Some Machining Shizzle

[Galvonaut]

That looks very sexy Andy!

[steviobee]

Wow, looks a nice bit of kit.

I bet you're suddenly finding lots of things that need making?

[The_Doctor]

Andy, you've got me interested. (Been thinking since you commented that you can make anything, recently). My need isn't demanding, just specific.. 3mm thick Al, type 6082 (HE30) T6 temper. No anodising needed, that stuff takes a good brushed finish and will keep it with good corrosion resistance. It's for a backplane on a 1U rack case with tightly packed connectors on one half. It needs high precision, clean edges to holes and edges, and sharp corners (internal bend radius 0.5mm max). My first one I made by hand, lots of filing... Works perfectly but I don't want to do it like that again! Can you tell me a likely cost to make a couple of them? Also, whether there is some way I can reduce cost by preparing appropriate data files in advance.

I can't find a clean outline of what I want right now but as a guide, it has 8 rectangular holes, three round ones, the remaining 25 or so being small drilled holes I can probably do myself so long as some pilot marks (basically, dents) are added to make that easy and fast. This wasn't a high priority for me but if I can get what I need economically I ought to have at it because it could make my life easier later.

[andy_con]

Depends on size of material?

[The_Doctor]

Well, you do know the size of a standard 1U rack case backplane? If I'm going to pay someone to do this for me I do need them to think about what I'm asking.

Anyway, 1U is 44.5mm (45 good enough for me) by 425mm. As I don't know exactly what rack case I'll be using and replacing its own backplane for, I'll assume 440mm long, as I can trim excess off here on a bandsaw. I bet the small size differences in 1U rack case variations will not be your main concern. I gave you a very close estimate in hole count and variety, that is likely the data that makes most difference. Bit more info: Most of the rectangular holes are USB sized, or similar. The largest are for DSUB 25 pin and two DSUB 9 pin standard hole sizes.

[andy_con]

425mm is to big for my machine sorry

[The_Doctor]

Ok. What's the limitation? Bear in mind that in one axis, my panel is REALLY small... Also, most of the holes are on one half of that length, and the remaining rectangular hole is at the other end. I can't tell from the picture of the Starmill, but it appears that a bit of shim might allow the far end to clear the sloping edge of the case if it will operate in open position.

[andy_con]

the starmill is far to small, id use my triac. but machinable surface is something like 300mm

[The_Doctor]

Ok. I'll try to remember that. I might come up with some Cunning Plan.. You got what I said though..? Actual holed area is going to be just 45 by 195 mm, then the backplane can be turned round for that last hole at far end.

So long as the unworked end can stick out somewhere without getting pranged during the operation, all's good. It's worth a mention that I did the join-the-dots drilling for the rectangular holes on my first one, using a little Proxxon drill stand fitted with a tiny 2-axis mill table. Got to be smaller than either of your tools, I think. Didn't have any case confining it though.

[andy_con]

um I stick a rule on the table tomorrow and see