Re: [Emc-users] Cam grinding....
If I understand correctly, what You mean by the "cutting above or below centerline", then Dave's sketch shows that it is inevitable anyway. If the code after offsetting is correct for producing required profile while in Decart's coordinates, then it will be correct also in polar coordinates. I totally agree that offsetting _after_ conversion to polar coordinates will produce incorrect parts. Viesturs 2011/6/16 Les Newell : > If the profile is offset before converting to polar coordinates then it > will allow for the situation where you are grinding above or below the > center line. If you convert the profile to polar then simply increase > the distance you will get errors in the resultant cam profile. > > Les > > > On 16/06/2011 16:40, Viesturs Lācis wrote: >> 2011/6/16 Dave: >>> On 6/15/2011 12:37 PM, andy pugh wrote: On 15 June 2011 17:07, Viesturs Lācis wrote: > And, if the required CAM profile is offset by the radius of the > grinding wheel, then moving the center of grinding wheel along that > line will produce the required profile. > I don't think that this is true for all shapes of cam. If you consider a cam with a flat or near-flat face, the wheel will often be grinding a part of the cam significantly above or below the centreline. >>> That is correct if you look at the diagram I attached via the link >>> you can see how that can be. >> I do not understand, where is the problem besides defining initial >> shape to be produced. >> Once that is done, my suggestion would give You the code to do it. >> Guys, where do You see the problem? Do You think that grinding wheel >> will not be moved away or closer to camshaft in a correct manner, when >> camshaft is rotated? >> >> Viesturs > > > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
If the profile is offset before converting to polar coordinates then it will allow for the situation where you are grinding above or below the center line. If you convert the profile to polar then simply increase the distance you will get errors in the resultant cam profile. Les On 16/06/2011 16:40, Viesturs Lācis wrote: > 2011/6/16 Dave: >> On 6/15/2011 12:37 PM, andy pugh wrote: >>> On 15 June 2011 17:07, Viesturs Lāciswrote: >>> And, if the required CAM profile is offset by the radius of the grinding wheel, then moving the center of grinding wheel along that line will produce the required profile. >>> I don't think that this is true for all shapes of cam. If you consider >>> a cam with a flat or near-flat face, the wheel will often be grinding >>> a part of the cam significantly above or below the centreline. >>> >>> >> That is correct if you look at the diagram I attached via the link >> you can see how that can be. > I do not understand, where is the problem besides defining initial > shape to be produced. > Once that is done, my suggestion would give You the code to do it. > Guys, where do You see the problem? Do You think that grinding wheel > will not be moved away or closer to camshaft in a correct manner, when > camshaft is rotated? > > Viesturs -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
2011/6/16 Dave : > On 6/15/2011 12:37 PM, andy pugh wrote: >> On 15 June 2011 17:07, Viesturs Lācis wrote: >> >>> And, if the required CAM profile is offset by the radius of the >>> grinding wheel, then moving the center of grinding wheel along that >>> line will produce the required profile. >>> >> I don't think that this is true for all shapes of cam. If you consider >> a cam with a flat or near-flat face, the wheel will often be grinding >> a part of the cam significantly above or below the centreline. >> >> > That is correct if you look at the diagram I attached via the link > you can see how that can be. I do not understand, where is the problem besides defining initial shape to be produced. Once that is done, my suggestion would give You the code to do it. Guys, where do You see the problem? Do You think that grinding wheel will not be moved away or closer to camshaft in a correct manner, when camshaft is rotated? Viesturs -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 6/14/11, andy pugh wrote: > On 14 June 2011 23:18, Przemek Klosowski > wrote: >> My understanding was that grinding doesn't require wheel diameter >> correction > > The wheel has a different diameter to the cam follower, so is tangent > to the work at a different point. I was talking about compensating for grinding wheel wear. The geometric correction due to finite grinding wheel diameter, as described in Dave's