Another Cam Grinder
- Thread starter Joachim Steinke
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walker
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Hi,
congratulations for the excellent work, an essential tool for finishing the cam internal combustion engines. I am also interested in the production of camshafts for micro motors, wanted to know if the design of this tool is available. I mean the dimensional drawings of all components that constitute it.
I await your reply, regards.
Ignazio
congratulations for the excellent work, an essential tool for finishing the cam internal combustion engines. I am also interested in the production of camshafts for micro motors, wanted to know if the design of this tool is available. I mean the dimensional drawings of all components that constitute it.
I await your reply, regards.
Ignazio
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Hi Achem
This post is just what ive been looking for!
I recently bought a fellow model Engeneers shop tools and a Quorn was with it.
I have been thinking about setting it up as a Cam grinder with the Master behind the degree wheel in much the same way you have done but was worried about having the master 1-1.
It never occured to me that only the lift and duration has to be 1-1.
Thank you for the inspiration, I need to study this.;D
here is a pic of the quorn with the tailstock installed, and another with its box of bits.
Pete
This post is just what ive been looking for!
I recently bought a fellow model Engeneers shop tools and a Quorn was with it.
I have been thinking about setting it up as a Cam grinder with the Master behind the degree wheel in much the same way you have done but was worried about having the master 1-1.
It never occured to me that only the lift and duration has to be 1-1.
Thank you for the inspiration, I need to study this.;D
here is a pic of the quorn with the tailstock installed, and another with its box of bits.
Pete
Lykle
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Hello Joachim,
After seeing this beautiful tool and looking over your website with even more wonderful machinery I can't help noticing that you use a lot of bronze.
Why is that? Isn't that an expensive option?
Don't get me wrong I think it is a wonderful combination and it makes your tools look absolutely beautiful. But I would hesitate just because of the cost.
Lykle
After seeing this beautiful tool and looking over your website with even more wonderful machinery I can't help noticing that you use a lot of bronze.
Why is that? Isn't that an expensive option?
Don't get me wrong I think it is a wonderful combination and it makes your tools look absolutely beautiful. But I would hesitate just because of the cost.
Lykle
ConductorX
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I am totally in awe of the incredible work and precision of both machines and machinists.
"G"
"G"
ICEpeter
Well-Known Member
Hello Wally,
Welcome here at this forum. Noticed you joined today but don't know much about you at this time. May be you could tell us a bit about you.
To your question: I must admit that I was stumped myself initially until I figured that when you make a scaled up master cam, you can not simply multiply the dimensions of the desired cam for use as the master cam to grind the cam. By scaling the cam profile by multiplying it by a factor of say 5, you will have a master cam that looks like the desired cam but when using it to grind a cam it will look a disaster.
The reason that the master cam shown in Achim's excellent thread looks distorted and not like the desired cam is, because in the scaling up of the master cam, you are not using multiplication but addition of certain dimensions. I have attached a sketch of a master cam that I made for use in a cam grinder based on Achim's design that will allow you to figure out how it was done. I also attach a picture of my cam grinder that I built inspired by Achim's design and concept which I shamelessly adopted. I give Achim full credit for that excellent design.
Peter J.
Welcome here at this forum. Noticed you joined today but don't know much about you at this time. May be you could tell us a bit about you.
To your question: I must admit that I was stumped myself initially until I figured that when you make a scaled up master cam, you can not simply multiply the dimensions of the desired cam for use as the master cam to grind the cam. By scaling the cam profile by multiplying it by a factor of say 5, you will have a master cam that looks like the desired cam but when using it to grind a cam it will look a disaster.
The reason that the master cam shown in Achim's excellent thread looks distorted and not like the desired cam is, because in the scaling up of the master cam, you are not using multiplication but addition of certain dimensions. I have attached a sketch of a master cam that I made for use in a cam grinder based on Achim's design that will allow you to figure out how it was done. I also attach a picture of my cam grinder that I built inspired by Achim's design and concept which I shamelessly adopted. I give Achim full credit for that excellent design.
Peter J.
ICEpeter
Well-Known Member
Hello Bill,
Yes I have other pictures. If you are interested I can send you via e-mail an information package I put together for five other HIMEM
members. To do that, I would need your e-mail. The package I
have contains sketches / drawings / pictures and description of
the features I incorporated into the design. It also described
what I used for the X / Y table. Mind you the sketches and
drawings are not CAD but pencil drawings / sketches.
When e-mailing, you will receive the information in 14 e-mails due to
limitations in the package size my e-mail provider applies.
Sorry for the strange reply format. I experience the display
problems other users are also having. Can not post or reply
properly because of that.
Regards,
Peter J.
Yes I have other pictures. If you are interested I can send you via e-mail an information package I put together for five other HIMEM
members. To do that, I would need your e-mail. The package I
have contains sketches / drawings / pictures and description of
the features I incorporated into the design. It also described
what I used for the X / Y table. Mind you the sketches and
drawings are not CAD but pencil drawings / sketches.
