Camshaft calc for milling cam

[Jack3M]

There is an older program out there that supposedly does this and puts the data in a spreadsheet. Unfortunately it will not run on my computer and I am not savee enough to make this all work.

The link I am posting will have the calc, info, and the source code.

Does anyone know of another program that will do this? Can anyone make this thing run? Could I bother someone to run my numbers on it and send me back a spreadsheet for the two cam lobes?
I am dead in the water without help on this, far beyond my mathematical abilities.
Thanks
http://www.modelenginenews.org/design/CamTable.html

 

[methuselah1]

Run it in Explorer. That version doesn't like Firefox. What engine are you making? A Westbury, perchance?

-Andrew

 

[Jasonb]

Rod who wrote the original CamCalc has a later version in his Dropbox account that runs on Excel

https://www.dropbox.com/s/74calqdlsss7qfz/cam with draw.xls?dl=0

 

[Jack3M]

Doesn't like Explorer either

 

[Jack3M]

Rod who wrote the original CamCalc has a later version in his Dropbox account that runs on Excel

https://www.dropbox.com/s/74calqdlsss7qfz/cam with draw.xls?dl=0

That works.....I think. I cannot figure out how to utilize the chart, I was hoping to get the cutter height change per 4 degrees, I guess 3 deg. is 3/4 turn on my rotory. (Depending on direction of rotation) there appears to be 20 cuts (either deeper or less deep) for the total rise that starts at apparently 61 degrees to reach the base radius until reaching the other side of the cam. I hope this makes some sense, I am having a heck of a time describing. My first inclination would be to calculate the total distance of lobe rise (.162") divided by 3 deg divided the 20 cuts shown on the graph? (0.162/3)/20=X ? That is .0027" change per pass? The numbers I am using are for the intake at this point. See photo. The calc is my GUESS.

Oh, yes, the Howell Vtwin

 

[stevehuckss396]

Can you post the spreadsheet here. I don't have a Dropbox account so I can't download it. It's free so not a copyright infringement.

 

[mgbyrne3]

I was able to download with Firefox from Dropbox without an account.

Note that spreadsheet wants lift entered in thousandths with base and flank radii in inches.

PDF has snips from the spreadsheet using dimensions as posted. Machining coords every 3 deg.

If you want every 4 deg, use every other entry in the "every 2 degree" table the spreadsheet generates.

 

[Jasonb]

jack it is not as simple as just dividing the total lift. You need to take into account that the cam is rotating so the "high point" will not always be directly above the centre line so the formula has some trigonometry in it. Also by making it rotation based not height based you get equally spaced facets around the cam, if it were height based their width would vary. See attached where the cosine is used,

If you want the indexing to be in different increments then on the machining co-ords sheet change the increments from 2 or 3 to 4 see attached

Steve it can be run in Dropbox without downloading or you can download without the need for an account.

 

[Jack3M]

Hmmm well when I run the program I don't get the data you show here, even when changing numbers, it only changes the circle graph. ???

 

[Jasonb]

Not an Excel expert so can't suggest much but it works for me, couple of screen shots where I have set lift as 85thou, image changes and so does the cutting data

You could try contacting Rod via ME forum, just click message member under his post CamCalc - Manual Numerical Control | Model Engineer

 

[Jack3M]

Well I guess I have to join as it won't let me message him, meanwhile, my image changes with the input, I just don't get the cutting data...or I can't find it. Will figure out how to contact Rod.

 

[Jasonb]

There are several tabs along the bottom, click them to get the different screens

 

[Jack3M]

Ahhhh thank you so much. I am such a dummy anymore about computer stuff, so many programs and really never have used a spread sheet before.