drawing, is of course necessary. -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 6/15/2011 12:37 PM, andy pugh wrote: > On 15 June 2011 17:07, Viesturs Lācis wrote: > >> And, if the required CAM profile is offset by the radius of the >> grinding wheel, then moving the center of grinding wheel along that >> line will produce the required profile. >> > I don't think that this is true for all shapes of cam. If you consider > a cam with a flat or near-flat face, the wheel will often be grinding > a part of the cam significantly above or below the centreline. > > That is correct if you look at the diagram I attached via the link you can see how that can be. Dave -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On Wednesday, June 15, 2011 12:40:32 PM andy pugh did opine: > On 15 June 2011 17:07, Viesturs Lācis wrote: > > And, if the required CAM profile is offset by the radius of the > > grinding wheel, then moving the center of grinding wheel along that > > line will produce the required profile. > > I don't think that this is true for all shapes of cam. If you consider > a cam with a flat or near-flat face, the wheel will often be grinding > a part of the cam significantly above or below the centreline. That effect also has to be accounted for, along with the face profile of the tappet, with the rate of lift or close being constrained by the diameter and face profile of the tappet. This can make a powerful argument in favor of mushroom faced tappets with a spherical face profile. One of the better, precomputer designs was in the big 6 Nash engines after WW-II. Using valves that were double sprung and deeply tuliped, a mushroom tappet whose face was about a 3 foot sphere and nearly 2" in diameter, allowed that engine to breath well and produce race winning horsepower at engine speeds that rather handily exceeded the accepted 4000 feet a minute in piston speeds. With a 4 & 3/8" stroke, nearly 8 grand was on tap for a block or so, but it needed a set of pistons and rings when you did it as it even broke the oil rings at that rpms. I think by sheer luck, the Nash folks hit a winner. Its too bad they didn't swap the bore and stroke measurements so the rest of the engine could survive the performance that valve train gave them. I had one for a couple of years, and I still remember tuning tricks that made that old bathtub a giant killer. How I managed to outlive its lack of brakes is another wonder but I did. Cheers, gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) You definitely intend to start living sometime soon. -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 15 June 2011 17:07, Viesturs Lācis wrote: > And, if the required CAM profile is offset by the radius of the > grinding wheel, then moving the center of grinding wheel along that > line will produce the required profile. I don't think that this is true for all shapes of cam. If you consider a cam with a flat or near-flat face, the wheel will often be grinding a part of the cam significantly above or below the centreline. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On Wednesday, June 15, 2011 12:21:07 PM Viesturs Lācis did opine: > 2011/6/15 andy pugh : > > On 15 June 2011 11:49, Dave wrote: > A better solution might be a custom kinematics module. > >> > >> That sounds interesting! > > > > Let me have a fiddle over the next few days, it might not be all that > > difficult to get something basic, then it is just a case of doing the > > hard sums. > > Well, I think that the code can be derived in following way: > 1) draw the required shape; Not a viable method today folks, at least when applied to dependable, high performance engines. Most cam profiles for IC engines today are computer generated to compensate for the flex characteristics in the valve train, and to reduce as much as possible, the instant forces, both of which can prolong the life of the valve train parts by an order of magnitude while maintaining the desired timing characteristics and staying within the limits of the tappet faces diameter and profile. Not having the software to do that 30 years ago is likely the reason that 305/327/350 Chevies had a cam & tappet life of about 5k miles, after which the performance went down and the fuel mileage went down even faster. I have seen 350 Chevy cams with 30k miles on them that had less than 1/16" of lift left at the valve. And got 2.5 mpg at 50 mph with an empty 14' box van box. A fresh cam & lifters and they were back to 12 mpg at 65 mph. That software is likely not allowed in the