When e-mailing, you will receive the information in 14 e-mails due to
limitations in the package size my e-mail provider applies.
Sorry for the strange reply format. I experience the display
problems other users are also having. Can not post or reply
properly because of that.
Regards,
Peter J.
wrljet
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RManley
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Hi Achim, amazing work and very inspiring. Can you please explain why you have used a follower the same size as the wheel instead of a roller, does this stop inaccuracies creeping in?
I am well on the way to having one based on your design and this is the final point.
Kind regards, R
I am well on the way to having one based on your design and this is the final point.
Kind regards, R
ICEpeter
Well-Known Member
Hello R..,
Although I am not Achim I might be able to answer your question. To get the answer, please read through Achims very first post about 1/3 through the first post is a bit of text that answers your question. Looking further down through the first post you will find a picture that corresponds to the earlier text where Achim shows the different shape follower he is using instead of the roller follower shown in an earlier picture. Hope this helps.
Peter J.
Although I am not Achim I might be able to answer your question. To get the answer, please read through Achims very first post about 1/3 through the first post is a bit of text that answers your question. Looking further down through the first post you will find a picture that corresponds to the earlier text where Achim shows the different shape follower he is using instead of the roller follower shown in an earlier picture. Hope this helps.
Peter J.
We have the same problem with inaccurate reproduction on the cam in relation to the master.
It all comes from the geometry of the rocking action mechanism.
Two similar "rocking arm" machines were made here a few years back.
One with mechanical operation on the adjustments, cut depth etc.
The other with largely electronic "automatic" control.
The way it was overcome by George Punter was to make the "following mechanism" linear in motion.
The necessity came from the need to produce replacement complex cams from old motorcycle engines for which he has made a name for himself.
The outcome of the linear motion grinder is that a cam of "any" size can be made which is, as I said earlier, an exact reproduction of the master.
It all comes from the geometry of the rocking action mechanism.
Two similar "rocking arm" machines were made here a few years back.
One with mechanical operation on the adjustments, cut depth etc.
The other with largely electronic "automatic" control.
The way it was overcome by George Punter was to make the "following mechanism" linear in motion.
The necessity came from the need to produce replacement complex cams from old motorcycle engines for which he has made a name for himself.
The outcome of the linear motion grinder is that a cam of "any" size can be made which is, as I said earlier, an exact reproduction of the master.
ICEpeter
Well-Known Member
Hello Jeff,
I am certainly no expert on the subject of cam geometry and the geometric closeness of a cam that is generated using a master cam in a swing frame grinder.
The master cam I created for use in my cam / crankshaft grinder is five times the size of the actual cam that I needed to grind. My master cams were created in CAD and machined on a CNC mill and the master cam geometry was confirmed after machining.
If certain requirements in the design and building of a swing frame grinder are adhered to, it appears that the resulting cam being ground is very close to what the cam geometry requires. In testing my grinder initially, I made a cam ground to the 2 dimensions that could easily be measured during the grinding process such as base circle diameter and total cam height. These dimensions correlated to each other as per the cam geometry to within 1/2 thousands of the design geometry. After stopping the grinding at that point the cam was mounted to my lathe spindle in conjunction with a degree wheel and the cam profile was measured / compared to the design profile vectors and it was found that the vector length of the ground cam matched the theoretical design vectors within about a thousands of an inch. I figured that was good enough for me. So I left it at that and was satisfied with the results - kept on making my camshafts accordingly.
I am of the opinion that the cams I am grinding are accurate within close tolerances because the use of the oversized master cam being made using CAD and CNC reduces any geometrical errors during the grinding by possibly a factor of 5.
As I said I am no cam expert, maybe somebody who knows this subject better than myself can enlighten me.
Peter J.
I am certainly no expert on the subject of cam geometry and the geometric closeness of a cam that is generated using a master cam in a swing frame grinder.
The master cam I created for use in my cam / crankshaft grinder is five times the size of the actual cam that I needed to grind. My master cams were created in CAD and machined on a CNC mill and the master cam geometry was confirmed after machining.
If certain requirements in the design and building of a swing frame grinder are adhered to, it appears that the resulting cam being ground is very close to what the cam geometry requires. In testing my grinder initially, I made a cam ground to the 2 dimensions that could easily be measured during the grinding process such as base circle diameter and total cam height. These dimensions correlated to each other as per the cam geometry to within 1/2 thousands of the design geometry. After stopping the grinding at that point the cam was mounted to my lathe spindle in conjunction with a degree wheel and the cam profile was measured / compared to the design profile vectors and it was found that the vector length of the ground cam matched the theoretical design vectors within about a thousands of an inch. I figured that was good enough for me. So I left it at that and was satisfied with the results - kept on making my camshafts accordingly.
I am of the opinion that the cams I am grinding are accurate within close tolerances because the use of the oversized master cam being made using CAD and CNC reduces any geometrical errors during the grinding by possibly a factor of 5.
As I said I am no cam expert, maybe somebody who knows this subject better than myself can enlighten me.
Peter J.
