Box Spanner Fix

[mzt]

Some days ago, I had to apply a pipe to the handle of the box spanner I?m using on the mill, to remove an overtightened drill chuck:
ended with the business end of the spanner breaking into pieces, luckily the chuck was released at the same moment.

This is definitely not a fix, but I needed something made quickly (and it is still working after a few days. Might end up with
press fitting a collar to this one, someday)



 
But I want a more durable one (though the above one reminds me not to overtighten the chuck ANYTIME I?m using it).

Started with this



 
And drilled thru a portion of it to the distance between the flats of the square on the drawbar (8mm),




then some length of it to the distance between the opposite corners (10mm)



 
A quick visit to the marking bench



 
Then to the mill, to drill the four 1.5mm dia holes (some 12mm deep)



 
Took a picture of the other end, too, toghether with the next tool I?ll use, tomorrow.
(I wish I kew where the square file is gone: will do with the triangular one with a little more care).



Passing close to the vise, on my way to bed? ..it?s almost done now, but no pictures yet.

Marcello

[Jo]

Some days ago, I had to apply a pipe to the handle of the box spanner

I think most of us are guilty of trying that one . It is worth press fitting that collar on to the original tool, that jubilee clip is just asking to catch on something and get in the way.

I like your idea of drilling out the corners to give you something to aim for when filing . I wonder would it have been worth drilling these corner holes before the center to avoid the risk of them breaking through into the main bore? 

Jo

[mzt]

I wonder would it have been worth drilling these corner holes before the center to avoid the risk of them breaking through into the main bore? 
Jo

The point is good, I wondered about that too.

Decided I could do better with wandering holes than with a wrongly shaped/dimensioned/positions square. Marking the square on the
surface plate having the wp. clamped to a V-block was trivial, no dimensions to be taken, no numbers, no calculations.
Plain swarfs without the related headaches, if I'm making my point clearer.

They all went straight, btw: spot drilling each of them, then drilling before moving the axes helped.
Had they wandered towards the bore, well, it was not going to be a cyl. for some engine, only a start for a box spanner: there will be filing works into that.

Marcello

[mzt]

The spanner shaft (a 12mm bolt, should be strong enough for the job) turned to .07mm interference fit,
drilled for the handle, tapped for a set screw.



 
Now in the press, barely within the envelope of the machine
 


Here it is! I?m definitely satisfied with the fit and finish of the square socket.
May add a taper pin, or have somebody welding the parts together, someday.




Marcello

[steamer]

Hey Marcello,

Looks great!   .003"  ( .07mm) is a pretty tight press.   A taper pin might be advisable if your going to add that pipe to it again though.

Nice hand work on the socket!

Dave

[mzt]

Got a box of 20 1/8" taper pins, but no reamer that taper. 
Will get around trying the make of some taper D-bit from HSS, someday.
Gotta get around fitting a decent toolpost grinder on the lathe, first.
I'm spending too much time into building engines and not enough on tooling, that's the problem.

Marcello

[steamer]

Hey Marcello,

Either that or just add a hardend straight pin....that would lock it ...no special reamer required...just thinking out loud

Cheers!   

Dave

[Jo]

I'm spending too much time into building engines and not enough on tooling, that's the problem.

Marcello

Any time in the workshop is good time .

Jo

[Mike R]

I'm spending too much time into building engines and not enough on tooling, that's the problem.

Marcello

quite the opposite problem for me!

Looks like a well made tool, should last you a lifetime now! I believe a simple roll pin will be more than enough to keep that from ever moving.

Mike

[mzt]

Now I have a working replacement wrench, I can take the risk of fixing the broken one, finally.
First of all, I removed the jubilee clip and paper tape that were holding the loctited part in place,
then put it into the lathe to gain a round end: was not sure about applying intermittent cuts to a glued part,
but it did not move. That material is glass hard, btw. 



 
Next, I turned an alu. collar to press fitting diameter. I suppose steel would have done better, but there
were some alu. tubing odds into the box: too tempting.

Press-fitting the collar. 




The finished job.



 
As for the homemade one, I managed to fit an 1/8" taper pin in it.



I measured the diameter of the pin at (A) and (B), then divided the distance from A to B by the number of drills
I had... then it was only a matter of applying enough force to have the pin squeezed down the stepped hole.


Marcello

[steamer]

Now there's a piece of sideways thinking!   I like it!

Nice Job Marcello!   

Dave