same room with an internet connection so we're not likely going to be able to draw a profile that competes. > 2) offset by radius of grinding wheel; > 3) that would produce the shape in XY coordinates; > 4) now these XY coordinates have to be transformed to polar > coordinates, where angle is A and radius is X, Z or whichever > coordinate that moves the grinding wheel; > > That transformation can be done in following way: > 1) origin of XY should be in the point, which corresponds to > centerline (axis of rotation) of CAMshaft; > 2) split the code in very small linear moves; > 3) sqrt of X^2 + Y^2 is the position of grinding wheel; > 4) atan2(Y,X) is the position of angular axis; > > The code will not be very optimized, but at least it should work. > When placed in a subroutine, repeating the moves, each time a > little-bit closer to center, should make the final code pretty usable. > > Viesturs > > > -- EditLive Enterprise is the world's most technically advanced > content authoring tool. Experience the power of Track Changes, Inline > Image Editing and ensure content is compliant with Accessibility > Checking. http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Flattery is like cologne -- to be smelled, but not swallowed. -- Josh Billings -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
2011/6/15 andy pugh : > > I think that this would work, though the offset would need to be in > the direction at right-angles to the cam profile local to the point > being considered. > > Whereas this needs to be with the cam axis as the centre. > > Typically a cam profile is derived from a table of rotation angle and > lift (or so I understand) so the input data is in polar coordinates. > (well, probably cylindrical coordinates) It does not matter, how the toolpath is expressed - in Decart's coordinates or in polar cordinates. And, if the required CAM profile is offset by the radius of the grinding wheel, then moving the center of grinding wheel along that line will produce the required profile. I think that it is just another case of tool radius compensation and offsetting part's contour for that purpose. But I agree, that the shape of the profile has to be defined before all this, and I don't really have an idea, how that should be done. I am just suggesting, how to produce g-code for that. That conversion from Decart to polar coordinates can easily be handled in a spreadsheet. Before that a small operation in text editor is needed - replace all axis letters with a "space+letterr+space", so that all that text can be broken into columns with a "space" as delimiter and then with formulas they can easily be converted, unnecessary columns removed. Viesturs -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 15 June 2011 13:51, Viesturs Lācis wrote: > Well, I think that the code can be derived in following way: > 1) draw the required shape; > 2) offset by radius of grinding wheel; > 3) that would produce the shape in XY coordinates; I think that this would work, though the offset would need to be in the direction at right-angles to the cam profile local to the point being considered. > 4) now these XY coordinates have to be transformed to polar > coordinates, where angle is A and radius is X, Z or whichever > coordinate that moves the grinding wheel; Whereas this needs to be with the cam axis as the centre. Typically a cam profile is derived from a table of rotation angle and lift (or so I understand) so the input data is in polar coordinates. (well, probably cylindrical coordinates) -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
2011/6/15 andy pugh : > On 15 June 2011 11:49, Dave wrote: A better solution might be a custom kinematics module. >> >> That sounds interesting! > > Let me have a fiddle over the next few days, it might not be all that > difficult to get something basic, then it is just a case of doing the > hard sums. Well, I think that the code can be derived in following way: 1) draw the required shape; 2) offset by radius of grinding wheel; 3) that would produce the shape in XY coordinates; 4) now these XY coordinates have to be transformed to polar coordinates, where angle is A and radius is X, Z or whichever coordinate that moves the grinding wheel; That transformation can be done in following way: 1) origin of XY should be in the point, which corresponds to centerline (axis of rotation) of CAMshaft; 2) split the code in very small linear moves; 3) sqrt of X^2 + Y^2 is the position of grinding wheel; 4) atan2(Y,X) is the position of angular axis; The code will not be very optimized, but at least it should work. When placed in a subroutine, repeating the moves, each time a little-bit closer to center, should make the final code pretty usable. Viesturs -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 15 June 2011 11:49, Dave wrote: >>>A better solution might be a custom kinematics module. > > That sounds interesting! Let me have a fiddle over the next few days, it might not be all that difficult to get something basic, then it is just a case of doing the hard sums. