Sunday, 4 January 2015

Toolmaking.. A Harold Hall project

So I've had a grand day in the shed!.. I've made this which is going to be a dial test indicator stand.. and more! It's a project from one of the great Harold Hall's workshop series book "Model Engineers Workshop Projects"

So it's a type of clamp joint that can set the 2 bars tight by just screwing down on the "nut" handle...

You can see it here in it's component form.. In the book Harold suggests making a large collection of these along with end clamps for different dial gauges in your collection as well as a plethora of other things.. small jewellers vice, clamp bases, universal rotating clamps etc.. He has suggestions to clamp the rig to tee slotted tables on milling machines, bases to be held in bench vices etc.. there is no end to the uses of a collection of these! You can see the range and view the project on Harold's website HERE (Note Harold and many others have made this stuff much better than me.. I tend to use the books/sites to get the idea but make up my own dimensions for things based on the scrap I have in stock!)

I am particularly proud (spot the newbie machinist/model engineer!) with the handle I've made that acts as a nut to close the clamp.. so it's a couple of bits of mild steel turned to shape but I made the handle part a good accurate interference fit by reaming the hole in the nut to exactly 4mm and turning the handle shaft to 4.05.. then a quick squeeze in the vice and hey presto!

So I also had to cut the slots in the clamps as well and I used the Milling machine for this with a slitting saw. The only slitting saws I have are very small and cheap and came with a thin dremel style mandrel so another job today was to make a 10mm mandrel for the slitting saw so I could use it in the mill.

Also I used this drill clamp I made a while back on the milling machine.. I chucked it in the woodburner and heated to cherry red and then quenched it in some engine oil with soot mixed in to tool black it!

My first attempt at slitting saw use! Went ok!

1 comment:

Andy from Workshopshed said...

A great tool, should be flexible for use with other things tool. Harold has got some great creations over on his website too.