Grinding flat surfaces on vertical mill?

[Cowbell]

(Warning, rookie alert)

I'm looking to make some mounting posts, ala:



(a little thicker than these)

I've got my round bar stock sitting around. I figured what I would do is band saw off some approximate length pieces and grind them down nice and flat before drilling. 2 questions:

- Would you guys recommend some kind of grinding operation to get the surfaces flat, or should I just run an end mill over them to surface them down (maybe grinding afterwards)? What's the standard technique for grinding something down using a mill/drill press (again, beginner )?

- General machining question. When you've got a length of (round) metal that you want to make perfectly flat and perpendicular to the length on both ends, but at the moment neither end is even close, how do you get the piece set up to be machined? What's your reference point for "flat"? See below:

[Cowbell]

I just realized this should probably be in the General Machining forum. Could an admin move this when they get the chance? Sorry.

[Mcgyver]

we're just looking at a pic - I can guess but don't really know whether they are 1/8 think or 2" thick - makes a big difference in how you are able to hold the part. A big 2” thick section has enough substance to clamp in the vice and a machinists square or indicator will get the cylindrical wall perpendicular to the table… if they are 1/8, keep reading.

Generally grinding is something that is done to something that is hardened and/or something that is being worked to very small tolerances - i.e. with a grinding wheel in a surface grinder, cylindrical grinder etc. As a newbie, I'm guessing you’re thinking 'remove material' but it just came out sounding like grinding

If the pieces are small, it can be awkward to get the ends in parallel planes because it can be tricky to hold thin round pieces, especially with the mil. Do you have a lathe? It’s the right tool for the job, although as the thickness/dia ratio decreases (they look more and more like washers) it requires increased ingenuity to do because it gets harder to hold them.. For something like you shown, it should be a piece of cake to hold them in the three jaw and face and drill.

Lacking a lathe, will the dia fit in one of your collets? if so clamp a tool in the vice and spin the work piece – kind of like a vertical lathe

what are they for, and how accurate to they have to be? If they are small and not a lot of accuracy is required, don’t dismiss the humble file

[Cowbell]

They're 1.5" diameter aluminum round stock (I also have 1.25"). What I want to do is make posts out of them about 1.5-2" in length with drilled out centers for bolts. I want to use the posts to raise my mill above the workbench surface and bolt it down. Kind of a bootstrapping bit of machine work



So I'd like them reasonably smooth, flat and even.

Side note : My overall goal here is to mount the mill inside of a rubber tub for use with a flood cooling setup. I want the mill raised above the surface of the tub so it doesn't touch liquid, and I want to use the round posts to squish down the big rubber washers sealing off the bolt holes.