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 6/14/2011 9:11 PM, andy pugh wrote: > On 14 June 2011 23:32, Dave wrote: > > >> I'm thinking some trig could be done in EMC2 to accomplish the >> same thing.. >> > Possibly, yes. > Not in G-code, it has no way to handle arrays with curves in well (it > might be possible with computed parameters, like > #[100 + #1] = [sin[#2]] which is valid, but it would be a struggle. > > I did my eccentric turning with a HAL module which computed the > required offset, and I interposed it between axis.0.position-cmd and > stepgen.0….. > > A better solution might be a custom kinematics module. You could load > it with a profile file format as a parameter, and have a wheel-radius > pin which was used in the calculations of joint.0 as a function of X > and A. > > > I was thinking of computed parameters.. It would probably get messy but it would only have to be done once. :-) I didn't realize that was your video .. that was interesting. >>A better solution might be a custom kinematics module. That sounds interesting! -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 14 June 2011 23:32, Dave wrote: > I'm thinking some trig could be done in EMC2 to accomplish the > same thing.. Possibly, yes. Not in G-code, it has no way to handle arrays with curves in well (it might be possible with computed parameters, like #[100 + #1] = [sin[#2]] which is valid, but it would be a struggle. I did my eccentric turning with a HAL module which computed the required offset, and I interposed it between axis.0.position-cmd and stepgen.0….. A better solution might be a custom kinematics module. You could load it with a profile file format as a parameter, and have a wheel-radius pin which was used in the calculations of joint.0 as a function of X and A. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
Hello everybody, My father, my brother and I have a little workshop and we make camshafts as spare parts for the local market here in Argentina. Given the situation in our country with the medium and little manufacturers like us, it's almost impossible for us to adquire a CNC camshaft grinding machine (A seller once quoted me one 1995 landis for $195,000 dolars), so that says pretty much all. Obviously we use standard grinding machines, with a master that guides a pivot to make the shape of the lobe. Anyway, the problem is that new cnc camshaft grinders, have linear motors, and hydrostatic ways, so it's really complicated to adapt an existing machine to achieve the quality that new machines have, also the new ones weight 10 tns like the old ones, so it's like retrofitting a train. But I think that with a ballscrew may be good results can be achieved, obviously not as good as the ones with an original machine. Another way would be to attach a servo motor on the pivot, and then move it to recreate the shape of the lobe instead of using a master. I'm really interested in this project so I hope I can help! Thanks as always for this space, and for good job with EMC! Best regards. Leonardo Marsaglia. 2011/6/14 H & J Johnson > It doesn't matter, the wheel diameter is going to change in time due to use > so it will effect the final part dims, this is why cam grinding requires > multiple passes [one reason]. > I've seen machine tools that use lasers to measure wear on end mills and > such, I suppose that is possible w/ a stone as well but probably an > expensive pc of hardware [laser micrometer]. > > J Johnson > > > My understanding was that grinding doesn't require wheel diameter > > correction because the precision grinding happens on one side of the > > wheel: > > > > || wheel moves this way --> > > -xx--workpiece > > > > On 6/14/11, Martin Dobbins wrote: > > > > > > Sherline sells a miniature version of what you are talking > > about, and since > > > they sell their CNC machines with EMC installed it's probably > > done with > > > that. There's a picture here: > > > > > > http://www.sherline.com/images/CamGrindCallouts.jpg > > > > > > and a couple of you tube videos here: > > > > > > http://www.youtube.com/watch?v=OIWyGtXEgR4 > > > > > > and here: > > > > > > http://www.youtube.com/watch?v=PlZDg0rpIi8 > > > > > > I understand Joe Martin (owner of Sherline) hand wrote the G > > code for this, > > > he might let you have it if you drop him a note. > > > > > > Hope that helps? > > > > > > Martin > > > > > > > > >> > > >> Guys, > > >> > > >> I know a guy who is interested in using EMC2 to control a cam > > grinding>> operation - as in automotive type camshafts cam lobe > > grinding.