Hi All,
We'll i've slowly been progressing from little toy routers and mills machining plastic upto a big industrial steel munching bridgeport. I've taken time to learn cad, and cam to a level where I can do something useful with it and what a steep learning curve that was.
Now I have a new problem and I'd be every so greatful for some advice from seasoned machinests.
In the good old days of the 'toy' machines i was only cutting plastics usually quite thin with equally small cutters. Typicallly I would hold a part in a vice just so it was firm but not too tight so as to warp the material and use double sided tape underneath to hold everything in place. It was cheap, simple and effective (if a little crude) and even worked on the occasional bit of ali so long as i used a small diameter cutter with low feeds and pass depths.
Now i'm in a whole new world of considerably faster feeds/speeds/ bigger cutters and chunkier metal. Having learnt some cad/cam basics and thinking that was the hardest part out the way i'm now struggling with what i thought would be the simplest thing - holding the workpiece down to the table!
So i'm trying to machine out this simple part from a piece of ali that is the same thickness as the part needs to be in the thickest point (10mm) and theres only about 14mm spare material round the outside. (i'm trying to make this from offcuts rather than spending out money on new stock!)
I put the material in the vice and made a toolpath with tabs on the outer contour, the intention being that there would be enouhh material to hold it in place to finish the cut and then it would be a small job to finish off with a hacksaw. However it didnt really work as planned and when all the tabs where cut the part slipped out the jaws and i had to abort.
So given the part and the circumstances i'd be really greatful for some tips on good workholding technique that would work in this situation.
A technique i have used a few times is clamping a block of wood into the vice , drillling some holes in the ali material to be machiend by hand and then screwing the ali plate to the wood. again its crude and you do tend to get a bit of movement/vibration but it has got me by but i'd really like to learn some better options even if it means buygin some special kit.
I had an idea about maybe getting a big thick ali/steel plate and drlling/tapping a few hundred M6 holes in it and then useing that to screw clamps into. Not sure if it would be as good as I'd hope tho. i could see the threadded holes gettign clogged with swarf in no time.