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form_change
07-22-2011, 03:33 AM
One capability that I have not got but would like to have in my workshop is something that would enable me to do some precision grinding. The only reasonable space that I have left for this sort of equipment is a space 600x600mm on top of one of my trolleys so I can't accommodate anything too big. Every so often it would be useful to be able to grind a small surface or shaft (or sharpen cutting tools in a controlled manner, rather than offhand).
A number of T&C grinders have rudimentary surface and cylindrical capabilities so one of them might do the job. I have a set of Stent castings that I'm slowly doing something with but over the years I've noticed articles in magazines that make major changes in layout to make it more useful, but usually at the expense of other capabilities. From a design point of view I don't like the way some things have been done on it either. Whether it will meet my needs I'm not sure already I'm thinking of how to change things around and when I look at the bed I'm thinking that it might be smaller that ideal for the sorts of things that I might like to do. Is there a better option out there for a Universal grinder?

I'd be interested to have thoughts on what characteristics and features members regard as essential (as well as nice to have) on a small grinder, be it T&C or surface. (I'm defining small as having say around 8" of longitudinal travel and probably around 4" width - so be able to grind a 8x4" surface or a piece of shaft say 8 to 10" long and up to 2" in diameter (including cutters/ drills))

Michael

(Some questions to ponder -
what amount of vertical travel is most useful?
Is power feed necessary on a small machine?
Fixed bed and moving head vs. moving bed and fixed head?
Bridge or pillar construction?
On our imaginary ideal machine would being able to turn the wheel axis vertically (slash/ blanchard grinder style) be any use?)

brozier
07-22-2011, 04:08 AM
Hi Michael,

I have a small Union T&C Grinder and am just about to buy a small Surface grinder.

I'm always hitting up against the work envelope of such a small benchtop machine. I'd suggest you think about what size items you want to work on before designing.

As an example I wanted to grind all the MT2 drills I have - to achieve this I've had to produce a fixture which overhangs the bed by a considerable amount just to accomodate the length of the drill.

I would say having a rack and pinion type fast feed on one axis would be as good as having power feed.

I would think moving bed is the way to go.

Rather than turning the wheel head being able to change the position of the wheel head in relation to the bed would give the most flexibility.

Best regards
Bryan

Ian B
07-22-2011, 04:40 AM
Brian,

I too have a Union T&C grinder. Nice compact piece of kit, with which I can *just* grind 10" long planer blades. I find the infeed counterintuitive - they should have put a left hand thread on it, but ok.

The biggest snag with using it as a surface grinder is the lack of a fine downfeed - the coarse thread and bevel gears really aren't designed for taking off another couple of tenths. No doubt something could be made, but as it comes from the factory,it's not much of a surface grinder.

Ian

form_change
07-22-2011, 05:52 AM
Interesting points - I hadn't thought about the down feed needing to be finer on a surface grinder than on a T&C grinder, but it stands to reason that it would need to be.

We had a Kent surface grinder at one place I worked and it had the rack and pinion feed which was fine but for other types of grinding would it need to be slower and/ or more controlled?

Probably the best example of something that would have been handy for something like this is a hardened collet that I have. I need to take around 0.25mm from the diameter as well as trim a little from the end (I found an incomplete tool holder set and am adapting a 3/4" collet from another application). I have a planer with 12" blades so fitting them on would be nice, but not a 'must have' because the grinding envelope for everything else is way smaller. Mounting extended jigging is not an issue (for say a long drill bit) but I haven't got the space for a permanent 'large' grinder like RC's Macson.

Michael

Dunc
07-22-2011, 07:53 AM
"The Home Machinist's Surface Grinder" was an article by Robert Byler in HSM May-June 2006 to Sep-Oct 2006 inclusive.