Edward Forrest 5 cyl engine, how to cut the cams?

[Majormallock]

Hi all I am building the above engine, have machined the cam blank, now would like to know the best method of cutting the cam. They are not like other cams I have made, so would like to know how other folk have gone about it before I invent a new method! Never a good idea!

 

[tornitore45]

Rotary Table Vertical axis small end mill Move X axis turn plunge repeat use a travel indicator if you do not trust the dials.

Rotary table Horizontal axis small Ball end mill Move Z axis turn, traverse the cam width, repeat

I did as above but used a regular end mill and fouled up on the rising slope because the end mill cut metal ahead that is not supposed to be cut.

A lot of machining time and metal down the drain, had to re do.

Careful where the lobes overlap, do not move in the "other lane".
Be on the metal safe side a couple of thou and smooth out with emery on a stick.

Learn from my mistake

 

[petertha]

Some pics & verbiage here to add to your reading pile. He also did a neat trick to allow the cam assembly to be shifted relative to ring gear in order to play with timing if you were so inclined. (Can't alter the intake or exhaust duration or angles between one another, but can shift relative entire cam relative to TDC.)
https://www.***************.com/threads/edwards-radial-5-build-thread-photos.84362/page-12

 

[Majormallock]

Rotary Table Vertical axis small end mill Move X axis turn plunge repeat use a travel indicator if you do not trust the dials.

Rotary table Horizontal axis small Ball end mill Move Z axis turn, traverse the cam width, repeat

I did as above but used a regular end mill and fouled up on the rising slope because the end mill cut metal ahead that is not supposed to be cut.

A lot of machining time and metal down the drain, had to re do.

Careful where the lobes overlap, do not move in the "other lane".
Be on the metal safe side a couple of thou and smooth out with emery on a stick.

Learn from my mistake

Thank you very much, just what a wanted, Made enough of my own mistakes to know that are avoidable with the wisdom of others.

 

[Majormallock]

Some pics & verbiage here to add to your reading pile. He also did a neat trick to allow the cam assembly to be shifted relative to ring gear in order to play with timing if you were so inclined. (Can't alter the intake or exhaust duration or angles between one another, but can shift relative entire cam relative to TDC.)
https://www.***************.com/threads/edwards-radial-5-build-thread-photos.84362/page-12

Unfortunately the web page wouldn't load, but I understand what you mean by altering the cam timing. On the plans there is not adjustment and the gears mean it could be a tooth or more out! One of the problems with this build has been the lack of build note, just have the plans! Part of the challenge huh?

 

[gasbur]

here is a link to machine a cam :

http://modelenginenews.org/design/CamTable.html

 

[a41capt]

Some pics & verbiage here to add to your reading pile. He also did a neat trick to allow the cam assembly to be shifted relative to ring gear in order to play with timing if you were so inclined. (Can't alter the intake or exhaust duration or angles between one another, but can shift relative entire cam relative to TDC.)
https://www.***************.com/threads/edwards-radial-5-build-thread-photos.84362/page-12[/QUOTE

I’m unable to load the page also. It appears to be an incomplete web address?

Thanks,
John W

 

[petertha]

Sorry. I keep forgetting this site does not allow links to certain other hobby sites. If you navigate to The Hobby Machinist dot com & do a search for 'Edwards Radial 5 Build Thread' (username JRaut) ~ post 116, you will see the reference.

 

[Majormallock]

Sorry. I keep forgetting this site does not allow links to certain other hobby sites. If you navigate to The Hobby Machinist dot com & do a search for 'Edwards Radial 5 Build Thread' (username JRaut) ~ post 116, you will see the reference.

Thanks for this, I did as you suggested and found the thread and went through it in detail. Lots of good stuff found. I now want a Bridport with limited cnc abilities! However I will use some of the same techniques mandraulicaly