>> > > >> Usually a large diameter grinding wheel is moved in and out to > > grind the > > >> cam profile. Compensation for the wheel diameter is required. > > >> > > >> Has anyone ever done this before with EMC2 or otherwise? > > Attached is > > >> a diagram which is exaggerated in that the grinding wheel is > > usually>> much larger. > > >> > > >> A cam grinding machine looks like a lathe but the grinding > > wheel which > > >> is usually .75 inches wide and usually quite large - perhaps 12 > > inches>> or more in diameter and it moves in and out as the > > camshaft revolves to > > >> grind the profile. > > >> > > >> Here is a diagram that shows the wheel to cam situation: > > >> http://imagebin.org/158266 > > >> > > >> Dave > > >> > > >> > > -- > > >> EditLive Enterprise is the world's most technically advanced > > content>> authoring tool. Experience the power of Track Changes, > > Inline Image > > >> Editing and ensure content is compliant with Accessibility > > Checking.>> http://p.sf.net/sfu/ephox-dev2dev > > >> ___ > > >> Emc-users mailing list > > >> Emc-users@lists.sourceforge.net > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > - > > - > > > EditLive Enterprise is the world's most technically advanced content > > > authoring tool. Experience the power of Track Changes, Inline Image > > > Editing and ensure content is compliant with Accessibility Checking. > > > http://p.sf.net/sfu/ephox-dev2dev > > > ___ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > --- > > --- > > EditLive Enterprise is the world's most technically advanced content > > authoring tool. Experience the power of Track Changes, Inline Image > > Editing and ensure content is compliant with Accessibility Checking. > > http://p.sf.net/sfu/ephox-dev2dev > >
Re: [Emc-users] Cam grinding....
It doesn't matter, the wheel diameter is going to change in time due to use so it will effect the final part dims, this is why cam grinding requires multiple passes [one reason]. I've seen machine tools that use lasers to measure wear on end mills and such, I suppose that is possible w/ a stone as well but probably an expensive pc of hardware [laser micrometer]. J Johnson > My understanding was that grinding doesn't require wheel diameter > correction because the precision grinding happens on one side of the > wheel: > > || wheel moves this way --> > -xx--workpiece > > On 6/14/11, Martin Dobbins wrote: > > > > Sherline sells a miniature version of what you are talking > about, and since > > they sell their CNC machines with EMC installed it's probably > done with > > that. There's a picture here: > > > > http://www.sherline.com/images/CamGrindCallouts.jpg > > > > and a couple of you tube videos here: > > > > http://www.youtube.com/watch?v=OIWyGtXEgR4 > > > > and here: > > > > http://www.youtube.com/watch?v=PlZDg0rpIi8 > > > > I understand Joe Martin (owner of Sherline) hand wrote the G > code for this, > > he might let you have it if you drop him a note. > > > > Hope that helps? > > > > Martin > > > > > >> > >> Guys, > >> > >> I know a guy who is interested in using EMC2 to control a cam > grinding>> operation - as in automotive type camshafts cam lobe > grinding.>> > >> Usually a large diameter grinding wheel is moved in and out to > grind the > >> cam profile. Compensation for the wheel diameter is required. > >> > >> Has anyone ever done this before with EMC2 or otherwise? > Attached is > >> a diagram which is exaggerated in that the grinding wheel is > usually>> much larger. > >> > >> A cam grinding machine looks like a lathe but the grinding > wheel which > >> is usually .75 inches wide and usually quite large - perhaps 12 > inches>> or more in diameter and it moves in and out as the > camshaft revolves to > >> grind the profile. > >> > >> Here is a diagram that shows the wheel to cam situation: > >> http://imagebin.org/158266 > >> > >> Dave > >> > >> > -- > >> EditLive Enterprise is the world's most technically advanced > content>> authoring tool. Experience the power of Track Changes, > Inline Image > >> Editing and ensure content is compliant with Accessibility > Checking.>> http://p.sf.net/sfu/ephox-dev2dev > >> ___ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > - > - > > EditLive Enterprise is the world's most technically advanced content > > authoring tool. Experience the power of Track Changes, Inline Image > > Editing and ensure content is compliant with Accessibility Checking. > > http://p.sf.net/sfu/ephox-dev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > --- > --- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
