Thanks for responding, I should have been clearer.

I can't find any height info from ball ring to platform base for the Birns unit.
B+H was out of stock so couldn't ask someone to measure it.

Bolting these to the wood platform is not an issue, my concern is is there enough
height for leveling with both of my fluid heads?

Miller is a bit more expensive for what the number of shoots I expect usage for.

The Miller has a maximum height of 150mm.

A lot of the hi-hats are for 100 & 150mm dia balls. You could talk to http://www.visualproducts.com/store03.asp?ID=53&Cat=48Visual Products[/link] to see if they have a used 75mm Hi-Hat, but I can't see anything on their list; very helpful people.

In places where high hats are common they're more likely to be 100 or 150 mm, as Serena says, so finding a used one might be hard. Still, it's worth looking.

The problem you're talking about is when the Knob under the ball is too long and bottoms out on the board you mount the high hat on. Maybe one possibility would be to cut a hole out of the board to make more clearance. That might be less appealing if it's a dolly surface.

Rob Mack

One can buy 75mm to 100mm adaptor rings, we have two of these on hand. Yes Miller use a rather long 'bolt' on the bottom of their bowls, simply so it's easier to screw in on. They also make a couple of shorter ones for exactly this situation. However I'm 99.9% certain that their high hat is tall enough to allow the 'bolt' to fit inside their HiHat. We have two Miller 100mm HiHats of considerable vintage and never had a problem with fitting any head to them.
Where we do have the problem is on top of the Losmandy risers for their Spider Dolly. All GFM equipment has more than enough clearance also.
Bob.

I was struggling for the word last night. Bolt, Knob...here in the bay area it's a tie-down, and probably so in the rest of the US. Helpful when on the phone with Birns & Sawyer.

Picky detail but I was at a loss for the word and it bugged me.

Rob

Down here a tie down is ... a thing to tie something down, like you use on a semi trailer to hold the load in place.

One tip for anyone that owns / buys a HiHat. Bolt it to it's own piece of wood first and then you can bolt that to the dolly and also use the HiHat by itself on the ground for those really low shots. Of course if you've got a Miller Solo you don't need the HiHat to get VERY low down.

Bob.

BOB:
I knew you could not help rub the SOLO legs in my face!
(several years ago we agreed on the Miller DS10 fluid head but not on the legs)

EVERYONE:
THANKS to everyone for your help. I may look into the short doo-hicky that
clamps the ball into the bowl. Is a semi-trailer not fully a trailer?

At $150 for the Birns unit I might be better off getting a friend to make me a
platform out of aluminum or brass. A bar-b-qued steak and two beers is
alot cheaper!

EDIT: My Sachtler exploded view diagram shows the doo-hicky is a TIEDOWN-75MM

Seeing as how I'm a stones throw from the Miller stand at SMPTE I wandered over there today on another mission but also had a look at their HiHats. They have two, one is just the basic HiHat, the other has a very short set of legs and feet, that might be more versatile.

Anyways, if the Tiedown is too long (and I doubt it will be) if you mount the HiHat on a piece of 3/4" MDF and cut a large hole in the middle the 'nut' of the tiedown should clear.

Heck, here's a thought, I'll measure the clearance and post the result for you tomorrow night.

Trying to machine one of these things isn't that easy I think, it'd be nice to have someone make you one but I think it's a fair bit of machining.

And BTW, I completely forgot about the 'legs' discussion.

Bob.

Took tape and measured this for you today. The Miller has 5" clearance between the bottom of the bowl and the bottom of the legs. If your nut thingy is less that 5" it'll fit. Actually if it's less than 5.5" you'll be OK as the nut has a washer thats concave.

HTH

Bob.