Idiot Check - any better ideas?

[small.planes]

Morning All,

I need to hold and position a large (12"Dia, approx 15" high, but with quite a lot milled out) piece of metal.
I need to rotate it in the cylindrical axis, and also tip it up and down a bit.
My plan (such as it is) is to use my (new to me) universal dividing head to do this.
The object has 4 M12 holes tapped in the backside, which I can use to mount it.
Dividing head is Int40 taper, so I think that I can use an Int40 shell mill holder, and replace the shell mill bit with a large 'plate' (for want of a better description) to bolt to the sample, and then 'just' mount my new monster 'shell mill stand in' in the head (suitably bolted to a large item).
We need the overhang so that top and bottom are accessable at once. Will a dividing head be man enough? (I think so)
Any obvious gotchas Ive missed?
Any better Ideas?

cheers

Dave

[John Stevenson]

Got some blank BT40's with the thread and head unmachined if they would suit better than a shell mill holder.
Head is probably 2-1/2" diameter.
Also got a dummy spindle for holding it off a scrap Herbert mill for loan if needed.

.

[Timleech]

You've not had that fine dividing head of mine for five minutes & it sounds as though you're planning to wreck it
I suppose it all depends how heavy the thing is, and what you'e planning to do to it.
If there's any way to add temporary support at the edges while you're doing whatever you have to do (bits of packing, even wooden wedges) then do so.

Tim

[small.planes]

Actually, by the time Id had it 5 mins it was totally in pieces on the bench so I could unsieze the tilt, and clean out the solidified old grease
It in nice condition internally, and a lot cleaner externally now

Its a (mostly) static load (just moved by hand to repose it).
I figure that actual milling of things in it would put considerable loads on it, so it should be strong enough?
We are running some optical tests to determine the best way to measure a full blisk, this is just a small segment.

John,
I might pop over one evening this week with a couple of photos to pick your brains if thats ok?

Dave

[Timleech]

Actually, by the time Id had it 5 mins it was totally in pieces on the bench so I could unsieze the tilt, and clean out the solidified old grease
It in nice condition internally, and a lot cleaner externally now

I did tell you that for the price you would get it exactly 'as found'

Its a (mostly) static load (just moved by hand to repose it).
I figure that actual milling of things in it would put considerable loads on it, so it should be strong enough?
We are running some optical tests to determine the best way to measure a full blisk, this is just a small segment.


Dave

They're good strong units, I'm sorry that I didn't come across that one when I was looking for one.
What on earth is a 'blisk'?

Tim

[John Stevenson]

What on earth is a 'blisk'?

Tim

It's a disk with a bump on it, sorry I'll get me coat...................

.

[small.planes]

actually its a bladed disk, single piece forged and machined gas turbine compressor / turbine wheel. apparently stronger, but a lot more difficult to measure (need to do both sides at once....)

A related question:

The overall length of this lot when pivoting means I need to move the whole shooting match up and down by about 850mm ~(and a similare amount forwards/backwards) so the bit we want to measure stays in shot. Any bright ideas?

Dave