Cutting a vee groove with basic equipment

I wish to cut a 90degree vee groove about 5/16" / 3/8" deep across a piece of flat steel about 3" wide.
I have a small lathe with a fixed vertical slide (its table can rotated in the vertical, but NOT the horizontal). I do not have either a 45degree or adjustable angle plate. I have a small collection of ordinary slot and end mills up to about 12mm. I cannot think of a satisfactory way of setting this job up without an appropriate angle plate, but even if I had one I'm abit concerned that the amount of overhang that would result might be a bit much for a relatively light milling set up. If I try to manually mount it with packing pieces etc Its going to be v. difficult to clamp to the slide, and how accurate the final angle would be is debateable. I cannot mount everything on the cross-slide as it isn't slotted. (the vertical slide bolts on directly), so cannot do it that way. Any suggestions anyone?
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MikeH_QB wrote:

I don't know whether it would work, but how about using a 45/90 degree countersink with the work at right angles to the lathe axis?
You might have to cut a few slots with smaller milling cutters first.
Are 45/90 degree milling cutters available?
-- Peter Fairbrother
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Yes, I suggest:
http://www.mscjlindustrial.co.uk/CGI/INPDFF?PMCTLG &PMPAGE%0&PMITEM=B GISC-43614M
If you go to the J&L website and look at the current special offer flyer, you will see they are on offer this month - 17.17 + VAT for the 1/2" size.
I have done this using an ordinary countersink cutter, but they are not optimised for milling and struggled a bit - did work, wore the cutter out a bit. As you suggest, best to use a slot drill, and I would then add, cut each side separately in turn. Best anyway to leave a small slot in the bottom of the V-groove to avoid the risk of bottoming - see how it's done on commercial V-blocks.
David
--
David Littlewood

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if you've the time, why not mark the v out, hacksaw the centre to depth, mark both sides of the v with the saw and then saw to the centre then finish with a file? you describe the finished size as "about", its suprising how close you can file when you have to!
--
willowkevin
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Thanks for all the comments guys. Although the actual size isn't critical, it needs to be accurate (parallel to base and straight etc) as it is part of a jig to hold small section bar stock for machining.. I'm afraid my filing just isn't that good these days! Also funds are a bit limited to buy new cutters just for a one off. I'll probably hack it out as near as and just try to mill to finished size as best I can! - Sometimes you can actually see a solution when you physically try to set it up and do it, when it has not been obvious 'in theory' beforehand.
regards, Mike
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