Milling machine clamps

[egaParticipant @ega]

Posted by John Hinkley on 19/11/2021 15:31:43:

Well, I like making tooling! So there. I read through this thread and had a little ponder…..

A few minutes at the mouse and keyboard and I came up with this alternative to the usual "toothed" clamping system, which I think would be difficult to reproduce accurately in the home workshop. The idea is to drill a series of equally spaced holes (2mm dia. in my case) along a line at 45° to the major axis and then mill away half of the resulting holes. Make up the pillar and strap as shown and use silver steel rod or similar to lock the piece together. Varying the length to taste and you have a set of clamps that nobody else has got – OK, and probably don't want!

The number of pins used is optional. I have 'used' three for simplicity.

Just a thought.

John

Edited By John Hinkley on 19/11/2021 15:32:31

Bravo!

I think I would glue the pins in to save workshop Esperanto.

[HOWARDTParticipant @howardt]

Whilst this type of generic clamp is used by most people it is not a good clamping system. The clamps should have a relief behind the front edge so that they hold the part down along a line not a face. With the step heel support you need to st the clamp higher at the back than the front to clamp on the nose otherwise you could be holding the part along its edge as the clamp tips back. I must admit i use these and one day will remember to machine a relief behind the clamp nose and round it. For those who don't understand look at a fixture component supplier such as WDS.

[Bo’sunParticipant @bosun58570]

Thanks for all the suggestions and ideas. Making clamps sounds like a good idea, although as Jason says, rather model making than toolmaking (unless you have no option of course). Part of the dilemma I guess, is the "chicken & egg" lark. I need some clamps to start with before I can start making tooling. Time to ponder.

[old martParticipant @oldmart]

I would buy the ARC set, the stepped blocks are slow to make unless you want the practice, and I would only make up some longer and better fitting tee slot nuts.

[ZanParticipant @zan]

In the set I revered to earlier, I still had to make the t nurs the correct size were 12mm and too big. Even for the Bridgeport with the size of work I do. If I was building a big 7 1/4 or 6” traction engine it would be a different matter

john Yes I’d glue in thoes pins, but in use does the clamping forces tend to push the vertical block back, and there’s not a lot of height adjustment compared to a stepped block this would  I think be worse when there’s a height difference between the packing height and work.  However an interesting solution.   Originally I used a system similar to tugs, but the stepped blocks are a lot better

Edited By Zan on 19/11/2021 17:11:15

[Bill PhinnParticipant @billphinn90025]

You can buy separate M10 clamps here

and step blocks here.

As others have said, they're not great value when bought separately, but in my experience these particular ones are at least well made.

On which note, a 58pc set of clamps I bought from Arc was obviously much better made than a different size 58pc set I bought from Chester Hobby Store.

[JasonBModerator @jasonb]

The usual "saw tooth" profile of the common supports and clamp ends should be easy enough to reproduce in the hobby workshop all that is needed is a flycutter with bit ground to produce an 80deg or so dovetail profile. Rough the work out at your desired angle and then just step over and down by the same increments using the flycutter to cut the teeth.

[Ramon WilsonParticipant @ramonwilson3]

If you make your clamp bars with a tapped hole in one end – always assuming you don't consider making something for your self to use a waste of time – then the need for stepped clamping is more or less eradicated.

My collection of 6mm capheads range from 8mm long to about 120mm – anything longer I use studding. A reversed caphead in the clamp gives a good clamping supporting surface and is infinitely adjustable

I have a set of those Picador blocks that are shown above – I don't think they've seen the light of day for forty odd years – indeed the way they easily keep falling apart as you're trying to set them up and difficulties of holding them in place on a faceplate led me to the system I now use. If you have a stack of them a caphead dropped through them but short of the table keeps them in line.

It's always desirable to buy 'kit' – not least a clamp kit to mount beside the mill. Depending on what you are going to make of course but something based on the above is far more practical for the milling machine in question than spending on something that for the greater part will sit idle.

As always, it's down to choice – horses etc., but I think I'd rather spend a few hours using my new mill for making something that I will use forever on it and spend the money on something I can't – a decent set of parallels for instance.

What ever way you go Bosun enjoy your machining

 

Tug

 

 

Tug

Edited By Ramon Wilson on 19/11/2021 22:40:09

[David George 1Participant @davidgeorge1]

I live near Bonham and Turner and they supply most clamp fixtures from studs, nuts, step blocks, T nuts etc if I don't feel like making a clamp or fixture.

https://www.boneham.co.uk/clamping-and-fixing/?count=46

David

[Author]

Posts