Yes, when I looked a little further it appears when you purchase the cam grinding system you get a code which gives you access to the software that generates the G code. http://www.sherline.com/8650pg.htm You could use a separate software package to generate the G code, but I will bet you could generate what's needed directly through G code subroutines. Failing that, if this guy is willing to make the effort to get hold of Joe Martin directly, I'm sure they could beat out a deal for his getting access to the software. Martin > > The guy who contacted me tried to contact Sherline and I was told he was > unsuccessful in getting access to the software. Perhaps it is only > sold with the Cam grinding package which might make sense. > > Dave > > On 6/14/2011 3:01 PM, Martin Dobbins wrote: > > Sherline sells a miniature version of what you are talking about, and since > > they sell their CNC machines with EMC installed it's probably done with > > that. There's a picture here: > > > > http://www.sherline.com/images/CamGrindCallouts.jpg > > > > and a couple of you tube videos here: > > > > http://www.youtube.com/watch?v=OIWyGtXEgR4 > > > > and here: > > > > http://www.youtube.com/watch?v=PlZDg0rpIi8 > > > > I understand Joe Martin (owner of Sherline) hand wrote the G code for this, > > he might let you have it if you drop him a note. > > > > Hope that helps? > > > > Martin > > > > > > > >> Guys, > >> > >> I know a guy who is interested in using EMC2 to control a cam grinding > >> operation - as in automotive type camshafts cam lobe grinding. > >> > >> Usually a large diameter grinding wheel is moved in and out to grind the > >> cam profile. Compensation for the wheel diameter is required. > >> > >> Has anyone ever done this before with EMC2 or otherwise?Attached is > >> a diagram which is exaggerated in that the grinding wheel is usually > >> much larger. > >> > >> A cam grinding machine looks like a lathe but the grinding wheel which > >> is usually .75 inches wide and usually quite large - perhaps 12 inches > >> or more in diameter and it moves in and out as the camshaft revolves to > >> grind the profile. > >> > >> Here is a diagram that shows the wheel to cam situation: > >> http://imagebin.org/158266 > >> > >> Dave > >> > >> -- > >> EditLive Enterprise is the world's most technically advanced content > >> authoring tool. Experience the power of Track Changes, Inline Image > >> Editing and ensure content is compliant with Accessibility Checking. > >> http://p.sf.net/sfu/ephox-dev2dev > >> ___ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > -- > > EditLive Enterprise is the world's most technically advanced content > > authoring tool. Experience the power of Track Changes, Inline Image > > Editing and ensure content is compliant with Accessibility Checking. > > http://p.sf.net/sfu/ephox-dev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
The cam grinders I have seen dive straight into the cam face as the camshaft turns. Flat tappet cams are tapered from side to side so the tappet rotates as the camshaft turns to distribute the wear on the tappet.Roller camshafts are straight across. The guy I am talking to wants to move the grinding wheel in and out as the cam turns to regrind existing cams. Think of a tool post mounted grinder on a lathe with a cam in the chuck. The toolpost would move in and out as the cam turned similar to the video that Andy linked to in his message. Here is an old style cam shaft grinder where the bed rocks back and forth. http://www.youtube.com/watch?v=9R8y-aHvI8g Here is a big crankshaft grinding machine that is for sale . nothing to do with my camshaft question I just thought that it was really well done and the music is nice for machine junkies like us .. :-) http://www.youtube.com/watch?v=yS9hk9ti9WQ&feature=related Dave On 6/14/2011 6:18 PM, Przemek Klosowski wrote: > My understanding was that grinding doesn't require wheel diameter > correction