Making Cams

[DaveRC]

I am sure this has been covered before, in fact I know it has but I just can't find it... ???

I need to make, what looks like, two very simple cams for the Upshur vertical I am making, I have re-read MB post on the way he did his, sorry just don't get that at all... scratch.gif

I am sure I have seen a method using the mill and a RT (which I have) and a program that produces a plot of angles and cutting depths, so you use the RT with the Z access on the mill to create the cam profile. I can't find it again and forgotten what it's called, but made perfect sense to me when I saw it.

Can anyone please point me in the right direction please...

Thanks

Dave

 

[Metal Butcher]

Dave, can you post a drawing of just the cam? The way I make cams is really simple. I take another look at mt post. I guess I didn't explain it well enough. I'll try to help.

-MB

 

[Lakc]

The program you might be referring to is from here http://modelenginenews.org/
Look under resources--design center on the left hand side map. I have tried it several different ways, and always seem to go back to the milling them.

 

[Metal Butcher]

Dave, Copy and paste the part(s) you don't understand. This is from Page #5, Repy #67 of my build thread. I'll try to help as best as I can.

67) Today's post will show how I made the cam and cam gear carrier, and also the crank gear hub. It's a quick and simple method that has worked well for me in the past. A 3/4" Steel bar was machined down to the specified major diameter of the cam on the lathe. I profiled the blank for the cam using a spin fixture mounted on my mill. The end mill was lowered .001" at a time till it touched the work piece, and then shifted off to the end and lowered to the specified minor diameter of the cam. After the cutter was taversed back and forth to make the first cut the spin fixture was reset 10 degrees to take another cut. It took 25 cuts (0 to 24, inclusive) to match the 120 degree shown on the plans as a 1/4" remaining on the major diameter. To reduce the time needed to blend the flats created by the incremental milling, I moved the pin on the spin fixture from the #1 position up to #5. This gave me 23 cuts in-between the previous ones, cutting the increments (flats) in half. In the picture below you can see the smaller steps, created by what I call double-cutting, that will require much less blending time compared to what I've done in the past.

I'm having a problem today with my computer. I keep loosing my connection, so be patient.

-MB

 

[DaveRC]

Thanks MB,

Maybe I will start with this,

I profiled the blank for the cam using a spin fixture mounted on my mill

What is a spin fixture....?

I think not understanding what this was made the rest make no sence....

 

[DaveRC]

The program you might be referring to is from here http://modelenginenews.org/
Look under resources--design center on the left hand side map. I have tried it several different ways, and always seem to go back to the milling them.

Yes, that was the one I was looking for, thanks....

Gona wait and see what MB comes back with....

 

[Metal Butcher]

Thanks MB,

Maybe I will start with this,

I profiled the blank for the cam using a spin fixture mounted on my mill

What is a spin fixture....?

I think not understanding what this was made the rest make no sence....

5-C Spin-Dex. Imported clones are about $30 to $40.

http://www.swissprec.com/PDF/BRAND/2008/65.pdf

http://compare.ebay.com/like/330467...fd93acb&itemid=330467289009&ff4=263602_309572


A 5-C Spin-Dex is also called a 'Stevenson's' in other parts of the world.

http://www.arceurotrade.co.uk/Catalogue/Collets/5C-Fixtures

-MB

 

[metalmad]

Hi Dave
If you do not have a spin thinginy or dividing head maybe you should have a go at doing your Cams in the lathe ?
I think I posted some pics in my "sows ear Build"
The blank is bolted to a mandrel and done in much the same way (50 or so cuts)
Pete

 

[pmerritt]

Has anyone out there used the method described by William Wilkins in issue seven of Model Engine Builder? Not sure if it would apply to this engine though.

Peter

 

[stevehuckss396]

If you do not have a spin thinginy or dividing head maybe you should have a go at doing your Cams in the lathe ?

If it's still there I posted an article on how to turn camshafts in the lathe. "Offset tunning the camshaft" or something like that. Give it a read, it could spark a few ideas.

 

[gbritnell]

Hi Dave,
Is this what you're looking for?
http://www.homemodelenginemachinist.com/index.php?topic=5714.0
gbritnell

 

[cfellows]

Dave, you might be talking about the cam I made using a rotary table and a boring head on a mill. Look at reply #52 (page 11) in this thread:

http://www.homemodelenginemachinist.com/index.php?topic=6352.150

Chuck

 

[DaveRC]

Thanks guys for all your help and responses....

Hi Dave,
Is this what you're looking for?
http://www.homemodelenginemachinist.com/index.php?topic=5714.0
gbritnell

Yes, almost, although I am not to sure about cutting the cams and the shaft all in one, but I will have a good look into doing this.

MB, I have never seen this 'spin fixture', which would make sence why I did not understand the way you made them...

I think I am going to go with using the RT on the mill and plotting the cutting depth using a table from http://modelenginenews.org/ this makes the most to me and if it makes sense to me then that's one less thing to confuse me, which does not take much... scratch.gif

Dave

 

[Maryak]

Another way using the mill.

http://www.homemodelenginemachinist.com/index.php?topic=5060.msg103979#msg103979

Hope this helps

Best Regards
Bob

 

[agmachado]

Hi Guys,

The Sherline CNC CAM Grinder can be ideal, but a bit expensive.

http://www.sherline.com/8650pg.htm

Video 1:
[ame=http://www.youtube.com/watch?v=OIWyGtXEgR4]http://www.youtube.com/watch?v=OIWyGtXEgR4[/ame]

Video 2:
[ame=http://www.youtube.com/watch?v=PlZDg0rpIi8]http://www.youtube.com/watch?v=PlZDg0rpIi8[/ame]

Regards,

Alexandre

 

[mu38&Bg#]

I didn't know Sherline was selling the cam grinder.

 

[agmachado]

Hi Dieselpilot,

They have recently started to sell.

Really cool, right?

Cheers,

Alexandre