The Do's and don't of making circular clamps.

**tonyfoale** · Dec 17, 2019, 03:58 PM

Making clamps for a mill or drill quill or a high speed spindle etc. would seem to be a subject hardly worth discussing, but I have often come across designs which are sadly lacking in some area. I have made a 17 minute video which looks at the good and bad aspects of design and manufacture.

Here are a few photos to wet your appetite:

The Do's and don't of making circular clamps.-dsc_1988.jpg

The Do's and don't of making circular clamps.-dsc_1967.jpg

The Do's and don't of making circular clamps.-dsc_1986.jpg

Click images for full size.

The Do's and don't of making circular clamps.-dsc_1975.jpg

The Do's and don't of making circular clamps.-dsc_1972.jpg

The Do's and don't of making circular clamps.-dsc_1991.jpg

**DIYer** · Dec 18, 2019, 12:04 AM

Thanks tonyfoale! We've added your Circular Clamp to our Clamps category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:

Circular Clamp by tonyfoale

tags: clamp

**Carnel** · Dec 19, 2019, 02:31 AM

Tony, I made a fixture for a Dremel for my drill-mill quill from plywood also with the Dremel placed eccentric wrt the quill. But the angular play of the quill made accurate work impossible. In your set-up the CNC ball screw fixes that problem. I am in progress now to make a centric fixture for the Dremel.

**tonyfoale** · Dec 19, 2019, 03:09 AM

Originally Posted by Carnel

Tony, I made a fixture for a Dremel for my drill-mill quill from plywood also with the Dremel placed eccentric wrt the quill. But the angular play of the quill made accurate work impossible. In your set-up the CNC ball screw fixes that problem. I am in progress now to make a centric fixture for the Dremel.

Carnel,

You may find this post on a sensitive drill useful also;

DIY high speed sensitive drill press.

**Carnel** · Dec 19, 2019, 11:27 AM

Hi Tony, very interesting video. The reason that I want to make a drill-mill fixture for my Dremel is that I want to use the cross table of it, primarily for milling PC boards. So a sensitive drill press is not what I want, but I like your detailed approach of that problem very much. As for springs and counterweights: are you aware that a DC motor can act as a torque motor? With the current setting you can easily adjust the torque which does not depend on the position, comparable with a counterweight. Also universal motors from home appliances can be used for this application.

Regards,
Harry

**Toolmaker51** · Dec 22, 2019, 07:45 PM

Cylindrical clamps with bad form are rather common. That shouldn't be the case, maybe accountants are in charge making band blades available. While extreme slitting isn't guaranteed bad, it can weaken an otherwise secure fit.
Personally I bore size-for-size too, but the clamp is prepared differently. Often this entails drill/ tap of bolts, rough bore, separating the halves, milling the joint flat, reassembly with shim occupying what will be the finished split, then completing the bores. Yes, bit more labor intensive, but I rarely can tie up a machine tool for g-jobs. This helps breaking any process into shorter steps.

Tony's video features just about if not all considerations of successful cylinder clamp mechanics. Aspect being offset, would make [my] milled joint tenuous without CNC or careful trigonometry.