...more a ham-fisted one!
although I like my large bench drill, but because most of the parts I make are small I find the slots in the table too wide for my needs. So like most people I dare say, I take to bolting parts to various sub plates / angle plates etc. but what I really want is one fixture that could replace the various angle iron / scrap blocks that I've accumulated and are now lurking somewhere in the shed.
I decided that what I wanted was something that would allow me to drill cross holes reasonably accurately in round bar , could hold round bar (or conrods) vertically and give me decent vertical and horizontal clamping surfaces. I also wanted to make it out of some of the larger pieces of flat bar I had.
this is what I eventually made (you can see the original mk 1 version to the left of the table)
made out of 8mm flat bar (except of coarse the wide side which is 20mm) purely because I already had enough of the stuff, the only thing I had to buy was the cutter for the vee grooves.
heres how I cut the long vee on the table top. not a job the peatol was designed for!
the base was clamped to an angle plate while the edge rested on two pieces of flat bar to raise it to the desired height. Then it was a case of feed in about 25mm , unclamp, move along etc. A slow job. The base is 150mm long.
Incidentally, the cutter is a 120* multi flute counter sink. And yes I did have to first cut a groove with a 1/16 slot drill to allow it to cut.
I chose 120* over 90* because it allowed me to cut a wider groove than what a 90* cutter would. (don't forget the plates only 8mm thick)
here's the top. I was surprised not to see more chatter marks, most of which where easily removed with a few strokes of a flat file
the hole was made with an 11mm slot drill (biggest I had, well, sharp one anyway!) at the same time as I cut the groove, although I made the mistake of cutting groove first. didn't make feeding the slot drill in very easy.
rather than bolt the sides directly to the base, I used 12mm SQ bar .
I decided on this way of assembly because it was,
easier to file 2 sides of the bar square, and
easier to adjust the three sides square to each other
the 20mm side I filed square and bolted it straight to the base. The sides aren't bolted to each other. Once I had them set up square i didn't want to introduce any other clamping forces that might pull them out. It was then a case of over to the drill and drill and bolt a base on.
If you look closely , you will see the sides overhang the top and base. this is deliberate. To have the edges flat and square to the sides would have involved a lot more filing than I wanted to spend on the project. (with tooling I'm very utilitarian minded) and if the top/base overhangs, I would not be able to set it on it's edge as here. those two slots have proved quite handy, although I could have just as easily used the large vertical vee.
I made a small 'top hat' to fit the 11mm hole and 3 small drill guides of 1.9mm, 2.4mm, and 2.9mm. (hopefully handy for following thru' with hand reamers 2mm , 2.5mm & 3mm) . it's held in place by a small clamp underneath the table, although to show you how I just made things up as I went along , here's what I had to do to the base of the top hat and side of the clamp. At least if I want to leave the clamp in place.
both parts where fouling on the edge of the 12mm SQ bar. I turned down a piece of bar to fit the hole to help in lining it up with the drill axis
the last thing was to make a quick and dirty clamp and nut to allow it to be bolted to the table
I'm quite happy about it, although I'm under no illusions about the accuracy of the vee groove. It is just for quick jobs. For accurate work I have a fixture that fits on the peatol cross-slide. Now it's just a case of slowly peppering it with 5mm clamping holes as and when the case needs.
would I change anything? well, it would have been nice to have been able to have cut a larger hole than 11mm. The largest bar I can fit thru' the top hat is 6mm. Although I can line the hole up with the lathe axis easily enough and start with a spotting drill. And I would have liked to have had the side with the 2 slots longer so that they would clear the opposite face. If you look at the photo , I'm limited as to what size rod I can clamp by the gap between the two sides.
but at the moment it's fulfilling all my needs. Heck! it's a damn sight better than this set-up which got me first thinking about building it
thanks for looking
peter
