"Extending" a Square Bar - DG-825 Drill Attachment

[silverhawk]

A little back ground :

I have a Blue Point DG-825 drill sharpener, and I have an aircraft drill bit (1/4" diameter) I need to sharpen. Trying to marry the tool to the task is a bit difficult, as the square bar that the support end sits on is not long enough.

Does anyone know how to remove that square bar to re-insert another one that IS longer from these "General" type drill bit sharpeners?

Or, is there a better way to "extend" the square bar rather than drilling a threaded hole into the end and bolting an "extension" into place (threaded section could twist causing misalignment)?

 

[ChazzC]

I would expect there would be a roll pin somewhere in the casting, but can't see any from the photos I found. Is there a hidden fastener behind this plate:

 

[silverhawk]

There is not a fastener behind that. I thought at first one of those screws fit into that bar, but it did not come lose after removing.

Here it is under that indexing plate :

 

[pavyan]

This bar is probably anchored in the casting and cannot be removed without destroying the sharpener body (Al-Zn?).
So, because I think that this square bar is ordinary low-carbon steel*, I would weld it with a square bar of the same cross-section (started by clamping the welding parts in a vice so that they "meet" perfectly), next mill/grind/file thoroughly the irregularities and finally straighten the extended bar. I think this would be the best method.

*I don't see why it should be a quality (hardening) steel - but to be sure, you can cut off a little piece and perform a hardening test from a temperature of 800-850°C in water: the steel should harden only a little at most.
PS: You can also rivet both parts with steel rivets "on the overlap", but I don't like rivetting because is not elegant

 

[silverhawk]

This bar is probably anchored in the casting and cannot be removed without destroying the sharpener body (Al-Zn?).
So, because I think that this square bar is ordinary low-carbon steel*, I would weld it with a square bar of the same cross-section (started by clamping the welding parts in a vice so that they "meet" perfectly), next mill/grind/file thoroughly the irregularities and finally straighten the extended bar. I think this would be the best method.

*I don't see why it should be a quality (hardening) steel - but to be sure, you can cut off a little piece and perform a hardening test from a temperature of 800-850°C in water: the steel should harden only a little at most.
PS: You can also rivet both parts with steel rivets "on the overlap", but I don't like rivetting because is not elegant

Thank you. I had completely forgotten about the possibility of welding. That would make things MUCH easier, and then I wouldn't even have to mill any odd keyways.

I can't rivet because then I lose the ability to move the tail rest back up for shorter drill bits.

I think this is the way to go.

 

[pavyan]

Of course, I was thinking about this type of connection - i.e. conical head rivets