Darren,
You need to keep in mind that some of us don't have much of a clue about machining in general.
Neither do I. I make it up as I go along.
But if you lot want to carry on believing me!!
After a bit of beauty sleep (and boy, do I need it), I am showing you what I got up to today.
I tightened the newly made screw into the mounting, so it was in it's normal operating position when tightened up.
Because it is always easier to tighten something up when pushing down on it, I marked up the position for the profiled handle, and also made sure it wasn't sticking straight out, but angled down a bit, explanation later.
The hole was drilled and tapped for the profile, and the position was checked. All OK.
The screw bit was given a bit of hand profiling and cleaning up.
After screwing the two bits together with a bit of loctite on the joint, the main bits are done.
Remember me saying about asking neighbours not to throw anything away. Well my next door neighbour thinks he is a bit of a carpenter (a nail it and glue it man really), was given an old drop side baby's cot to recycle, he asked me if I wanted the metal rods off it. I took them with thanks.
Once it has had the crap plating emeried off, it will be ideal for what I am doing.
Cleaned up and faced off, a perfect fit in the hole.
All three rods had a 5mm flat machined on their sides. This is for the holding screw to press against, and if any damage is caused on the rod by the screw, it will still slide freely in the hole.
The two shorter rods were drilled and had a length of smaller rod loctited into the ends of them. Then all three were polished on the tip faces. Not only should the tips be square and flat, but there must be no sharp edges either. The last thing you want is to put a nearly finished soft surfaced part against the stop, and end up with a mark on the surface of the job.
So now I have three different sized stops, 8mm, 5mm & 3mm. This range should be fine for almost every job that needs a back stop.
Now to the locking screw.
A bit of rough bar was turned down to just smaller than the thickness of the main holder. A 6mm thread was put on the end of the bar so that it was just a bit short of the length of the hole it was going into. On the end of the thread, a 3mm plain hole was drilled about 10mm deep.
A 3mm spigot was turned on the end of a bit of 5mm diameter phos bronze, it could have just as easily been brass. It was then parted off about 7mm long (not critical as it is turned to length later.)
The bronze slug was loctited into the end of the screw.
As you can see, the screw with the tip on is now way too long.
BTW, because the tip is 5mm diameter, it will easily go thru a 6mm tapped hole, as it is smaller than the root diameter of the 6mm thread.
The tip was gradually reduced in length until, with the bar well gripped, there was about 0.5mm gap under the screw head.
A small profiled handle was made for the screw, and the screw itself was given a bit of shaping. The handle was positioned in the screw so that when it was tight, it ran down the main clamp bar, stopping it from being a nuisance by sticking out and getting in the way.
So now, all bits are finished, time to see if it will do the job.
With one of the small bars in, you can see, even if it is fully adjusted back, it would still keep anything in the jaws away from the drop edge of the jaw bottom.
The large bar will be able to cope with almost anything along the whole jaw length.
All pins can operate from the jaw base to about 25mm above the jaw top, and just over 50mm jaw opening.
If these won't cope, I don't know what will.
It all stows behind the vice when not in use. The vice can be operated as though it wasn't there.
Now back to the clamp screw angle. With it in the stowed (and used) position, the full depth of the vice can still be used.
That's it, job done.
Now for the sermon.
Why has the old fart taken this much trouble over a backstop?
Anyone that knows me, knows that I won't make any sort of gizmo's or tooling without it having a good useful life. I use a backstop all the time, and because my old one is now difficult to use in the setup I now have, the new has taken over from the old.
The next bit is about the way I work.
If I was making something for a one off job, it most probably wouldn't even get the rust removed. On this one, it is now a part of my workshop, and as such is made to the best of my abilities. If that means spending a couple of days shaping up handles to make it match, then so be it. As long as it sees me out, and most probably a few of the next owners as well, I am happy.
For sale, one old, overused, crappy old mill backstop. Offers invited.
Bogs
