters. Then look at piston stroke of 5+ inches. , almost the height of a single cylinder engine complete. Some auto engines have valve lift higher than the entire piston stroke distance of our engines. So possibly sing basic timing might at least get a running engine. A few thousandths cam lift might make a difference. Timing will affect it some of course. As will igniti9n timing . When It gets to flame travel speed our engines would likely see it as nearly 8nstantageous. Most yard equipment engines run about 28 degrees advance. I’ve had model airplane engines with variable advance but just an auto retard for starting worked best. My hot rod rc engines worked best running at maximum power output with an inflight fuel adjustment. A simple mosque resulted in an engine out dead stick landing. So compromises had to be made. Generally something as slightly cooler exhaust temp and try to maintain this throughout the flight. Running right on the edge as we called it.
I’ve only heard of model cam grinders so even that would be an engineering challenge. Granted you could machine or grind with modern cnc but you still need to “tell” the machine what to do. I’m not sure if the tech dept of these companies could help or not. I had excellent experience in the auto racing part but small engines might be well outside their area.
Hi I use and find CamCalc is very good, have a look at it. Put in parameters and of you go.
ninefinger
Well-Known Member
I wish I could get CamCalc to work - being Java based I can't seem to get it to run on my machine, even after downloading Java on Internet Explorer and rebooting. Has anybody looked into updating this? Not the sort of thing thats in my wheelhouse (coding) but appears that given the source code is available it should be doable.
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I was looking into that app before & lost interest. Do the instructions in this link help?
https://www.model-engineer.co.uk/forums/postings.asp?th=133470
https://www.model-engineer.co.uk/forums/postings.asp?th=133470
https://github.com/deadsy/sdfx
Possibly not the answer you are looking for, but I wrote some code (Go) and one of the things it does is cam design. Flat flank and three arc cams can be designed from parameters.
E.g. Here's a ETW Wallaby camshaft with 3-arc cams.
Possibly not the answer you are looking for, but I wrote some code (Go) and one of the things it does is cam design. Flat flank and three arc cams can be designed from parameters.
E.g. Here's a ETW Wallaby camshaft with 3-arc cams.
A spreadsheet
