Holding down clamps

Wixroyd and WDS come to mind but the cost may surprise you as they sell to industry.

Martin C

Making your own should not be too difficult? It is where my extra clamping bars have come from - off my mill. About the best way to get them the size you actually need!

MSC also do them but at about £10 a pop almost as cheap to buy a set and just use the bars out of that.

Pop "used milling clamps" into ebay, there are a few sets on there...

This one from Zoro is reasonably priced:

https://www.zoro.co.uk/shop/spindle-nose-and-workholding/clamping-components/sc105225-55-x-25-x-12mm-m10-step-clamp/p/ZT1125807X

I thought of that but didn't fancy doing the serrated ends.

Cheers

Peter

I had a shufti there but couldn't find what I wanted. Prices seemed optimistic. $175 for a kant clamp for instance, I've just made a pair for 25 quid which was mostly paying for a firm to water cut the frames.

I thought of that, too. Flogging the rest seperately on eBay could recover the cost of the bits I keep !

,Thank you ! Those are more like it. Not the bolt size but I can work around that.

Cheers

Peter

There was a hint in one of the Mags (MEW? ) recently suggesting milling a slot out of the centre of the width of the low end of the triangular riser blocks to avoid/ reduce the tendency for the clamp bolt and the riser to foul each other.

Peter

Alternative to buying would be to make tapped end ones to take a bolt size of your choice. Tapped hole is much easier than steps.

Like these from the Zoro site

**LINK**

https://www.zoro.co.uk/shop/spindle-nose-and-workholding/clamping-components/cc06-tapped-end-plain-clamp/f/3075

Need a washer to protect the table or fit a soft end and run down inside the table tee slots. I've always found the step blocks somewhat cumbersome and, in the case of my Bridgeport, a bit narrow as they are barely wide enough to span the table slots so the straps are best placed at an angle. Which is frequently inconvenient.

One day I will be sufficiently annoyed to make a batch!

Clive

If the problem is simply the triangular block hitting the stud/bolt then just stand the triangle on a bock of something which will raise it up and therefore away from the stud

Edited By JasonB on 01/02/2023 19:23:57

That's an interesting idea.

Cheers

Peter

Correct practice is to have the stud close to the piece being held down so the triangular block shouldn't be close enough to the stud to interfere with it.

As Jason says use a raising block if need be.

Generally such interference indicates that the set up is iffy so clamping forces may prove inadequate.

For our sizes of work a simple flat bar resting on one step will be sufficiently secure unless the job is very thin in which case the block may tilt due to the offset loading. Leaving aside the slight undercut on the steps that makes it easier to slide the block and strap assembly around without disconnection there seems no overwhelming engineering reason for the multiple steps. Engaging on only one step should be amply strong enough to fracture a Tee slot or snap a stud if you use really long spanner.

Putting the appropriate undercut on a single step if making your own clamp bars is easy enough. Judging by my set great angular accuracy is not needed.

Clive

I've made effective clamp bars by bolting two strips of black mild steel together at their ends and centrally, with stud-clearance width spacers between them. They could use a clearance hole in one and tapped in the other.

Note that the bars should be rectangular section and assembled wide sides vertically, for stiffness.

They do not sit on the steps but on plain blocks, or pairs of stepped blocks engaging each other to give flat clamp seats. Nor would I rely on using a single step.

I've also augmented my clamp-set, of the type in you original photo, with two sets at different lengths of 3/8" UNC bolts having ascertained that is the right thread. I put large washers under the bolt heads.This often allows a much more compact set-up than using the normal studs and flanged-nuts.

It's worth too making some T-nuts with much smaller, e.g. 1/4" or M6, threads, to assist clamping small work-pieces with suitable holes through them by nature. Ensure the screw cannot wind right through the nut.

Thank you for the thought provoking ideas. It seems Chronos do a complete set for 40 quid including postage !