Having found that the machine worked at much higher speeds than originally thought
it occurred to me that using it as a vertical hack saw would also be a possibility
so I made adaptors for fitting a fine tooth junior hack saw blade so as to try out
See Sk. 3 for the fitting method I adopted.
Tensioning the blade seemed likely to be a problem but to carry out the initial tests
with the minimum of additional items I chose to leave the two screws that secure
the Upper File Support (42) loose so that the outer end dropped slightly, say just
1mm. With the saw in place these screws were tightened thereby tensioning the blade.
In use it coped quite well with 2mm thick steel and 3mm thick aluminium, but it did
occasionally grab the workpiece on the up stroke, lifting it from the table which
was disconcerting. I needed to do further tests and was hesitant to use it for other
than quite large parts as I do not fancy getting my fingers too near the saw blade.
At this stage I felt the user should attempt this use of the machine with considerable
care but needing very little by way of special items to be made, if found unacceptable,
very little wasted time will result. Abra files could be mounted similarly using
a round hole to accept them rather than the slot.
Having completed the machine and run it I am more than happy with the result and
the lack of any major problems leading up to that point.
A very minor point is that I had designed the table to tilt to 45°, which it does.
However, the one part of the machine that I designed on the job was the file adaptors
and as a result overlooked that these would foul the underside of the table in the
45° position. This can be overcome by machining a slope on the front edge of the
adaptor or machining a recess on the underside of the table. The easiest way out
though is to run the machine at a slightly reduced stroke length.
I am sure that many readers will find this machine an interesting project whilst
others may wish to limit the work involved. With that in mind there are two areas
where the machine can be simplified quite significantly but both eliminating the
most interesting parts of the manufacturing process.