because the precision grinding happens on one side of the > wheel: > > || wheel moves this way --> > -xx--workpiece > > On 6/14/11, Martin Dobbins wrote: > >> Sherline sells a miniature version of what you are talking about, and since >> they sell their CNC machines with EMC installed it's probably done with >> that. There's a picture here: >> >> http://www.sherline.com/images/CamGrindCallouts.jpg >> >> and a couple of you tube videos here: >> >> http://www.youtube.com/watch?v=OIWyGtXEgR4 >> >> and here: >> >> http://www.youtube.com/watch?v=PlZDg0rpIi8 >> >> I understand Joe Martin (owner of Sherline) hand wrote the G code for this, >> he might let you have it if you drop him a note. >> >> Hope that helps? >> >> Martin >> >> >> >>> Guys, >>> >>> I know a guy who is interested in using EMC2 to control a cam grinding >>> operation - as in automotive type camshafts cam lobe grinding. >>> >>> Usually a large diameter grinding wheel is moved in and out to grind the >>> cam profile. Compensation for the wheel diameter is required. >>> >>> Has anyone ever done this before with EMC2 or otherwise?Attached is >>> a diagram which is exaggerated in that the grinding wheel is usually >>> much larger. >>> >>> A cam grinding machine looks like a lathe but the grinding wheel which >>> is usually .75 inches wide and usually quite large - perhaps 12 inches >>> or more in diameter and it moves in and out as the camshaft revolves to >>> grind the profile. >>> >>> Here is a diagram that shows the wheel to cam situation: >>> http://imagebin.org/158266 >>> >>> Dave >>> >>> -- >>> EditLive Enterprise is the world's most technically advanced content >>> authoring tool. Experience the power of Track Changes, Inline Image >>> Editing and ensure content is compliant with Accessibility Checking. >>> http://p.sf.net/sfu/ephox-dev2dev >>> ___ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> >> -- >> EditLive Enterprise is the world's most technically advanced content >> authoring tool. Experience the power of Track Changes, Inline Image >> Editing and ensure content is compliant with Accessibility Checking. >> http://p.sf.net/sfu/ephox-dev2dev >> ___ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
The guy who contacted me tried to contact Sherline and I was told he was unsuccessful in getting access to the software. Perhaps it is only sold with the Cam grinding package which might make sense. Dave On 6/14/2011 3:01 PM, Martin Dobbins wrote: > Sherline sells a miniature version of what you are talking about, and since > they sell their CNC machines with EMC installed it's probably done with that. > There's a picture here: > > http://www.sherline.com/images/CamGrindCallouts.jpg > > and a couple of you tube videos here: > > http://www.youtube.com/watch?v=OIWyGtXEgR4 > > and here: > > http://www.youtube.com/watch?v=PlZDg0rpIi8 > > I understand Joe Martin (owner of Sherline) hand wrote the G code for this, > he might let you have it if you drop him a note. > > Hope that helps? > > Martin > > > >> Guys, >> >> I know a guy who is interested in using EMC2 to control a cam grinding >> operation - as in automotive type camshafts cam lobe grinding. >> >> Usually a large diameter grinding wheel is moved in and out to grind the >> cam profile. Compensation for the wheel diameter is required. >> >> Has anyone ever done this before with EMC2 or otherwise?Attached is >> a diagram which is exaggerated in that the grinding wheel is usually >> much larger. >> >> A cam grinding machine looks like a lathe but the grinding wheel which >> is usually .75 inches wide and usually quite large - perhaps 12 inches >> or more in diameter and it moves in and out as the camshaft revolves to >> grind the profile. >> >> Here is a diagram that shows the wheel to cam situation: >> http://imagebin.org/158266 >> >> Dave >> >> -- >> EditLive Enterprise is the world's most technically advanced content >> authoring tool. Experience the power of Track Changes, Inline Image >> Editing and ensure content is compliant with Accessibility Checking. >> http://p.sf.net/sfu/ephox-dev2dev >> ___ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 6/14/2011 2:33 PM, andy pugh wrote: >> Has anyone ever done this before with EMC2 or otherwise? >> > No, but I would expect the wheel to follower radius differences to be > handled by the cam CAM. > > The closest I have got is: http://www.youtube.com/watch?v=FpP7iTKuWpw > > I saw that also... interesting but not the same. I was thinking that a CAM software package should be able to do this and indeed Mastercam has an addin that can do it, but Mastercam is serious $$.I'm thinking some trig could be done in EMC2 to accomplish the same thing.. Dave -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
