# Edge cam clamps



## churchjw (Oct 27, 2011)

Next stage of the project I am working on needed some very low profile clamps so I decided to make some edge cam clamps.  This is not an idea I came up with.  There is a great site http://rick.sparber.org/ that has a great step by step of the process. http://rick.sparber.org/Articles/tc.pdf

For mine I am using 1/4-20 bolts so I had to down size some of it.  

Step 1 is to make a jig to turn the bolt heads to make the cam. 

Ok so apparently I hit my picture upload limit so I am switching to flickr.

http://www.flickr.com/photos/24370911@N08/6287140193/

This pic shows facing the stock.  Its just a short piece of scrap pulled from my scrap box.

http://www.flickr.com/photos/24370911@N08/6287659140/

Next turn the stock around and put back into the chuck with a piece of shim stock on one of the jaws.  The thickness of the stock determines the amount of cam action from the bolt head.  I am using 1/4-20 button head bolts.  The head of the bolt is .475" so the rim under the edge is around .110".  I used a .102 shim.  

http://www.flickr.com/photos/24370911@N08/6287143419/
http://www.flickr.com/photos/24370911@N08/6287664064/

Faced and taped the stock for 1/4-20.

http://www.flickr.com/photos/24370911@N08/6287665576/

Take the shim out and put part back in chuck.  You can see the hole is offset by .102"

http://www.flickr.com/photos/24370911@N08/6287148345/

Thread a bolt into the part and turn the head down to .375".

Next step is to make the edge clamp part.

http://www.flickr.com/photos/24370911@N08/6287670334/

Started with .625" W1 drill rod.  This is what I needed the spider to help hold. LOL

http://www.flickr.com/photos/24370911@N08/6287152883/

Drilled with a H drill to give the bolt room to cam.  

http://www.flickr.com/photos/24370911@N08/6287673312/

Used a .375" end mill to cut a .075" deep pocket in the end.  I know there is some way to do this with a boring bar but this seemed faster and worked ok.  Used my new readout on the tail stock to get the depth right.  Worked great.

http://www.flickr.com/photos/24370911@N08/6287156053/

Not really part of this project but I had to do a little regrinding on a cheap braze on carbide cutter so had to reset the height.  Made this little tool sometime back out of a cheap square that I got that turned out to not be square.  I quick and very accurate way to set tools for a quick change tool post.    

http://www.flickr.com/photos/24370911@N08/6287159165/
http://www.flickr.com/photos/24370911@N08/6287160435/

Using the angle tool to cut the knife edge on the clamps.  This shows three ready to be cut off.

http://www.flickr.com/photos/24370911@N08/6287680874/

Here is the last clamp being cut off.  

http://www.flickr.com/photos/24370911@N08/6287157739/

Here is testing to see if they work.  I was shock at how much holding power they have.  With just a little snug on the clamp I could not move the stock.

http://www.flickr.com/photos/24370911@N08/6287163357/

After a little heat treating on the clamps here is the final configuration for the jig.  Only need to loosen one clamp to remove the part.  The jig does not have to be square for this project all I am going to be doing is drilling a hole.  It just has to hold tight and be very repeatable.  

Over all the clamps worked great.

Jeff


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