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sid_galt
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Why are camshafts normally grinded? Is diecasting and then welding camlobes to a shaft too expensive and/or does it give less strength?
FredGarvin said:- Dimensional control
FredGarvin said:- Surface finish
Having a 2D profile has nothing to do with it. When I say dimensional control, I mean in the sense that most rotating surfaces such as those found on cams running locations and bearing locations are held to very tight tolerances that are not achievable (easily) any other way. You definitely will not hold four decimal places (english) out of a die or casting. It must have secondary machining operations after the bulk deformation process. The thing about welding, ESPECIALLY on rotating hardware is that it is difficult to maintain runout on all of the surfaces. You would have to go through rounds of annealing after the weld along with straightening. It would add more work. We weld shaft sections sometimes, especially for one of a kind R&D hardware. However, there is a real art to getting it right plus getting the rotating group to balance in the end.sid_galt said:What do you mean by dimensional control? Forgetting other factors for a movement, can't cam lobes be made in dies since cams only have a 2d profile, not a 3d one.
Yes. You are correct. I would assume that the final machining is a fine cut grind, akin to a very light lathe cut, to get the surface roughness required.sid_galt said:Can't surface finish be done through grinding after the casting? That would save a lot of grinding.
I have seen industry articles saying that cam machining is getting to be very difficult because of the 3D aspect. I am not sure if the 2D has been done away with. I guess in the context of the original question it doesn't really matter.Averagesupernova said:Actually I'm not sure if a cam on an engine camshaft really is a 2D profile. If you pull a valve cover and watch the pushrods while the engine is running you will notice that they spin. There is only one way I know of for this to happen and that for the cam lobe to be ground slightly larger on one side. Usually the lifter has a slight convex shape to the part that contacts the cam. Come to think of it I've noticed the wear pattern on a camshaft and it is usually off to one side.
The cost of grinding camshafts varies depending on the type of camshaft, the materials used, and the labor costs of the grinding process. On average, grinding a camshaft can cost anywhere from $200 to $1000.
Grinding camshafts can improve the performance and durability of an engine. It allows for more precise and consistent timing, which can result in better power and torque. Additionally, grinding can reduce the weight of the camshaft, resulting in better fuel efficiency.
Yes, grinding a camshaft can affect its strength. While it can improve the strength and durability of the camshaft by removing any imperfections or surface damage, it can also weaken the camshaft if too much material is removed during the grinding process.
If you are experiencing performance issues with your engine, such as rough idling or decreased power, it may be a sign that your camshaft needs to be ground. Additionally, if your camshaft is visibly worn or damaged, it may need to be ground to restore its optimal performance.
Grinding a camshaft requires specialized equipment and knowledge. It is not recommended for individuals to attempt to grind a camshaft themselves unless they have extensive experience and access to the necessary tools. It is best to take your camshaft to a professional who has the expertise and equipment to properly grind it.