On 14 June 2011 23:18, Przemek Klosowski wrote: > My understanding was that grinding doesn't require wheel diameter > correction The wheel has a different diameter to the cam follower, so is tangent to the work at a different point. So, first you calculate the cam profile from lift and angle and follower radius (infinite for flat ones) Then you work out the wheel position for cam angle and grinding wheel radius. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
My understanding was that grinding doesn't require wheel diameter correction because the precision grinding happens on one side of the wheel: || wheel moves this way --> -xx--workpiece On 6/14/11, Martin Dobbins wrote: > > Sherline sells a miniature version of what you are talking about, and since > they sell their CNC machines with EMC installed it's probably done with > that. There's a picture here: > > http://www.sherline.com/images/CamGrindCallouts.jpg > > and a couple of you tube videos here: > > http://www.youtube.com/watch?v=OIWyGtXEgR4 > > and here: > > http://www.youtube.com/watch?v=PlZDg0rpIi8 > > I understand Joe Martin (owner of Sherline) hand wrote the G code for this, > he might let you have it if you drop him a note. > > Hope that helps? > > Martin > > >> >> Guys, >> >> I know a guy who is interested in using EMC2 to control a cam grinding >> operation - as in automotive type camshafts cam lobe grinding. >> >> Usually a large diameter grinding wheel is moved in and out to grind the >> cam profile. Compensation for the wheel diameter is required. >> >> Has anyone ever done this before with EMC2 or otherwise?Attached is >> a diagram which is exaggerated in that the grinding wheel is usually >> much larger. >> >> A cam grinding machine looks like a lathe but the grinding wheel which >> is usually .75 inches wide and usually quite large - perhaps 12 inches >> or more in diameter and it moves in and out as the camshaft revolves to >> grind the profile. >> >> Here is a diagram that shows the wheel to cam situation: >> http://imagebin.org/158266 >> >> Dave >> >> -- >> EditLive Enterprise is the world's most technically advanced content >> authoring tool. Experience the power of Track Changes, Inline Image >> Editing and ensure content is compliant with Accessibility Checking. >> http://p.sf.net/sfu/ephox-dev2dev >> ___ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
Sherline sells a miniature version of what you are talking about, and since they sell their CNC machines with EMC installed it's probably done with that. There's a picture here: http://www.sherline.com/images/CamGrindCallouts.jpg and a couple of you tube videos here: http://www.youtube.com/watch?v=OIWyGtXEgR4 and here: http://www.youtube.com/watch?v=PlZDg0rpIi8 I understand Joe Martin (owner of Sherline) hand wrote the G code for this, he might let you have it if you drop him a note. Hope that helps? Martin > > Guys, > > I know a guy who is interested in using EMC2 to control a cam grinding > operation - as in automotive type camshafts cam lobe grinding. > > Usually a large diameter grinding wheel is moved in and out to grind the > cam profile. Compensation for the wheel diameter is required. > > Has anyone ever done this before with EMC2 or otherwise?Attached is > a diagram which is exaggerated in that the grinding wheel is usually > much larger. > > A cam grinding machine looks like a lathe but the grinding wheel which > is usually .75 inches wide and usually quite large - perhaps 12 inches > or more in diameter and it moves in and out as the camshaft revolves to > grind the profile. > > Here is a diagram that shows the wheel to cam situation: > http://imagebin.org/158266 > > Dave > > -- > EditLive Enterprise is the world's most technically advanced content > authoring tool. Experience the power of Track Changes, Inline Image > Editing and ensure content is compliant with Accessibility Checking. > http://p.sf.net/sfu/ephox-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Cam grinding....
> Has anyone ever done this before with EMC2 or otherwise? No, but I would expect the wheel to follower radius differences to be handled by the cam CAM. The closest I have got is: http://www.youtube.com/watch?v=FpP7iTKuWpw -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" -- EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
