Todays crown ...

this evening we made a new crown
Tom took POM and so we need no adhesive plate

next step will be a rail with an adjustable quick release

mediavets wrote:

What is POM - some sort of plastic?

yes, it is Polyoxymethylene

mediavets wrote:

You don't need to add friction material to the back of it?

no, as we made it a lil bit rough on the back

mediavets wrote:

Did you have keyed hole or have you made some other way to key the crown to shaft?

yes, a keyed hole

mediavets wrote:

Will it take a tapped hole?  How easy might it be to strip the threads - can you use metal bolts to attach a rail?

I am not sure how we will attach the rail, tapped hole is not durable - but screw/nut will do it

mediavets wrote:

Can I have one?

I have to bargain with my son and it needs patience as we out of POM

This is UK price for 100mm diameter rod in small lengths :
http://www.goodfellow.com/A/Polyoxymeth … lymer.HTML

Is this similar to price in Germany?

It seems to be a rather expensive material.

Last edited by mediavets (2008-12-17 22:07:22)

Any news in the crown-modification front ?

I have found some hardwood (2,10 M) at the DIY shop, ± the same size as the Merlin rail :-)
A cabinetmaker around the corner did the edges and made one part 3mm less thick.
15 EU ! total costs

Today I made 2 arms,
one for the 5D and one for the 450D.
The original Merlin arm is 13 mm thick, the original wood is 12,5mm.
With some little elastic parts (from the mailman.:-)), added against friction, the wooden rail is perfect.
BTW use the mountingscrew on top !

The 5D rail is 3mm less thick and left/right is oké with the original crown.
The only problem now is that with shorter lenses this solution does not work.
If you need to shift the 5D frontwards to get in the NP, the camera hits the crown.
The 17-40, 85 and 100mm will work perfect without crownmodification.
The longer lenses like 70-200 and 300mm wil work on the "fat, 3mm+" arm.
Left/right is 3mm off but who cares.
Look at the images to get the idea and there's a QT at:
http://tinyurl.com/dll47m
The 17-40 is almost in NP at the 5D, I just have to shift it backwards slightly, The 450 is ±oké.
Have Fun !

BTW the cap is sprayed black (satin) and will be resprayed Matte

Last edited by bigwade (2009-01-25 02:18:18)

BeeZed wrote:

I wonder if we could make a wooden crown?

Yes, why not? Just use a wood strong enough to avoid flexion...

If the circle was small enough to fit, it wouldn't need to be perfectly round, and could be cut by hand using a jigsaw. I think it would need to be centred though. There is still the issue of the friction piece though. I sold my smaller camera, so I have more interested in this problem than before. The real goal for me would be to but a smaller arca swiss compatible clamp, so I can use my rails more easily.

It could be nice to design some sort of universal crown, so it can be used by anyone, with a large number of accessories. Based on the existing design (jpeg link in the previous post), feel free to propose modifications you think usefull.

Then, once we have something good, we could ask a company to make it for us (I have some ideas).

bigwade wrote:

Oké, if we forget the Arca and Manfrotto systems, the new crown
needs a simular clambsystem the Merlin has now but much smaller.
With the height of the rail we can vary the A value.
And these rails can simply made from wood. (light and strong)
Is that your idea ?

Frank,

I think perhaps Frederic is thinking more along the lines of bolting the rail to the crown, rather than having some sort of dovetail clamp. You could of course still use an Arca or other type of QR plate on the rail to mount the camera.

Nodal Ninja offers a slim QR plate now for their pano heads.
http://www.red-door.co.uk/pages/product … parts.html

Last edited by mediavets (2009-01-29 18:17:20)

mediavets wrote:

I think perhaps Frederic is thinking more along the lines of bolting the rail to the crown, rather than having some sort of dovetail clamp. You could of course still use an Arca or other type of QR plate on the rail to mount the camera.
Nodal Ninja offers a slim QR plate now for their pano heads.
http://www.red-door.co.uk/pages/product … parts.html

A sort of dovetail clamp, but much, much smaller is IMHO the only way to serve different needs, like camerabrands and types.
I have a test/demo NN QR here and it's rather heavy.. and it's 25mm thick. (base+rail)
Base only is 20,5mm, with the exra part/block to fit in the NN5 Rail, without it is 17mm.
This can be mounted on the crown, we can ask Nick Fan to make a smaller version, without the block.
EDIT: the block can be removed..
The idea is the same.....the NN QM is a ± dovetail clamp.
But it's a ±80 euro solution without rails.
crown (austria) + mount/dovetail clamp (NN)
grtz!

Last edited by bigwade (2009-01-29 23:24:23)

Paul wrote:

quenox qr is avail. in two sizes 7.99 and 9.99 €

link ?

found it:
http://tinyurl.com/chjazo

Last edited by bigwade (2009-01-29 23:10:01)

I guess you will have some flex with the cork on the QR part.
btw how are you going to mount the base ?
BTW I like your crown, well done

bigwade wrote:

BTW this is a nice part:

search for "spirit level 3 axis" on ebay and you can get a 3 for same ...